Class JXG.Board

↳ JXG.Board

JXG.Board controls all properties and methods used to manage a geonext board like managing geometric elements, managing mouse and touch events, etc. You probably don't want to use this constructor directly. Please use JXG.JSXGraph.initBoard to initialize a board.

Defined in: board.js.

Class Summary
Constructor Attributes	Constructor Name and Description
	JXG.Board(container, renderer, id, origin, zoomX, zoomY, unitX, unitY, canvasWidth, canvasHeight, attributes) Constructs a new Board object.

Attributes Summary
Field Attributes	Field Name and Description
	animationDelay Time (in msec) between two animation steps.
	axis Show default axis.
	boundingbox Bounding box of the visible area in user coordinates.
	defaultAxes Attributes for the default axes in case of the attribute axis:true in JXG.JSXGraph#initBoard.
	description Description string for the board.
	document Supply the document object.
	drag Control the possibilities for dragging objects.
	fullscreen Attribute(s) to control the fullscreen icon.
	ignoreLabels If set true and hasPoint() is true for both an element and it's label, the element (and not the label) is taken as drag element.
	keepAspectRatio If set to true the bounding box might be changed such that the ratio of width and height of the hosting HTML div is equal to the ratio of width and height of the bounding box.
	keyboard Control using the keyboard to change the construction.
	maxboundingbox Maximal bounding box of the visible area in user coordinates.
	maxFrameRate Maximum frame rate of the board, i.e.
	maxNameLength Maximum number of digits in automatic label generation.
	minimizeReflow Change redraw strategy in SVG rendering engine.
	moveTarget Element which listens to move events of the pointing device.
	offsetX A number that will be added to the absolute position of the board used in mouse coordinate calculations in JXG.Board#getCoordsTopLeftCorner.
	offsetY A number that will be added to the absolute position of the board used in mouse coordinate calculations in JXG.Board#getCoordsTopLeftCorner.
	pan Control the possibilities for panning interaction (i.e.
	registerEvents Allow user interaction by registering mouse, pointer and touch events.
	renderer Default rendering engine.
	resize Control if JSXGraph reacts to resizing of the JSXGraph container element by the user / browser.
	screenshot Attributes to control the screenshot function.
	selection Control the possibilities for a selection rectangle.
	showClearTraces Show a button which allows to clear all traces of a board.
	showCopyright Show copyright string in canvas.
	showFullscreen Show a button in the navigation bar to start fullscreen mode.
	showInfobox If true, the infobox is shown on mouse/pen over for all points which have set their attribute showInfobox to 'inherit'.
	showNavigation Display of navigation arrows and zoom buttons in the navigation bar.
	showReload Show a button in the navigation bar to force reload of a construction.
	showScreenshot Show a button in the navigation bar to enable screenshots.
	showZoom Display of zoom buttons in the navigation bar.
	takeFirst If true the first element of the set JXG.board.objects having hasPoint==true is taken as drag element.
	takeSizeFromFile If true, when read from a file or string - the size of the div can be changed by the construction text.
	title Title string for the board.
	zoom Control the possibilities for zoom interaction.
	zoomFactor Additional zoom factor multiplied to JXG.Board#zoomX and JXG.Board#zoomY.
	zoomX Zoom factor in horizontal direction.
	zoomY Zoom factor in vertical direction.

Field Summary
Field Attributes	Field Name and Description
<private>	_board_touches Keeps a list of pointer devices which are currently touching the screen.
<private>	_drag_offset Offset for large coords elements like images
<private>	_inputDevice Stores the input device used in the last down or move event.
<private>	_isResizing A flag which tells us if a resize is in process
<private>	_isScrolling A flag which tells us if the user is scrolling the viewport
	addEvent Alias of JXG.Board.on.
	animationObjects Stores all the objects that are currently running an animation.
<constant>	BOARD_MODE_DRAG Board is in drag mode, objects aren't highlighted on mouse over and the object referenced in JXG.Board#mouse is updated on mouse movement.
<constant>	BOARD_MODE_MOVE_ORIGIN In this mode a mouse move changes the origin's screen coordinates.
<constant>	BOARD_MODE_NONE Board is in no special mode, objects are highlighted on mouse over and objects may be clicked to start drag&drop.
<constant>	BOARD_MODE_ZOOM Update is made with high quality, e.g.
<constant>	BOARD_QUALITY_HIGH Update is made with high quality, e.g.
<constant>	BOARD_QUALITY_LOW Update is made with low quality, e.g.
<private>	canvasHeight Canvas Height
<private>	canvasWidth Canvas width.
	container The html-id of the html element containing the board.
	containerObj Pointer to the html element containing the board.
	cPos Cached result of getCoordsTopLeftCorner for touch/mouseMove-Events to save some DOM operations.
	currentCBDef The current color blindness deficiency is stored in this property.
	dependentBoards An array containing all other boards that are updated after this board has been updated.
	dimension Dimension of the board.
	downObjects Collects all elements that triggered a mouse down event.
	drag_dx The distance from the mouse to the dragged object in x direction when the user clicked the mouse button.
	drag_dy The distance from the mouse to the dragged object in y direction when the user clicked the mouse button.
	drag_position The last position where a drag event has been fired.
	elementsByName An associative array to store the objects of the board by name.
	geonextCompatibilityMode If GEONExT constructions are displayed, then this property should be set to true.
<private>	grids Grids keeps track of all grids attached to this board.
	groups An associative array containing all groups belonging to the board.
	hasMouseHandlers A flag which tells if the board registers mouse events.
	hasMouseUp A flag which tells if the board the JXG.Board#mouseUpListener is currently registered.
	hasPointerHandlers A flag which stores if the board registered pointer events.
	hasPointerUp A flag which tells us if the board has a pointerUp event registered at the moment.
	hasTouchEnd A flag which tells if the board the JXG.Board#touchEndListener is currently registered.
	hasTouchHandlers A flag which tells if the board registers touch events.
	highlightedObjects An associative array containing all highlighted elements belonging to the board.
	infobox Infobox close to points in which the points' coordinates are displayed.
	inUpdate During the update process this is set to false to prevent an endless loop.
	isSelecting A flag which tells us if the user is selecting
	isSuspendedRedraw If true updates are skipped.
<private>	keepaspectratio Keep aspect ratio if bounding box is set and the width/height ratio differs from the width/height ratio of the canvas.
	mode The board mode the board is currently in.
	mouse References to the object that is dragged with the mouse on the board.
	needsFullUpdate Full updates are needed after zoom and axis translates.
	numObjects Number of objects ever created on this board.
	objects An associative array containing all geometric objects belonging to the board.
	objectsList An array containing all geometric objects on the board in the order of construction.
	options Some standard options
<private>	origin Coordinates of the boards origin.
	positionAccessLast Contains the last time (epoch, msec) since the last getCoordsTopLeftCorner call which was not thrown away.
	reducedUpdate If reducedUpdate is set to true then only the dragged element and few (e.g.
	removeEvent Alias of JXG.Board.off.
	selectingBox A bounding box for the selection
	selectingMode A flag which tells us if the board is in the selecting mode
	touches Keeps track on touched elements, like JXG.Board#mouse does for mouse events.
	touchMoveLast Contains the last time (epoch, msec) since the last touchMove event which was not thrown away or since touchStart because Android's Webkit browser fires too much of them.
	touchMoveLastId Contains the pointerId of the last touchMove event which was not thrown away or since touchStart because Android's Webkit browser fires too much of them.
<private>	unitX The number of pixels which represent one unit in user-coordinates in x direction.
<private>	unitY The number of pixels which represent one unit in user-coordinates in y direction.
	updateQuality The update quality of the board.
	xmlString A string containing the XML text of the construction.

Method Summary
Method Attributes	Method Name and Description
<private>	_createSelectionPolygon(attr) Create the internal selection polygon, which will be available as board.selectionPolygon.
<private>	_getPointerInputDevice(evt) Determine which input device is used for this action.
<private>	_isPointerRegistered(evt) Check if pointer event is already registered in JXG.Board#_board_touches.
<private>	_isRequiredKeyPressed(evt, action) Test if the required key combination is pressed for wheel zoom, move origin and selection
<private>	_moveSelecting(pos) Update the selection rectangle during a move event.
<private>	_pointerClearTouches() Remove all registered fingers from JXG.Board#_board_touches.
<private>	_pointerRemoveTouches(evt) Deregisters a pointer event in JXG.Board#_board_touches.
<private>	_pointerStorePosition(evt) Store the position of a pointer event.
<private>	_setSelectionPolygonFromBox() Update the Selection rectangle.
<private>	_startSelecting(pos) Start the selection of a region.
<private>	_stopSelecting(evt) Update the selection rectangle during an up event.
<private>	_testForSelection(evt) Test if a down event should start a selection.
	addAnimation(element) Adds an animation.
	addChild(board) Adds a dependent board to this board.
	addConditions(str) Add conditional updates to the elements.
	addEventHandlers() Add all possible event handlers to the board object
	addFullscreenEventHandlers() Add fullscreen events which update the CSS transformation matrix to correct the mouse/touch/pointer positions in case of CSS transformations.
	addGrid() Adds a grid to the board according to the settings given in board.options.
	addHook(hook, m, context) Please use JXG.Board.on instead.
	addMouseEventHandlers() Registers mouse move, down and wheel event handlers.
	addPointerEventHandlers() Registers the MSPointer* event handlers.
	addTouchEventHandlers(appleGestures) Register touch start and move and gesture start and change event handlers.
	animate() General purpose animation function.
	applyZoom() Apply update on all objects with the new zoom-factors.
	calculateSnapSizes() Calculates adequate snap sizes.
<private>	checkFrameRate(evt) Returns false if the event has been triggered faster than the maximum frame rate.
	clearTraces() Delete the elements drawn as part of a trace of an element.
	clickDownArrow() Handler for click on down arrow in the navigation bar
	clickLeftArrow() Handler for click on left arrow in the navigation bar
	clickRightArrow() Handler for click on right arrow in the navigation bar
	clickUpArrow() Handler for click on up arrow in the navigation bar
	create(elementType, parents, attributes) Creates a new geometric element of type elementType.
	createElement() Deprecated name for JXG.Board.create.
	createRoulette(c1, c2, start_c1, stepsize, direction, time, pointlist) Function to animate a curve rolling on another curve.
	dehighlightAll() Remove highlighting of all elements.
	displayInfobox(val) Set infobox visible / invisible.
	emulateColorblindness(deficiency) Initializes color blindness simulation.
	finalizeAdding(obj) After construction of the object the visibility is set and the label is constructed if necessary.
	fullscreenListener(evt) If fullscreen mode is toggled, the possible CSS transformations which are applied to the JSXGraph canvas have to be reread.
	fullUpdate() Runs through all elements and calls their update() method and update the conditions.
	generateId() Generates unique id for a board.
	generateName(object) Generates an unique name for the given object.
	gestureChangeListener(evt) Triggered on iOS/Safari while the user inputs a gesture (e.g.
	gestureStartListener(evt) Called by iOS/Safari as soon as the user starts a gesture.
	getAllObjectsUnderMouse(evt) Collects all elements under current mouse position.
	getAllUnderMouse(evt) Collects all elements under current mouse position plus current user coordinates of mouse cursor.
	getBoundingBox() Get the bounding box of the board.
	getCoordsTopLeftCorner() Calculates mouse coordinates relative to the boards container.
	getMousePosition(e, i) Get the position of the mouse in screen coordinates, relative to the upper left corner of the host tag.
<private>	getScrCoordsOfMouse(x, y) Returns the input parameters in an array.
	getUsrCoordsOfMouse(evt) This method calculates the user coords of the current mouse coordinates.
	hasPoint(x, y) Checks if the given point is inside the boundingbox.
	highlightCustomInfobox(text, el) Changes the text of the info box to what is provided via text.
	highlightInfobox(x, y, el) Changes the text of the info box to show the given coordinates.
	initGeonextBoard() Initialize some objects which are contained in every GEONExT construction by default, but are not contained in the gxt files.
	initInfobox() Initialize the info box object which is used to display the coordinates of points near the mouse pointer,
	initMoveObject(x, y, evt, type) Collects all elements below the current mouse pointer and fulfilling the following constraints: isDraggable visible not fixed not frozen
	initMoveOrigin(x, y) Initiate moving the origin.
	keyDownListener(evt) Allow moving of JSXGraph elements with arrow keys and zooming of the construction with + / -.
	keyFocusInListener(evt) Event listener for SVG elements getting focus.
	keyFocusOutListener(evt) Event listener for SVG elements losing focus.
	migratePoint(src, dest, copyName) Migrate the dependency properties of the point src to the point dest and delete the point src.
	mouseDownListener(evt) This method is called by the browser when the mouse button is clicked.
	mouseMoveListener(evt) This method is called by the browser when the mouse is moved.
	mouseUpListener(evt) This method is called by the browser when the mouse button is released.
	mouseWheelListener(evt) Handler for mouse wheel events.
	moveObject(x, y, o, evt, type) Moves an object.
	moveOrigin(x, y, diff) Moves the origin and initializes an update of all elements.
<private>	originMoveEnd() Stop moving the origin with one finger
	pointerDownListener(evt, object) This method is called by the browser when a pointing device is pressed on the screen.
	pointerMoveListener(evt) Called periodically by the browser while the user moves a pointing device across the screen.
	pointerUpListener(evt) Triggered as soon as the user stops touching the device with at least one finger.
	prepareUpdate() Sets for all objects the needsUpdate flag to "true".
	removeAncestors(object) Removes the ancestors of an object an the object itself from board and renderer.
	removeChild(board) Deletes a board from the list of dependent boards.
	removeEventHandlers() Remove all event handlers from the board object
	removeFullscreenEventHandlers() Remove all registered event handlers regarding fullscreen mode.
	removeGrids() Removes all grids assigned to this board.
	removeHook(id) Please use JXG.Board.off instead.
	removeKeyboardEventHandlers() Remove all registered touch event handlers.
	removeMouseEventHandlers() De-register mouse event handlers.
	removeObject(object, saveMethod) Removes object from board and renderer.
	removePointerEventHandlers() Remove MSPointer* Event handlers.
	removeTouchEventHandlers() Remove all registered touch event handlers.
	resizeContainer(canvasWidth, canvasHeight, dontset, dontSetBoundingBox) Change the height and width of the board's container.
	resizeListener() Fallback solutions if there is no resizeObserver available in the browser.
<private>	saveStartPos(obj, targets) Helper function which returns a reasonable starting point for the object being dragged.
	scrollListener(evt) Listener to watch for scroll events.
	select(str, onlyByIdOrName) Select a single or multiple elements at once.
	setBoundingBox(bbox, keepaspectratio, setZoom) Set the bounding box of the board.
	setId(obj, type) Composes an id for an element.
	setZoom(fX, fY) Sets the zoom level to `fX` resp `fY`.
	showDependencies() Lists the dependencies graph in a new HTML-window.
	showXML() Lists the XML code of the construction in a new HTML-window.
	startIntersectionObserver() Watch for changes of the visibility of the JSXGraph container element.
	startResizeObserver() Start observer which reacts to size changes of the JSXGraph container div element.
	startSelectionMode() Start selection mode.
	stopAllAnimation() Cancels all running animations.
	stopIntersectionObserver() Stop the intersection observer
	stopResizeObserver() Stops the resize observer.
	stopSelectionMode() Finalize the selection: disable selection mode and return the coordinates of the selection rectangle.
	suspendUpdate() Stop updates of the board.
	toFullscreen(id) Expand the JSXGraph construction to fullscreen.
	touchEndListener(evt) Triggered as soon as the user stops touching the device with at least one finger.
	touchMoveListener(evt) Called periodically by the browser while the user moves his fingers across the device.
<private>	touchOriginMove(evt) Move the origin with one finger
	touchStartListener(evt) This method is called by the browser when a finger touches the surface of the touch-device.
<private>	touchStartMoveOriginOneFinger(evt) Start moving the origin with one finger.
	twoFingerMove(p1, p2, o, evt) Moves elements in multitouch mode.
	twoFingerTouchObject(tar, drag, id) Moves, rotates and scales a line or polygon with two fingers.
	unsuspendUpdate() Enable updates of the board.
	update(drag) Runs through most elements and calls their update() method and update the conditions.
	updateConditions()
	updateContainerDims() Update the width and height of the JSXGraph container div element.
	updateCoords() Update the coords object of all elements which possess this property.
	updateCSSTransforms() Update CSS transformations of type scaling.
	updateElements(drag) Runs through all elements and calls their update() method.
	updateHooks(m) Runs through all hooked functions and calls them.
	updateInfobox(el) Updates and displays a little info box to show coordinates of current selected points.
	updateRenderer() Runs through all elements and calls their update() method.
	updateRendererCanvas() Runs through all elements and calls their update() method.
	zoom100() Reset the zoom level to the original zoom level from initBoard(); Additionally, if the board as been initialized with a boundingBox (which is the default), restore the viewport to the original viewport during initialization.
	zoomAllPoints() Zooms the board so every visible point is shown.
	zoomElements(elements) Reset the bounding box and the zoom level to 100% such that a given set of elements is within the board's viewport.
	zoomIn(x, y) Zooms into the board by the factors board.attr.zoom.factorX and board.attr.zoom.factorY and applies the zoom.
	zoomOut(x, y) Zooms out of the board by the factors board.attr.zoom.factorX and board.attr.zoom.factorY and applies the zoom.

Event Summary
Event Attributes	Event Name and Description
	boundingbox() The bounding box of the board has changed.
	down(e) Whenever the user starts to touch or click the board.
	hit(e, el, target) Whenever an element is highlighted this event is fired.
	mousedown(e) Whenever the user starts to click on the board.
	mousehit(e, el, target) Whenever an element is highlighted this event is fired.
	mousemove(e, mode) This event is fired whenever the user is moving the mouse over the board.
	mousemoveselecting() A move event while selecting of a region is active from a device sending mouse events.
	mousestartselecting() Select a region is started during a down event from a device sending mouse events or by calling JXG.Board.startSelectionMode.
	mousestopselecting() Selection of a region is stopped during an up event from a device sending mouse events.
	mouseup(e) Whenever the user releases the mousebutton over the board.
	move(e, mode) This event is fired whenever the user is moving the finger or mouse pointer over the board.
	moveselecting() A move event while selecting of a region is active.
	pendown(e) Whenever the user taps the pen on the board.
	penmove(e, mode) This event is fired whenever the user is moving the pen over the board.
	pointerdown(e) Whenever the user starts to click on the board with a device sending pointer events.
	pointermove(e, mode) This event is fired whenever the user is moving the mouse over the board with a device sending pointer events.
	pointermoveselecting() Select a region is started during a down event from a device sending mouse events.
	pointerstartselecting() Select a region is started during a down event from a device sending pointer events or by calling JXG.Board.startSelectionMode.
	pointerstopselecting() Selection of a region is stopped during an up event from a device sending pointer events.
	pointerup(e) Whenever the user releases the mousebutton over the board with a device sending pointer events.
	startselecting() Select a region is started during a down event or by calling JXG.Board.startSelectionMode
	stopselecting() Selection of a region is stopped during an up event.
	touchend(e) Whenever the user stops touching the board.
	touchmove(e, mode) This event is fired whenever the user is moving the finger over the board.
	touchmoveselecting() Select a region is started during a down event from a device sending touch events.
	touchstart(e) Whenever the user starts to touch the board.
	touchstartselecting() Select a region is started during a down event from a device sending touch events or by calling JXG.Board.startSelectionMode.
	touchstopselecting() Selection of a region is stopped during an up event from a device sending touch events.
	up(e) Whenever the user stops to touch or click the board.
	update() This board is updated.

Class Detail

JXG.Board(container, renderer, id, origin, zoomX, zoomY, unitX, unitY, canvasWidth, canvasHeight, attributes)

Constructs a new Board object.

Parameters:
{String} container: The id or reference of the HTML DOM element the board is drawn in. This is usually a HTML div.
{JXG.AbstractRenderer} renderer: The reference of a renderer.
{String} id: Unique identifier for the board, may be an empty string or null or even undefined.
{JXG.Coords} origin: The coordinates where the origin is placed, in user coordinates.
{Number} zoomX: Zoom factor in x-axis direction
{Number} zoomY: Zoom factor in y-axis direction
{Number} unitX: Units in x-axis direction
{Number} unitY: Units in y-axis direction
{Number} canvasWidth: The width of canvas
{Number} canvasHeight: The height of canvas
{Object} attributes: The attributes object given to JXG.JSXGraph.initBoard

Attribute Detail

{Number} animationDelay

Time (in msec) between two animation steps. Used in JXG.CoordsElement#moveAlong, JXG.CoordsElement#moveTo and JXG.CoordsElement#visit.
Defined in: options.js.

See:: JXG.CoordsElement#moveAlong; JXG.CoordsElement#moveTo; JXG.CoordsElement#visit

Default Value:: 35

{Boolean} axis

Show default axis. If shown, the horizontal axis can be accessed via JXG.Board.defaultAxes.x, the vertical axis can be accessed via JXG.Board.defaultAxes.y. Both axes have a sub-element "defaultTicks". Value can be Boolean or an object containing axis attributes.
Defined in: options.js.

Default Value:: false

{Array} boundingbox

Bounding box of the visible area in user coordinates. It is an array consisting of four values: [x₁, y₁, x₂, y₂] The canvas will be spanned from the upper left corner (₁, y₁) to the lower right corner (x₂, y₂).
Defined in: options.js.

var board = JXG.JSXGraph.initBoard('jxgbox', {
        boundingbox: [-5, 5, 5, -5],
        axis: true
    });

Default Value:: [-5, 5, 5, -5]

{Object} defaultAxes

Attributes for the default axes in case of the attribute axis:true in JXG.JSXGraph#initBoard.
Defined in: options.js.

{String} description

Description string for the board. Primarily used in an invisible text element which is adressed by the attribute 'aria-describedby' from the JSXGraph container. JSXGraph creates a new div-element with id "{containerid}_ARIAdescription" containing this string.
Defined in: options.js.

See:: JXG.Board#title

Default Value:: ''

{DOM object} document

Supply the document object. Defaults to window.document
Defined in: options.js.

Default Value:: false (meaning window.document)

{Object} drag

Control the possibilities for dragging objects. Possible sub-attributes with default values are:

drag: {
  enabled: true   // Allow dragging
}

Defined in: options.js.

{Object} fullscreen

Attribute(s) to control the fullscreen icon. The attribute "showFullscreen" controls if the icon is shown. The following attribute(s) can be set:

symbol (String): Unicode symbol which is shown in the navigation bar. Default: '\u25a1'
id (String): Id of the HTML element which is brought to full screen or null if the JSXgraph div is taken. It may be an outer div element, e.g. if the old aspect ratio trick is used. Default: null, i.e. use the JSXGraph div.

Defined in: options.js.

var board = JXG.JSXGraph.initBoard('35bec5a2-fd4d-11e8-ab14-901b0e1b8723',
            {boundingbox: [-8, 8, 8,-8], axis: true,
            showcopyright: false,
            showFullscreen: true,
            fullscreen: {
                 symbol: '\u22c7'
             }
            });
var pol = board.create('polygon', [[0, 1], [3,4], [1,-4]], {fillColor: 'yellow'});

See:: JXG.Board#showFullscreen

{Booelan} ignoreLabels

If set true and hasPoint() is true for both an element and it's label, the element (and not the label) is taken as drag element. If set false and hasPoint() is true for both an element and it's label, the label is taken (if it is on a higher layer than the element)
Defined in: options.js.

Default Value:: true

{Boolean} keepAspectRatio

If set to true the bounding box might be changed such that the ratio of width and height of the hosting HTML div is equal to the ratio of width and height of the bounding box. This is necessary if circles should look like circles and not like ellipses. It is recommended to set keepAspectRatio = true for geometric applets. For function plotting keepAspectRatio = false might be the better choice.
Defined in: options.js.

See:: JXG.Board#boundingbox; JXG.Board#setBoundingBox

Default Value:: false

{Object} keyboard

Control using the keyboard to change the construction.

enabled: true / false
dx: horizontal shift amount per key press
dy: vertical shift amount per key press
panShift: zoom if shift key is pressed
panCtrl: zoom if ctrl key is pressed

Defined in: options.js.

var board = JXG.JSXGraph.initBoard("jxgbox", {boundingbox: [-5,5,5,-5],
    axis: true,
    showCopyright:true,
    showNavigation:true,
    keyboard: {
        enabled: true,
        dy: 30,
        panShift: true,
        panCtrl: false
    }
});

See:: JXG.Board#keyDownListener; JXG.Board#keyFocusInListener; JXG.Board#keyFocusOutListener

{Array} maxboundingbox

Maximal bounding box of the visible area in user coordinates. It is an array consisting of four values: [x₁, y₁, x₂, y₂] The bounding box of the canvas must be inside of this maximal boundings box.
Defined in: options.js.

var board = JXG.JSXGraph.initBoard('jxgbox', {
        boundingbox: [-5, 5, 5, -5],
        maxboundingbox: [-8, 8, 8, -8],
        pan: {enabled: true},
        axis: true
    });

See:: JXG.Board#boundingbox

Default Value:: [-Infinity, Infinity, Infinity, -Infinity]

{Number} maxFrameRate

Maximum frame rate of the board, i.e. maximum number of updates per second triggered by move events.
Defined in: options.js.

Default Value:: 40

{Number} maxNameLength

Maximum number of digits in automatic label generation. For example, if set to 1 automatic point labels end at "Z". If set to 2, point labels end at "ZZ".
Defined in: options.js.

See:: JXG.Board#generateName

Default Value:: 1

{String} minimizeReflow

Change redraw strategy in SVG rendering engine.

This optimization seems to be obsolete in newer browsers (from 2021 on, at least) and even slow down the constructions. Therefore, the default is set to 'none' since v1.2.4.

If set to 'svg', before every redrawing of the JSXGraph construction the SVG sub-tree of the DOM tree is taken out of the DOM. If set to 'all', before every redrawing of the JSXGraph construction the complete DOM tree is taken out of the DOM. If set to 'none' the redrawing is done in-place. Using 'svg' or 'all' speeds up the update process considerably. The risk is that if there is an exception, only a white div or window is left.
Defined in: options.js.

Default Value:: 'none'

{HTML node or document} moveTarget

Element which listens to move events of the pointing device. This allows to drag elements of a JSXGraph construction outside of the board. Especially, on mobile devices this enhances the user experience. However, it is recommended to allow dragging outside of the JSXGraph board only in certain constructions where users may not "loose" points outside of the board. Then points may become unreachable.

A situation where dragging outside of the board is uncritical is for example if only sliders are used to interact with the construction.

Possible values for this attributes are:

an element specified by document.getElementById('some id');
null: to use the JSXgraph container div element
document

Defined in: options.js.

    var board = JXG.JSXGraph.initBoard('jxgbox', {
        boundingbox: [-5,5,5,-5],
        axis: true,
        moveTarget: document
    });

Default Value:: null

{Number} offsetX

A number that will be added to the absolute position of the board used in mouse coordinate calculations in JXG.Board#getCoordsTopLeftCorner.
Defined in: options.js.

See:: JXG.Board#offsetY

Default Value:: 0

{Number} offsetY

A number that will be added to the absolute position of the board used in mouse coordinate calculations in JXG.Board#getCoordsTopLeftCorner.
Defined in: options.js.

See:: JXG.Board#offsetX

Default Value:: 0

{Object} pan

Control the possibilities for panning interaction (i.e. moving the origin). Possible sub-attributes with default values are:

pan: {
  enabled: true   // Allow panning
  needTwoFingers: false, // panning is done with two fingers on touch devices
  needShift: true, // mouse panning needs pressing of the shift key
}

Defined in: options.js.

{Boolean} registerEvents

Allow user interaction by registering mouse, pointer and touch events.
Defined in: options.js.

Default Value:: true

{String} renderer

Default rendering engine. Possible values are 'svg', 'canvas', 'vml', 'no', or 'auto'. If the rendering engine is not available JSXGraph tries to detect a different engine.

In case of 'canvas' it is advisable to call 'board.update()' after all elements have been constructed. This ensures that all elements are drawn with their intended visual appearance.
Defined in: options.js.

Default Value:: 'auto'

{Object} resize

Control if JSXGraph reacts to resizing of the JSXGraph container element by the user / browser. The attribute "throttle" determines the minimal time in msec between to resize calls.
Defined in: options.js.

    var board = JXG.JSXGraph.initBoard('jxgbox', {
        boundingbox: [-5,5,5,-5],
        keepAspectRatio: true,
        axis: true,
        resize: {enabled: true, throttle: 200}
    });

See:: JXG.Board#startResizeObserver; JXG.Board#resizeListener

{Object} screenshot

Attributes to control the screenshot function. The following attributes can be set:

scale: scaling factor (default=1.0)
type: format of the screenshot image. Default: png
symbol: Unicode symbol which is shown in the navigation bar. Default: '\u2318'
css: CSS rules to format the div element containing the screen shot image
cssButton: CSS rules to format the close button of the div element containing the screen shot image

Defined in: options.js.

{Object} selection

Control the possibilities for a selection rectangle. Starting a selection event triggers the "startselecting" event. When the mouse pointer is released, the "stopselecting" event is fired. The "stopselecting" event must be supplied by the user.

Possible sub-attributes with default values are:

selection: {
  enabled: false,
  name: 'selectionPolygon',
  needShift: false,  // mouse selection needs pressing of the shift key
  needCtrl: true,    // mouse selection needs pressing of the shift key
  withLines: false,  // Selection polygon has border lines
  vertices: {
      visible: false
  },
  fillColor: '#ffff00',
  visible: false      // Initial visibility. Should be set to false always
}

Board events triggered by selection manipulation: 'startselecting', 'stopselecting', 'mousestartselecting', 'mousestopselecting', 'pointerstartselecting', 'pointerstopselecting', 'touchstartselecting', 'touchstopselecting'.
Defined in: options.js.

board.on('stopselecting', function(){
    var box = board.stopSelectionMode(),
    // bbox has the coordinates of the selectionr rectangle.
    // Attention: box[i].usrCoords have the form [1, x, y], i.e.
    // are homogeneous coordinates.
    bbox = box[0].usrCoords.slice(1).concat(box[1].usrCoords.slice(1));
    // Set a new bounding box
    board.setBoundingBox(bbox, false);
});

See:: JXG.Board#startSelectionMode; JXG.Board#stopSelectionMode

{Boolean} showClearTraces

Show a button which allows to clear all traces of a board.
Defined in: options.js.

Default Value:: false

{Boolean} showCopyright

Show copyright string in canvas.
Defined in: options.js.

Default Value:: true

{Boolean} showFullscreen

Show a button in the navigation bar to start fullscreen mode.
Defined in: options.js.

See:: JXG.Board#fullscreen

Default Value:: false

{Boolean} showInfobox

If true, the infobox is shown on mouse/pen over for all points which have set their attribute showInfobox to 'inherit'. If a point has set its attribute showInfobox to false or true, that value will have priority over this value.
Defined in: options.js.

See:: Point#showInfobox

Default Value:: true

{Boolean} showNavigation

Display of navigation arrows and zoom buttons in the navigation bar.
Defined in: options.js.

Default Value:: true

{Boolean} showReload

Show a button in the navigation bar to force reload of a construction. Works only with the JessieCode tag.
Defined in: options.js.

Default Value:: false

{Boolean} showScreenshot

Show a button in the navigation bar to enable screenshots.
Defined in: options.js.

Default Value:: false

{Boolean} showZoom

Display of zoom buttons in the navigation bar. To show zoom buttons, additionally showNavigation has to be set to true.
Defined in: options.js.

Default Value:: true

{Boolean} takeFirst

If true the first element of the set JXG.board.objects having hasPoint==true is taken as drag element.
Defined in: options.js.

Default Value:: false

{Boolean} takeSizeFromFile

If true, when read from a file or string - the size of the div can be changed by the construction text.
Defined in: options.js.

Default Value:: false

{String} title

Title string for the board. Primarily used in an invisible text element which is adressed by the attribute 'aria-labelledby' from the JSXGraph container. JSXGraph creates a new div-element with id "{containerid}_ARIAlabel" containing this string.
Defined in: options.js.

See:: JXG.Board#description

Default Value:: ''

{Object} zoom

Control the possibilities for zoom interaction. Possible sub-attributes with default values are:

zoom: {
  factorX: 1.25,  // horizontal zoom factor (multiplied to JXG.Board#zoomX)
  factorY: 1.25,  // vertical zoom factor (multiplied to JXG.Board#zoomY)
  wheel: true,     // allow zooming by mouse wheel or
  				   // by pinch-to-toom gesture on touch devices
  needShift: true,   // mouse wheel zooming needs pressing of the shift key
  min: 0.001,        // minimal values of JXG.Board#zoomX and JXG.Board#zoomY, limits zoomOut
  max: 1000.0,       // maximal values of JXG.Board#zoomX and JXG.Board#zoomY, limits zoomIn

  pinchHorizontal: true, // Allow pinch-to-zoom to zoom only horizontal axis
  pinchVertical: true,   // Allow pinch-to-zoom to zoom only vertical axis
  pinchSensitivity: 7    // Sensitivity (in degrees) for recognizing horizontal or vertical pinch-to-zoom gestures.
}

Deprecated: zoom.eps which is superseded by zoom.min
Defined in: options.js.

{Number} zoomFactor

Additional zoom factor multiplied to JXG.Board#zoomX and JXG.Board#zoomY.
Defined in: options.js.

Default Value:: 1.0

{Number} zoomX

Zoom factor in horizontal direction.
Defined in: options.js.

See:: JXG.Board#zoomY

Default Value:: 1.0

{Number} zoomY

Zoom factor in vertical direction.
Defined in: options.js.

See:: JXG.Board#zoomX

Default Value:: 1.0

Field Detail

<private> {Array} _board_touches

Keeps a list of pointer devices which are currently touching the screen.

<private> {Array} _drag_offset

Offset for large coords elements like images

Default Value:: [0, 0]

<private> {String} _inputDevice

Stores the input device used in the last down or move event.

Default Value:: 'mouse'

<private> {Boolean} _isResizing

A flag which tells us if a resize is in process

See:: JXG.Board#resizeListener

Default Value:: false

<private> {Boolean} _isScrolling

A flag which tells us if the user is scrolling the viewport

See:: JXG.Board#scrollListener

Default Value:: false

addEvent

Alias of JXG.Board.on.

{Object} animationObjects

Stores all the objects that are currently running an animation.

<constant> {Number} BOARD_MODE_DRAG

Board is in drag mode, objects aren't highlighted on mouse over and the object referenced in JXG.Board#mouse is updated on mouse movement.

See:: JXG.Board#drag_obj

<constant> {Number} BOARD_MODE_MOVE_ORIGIN

In this mode a mouse move changes the origin's screen coordinates.

<constant> {Number} BOARD_MODE_NONE

Board is in no special mode, objects are highlighted on mouse over and objects may be clicked to start drag&drop.

<constant> {Number} BOARD_MODE_ZOOM

Update is made with high quality, e.g. graphs are evaluated at much more points.

See:: JXG.Board#updateQuality

<constant> {Number} BOARD_QUALITY_HIGH

Update is made with high quality, e.g. graphs are evaluated at much more points.

See:: JXG.Board#updateQuality

<constant> {Number} BOARD_QUALITY_LOW

Update is made with low quality, e.g. graphs are evaluated at a lesser amount of points.

See:: JXG.Board#updateQuality

<private> {Number} canvasHeight

Canvas Height

<private> {Number} canvasWidth

Canvas width.

{String} container

The html-id of the html element containing the board.

{Object} containerObj

Pointer to the html element containing the board.

{Array} cPos

Cached result of getCoordsTopLeftCorner for touch/mouseMove-Events to save some DOM operations.

currentCBDef

The current color blindness deficiency is stored in this property. If color blindness is not emulated at the moment, it's value is 'none'.

{Array} dependentBoards

An array containing all other boards that are updated after this board has been updated.

See:: JXG.Board#addChild; JXG.Board#removeChild

{Number} dimension

Dimension of the board.

Default Value:: 2

{Array} downObjects

Collects all elements that triggered a mouse down event.

{Number} drag_dx

The distance from the mouse to the dragged object in x direction when the user clicked the mouse button.

See:: JXG.Board#drag_dy; JXG.Board#drag_obj

{Number} drag_dy

The distance from the mouse to the dragged object in y direction when the user clicked the mouse button.

See:: JXG.Board#drag_dx; JXG.Board#drag_obj

{Array} drag_position

The last position where a drag event has been fired.

See:: JXG.Board#moveObject

{Object} elementsByName

An associative array to store the objects of the board by name. the name of the object is the key and value is a reference to the object.

{Boolean} geonextCompatibilityMode

If GEONExT constructions are displayed, then this property should be set to true. At the moment there should be no difference. But this may change. This is set in JXG.GeonextReader.readGeonext.

See:: JXG.GeonextReader.readGeonext

Default Value:: false

<private> {Array} grids

Grids keeps track of all grids attached to this board.

{Object} groups

An associative array containing all groups belonging to the board. Key is the id of the group and value is a reference to the object.

{Boolean} hasMouseHandlers

A flag which tells if the board registers mouse events.

Default Value:: false

{Boolean} hasMouseUp

A flag which tells if the board the JXG.Board#mouseUpListener is currently registered.

Default Value:: false

{Boolean} hasPointerHandlers

A flag which stores if the board registered pointer events.

Default Value:: false

{Boolean} hasPointerUp

A flag which tells us if the board has a pointerUp event registered at the moment.

Default Value:: false

{Boolean} hasTouchEnd

A flag which tells if the board the JXG.Board#touchEndListener is currently registered.

Default Value:: false

{Boolean} hasTouchHandlers

A flag which tells if the board registers touch events.

Default Value:: false

{Object} highlightedObjects

An associative array containing all highlighted elements belonging to the board.

{JXG.Text} infobox

Infobox close to points in which the points' coordinates are displayed. This is simply a JXG.Text element. Access through board.infobox. Uses CSS class .JXGinfobox.

{Boolean} inUpdate

During the update process this is set to false to prevent an endless loop.

Default Value:: false

{Boolean} isSelecting

A flag which tells us if the user is selecting

Default Value:: false

{Boolean} isSuspendedRedraw

If true updates are skipped.

<private> {Boolean} keepaspectratio

Keep aspect ratio if bounding box is set and the width/height ratio differs from the width/height ratio of the canvas.

{Number} mode

The board mode the board is currently in. Possible values are

JXG.Board.BOARD_MODE_NONE
JXG.Board.BOARD_MODE_DRAG
JXG.Board.BOARD_MODE_MOVE_ORIGIN

{JXG.GeometryElement} mouse

References to the object that is dragged with the mouse on the board.

See:: JXG.Board#touches

{Boolean} needsFullUpdate

Full updates are needed after zoom and axis translates. This saves some time during an update.

Default Value:: false

{Number} numObjects

Number of objects ever created on this board. This includes every object, even invisible and deleted ones.

{Object} objects

An associative array containing all geometric objects belonging to the board. Key is the id of the object and value is a reference to the object.

{Array} objectsList

An array containing all geometric objects on the board in the order of construction.

{JXG.Options} options

Some standard options

<private> {Object} origin

Coordinates of the boards origin. This a object with the two properties usrCoords and scrCoords. usrCoords always equals [1, 0, 0] and scrCoords stores the boards origin in homogeneous screen coordinates.

{Number} positionAccessLast

Contains the last time (epoch, msec) since the last getCoordsTopLeftCorner call which was not thrown away.

{Boolean} reducedUpdate

If reducedUpdate is set to true then only the dragged element and few (e.g. 2) following elements are updated during mouse move. On mouse up the whole construction is updated. This enables us to be fast even on very slow devices.

Default Value:: false

removeEvent

Alias of JXG.Board.off.

{Array} selectingBox

A bounding box for the selection

Default Value:: [ [0,0], [0,0] ]

{Boolean} selectingMode

A flag which tells us if the board is in the selecting mode

Default Value:: false

{Array} touches

Keeps track on touched elements, like JXG.Board#mouse does for mouse events.

See:: JXG.Board#mouse

{Number} touchMoveLast

Contains the last time (epoch, msec) since the last touchMove event which was not thrown away or since touchStart because Android's Webkit browser fires too much of them.

{Number} touchMoveLastId

Contains the pointerId of the last touchMove event which was not thrown away or since touchStart because Android's Webkit browser fires too much of them.

<private> {Number} unitX

The number of pixels which represent one unit in user-coordinates in x direction.

<private> {Number} unitY

The number of pixels which represent one unit in user-coordinates in y direction.

{Number} updateQuality

The update quality of the board. In most cases this is set to JXG.Board#BOARD_QUALITY_HIGH. If JXG.Board#mode equals JXG.Board#BOARD_MODE_DRAG this is set to JXG.Board#BOARD_QUALITY_LOW to speed up the update process by e.g. reducing the number of evaluation points when plotting functions. Possible values are

BOARD_QUALITY_LOW
BOARD_QUALITY_HIGH

See:: JXG.Board#mode

{String} xmlString

A string containing the XML text of the construction. This is set in JXG.FileReader.parseString. Only useful if a construction is read from a GEONExT-, Intergeo-, Geogebra-, or Cinderella-File.

Method Detail

<private> {Object} _createSelectionPolygon(attr)

Create the internal selection polygon, which will be available as board.selectionPolygon.

Parameters:
{Object} attr: board attributes, e.g. the subobject board.attr.

Returns:: {Object} pointer to the board to enable chaining.

<private> {String} _getPointerInputDevice(evt)

Determine which input device is used for this action. Possible devices are 'touch', 'pen' and 'mouse'. This affects the precision and certain events. In case of no browser, 'mouse' is used.

Parameters:
{Event} evt: The browsers event object.

Returns:: {String} 'mouse', 'pen', or 'touch'

See:: JXG.Board#pointerDownListener; JXG.Board#pointerMoveListener; JXG.Board#initMoveObject; JXG.Board#moveObject

<private> {Boolean} _isPointerRegistered(evt)

Check if pointer event is already registered in JXG.Board#_board_touches.

Parameters:
{Object} evt: Event object

Returns:: {Boolean} true if down event has already been sent.

<private> {Boolean} _isRequiredKeyPressed(evt, action)

Test if the required key combination is pressed for wheel zoom, move origin and selection

Parameters:
{Object} evt: Mouse or pen event
{String} action: String containing the action: 'zoom', 'pan', 'selection'. Corresponds to the attribute subobject.

Returns:: {Boolean} true or false.

<private> _moveSelecting(pos)

Update the selection rectangle during a move event.

Parameters:
{Array} pos: Screen coordiates of the move event

<private> {JXG.Board} _pointerClearTouches()

Remove all registered fingers from JXG.Board#_board_touches. This might be necessary if too many fingers have been registered.

Returns:: {JXG.Board} Reference to the board

<private> {JXG.Board} _pointerRemoveTouches(evt)

Deregisters a pointer event in JXG.Board#_board_touches. It happens if a finger has been lifted from the screen.

Parameters:
{Object} evt: Event object

Returns:: {JXG.Board} Reference to the board

<private> {JXG.Board} _pointerStorePosition(evt)

Store the position of a pointer event. If not yet done, registers a pointer event in JXG.Board#_board_touches. Allows to follow the path of that finger on the screen. Only two simultaneous touches are supported.

Parameters:
{Object} evt: Event object

Returns:: {JXG.Board} Reference to the board

<private> _setSelectionPolygonFromBox()

Update the Selection rectangle.

<private> _startSelecting(pos)

Start the selection of a region.

Parameters:
{Array} pos: Screen coordiates of the upper left corner of the selection rectangle.

<private> _stopSelecting(evt)

Update the selection rectangle during an up event. Stop selection.

Parameters:
{Object} evt: Event object

<private> _testForSelection(evt)

Test if a down event should start a selection. Test if the required keys are pressed. If yes, JXG.Board.startSelectionMode is called.

Parameters:
{Object} evt: Event object

{JXG.Board} addAnimation(element)

Adds an animation. Animations are controlled by the boards, so the boards need to be aware of the animated elements. This function tells the board about new elements to animate.

Parameters:
{JXG.GeometryElement} element: The element which is to be animated.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} addChild(board)

Adds a dependent board to this board.

Parameters:
{JXG.Board} board: A reference to board which will be updated after an update of this board occurred.

Returns:: {JXG.Board} Reference to the board

addConditions(str)

Add conditional updates to the elements.

Parameters:
{String} str: String containing coniditional update in geonext syntax

addEventHandlers()

Add all possible event handlers to the board object

addFullscreenEventHandlers()

Add fullscreen events which update the CSS transformation matrix to correct the mouse/touch/pointer positions in case of CSS transformations.

{JXG.Board} addGrid()

Adds a grid to the board according to the settings given in board.options.

Returns:: {JXG.Board} Reference to the board.

{Number} addHook(hook, m, context)

Please use JXG.Board.on instead.

Parameters:
{Function} hook: A function to be called by the board after an update occurred.
{String} m Optional, Default: 'update': When the hook is to be called. Possible values are mouseup, mousedown and update.
{Object} context Optional, Default: board: Determines the execution context the hook is called. This parameter is optional, default is the board object the hook is attached to.

Returns:: {Number} Id of the hook, required to remove the hook from the board.

addMouseEventHandlers()

Registers mouse move, down and wheel event handlers.

addPointerEventHandlers()

Registers the MSPointer* event handlers.

addTouchEventHandlers(appleGestures)

Parameters:
{Boolean} appleGestures: If set to false the gesturestart and gesturechange event handlers will not be registered. Since iOS 13, touch events were abandoned in favour of pointer events

{JXG.Board} animate()

General purpose animation function. This currently only supports moving points from one place to another. This is faster than managing the animation per point, especially if there is more than one animated point at the same time.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} applyZoom()

Apply update on all objects with the new zoom-factors. Clears all traces.

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} calculateSnapSizes()

Calculates adequate snap sizes.

Returns:: {JXG.Board} Reference to the board.

<private> {Boolean} checkFrameRate(evt)

Returns false if the event has been triggered faster than the maximum frame rate.

Parameters:
{Event} evt: Event object given by the browser (unused)

Returns:: {Boolean} If the event has been triggered faster than the maximum frame rate, false is returned.

See:: JXG.Board#pointerMoveListener; JXG.Board#touchMoveListener; JXG.Board#mouseMoveListener

{JXG.Board} clearTraces()

Delete the elements drawn as part of a trace of an element.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} clickDownArrow()

Handler for click on down arrow in the navigation bar

Returns:: {JXG.Board} Reference to the board

{JXG.Board} clickLeftArrow()

Handler for click on left arrow in the navigation bar

Returns:: {JXG.Board} Reference to the board

{JXG.Board} clickRightArrow()

Handler for click on right arrow in the navigation bar

Returns:: {JXG.Board} Reference to the board

{JXG.Board} clickUpArrow()

Handler for click on up arrow in the navigation bar

Returns:: {JXG.Board} Reference to the board

{Object} create(elementType, parents, attributes)

Creates a new geometric element of type elementType.

Parameters:
{String} elementType: Type of the element to be constructed given as a string e.g. 'point' or 'circle'.
{Array} parents: Array of parent elements needed to construct the element e.g. coordinates for a point or two points to construct a line. This highly depends on the elementType that is constructed. See the corresponding JXG.create* methods for a list of possible parameters.
{Object} attributes Optional: An object containing the attributes to be set. This also depends on the elementType. Common attributes are name, visible, strokeColor.

Returns:: {Object} Reference to the created element. This is usually a GeometryElement, but can be an array containing two or more elements.

createElement()

Deprecated name for JXG.Board.create.

createRoulette(c1, c2, start_c1, stepsize, direction, time, pointlist)

Function to animate a curve rolling on another curve.

Parameters:
{Curve} c1: JSXGraph curve building the floor where c2 rolls
{Curve} c2: JSXGraph curve which rolls on c1.
{number} start_c1: The parameter t such that c1(t) touches c2. This is the start position of the rolling process
{Number} stepsize: Increase in t in each step for the curve c1
{Number} direction
{Number} time: Delay time for setInterval()
{Array} pointlist: Array of points which are rolled in each step. This list should contain all points which define c2 and gliders on c2.

Examples:

{JXG.Board} dehighlightAll()

Remove highlighting of all elements.

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} displayInfobox(val)

Set infobox visible / invisible. It uses its property hiddenByParent to memorize its status. In this way, many DOM access can be avoided.

Parameters:
{Boolean} val: true for visible, false for invisible

Returns:: {JXG.Board} Reference to the board.

See:: JXG.Board#updateInfobox

{JXG.Board} emulateColorblindness(deficiency)

Initializes color blindness simulation.

Parameters:
{String} deficiency: Describes the color blindness deficiency which is simulated. Accepted values are 'protanopia', 'deuteranopia', and 'tritanopia'.

Returns:: {JXG.Board} Reference to the board

finalizeAdding(obj)

After construction of the object the visibility is set and the label is constructed if necessary.

Parameters:
{Object} obj: The object to add.

fullscreenListener(evt)

If fullscreen mode is toggled, the possible CSS transformations which are applied to the JSXGraph canvas have to be reread. Otherwise the position of upper left corner is wrongly interpreted.

Parameters:
{Object} evt: fullscreen event object (unused)

{JXG.Board} fullUpdate()

Runs through all elements and calls their update() method and update the conditions. This is necessary after zooming and changing the bounding box.

Returns:: {JXG.Board} Reference to the board

{String} generateId()

Generates unique id for a board. The result is randomly generated and prefixed with 'jxgBoard'.

Returns:: {String} Unique id for a board.

{String} generateName(object)

Generates an unique name for the given object. The result depends on the objects type, if the object is a JXG.Point, capital characters are used, if it is of type JXG.Line only lower case characters are used. If object is of type JXG.Polygon, a bunch of lower case characters prefixed with P_ are used. If object is of type JXG.Circle the name is generated using lower case characters. prefixed with k_ is used. In any other case, lower case chars prefixed with s_ is used.

Parameters:
{Object} object: Reference of an JXG.GeometryElement that is to be named.

Returns:: {String} Unique name for the object.

{Boolean} gestureChangeListener(evt)

Triggered on iOS/Safari while the user inputs a gesture (e.g. pinch) and is used to zoom into the board. Works on iOS/Safari and Android.

Parameters:
{Event} evt: Browser event object

Returns:: {Boolean}

{Boolean} gestureStartListener(evt)

Called by iOS/Safari as soon as the user starts a gesture. Works natively on iOS/Safari, on Android we emulate it.

Parameters:
{Event} evt

Returns:: {Boolean}

{Array} getAllObjectsUnderMouse(evt)

Collects all elements under current mouse position.

Parameters:
{Event} evt: Event object containing the mouse coordinates.

Returns:: {Array} Array of elements at the current mouse position.

See:: JXG.Board#getAllUnderMouse

{Array} getAllUnderMouse(evt)

Collects all elements under current mouse position plus current user coordinates of mouse cursor.

Parameters:
{Event} evt: Event object containing the mouse coordinates.

Returns:: {Array} Array of elements at the current mouse position plus current user coordinates of mouse.

See:: JXG.Board#getUsrCoordsOfMouse; JXG.Board#getAllObjectsUnderMouse

{Array} getBoundingBox()

Get the bounding box of the board.

Returns:: {Array} bounding box [x1,y1,x2,y2] upper left corner, lower right corner

{Array} getCoordsTopLeftCorner()

Calculates mouse coordinates relative to the boards container.

Returns:: {Array} Array of coordinates relative the boards container top left corner.

{Array} getMousePosition(e, i)

Get the position of the mouse in screen coordinates, relative to the upper left corner of the host tag.

Parameters:
{Event} e: Event object given by the browser.
{Number} i Optional: Only use in case of touch events. This determines which finger to use and should not be set for mouseevents.

Returns:: {Array} Contains the mouse coordinates in screen coordinates, ready for JXG.Coords

<private> {Array} getScrCoordsOfMouse(x, y)

Returns the input parameters in an array. This method looks pointless and it really is, but it had a purpose once.

Parameters:
{Number} x: X coordinate in screen coordinates
{Number} y: Y coordinate in screen coordinates

Returns:: {Array} Coordinates [x, y] of the mouse in screen coordinates.

See:: JXG.Board#getUsrCoordsOfMouse

{Array} getUsrCoordsOfMouse(evt)

This method calculates the user coords of the current mouse coordinates.

Parameters:
{Event} evt: Event object containing the mouse coordinates.

Returns:: {Array} Coordinates [x, y] of the mouse in user coordinates.

See:: JXG.Board#getScrCoordsOfMouse; JXG.Board#getAllUnderMouse

Examples:

{Boolean} hasPoint(x, y)

Checks if the given point is inside the boundingbox.

Parameters:
{Number|JXG.Coords} x: User coordinate or JXG.Coords object.
{Number} y Optional: User coordinate. May be omitted in case x is a JXG.Coords object.

Returns:: {Boolean}

{JXG.Board} highlightCustomInfobox(text, el)

Changes the text of the info box to what is provided via text.

Parameters:
{String} text
{JXG.GeometryElement} el Optional

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} highlightInfobox(x, y, el)

Changes the text of the info box to show the given coordinates.

Parameters:
{Number} x
{Number} y
{JXG.GeometryElement} el Optional: The element the mouse is pointing at

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} initGeonextBoard()

Initialize some objects which are contained in every GEONExT construction by default, but are not contained in the gxt files.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} initInfobox()

Initialize the info box object which is used to display the coordinates of points near the mouse pointer,

Returns:: {JXG.Board} Reference to the board

{Array} initMoveObject(x, y, evt, type)

Collects all elements below the current mouse pointer and fulfilling the following constraints:

isDraggable
visible
not fixed
not frozen

Parameters:
{Number} x: Current mouse/touch coordinates
{Number} y: current mouse/touch coordinates
{Object} evt: An event object
{String} type: What type of event? 'touch', 'mouse' or 'pen'.

Returns:: {Array} A list of geometric elements.

initMoveOrigin(x, y)

Initiate moving the origin. This is used in mouseDown and touchStart listeners.

Parameters:
{Number} x: Current mouse/touch coordinates
{Number} y: Current mouse/touch coordinates

keyDownListener(evt)

Allow moving of JSXGraph elements with arrow keys and zooming of the construction with + / -. Panning of the construction is done with arrow keys if the pan key (shift or ctrl) is pressed. The selection of the element is done with the tab key.

Parameters:
{Event} evt: The browser's event object

See:: JXG.Board#keyboard; JXG.Board#keyFocusInListener; JXG.Board#keyFocusOutListener

keyFocusInListener(evt)

Event listener for SVG elements getting focus. This is needed for highlighting when using keyboard control.

Parameters:
{Event} evt: The browser's event object

See:: JXG.Board#keyFocusOutListener; JXG.Board#keyDownListener; JXG.Board#keyboard

keyFocusOutListener(evt)

Event listener for SVG elements losing focus. This is needed for dehighlighting when using keyboard control.

Parameters:
{Event} evt: The browser's event object

See:: JXG.Board#keyFocusInListener; JXG.Board#keyDownListener; JXG.Board#keyboard

{JXG.Board} migratePoint(src, dest, copyName)

Migrate the dependency properties of the point src to the point dest and delete the point src. For example, a circle around the point src receives the new center dest. The old center src will be deleted.

Parameters:
{JXG.Point} src: Original point which will be deleted
{JXG.Point} dest: New point with the dependencies of src.
{Boolean} copyName: Flag which decides if the name of the src element is copied to the dest element.

Returns:: {JXG.Board} Reference to the board

{Boolean} mouseDownListener(evt)

This method is called by the browser when the mouse button is clicked.

Parameters:
{Event} evt: The browsers event object.

Returns:: {Boolean} True if no element is found under the current mouse pointer, false otherwise.

mouseMoveListener(evt)

This method is called by the browser when the mouse is moved.

Parameters:
{Event} evt: The browsers event object.

mouseUpListener(evt)

This method is called by the browser when the mouse button is released.

Parameters:
{Event} evt

{Boolean} mouseWheelListener(evt)

Handler for mouse wheel events. Used to zoom in and out of the board.

Parameters:
{Event} evt

Returns:: {Boolean}

moveObject(x, y, o, evt, type)

Moves an object.

Parameters:
{Number} x: Coordinate
{Number} y: Coordinate
{Object} o: The touch object that is dragged: {JXG.Board#mouse} or {JXG.Board#touches}.
{Object} evt: The event object.
{String} type: Mouse or touch event?

{JXG.Board} moveOrigin(x, y, diff)

Moves the origin and initializes an update of all elements.

Parameters:
{Number} x
{Number} y
{Boolean} diff Optional, Default: false

Returns:: {JXG.Board} Reference to this board.

<private> {null} originMoveEnd()

Stop moving the origin with one finger

Returns:: {null} null

{Boolean} pointerDownListener(evt, object)

This method is called by the browser when a pointing device is pressed on the screen.

Parameters:
{Event} evt: The browsers event object.
{Object} object: If the object to be dragged is already known, it can be submitted via this parameter

Returns:: {Boolean} ...

{Boolean} pointerMoveListener(evt)

Called periodically by the browser while the user moves a pointing device across the screen.

Parameters:
{Event} evt

Returns:: {Boolean}

{Boolean} pointerUpListener(evt)

Triggered as soon as the user stops touching the device with at least one finger.

Parameters:
{Event} evt

Returns:: {Boolean}

{JXG.Board} prepareUpdate()

Sets for all objects the needsUpdate flag to "true".

Returns:: {JXG.Board} Reference to the board

{JXG.Board} removeAncestors(object)

Removes the ancestors of an object an the object itself from board and renderer.

Parameters:
{JXG.GeometryElement} object: The object to remove.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} removeChild(board)

Deletes a board from the list of dependent boards.

Parameters:
{JXG.Board} board: Reference to the board which will be removed.

Returns:: {JXG.Board} Reference to the board

removeEventHandlers()

Remove all event handlers from the board object

removeFullscreenEventHandlers()

Remove all registered event handlers regarding fullscreen mode.

{JXG.Board} removeGrids()

Removes all grids assigned to this board. Warning: This method also removes all objects depending on one or more of the grids.

Returns:: {JXG.Board} Reference to the board object.

{JXG.Board} removeHook(id)

Please use JXG.Board.off instead.

Parameters:
{Number|function} id: The number you got when you added the hook or a reference to the event handler.

Returns:: {JXG.Board} Reference to the board

removeKeyboardEventHandlers()

Remove all registered touch event handlers.

removeMouseEventHandlers()

De-register mouse event handlers.

{JXG.Board} removeObject(object, saveMethod)

Removes object from board and renderer.

Performance hints: It is recommended to use the object's id. If many elements are removed, it is best to call board.suspendUpdate() before looping through the elements to be removed and call board.unsuspendUpdate() after the loop. Further, it is advisable to loop in reverse order, i.e. remove the object in reverse order of their creation time.

Parameters:
{JXG.GeometryElement|Array} object: The object to remove or array of objects to be removed. The element(s) is/are given by name, id or a reference.
{Boolean} saveMethod: If true, the algorithm runs through all elements and tests if the element to be deleted is a child element. If yes, it will be removed from the list of child elements. If false (default), the element is removed from the lists of child elements of all its ancestors. This should be much faster.

Returns:: {JXG.Board} Reference to the board

removePointerEventHandlers()

Remove MSPointer* Event handlers.

removeTouchEventHandlers()

Remove all registered touch event handlers.

{JXG.Board} resizeContainer(canvasWidth, canvasHeight, dontset, dontSetBoundingBox)

Change the height and width of the board's container. After doing so, JXG.JSXGraph.setBoundingBox is called using the actual size of the bounding box and the actual value of keepaspectratio. If setBoundingbox() should not be called automatically, call resizeContainer with dontSetBoundingBox == true.

Parameters:
{Number} canvasWidth: New width of the container.
{Number} canvasHeight: New height of the container.
{Boolean} dontset Optional, Default: false: If true do not set the CSS width and height of the DOM element.
{Boolean} dontSetBoundingBox Optional, Default: false: If true do not call setBoundingBox().

Returns:: {JXG.Board} Reference to the board

resizeListener()

Fallback solutions if there is no resizeObserver available in the browser. Reacts to resize events of the window (only). Otherwise similar to startResizeObserver(). To handle changes of the visibility of the JSXGraph container element, additionally an intersection observer is used. which watches changes in the visibility of the JSXGraph container element. This is necessary e.g. for register tabs or dia shows.

See:: JXG.Board#startResizeObserver; JXG.Board#startIntersectionObserver

<private> saveStartPos(obj, targets)

Helper function which returns a reasonable starting point for the object being dragged. Formerly known as initXYstart().

Parameters:
{JXG.GeometryElement} obj: The object to be dragged
{Array} targets: Array of targets. It is changed by this function.

scrollListener(evt)

Listener to watch for scroll events. Sets board._isScrolling = true

Parameters:
{Event} evt: The browser's event object

See:: JXG.Board#startResizeObserver; JXG.Board#resizeListener

{JXG.GeometryElement|JXG.Composition} select(str, onlyByIdOrName)

Select a single or multiple elements at once.

Parameters:
{String|Object|function} str: The name, id or a reference to a JSXGraph element on this board. An object will be used as a filter to return multiple elements at once filtered by the properties of the object.
{Boolean} onlyByIdOrName: If true (default:false) elements are only filtered by their id, name or groupId. The advanced filters consisting of objects or functions are ignored.

Returns:: {JXG.GeometryElement|JXG.Composition}

Examples:

{JXG.Board} setBoundingBox(bbox, keepaspectratio, setZoom)

Set the bounding box of the board.

Parameters:
{Array} bbox: New bounding box [x1,y1,x2,y2]
{Boolean} keepaspectratio Optional, Default: false: If set to true, the aspect ratio will be 1:1, but the resulting viewport may be larger.
{String} setZoom Optional, Default: 'reset': Reset, keep or update the zoom level of the board. 'reset' sets JXG.Board#zoomX and JXG.Board#zoomY to the start values (or 1.0). 'update' adapts these values accoring to the new bounding box and 'keep' does nothing.

Returns:: {JXG.Board} Reference to the board

{String} setId(obj, type)

Composes an id for an element. If the ID is empty ('' or null) a new ID is generated, depending on the object type. As a side effect JXG.Board#numObjects is updated.

Parameters:
{Object} obj: Reference of an geometry object that needs an id.
{Number} type: Type of the object.

Returns:: {String} Unique id for an element.

{JXG.Board} setZoom(fX, fY)

Sets the zoom level to fX resp fY.

Parameters:
{Number} fX
{Number} fY

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} showDependencies()

Lists the dependencies graph in a new HTML-window.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} showXML()

Lists the XML code of the construction in a new HTML-window.

Returns:: {JXG.Board} Reference to the board

startIntersectionObserver()

Watch for changes of the visibility of the JSXGraph container element.

See:: JXG.Board#startResizeObserver; JXG.Board#resizeListener

startResizeObserver()

Start observer which reacts to size changes of the JSXGraph container div element. Calls updateContainerDims(). If not available, an event listener for the window-resize event is started. On mobile devices also scrolling might trigger resizes. However, resize events triggered by scrolling events should be ignored. Therefore, also a scrollListener is started. Resize can be controlled with the board attribute resize.

See:: JXG.Board#updateContainerDims; JXG.Board#resizeListener; JXG.Board#scrollListener; JXG.Board#resize

startSelectionMode()

Start selection mode. This function can either be triggered from outside or by a down event together with correct key pressing. The default keys are shift+ctrl. But this can be changed in the options. Starting from out side can be realized for example with a button like this:

	<button onclick="board.startSelectionMode()">Start</button>

Examples:

{JXG.Board} stopAllAnimation()

Cancels all running animations.

Returns:: {JXG.Board} Reference to the board

stopIntersectionObserver()

Stop the intersection observer

See:: JXG.Board#startIntersectionObserver

stopResizeObserver()

Stops the resize observer.

See:: JXG.Board#startResizeObserver

{Array} stopSelectionMode()

Finalize the selection: disable selection mode and return the coordinates of the selection rectangle.

Returns:: {Array} Coordinates of the selection rectangle. The array contains two JXG.Coords objects. One the upper left corner and the second for the lower right corner.

{JXG.Board} suspendUpdate()

Stop updates of the board.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} toFullscreen(id)

Expand the JSXGraph construction to fullscreen. In order to preserve the proportions of the JSXGraph element, a wrapper div is created which is set to fullscreen.

The wrapping div has the CSS class 'jxgbox_wrap_private' which is defined in the file 'jsxgraph.css'

This feature is not available on iPhones (as of December 2021).

Parameters:
{String} id: (Optional) id of the div element which is brought to fullscreen. If not provided, this defaults to the JSXGraph div. However, it may be necessary for the aspect ratio trick which using padding-bottom/top and an out div element. Then, the id of the outer div has to be supplied.

Returns:: {JXG.Board} Reference to the board

Examples:

{Boolean} touchEndListener(evt)

Triggered as soon as the user stops touching the device with at least one finger.

Parameters:
{Event} evt

Returns:: {Boolean}

{Boolean} touchMoveListener(evt)

Called periodically by the browser while the user moves his fingers across the device.

Parameters:
{Event} evt

Returns:: {Boolean}

<private> {Boolean} touchOriginMove(evt)

Move the origin with one finger

Parameters:
{Object} evt: Event from touchMoveListener

Returns:: {Boolean} returns if the origin is moved.

{Boolean} touchStartListener(evt)

This method is called by the browser when a finger touches the surface of the touch-device.

Parameters:
{Event} evt: The browsers event object.

Returns:: {Boolean} ...

<private> {Boolean} touchStartMoveOriginOneFinger(evt)

Start moving the origin with one finger.

Parameters:
{Object} evt: Event from touchStartListener

Returns:: {Boolean} returns if the origin is moved.

twoFingerMove(p1, p2, o, evt)

Moves elements in multitouch mode.

Parameters:
{Array} p1: x,y coordinates of first touch
{Array} p2: x,y coordinates of second touch
{Object} o: The touch object that is dragged: {JXG.Board#touches}.
{Object} evt: The event object that lead to this movement.

twoFingerTouchObject(tar, drag, id)

Moves, rotates and scales a line or polygon with two fingers.

Parameters:
{Array} tar: Array conatining touch event objects: {JXG.Board#touches.targets}.
{object} drag: The object that is dragged:
{Number} id: pointerId of the event. In case of old touch event this is emulated.

{JXG.Board} unsuspendUpdate()

Enable updates of the board.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} update(drag)

Runs through most elements and calls their update() method and update the conditions.

Parameters:
{JXG.GeometryElement} drag Optional: Element that caused the update.

Returns:: {JXG.Board} Reference to the board

updateConditions()

updateContainerDims()

Update the width and height of the JSXGraph container div element. Read actual values with getBoundingClientRect(), and call board.resizeContainer() with this values.

If necessary, also call setBoundingBox().

See:: JXG.Board#startResizeObserver; JXG.Board#resizeListener; JXG.Board#resizeContainer; JXG.Board#setBoundingBox

{JXG.Board} updateCoords()

Update the coords object of all elements which possess this property. This is necessary after changing the viewport.

Returns:: {JXG.Board} Reference to this board.

updateCSSTransforms()

Update CSS transformations of type scaling. It is used to correct the mouse position in JXG.Board.getMousePosition. The inverse transformation matrix is updated on each mouseDown and touchStart event. It is up to the user to call this method after an update of the CSS transformation in the DOM.

{JXG.Board} updateElements(drag)

Runs through all elements and calls their update() method.

Parameters:
{JXG.GeometryElement} drag: Element that caused the update.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} updateHooks(m)

Runs through all hooked functions and calls them.

Parameters:
m

Returns:: {JXG.Board} Reference to the board

{JXG.Board} updateInfobox(el)

Updates and displays a little info box to show coordinates of current selected points.

Parameters:
{JXG.GeometryElement} el: A GeometryElement

Returns:: {JXG.Board} Reference to the board

See:: JXG.Board#displayInfobox; JXG.Board#showInfobox; Point#showInfobox

{JXG.Board} updateRenderer()

Runs through all elements and calls their update() method.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} updateRendererCanvas()

Runs through all elements and calls their update() method. This is a special version for the CanvasRenderer. Here, we have to do our own layer handling.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} zoom100()

Reset the zoom level to the original zoom level from initBoard(); Additionally, if the board as been initialized with a boundingBox (which is the default), restore the viewport to the original viewport during initialization. Otherwise, (i.e. if the board as been initialized with unitX/Y and originX/Y), just set the zoom level to 100%.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} zoomAllPoints()

Zooms the board so every visible point is shown. Keeps aspect ratio.

Returns:: {JXG.Board} Reference to the board

{JXG.Board} zoomElements(elements)

Reset the bounding box and the zoom level to 100% such that a given set of elements is within the board's viewport.

Parameters:
{Array} elements: A set of elements given by id, reference, or name.

Returns:: {JXG.Board} Reference to the board.

{JXG.Board} zoomIn(x, y)

Zooms into the board by the factors board.attr.zoom.factorX and board.attr.zoom.factorY and applies the zoom. The zoom operation is centered at x, y.

Parameters:
{Number} x Optional
{Number} y Optional

Returns:: {JXG.Board} Reference to the board

{JXG.Board} zoomOut(x, y)

Zooms out of the board by the factors board.attr.zoom.factorX and board.attr.zoom.factorY and applies the zoom. The zoom operation is centered at x, y.

Parameters:
{Number} x Optional
{Number} y Optional

Returns:: {JXG.Board} Reference to the board

Event Detail

boundingbox()

The bounding box of the board has changed.

down(e)

Whenever the user starts to touch or click the board.

Parameters:
{Event} e: The browser's event object.

hit(e, el, target)

Whenever an element is highlighted this event is fired.

var c = board.create('circle', [[1, 1], 2]);
board.on('hit', function(evt, el) {
    console.log("Hit element", el);
});

Parameters:
{Event} e: The browser's event object.
{JXG.GeometryElement} el: The hit element.
target

mousedown(e)

Whenever the user starts to click on the board.

Parameters:
{Event} e: The browser's event object.

mousehit(e, el, target)

Whenever an element is highlighted this event is fired.

Parameters:
{Event} e: The browser's event object.
{JXG.GeometryElement} el: The hit element.
target

See:: JXG.Board#hit

mousemove(e, mode)

This event is fired whenever the user is moving the mouse over the board.

Parameters:
{Event} e: The browser's event object.
{Number} mode: The mode the board currently is in

See:: JXG.Board#mode

mousemoveselecting()

A move event while selecting of a region is active from a device sending mouse events.

mousestartselecting()

Select a region is started during a down event from a device sending mouse events or by calling JXG.Board.startSelectionMode.

mousestopselecting()

Selection of a region is stopped during an up event from a device sending mouse events.

mouseup(e)

Whenever the user releases the mousebutton over the board.

Parameters:
{Event} e: The browser's event object.

move(e, mode)

This event is fired whenever the user is moving the finger or mouse pointer over the board.

Parameters:
{Event} e: The browser's event object.
{Number} mode: The mode the board currently is in

See:: JXG.Board#mode

moveselecting()

A move event while selecting of a region is active.

pendown(e)

Whenever the user taps the pen on the board.

Parameters:
{Event} e: The browser's event object.

penmove(e, mode)

This event is fired whenever the user is moving the pen over the board.

Parameters:
{Event} e: The browser's event object.
{Number} mode: The mode the board currently is in

See:: JXG.Board#mode

pointerdown(e)

Whenever the user starts to click on the board with a device sending pointer events.

Parameters:
{Event} e: The browser's event object.

pointermove(e, mode)

This event is fired whenever the user is moving the mouse over the board with a device sending pointer events.

Parameters:
{Event} e: The browser's event object.
{Number} mode: The mode the board currently is in

See:: JXG.Board#mode

pointermoveselecting()

Select a region is started during a down event from a device sending mouse events.

pointerstartselecting()

Select a region is started during a down event from a device sending pointer events or by calling JXG.Board.startSelectionMode.

pointerstopselecting()

Selection of a region is stopped during an up event from a device sending pointer events.

pointerup(e)

Whenever the user releases the mousebutton over the board with a device sending pointer events.

Parameters:
{Event} e: The browser's event object.

startselecting()

Select a region is started during a down event or by calling JXG.Board.startSelectionMode

stopselecting()

Selection of a region is stopped during an up event.

touchend(e)

Whenever the user stops touching the board.

Parameters:
{Event} e: The browser's event object.

touchmove(e, mode)

This event is fired whenever the user is moving the finger over the board.

Parameters:
{Event} e: The browser's event object.
{Number} mode: The mode the board currently is in

See:: JXG.Board#mode

touchmoveselecting()

Select a region is started during a down event from a device sending touch events.

touchstart(e)

Whenever the user starts to touch the board.

Parameters:
{Event} e: The browser's event object.

touchstartselecting()

Select a region is started during a down event from a device sending touch events or by calling JXG.Board.startSelectionMode.

touchstopselecting()

Selection of a region is stopped during an up event from a device sending touch events.

up(e)

Whenever the user stops to touch or click the board.

Parameters:
{Event} e: The browser's event object.

update()

This board is updated.

JSXGraph Reference

JavaScript must be enabled in order for you to use JSXGraph and JSXGraph reference. However, it seems JavaScript is either disabled or not supported by your browser.

Elements

Classes

Class JXG.Board