Class JXG.Group

↳ JXG.Group

In this class all group management is done.

Defined in: group.js.

Class Summary
Constructor Attributes	Constructor Name and Description
	JXG.Group(board, id, name, objects, attributes) Creates a new instance of Group.

Field Summary
Field Attributes	Field Name and Description
<private>	coords Cache coordinates of points.

Method Summary
Method Attributes	Method Name and Description
<private>	_addActionPoint(action, point) Generic method for JXG.Group@addTranslationPoint and JXG.Group@addRotationPoint
<private>	_removeActionPoint(action, point) Generic method for JXG.Group@removeTranslationPoint and JXG.Group@removeRotationPoint
<private>	_setActionPoints(action, objects) Generic method for JXG.Group@setTranslationPoints and JXG.Group@setRotationPoints
<private>	_update_apply_transformation(drag, t)
<private>	_update_centroid_center() Determine the Euclidean (affine) coordinates of the centroid of the group.
<private>	_update_find_drag_type()
<private>	_updateCoordsCache(el) Update the cached coordinates of a group element.
	addGroup(group) Adds all points in a group to this group.
	addParents(parents) Adds ids of elements to the array this.parents.
	addPoint(object) Adds an Point to this group.
	addPoints(objects) Adds multiple points to this group.
	addRotationPoint(point) Adds a point to the set of rotation points of the group.
	addScalePoint(point, direction) Adds a point to the set of the scale points of the group.
	addTranslationPoint(point) Adds a point to the set of the translation points of the group.
	getParents() List of the element ids resp.
	removePoint(point) Removes a point from the group.
	removeRotationPoint(point) Removes the rotation property from a point of the group.
	removeScalePoint(point) Removes the scaling property from a point of the group.
	removeTranslationPoint(point) Removes the translation property from a point of the group.
	setParents(parents) Sets ids of elements to the array this.parents.
<deprecated>	setProperty()
	setRotationCenter(object) Sets the center of rotation for the group.
	setRotationPoints(objects) Sets the rotation points of the group.
	setScaleCenter(object) Sets the center of scaling for the group.
	setScalePoints(objects, direction) Sets the scale points of the group.
	setTranslationPoints(objects) Sets the translation points of the group.
	ungroup() Releases all elements of this group.
	update() Sends an update to all group members.

Class Detail

JXG.Group(board, id, name, objects, attributes)

Creates a new instance of Group.

Parameters:
{JXG.Board} board
{String} id: Unique identifier for this object. If null or an empty string is given, an unique id will be generated by Board
{String} name: Not necessarily unique name, displayed on the board. If null or an empty string is given, an unique name will be generated.
{Array} objects: Array of points to add to this group.
{Object} attributes: Defines the visual appearance of the group.

Field Detail

<private> {Object} coords

Cache coordinates of points. From this and the actual position of the points, the translation is determined. It has to be kept updated in this class "by hand"-

See:: JXG.Group#_updateCoordsCache

Method Detail

<private> _addActionPoint(action, point)

Generic method for JXG.Group@addTranslationPoint and JXG.Group@addRotationPoint

Parameters:
action
point

<private> _removeActionPoint(action, point)

Generic method for JXG.Group@removeTranslationPoint and JXG.Group@removeRotationPoint

Parameters:
action
point

<private> _setActionPoints(action, objects)

Generic method for JXG.Group@setTranslationPoints and JXG.Group@setRotationPoints

Parameters:
action
objects

<private> _update_apply_transformation(drag, t)

Parameters:
drag
t

<private> {Array} _update_centroid_center()

Determine the Euclidean (affine) coordinates of the centroid of the group.

Returns:: {Array} array of length two,

<private> _update_find_drag_type()

<private> _updateCoordsCache(el)

Update the cached coordinates of a group element.

Parameters:
{String} el: element id of the group element whose cached coordinates are going to be updated.

Returns:: null

{JXG.Group} addGroup(group)

Adds all points in a group to this group.

Parameters:
{JXG.Group} group: The group added to this group.

Returns:: {JXG.Group} returns this group

{JXG.Object} addParents(parents)

Adds ids of elements to the array this.parents. This is a copy of Element.addParents.

Parameters:
{Array} parents: Array of elements or ids of elements. Alternatively, one can give a list of objects as parameters.

Returns:: {JXG.Object} reference to the object itself.

{JXG.Group} addPoint(object)

Adds an Point to this group.

Parameters:
{JXG.Point} object: The point added to the group.

Returns:: {JXG.Group} returns this group

{JXG.Group} addPoints(objects)

Adds multiple points to this group.

Parameters:
{Array} objects: An array of points to add to the group.

Returns:: {JXG.Group} returns this group

{JXG.Group} addRotationPoint(point)

Adds a point to the set of rotation points of the group. Dragging at one of these points results into a rotation of the whole group around the rotation center of the group {@see JXG.Group#setRotationCenter}.

Parameters:
{JXG.Point} point: JXG.Point element.

Returns:: {JXG.Group} returns this group

{JXG.Group} addScalePoint(point, direction)

Adds a point to the set of the scale points of the group. Dragging at one of these points results into a scaling of the whole group.

Parameters:
{JXG.Point} point: JXG.Point element.
{String} direction: Restricts the directions to be scaled. Possible values are 'x', 'y', 'xy'. Default value is 'xy'.

Returns:: {JXG.Group} returns this group

{JXG.Group} addTranslationPoint(point)

Adds a point to the set of the translation points of the group. Dragging one of these points results into a translation of the whole group.

Parameters:
{JXG.Point} point: JXG.Point element.

Returns:: {JXG.Group} returns this group

{Array} getParents()

List of the element ids resp. values used as parents in JXG.Board#create.

Returns:: {Array}

{JXG.Group} removePoint(point)

Removes a point from the group.

Parameters:
{JXG.Point} point

Returns:: {JXG.Group} returns this group

{JXG.Group} removeRotationPoint(point)

Removes the rotation property from a point of the group.

Parameters:
{JXG.Point} point: JXG.Point element.

Returns:: {JXG.Group} returns this group

{JXG.Group} removeScalePoint(point)

Removes the scaling property from a point of the group.

Parameters:
{JXG.Point} point: JXG.Point element.

Returns:: {JXG.Group} returns this group

{JXG.Group} removeTranslationPoint(point)

Removes the translation property from a point of the group.

Parameters:
{JXG.Point} point: JXG.Point element.

Returns:: {JXG.Group} returns this group

{JXG.Object} setParents(parents)

Sets ids of elements to the array this.parents. This is a copy of Element.setParents First, this.parents is cleared. See Group#addParents.

Parameters:
{Array} parents: Array of elements or ids of elements. Alternatively, one can give a list of objects as parameters.

Returns:: {JXG.Object} reference to the object itself.

setProperty()

Deprecated:
Use setAttribute

{JXG.Group} setRotationCenter(object)

Sets the center of rotation for the group. This is either a point or the centroid of the group.

Parameters:
{JXG.Point|String|Array|Function} object: A point which will be the center of rotation, the string "centroid", or an array of length two, or a function returning an array of length two.

Returns:: {JXG.Group} returns this group

{JXG.Group} setRotationPoints(objects)

Sets the rotation points of the group. Dragging at one of these points results into a rotation of the whole group around the rotation center of the group {@see JXG.Group#setRotationCenter}.

Parameters:
{Array|JXG.Point} objects: Array of JXG.Point or arbitrary number of JXG.Point elements.

Returns:: {JXG.Group} returns this group

{JXG.Group} setScaleCenter(object)

Sets the center of scaling for the group. This is either a point or the centroid of the group.

Parameters:
{JXG.Point|String} object: A point which will be the center of scaling, the string "centroid", or an array of length two, or a function returning an array of length two.

Returns:: {JXG.Group} returns this group

{JXG.Group} setScalePoints(objects, direction)

Sets the scale points of the group. Dragging at one of these points results into a scaling of the whole group.

Parameters:
{Array|JXG.Point} objects: Array of JXG.Point or arbitrary number of JXG.Point elements.
{String} direction: Restricts the directions to be scaled. Possible values are 'x', 'y', 'xy'. Default value is 'xy'. By default, all points of the group are translation points.

Returns:: {JXG.Group} returns this group

{JXG.Group} setTranslationPoints(objects)

Sets the translation points of the group. Dragging at one of these points results into a translation of the whole group.

Parameters:
{Array|JXG.Point} objects: Array of JXG.Point or arbitrary number of JXG.Point elements. By default, all points of the group are translation points.

Returns:: {JXG.Group} returns this group

{JXG.Group} ungroup()

Releases all elements of this group.

Returns:: {JXG.Group} returns this (empty) group

{JXG.Group} update()

Sends an update to all group members. This method is called from the points' coords object event listeners and not by the board.

Returns:: {JXG.Group} returns this group

JSXGraph 1.12.0 Reference

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Class JXG.Group