com.github.gwtd3.api.behaviour

Class Drag

java.lang.Object

com.google.gwt.core.client.JavaScriptObject

com.github.gwtd3.api.behaviour.Drag

All Implemented Interfaces:

IsFunction

public class Drag
extends com.google.gwt.core.client.JavaScriptObject
implements IsFunction

This behavior automatically creates event listeners to handle drag gestures on an element. Both mouse events and touch events are supported.

Usage:

 {
     @code
     Drag drag = D3.behavior.drag().on(DragEventType.drag, new MyDragListener());
     mySelection.call(drag);
 }
 

Author:

Anthony Schiochet

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Drag.DragEvent Provide access to the properties of a drag event.
static class	Drag.DragEventType Type of drag event to listen to.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Drag()

Method Summary

Methods

Modifier and Type	Method and Description
Drag	on(Drag.DragEventType type, DatumFunction<Void> listener) Registers the specified listener to receive events of the specified type from the drag behavior.
Drag	origin(DatumFunction<Coords> o) Set the origin accessor to the specified function.
Drag	origin(com.google.gwt.core.client.JavaScriptObject o) Set the origin accessor to the specified function.

Methods inherited from class com.google.gwt.core.client.JavaScriptObject

cast, createArray, createArray, createFunction, createObject, equals, hashCode, toSource, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Drag

protected Drag()

Method Detail

on

public final Drag on(Drag.DragEventType type,
      DatumFunction<Void> listener)

Registers the specified listener to receive events of the specified type from the drag behavior.

See Drag.DragEventType for more information.

Parameters:

type -

listener -

Returns:

origin

public final Drag origin(com.google.gwt.core.client.JavaScriptObject o)

Set the origin accessor to the specified function.

An origin accessor is used to determine the starting position (the “origin?) of the element being dragged; this allows the drag behavior to preserve the offset between the mouse position and the starting element position during drag. If the origin accessor is null, then the element position is set to the mouse position on drag; this can cause a noticeable jump on large elements. If an origin accessor is specified, the function is called on mousedown. The function is invoked in the same manner as other operator functions, being passed the current datum d and index i, with the this context as the clicked-on DOM element. To access the current event, use the global D3.event(). The origin accessor must return an object with x and y properties representing the starting coordinates of the element being dragged.

Frequently the origin accessor is specified as Object, or D3.identity(), which is equivalent to the identity function. This is suitable when the datum bound to the dragged element is already an object with x and y attributes representing its current position.

For example: http://bl.ocks.org/1557377

Parameters:

o - the origin accessor function, returning an object with x and y attributes.

Returns:

the object Drag.

origin

public final Drag origin(DatumFunction<Coords> o)

Set the origin accessor to the specified function.

An origin accessor is used to determine the starting position (the “origin?) of the element being dragged; this allows the drag behavior to preserve the offset between the mouse position and the starting element position during drag. If the origin accessor is null, then the element position is set to the mouse position on drag; this can cause a noticeable jump on large elements. If an origin accessor is specified, the function is called on mousedown. The function is invoked in the same manner as other operator functions, being passed the current datum d and index i, with the this context as the clicked-on DOM element. To access the current event, use the global D3.event(). The origin accessor must return an object with x and y properties representing the starting coordinates of the element being dragged.

Frequently the origin accessor is specified as Object, or D3.identity(), which is equivalent to the identity function. This is suitable when the datum bound to the dragged element is already an object with x and y attributes representing its current position.

For example: http://bl.ocks.org/1557377

Parameters:

o - the origin accessor function, returning an object with x and y attributes.

Returns:

the object Drag.