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<pre class="prettyprint lang-js"><span id='Ext-dd-DragTracker'>/**
</span> * A DragTracker listens for drag events on an Element and fires events at the start and end of the drag,
* as well as during the drag. This is useful for components such as {@link Ext.slider.Multi}, where there is
* an element that can be dragged around to change the Slider's value.
*
* DragTracker provides a series of template methods that should be overridden to provide functionality
* in response to detected drag operations. These are onBeforeStart, onStart, onDrag and onEnd.
* See {@link Ext.slider.Multi}'s initEvents function for an example implementation.
*/
Ext.define('Ext.dd.DragTracker', {
uses: ['Ext.util.Region'],
mixins: {
observable: 'Ext.util.Observable'
},
<span id='Ext-dd-DragTracker-property-active'> /**
</span> * @property {Boolean} active
* Indicates whether the user is currently dragging this tracker.
* @readonly
*/
active: false,
<span id='Ext-dd-DragTracker-property-dragTarget'> /**
</span> * @property {HTMLElement} dragTarget
* The element being dragged.
*
* Only valid during drag operations.
*
* If the {@link #delegate} option is used, this will be the delegate element which was mousedowned.
* @readonly
*/
<span id='Ext-dd-DragTracker-cfg-trackOver'> /**
</span> * @cfg {Boolean} trackOver
* Set to true to fire mouseover and mouseout events when the mouse enters or leaves the target element.
*
* This is implicitly set when an {@link #overCls} is specified.
*
* If the {@link #delegate} option is used, these events fire only when a delegate element is entered of left.
*/
trackOver: false,
<span id='Ext-dd-DragTracker-cfg-overCls'> /**
</span> * @cfg {String} overCls
* A CSS class to add to the DragTracker's target element when the element (or, if the {@link #delegate}
* option is used, when a delegate element) is mouseovered.
*
* If the {@link #delegate} option is used, these events fire only when a delegate element is entered of left.
*/
<span id='Ext-dd-DragTracker-cfg-constrainTo'> /**
</span> * @cfg {Ext.util.Region/Ext.Element} constrainTo
* A {@link Ext.util.Region Region} (Or an element from which a Region measurement will be read)
* which is used to constrain the result of the {@link #getOffset} call.
*
* This may be set any time during the DragTracker's lifecycle to set a dynamic constraining region.
*/
<span id='Ext-dd-DragTracker-cfg-tolerance'> /**
</span> * @cfg {Number} tolerance
* Number of pixels the drag target must be moved before dragging is
* considered to have started.
*/
tolerance: 5,
<span id='Ext-dd-DragTracker-cfg-autoStart'> /**
</span> * @cfg {Boolean/Number} autoStart
* Specify `true` to defer trigger start by 1000 ms.
* Specify a Number for the number of milliseconds to defer trigger start.
*/
autoStart: false,
<span id='Ext-dd-DragTracker-cfg-delegate'> /**
</span> * @cfg {String} delegate
* A {@link Ext.DomQuery DomQuery} selector which identifies child elements within the DragTracker's encapsulating
* Element which are the tracked elements. This limits tracking to only begin when the matching elements are mousedowned.
*
* This may also be a specific child element within the DragTracker's encapsulating element to use as the tracked element.
*/
<span id='Ext-dd-DragTracker-cfg-preventDefault'> /**
</span> * @cfg {Boolean} [preventDefault=true]
* Specify `false` to enable default actions on onMouseDown events.
*/
<span id='Ext-dd-DragTracker-cfg-stopEvent'> /**
</span> * @cfg {Boolean} [stopEvent=false]
* Specify `true` to stop the `mousedown` event from bubbling to outer listeners from the target element (or its delegates).
*/
constructor : function(config){
var me = this;
Ext.apply(me, config);
me.addEvents(
<span id='Ext-dd-DragTracker-event-mouseover'> /**
</span> * @event mouseover
* Fires when the mouse enters the DragTracker's target element (or if {@link #delegate} is
* used, when the mouse enters a delegate element).
*
* **Only available when {@link #trackOver} is `true`**
*
* @param {Object} this
* @param {Object} e event object
* @param {HTMLElement} target The element mouseovered.
*/
'mouseover',
<span id='Ext-dd-DragTracker-event-mouseout'> /**
</span> * @event mouseout
* Fires when the mouse exits the DragTracker's target element (or if {@link #delegate} is
* used, when the mouse exits a delegate element).
*
* **Only available when {@link #trackOver} is `true`**
*
* @param {Object} this
* @param {Object} e event object
*/
'mouseout',
<span id='Ext-dd-DragTracker-event-mousedown'> /**
</span> * @event mousedown
* Fires when the mouse button is pressed down, but before a drag operation begins. The
* drag operation begins after either the mouse has been moved by {@link #tolerance} pixels,
* or after the {@link #autoStart} timer fires.
*
* Return false to veto the drag operation.
*
* @param {Object} this
* @param {Object} e event object
*/
'mousedown',
<span id='Ext-dd-DragTracker-event-mouseup'> /**
</span> * @event mouseup
* @param {Object} this
* @param {Object} e event object
*/
'mouseup',
<span id='Ext-dd-DragTracker-event-mousemove'> /**
</span> * @event mousemove
* Fired when the mouse is moved. Returning false cancels the drag operation.
* @param {Object} this
* @param {Object} e event object
*/
'mousemove',
<span id='Ext-dd-DragTracker-event-beforestart'> /**
</span> * @event beforestart
* @param {Object} this
* @param {Object} e event object
*/
'beforedragstart',
<span id='Ext-dd-DragTracker-event-dragstart'> /**
</span> * @event dragstart
* @param {Object} this
* @param {Object} e event object
*/
'dragstart',
<span id='Ext-dd-DragTracker-event-dragend'> /**
</span> * @event dragend
* @param {Object} this
* @param {Object} e event object
*/
'dragend',
<span id='Ext-dd-DragTracker-event-drag'> /**
</span> * @event drag
* @param {Object} this
* @param {Object} e event object
*/
'drag'
);
me.dragRegion = new Ext.util.Region(0,0,0,0);
if (me.el) {
me.initEl(me.el);
}
// Dont pass the config so that it is not applied to 'this' again
me.mixins.observable.constructor.call(me);
if (me.disabled) {
me.disable();
}
},
<span id='Ext-dd-DragTracker-method-initEl'> /**
</span> * Initializes the DragTracker on a given element.
* @param {Ext.Element/HTMLElement} el The element
*/
initEl: function(el) {
var me = this;
me.el = Ext.get(el);
// The delegate option may also be an element on which to listen
me.handle = Ext.get(me.delegate);
// If delegate specified an actual element to listen on, we do not use the delegate listener option
me.delegate = me.handle ? undefined : me.delegate;
if (!me.handle) {
me.handle = me.el;
}
// Add a mousedown listener which reacts only on the elements targeted by the delegate config.
// We process mousedown to begin tracking.
me.mon(me.handle, {
mousedown: me.onMouseDown,
delegate: me.delegate,
scope: me
});
// If configured to do so, track mouse entry and exit into the target (or delegate).
// The mouseover and mouseout CANNOT be replaced with mouseenter and mouseleave
// because delegate cannot work with those pseudoevents. Entry/exit checking is done in the handler.
if (me.trackOver || me.overCls) {
me.mon(me.handle, {
mouseover: me.onMouseOver,
mouseout: me.onMouseOut,
delegate: me.delegate,
scope: me
});
}
},
disable: function() {
this.disabled = true;
},
enable: function() {
this.disabled = false;
},
destroy : function() {
this.clearListeners();
delete this.el;
},
// When the pointer enters a tracking element, fire a mouseover if the mouse entered from outside.
// This is mouseenter functionality, but we cannot use mouseenter because we are using "delegate" to filter mouse targets
onMouseOver: function(e, target) {
var me = this;
if (!me.disabled) {
if (Ext.EventManager.contains(e) || me.delegate) {
me.mouseIsOut = false;
if (me.overCls) {
me.el.addCls(me.overCls);
}
me.fireEvent('mouseover', me, e, me.delegate ? e.getTarget(me.delegate, target) : me.handle);
}
}
},
// When the pointer exits a tracking element, fire a mouseout.
// This is mouseleave functionality, but we cannot use mouseleave because we are using "delegate" to filter mouse targets
onMouseOut: function(e) {
var me = this;
if (me.mouseIsDown) {
me.mouseIsOut = true;
} else {
if (me.overCls) {
me.el.removeCls(me.overCls);
}
me.fireEvent('mouseout', me, e);
}
},
onMouseDown: function(e, target){
var me = this,
el;
// If this is disabled, or the mousedown has been processed by an upstream DragTracker, return
if (me.disabled ||e.dragTracked) {
return;
}
// This information should be available in mousedown listener and onBeforeStart implementations
me.dragTarget = me.delegate ? target : me.handle.dom;
me.startXY = me.lastXY = e.getXY();
me.startRegion = Ext.fly(me.dragTarget).getRegion();
if (me.fireEvent('mousedown', me, e) === false ||
me.fireEvent('beforedragstart', me, e) === false ||
me.onBeforeStart(e) === false) {
return;
}
// Track when the mouse is down so that mouseouts while the mouse is down are not processed.
// The onMouseOut method will only ever be called after mouseup.
me.mouseIsDown = true;
// Flag for downstream DragTracker instances that the mouse is being tracked.
e.dragTracked = true;
// See Ext.dd.DragDropManager::handleMouseDown
el = me.el.dom;
if (Ext.isIE && el.setCapture) {
el.setCapture();
}
if (me.preventDefault !== false) {
e.preventDefault();
}
Ext.getDoc().on({
scope: me,
mouseup: me.onMouseUp,
mousemove: me.onMouseMove,
selectstart: me.stopSelect
});
if (me.autoStart) {
me.timer = Ext.defer(me.triggerStart, me.autoStart === true ? 1000 : me.autoStart, me, [e]);
}
},
onMouseMove: function(e, target){
var me = this,
xy = e.getXY(),
s = me.startXY;
e.preventDefault();
me.lastXY = xy;
if (!me.active) {
if (Math.max(Math.abs(s[0]-xy[0]), Math.abs(s[1]-xy[1])) > me.tolerance) {
me.triggerStart(e);
} else {
return;
}
}
// Returning false from a mousemove listener deactivates
if (me.fireEvent('mousemove', me, e) === false) {
me.onMouseUp(e);
} else {
me.onDrag(e);
me.fireEvent('drag', me, e);
}
},
onMouseUp: function(e) {
var me = this;
// Clear the flag which ensures onMouseOut fires only after the mouse button
// is lifted if the mouseout happens *during* a drag.
me.mouseIsDown = false;
// If we mouseouted the el *during* the drag, the onMouseOut method will not have fired. Ensure that it gets processed.
if (me.mouseIsOut) {
me.mouseIsOut = false;
me.onMouseOut(e);
}
e.preventDefault();
// See Ext.dd.DragDropManager::handleMouseDown
if (Ext.isIE && document.releaseCapture) {
document.releaseCapture();
}
me.fireEvent('mouseup', me, e);
me.endDrag(e);
},
<span id='Ext-dd-DragTracker-method-endDrag'> /**
</span> * @private
* Stop the drag operation, and remove active mouse listeners.
*/
endDrag: function(e) {
var me = this,
doc = Ext.getDoc(),
wasActive = me.active;
doc.un('mousemove', me.onMouseMove, me);
doc.un('mouseup', me.onMouseUp, me);
doc.un('selectstart', me.stopSelect, me);
me.clearStart();
me.active = false;
if (wasActive) {
me.onEnd(e);
me.fireEvent('dragend', me, e);
}
// Private property calculated when first required and only cached during a drag
delete me._constrainRegion;
// Remove flag from event singleton. Using "Ext.EventObject" here since "endDrag" is called directly in some cases without an "e" param
delete Ext.EventObject.dragTracked;
},
triggerStart: function(e) {
var me = this;
me.clearStart();
me.active = true;
me.onStart(e);
me.fireEvent('dragstart', me, e);
},
clearStart : function() {
var timer = this.timer;
if (timer) {
clearTimeout(timer);
delete this.timer;
}
},
stopSelect : function(e) {
e.stopEvent();
return false;
},
<span id='Ext-dd-DragTracker-method-onBeforeStart'> /**
</span> * Template method which should be overridden by each DragTracker instance. Called when the user first clicks and
* holds the mouse button down. Return false to disallow the drag
* @param {Ext.EventObject} e The event object
* @template
*/
onBeforeStart : function(e) {
},
<span id='Ext-dd-DragTracker-method-onStart'> /**
</span> * Template method which should be overridden by each DragTracker instance. Called when a drag operation starts
* (e.g. the user has moved the tracked element beyond the specified tolerance)
* @param {Ext.EventObject} e The event object
* @template
*/
onStart : function(xy) {
},
<span id='Ext-dd-DragTracker-method-onDrag'> /**
</span> * Template method which should be overridden by each DragTracker instance. Called whenever a drag has been detected.
* @param {Ext.EventObject} e The event object
* @template
*/
onDrag : function(e) {
},
<span id='Ext-dd-DragTracker-method-onEnd'> /**
</span> * Template method which should be overridden by each DragTracker instance. Called when a drag operation has been completed
* (e.g. the user clicked and held the mouse down, dragged the element and then released the mouse button)
* @param {Ext.EventObject} e The event object
* @template
*/
onEnd : function(e) {
},
<span id='Ext-dd-DragTracker-method-getDragTarget'> /**
</span> * Returns the drag target. This is usually the DragTracker's encapsulating element.
*
* If the {@link #delegate} option is being used, this may be a child element which matches the
* {@link #delegate} selector.
*
* @return {Ext.Element} The element currently being tracked.
*/
getDragTarget : function(){
return this.dragTarget;
},
<span id='Ext-dd-DragTracker-method-getDragCt'> /**
</span> * @private
* @returns {Ext.Element} The DragTracker's encapsulating element.
*/
getDragCt : function(){
return this.el;
},
<span id='Ext-dd-DragTracker-method-getConstrainRegion'> /**
</span> * @private
* Return the Region into which the drag operation is constrained.
* Either the XY pointer itself can be constrained, or the dragTarget element
* The private property _constrainRegion is cached until onMouseUp
*/
getConstrainRegion: function() {
var me = this;
if (me.constrainTo) {
if (me.constrainTo instanceof Ext.util.Region) {
return me.constrainTo;
}
if (!me._constrainRegion) {
me._constrainRegion = Ext.fly(me.constrainTo).getViewRegion();
}
} else {
if (!me._constrainRegion) {
me._constrainRegion = me.getDragCt().getViewRegion();
}
}
return me._constrainRegion;
},
getXY : function(constrain){
return constrain ? this.constrainModes[constrain](this, this.lastXY) : this.lastXY;
},
<span id='Ext-dd-DragTracker-method-getOffset'> /**
</span> * Returns the X, Y offset of the current mouse position from the mousedown point.
*
* This method may optionally constrain the real offset values, and returns a point coerced in one
* of two modes:
*
* - `point`
* The current mouse position is coerced into the constrainRegion and the resulting position is returned.
* - `dragTarget`
* The new {@link Ext.util.Region Region} of the {@link #getDragTarget dragTarget} is calculated
* based upon the current mouse position, and then coerced into the constrainRegion. The returned
* mouse position is then adjusted by the same delta as was used to coerce the region.\
*
* @param constrainMode {String} (Optional) If omitted the true mouse position is returned. May be passed
* as `point` or `dragTarget`. See above.
* @returns {Number[]} The `X, Y` offset from the mousedown point, optionally constrained.
*/
getOffset : function(constrain){
var xy = this.getXY(constrain),
s = this.startXY;
return [xy[0]-s[0], xy[1]-s[1]];
},
constrainModes: {
// Constrain the passed point to within the constrain region
point: function(me, xy) {
var dr = me.dragRegion,
constrainTo = me.getConstrainRegion();
// No constraint
if (!constrainTo) {
return xy;
}
dr.x = dr.left = dr[0] = dr.right = xy[0];
dr.y = dr.top = dr[1] = dr.bottom = xy[1];
dr.constrainTo(constrainTo);
return [dr.left, dr.top];
},
// Constrain the dragTarget to within the constrain region. Return the passed xy adjusted by the same delta.
dragTarget: function(me, xy) {
var s = me.startXY,
dr = me.startRegion.copy(),
constrainTo = me.getConstrainRegion(),
adjust;
// No constraint
if (!constrainTo) {
return xy;
}
// See where the passed XY would put the dragTarget if translated by the unconstrained offset.
// If it overflows, we constrain the passed XY to bring the potential
// region back within the boundary.
dr.translateBy(xy[0]-s[0], xy[1]-s[1]);
// Constrain the X coordinate by however much the dragTarget overflows
if (dr.right > constrainTo.right) {
xy[0] += adjust = (constrainTo.right - dr.right); // overflowed the right
dr.left += adjust;
}
if (dr.left < constrainTo.left) {
xy[0] += (constrainTo.left - dr.left); // overflowed the left
}
// Constrain the Y coordinate by however much the dragTarget overflows
if (dr.bottom > constrainTo.bottom) {
xy[1] += adjust = (constrainTo.bottom - dr.bottom); // overflowed the bottom
dr.top += adjust;
}
if (dr.top < constrainTo.top) {
xy[1] += (constrainTo.top - dr.top); // overflowed the top
}
return xy;
}
}
});</pre>
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