/*!
* Ext JS Library 3.2.0
* Copyright(c) 2006-2010 Ext JS, Inc.
* licensing@extjs.com
* http://www.extjs.com/license
*/
/**
* @class Ext.dd.DragTracker
* @extends Ext.util.Observable
* 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}, 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}'s initEvents function for an example implementation.
*/
Ext.dd.DragTracker = Ext.extend(Ext.util.Observable, {
/**
* @cfg {Boolean} active
* Defaults to false.
*/
active: false,
/**
* @cfg {Number} tolerance
* Number of pixels the drag target must be moved before dragging is considered to have started. Defaults to 5.
*/
tolerance: 5,
/**
* @cfg {Boolean/Number} autoStart
* Defaults to false. Specify true to defer trigger start by 1000 ms.
* Specify a Number for the number of milliseconds to defer trigger start.
*/
autoStart: false,
constructor : function(config){
Ext.apply(this, config);
this.addEvents(
/**
* @event mousedown
* @param {Object} this
* @param {Object} e event object
*/
'mousedown',
/**
* @event mouseup
* @param {Object} this
* @param {Object} e event object
*/
'mouseup',
/**
* @event mousemove
* @param {Object} this
* @param {Object} e event object
*/
'mousemove',
/**
* @event dragstart
* @param {Object} this
* @param {Object} startXY the page coordinates of the event
*/
'dragstart',
/**
* @event dragend
* @param {Object} this
* @param {Object} e event object
*/
'dragend',
/**
* @event drag
* @param {Object} this
* @param {Object} e event object
*/
'drag'
);
this.dragRegion = new Ext.lib.Region(0,0,0,0);
if(this.el){
this.initEl(this.el);
}
Ext.dd.DragTracker.superclass.constructor.call(this, config);
},
initEl: function(el){
this.el = Ext.get(el);
el.on('mousedown', this.onMouseDown, this,
this.delegate ? {delegate: this.delegate} : undefined);
},
destroy : function(){
this.el.un('mousedown', this.onMouseDown, this);
},
onMouseDown: function(e, target){
if(this.fireEvent('mousedown', this, e) !== false && this.onBeforeStart(e) !== false){
this.startXY = this.lastXY = e.getXY();
this.dragTarget = this.delegate ? target : this.el.dom;
if(this.preventDefault !== false){
e.preventDefault();
}
var doc = Ext.getDoc();
doc.on('mouseup', this.onMouseUp, this);
doc.on('mousemove', this.onMouseMove, this);
doc.on('selectstart', this.stopSelect, this);
if(this.autoStart){
this.timer = this.triggerStart.defer(this.autoStart === true ? 1000 : this.autoStart, this);
}
}
},
onMouseMove: function(e, target){
// HACK: IE hack to see if button was released outside of window. */
if(this.active && Ext.isIE && !e.browserEvent.button){
e.preventDefault();
this.onMouseUp(e);
return;
}
e.preventDefault();
var xy = e.getXY(), s = this.startXY;
this.lastXY = xy;
if(!this.active){
if(Math.abs(s[0]-xy[0]) > this.tolerance || Math.abs(s[1]-xy[1]) > this.tolerance){
this.triggerStart();
}else{
return;
}
}
this.fireEvent('mousemove', this, e);
this.onDrag(e);
this.fireEvent('drag', this, e);
},
onMouseUp: function(e) {
var doc = Ext.getDoc();
doc.un('mousemove', this.onMouseMove, this);
doc.un('mouseup', this.onMouseUp, this);
doc.un('selectstart', this.stopSelect, this);
e.preventDefault();
this.clearStart();
var wasActive = this.active;
this.active = false;
delete this.elRegion;
this.fireEvent('mouseup', this, e);
if(wasActive){
this.onEnd(e);
this.fireEvent('dragend', this, e);
}
},
triggerStart: function(isTimer) {
this.clearStart();
this.active = true;
this.onStart(this.startXY);
this.fireEvent('dragstart', this, this.startXY);
},
clearStart : function() {
if(this.timer){
clearTimeout(this.timer);
delete this.timer;
}
},
stopSelect : function(e) {
e.stopEvent();
return false;
},
/**
* 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
*/
onBeforeStart : function(e) {
},
/**
* 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 {Array} xy x and y co-ordinates of the original location of the tracked element
*/
onStart : function(xy) {
},
/**
* Template method which should be overridden by each DragTracker instance. Called whenever a drag has been detected.
* @param {Ext.EventObject} e The event object
*/
onDrag : function(e) {
},
/**
* 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
*/
onEnd : function(e) {
},
/**
* Returns the drag target
* @return {Ext.Element} The element currently being tracked
*/
getDragTarget : function(){
return this.dragTarget;
},
getDragCt : function(){
return this.el;
},
getXY : function(constrain){
return constrain ?
this.constrainModes[constrain].call(this, this.lastXY) : this.lastXY;
},
getOffset : function(constrain){
var xy = this.getXY(constrain);
var s = this.startXY;
return [s[0]-xy[0], s[1]-xy[1]];
},
constrainModes: {
'point' : function(xy){
if(!this.elRegion){
this.elRegion = this.getDragCt().getRegion();
}
var dr = this.dragRegion;
dr.left = xy[0];
dr.top = xy[1];
dr.right = xy[0];
dr.bottom = xy[1];
dr.constrainTo(this.elRegion);
return [dr.left, dr.top];
}
}
});