/**
+ * @class Ext.util.ComponentDragger
+ * @extends Ext.dd.DragTracker
+ * <p>A subclass of Ext.dd.DragTracker which handles dragging any Component.</p>
+ * <p>This is configured with a Component to be made draggable, and a config object for the
+ * {@link Ext.dd.DragTracker} class.</p>
+ * <p>A {@link #} delegate may be provided which may be either the element to use as the mousedown target
+ * or a {@link Ext.DomQuery} selector to activate multiple mousedown targets.</p>
+ * @constructor Create a new ComponentTracker
+ * @param {object} comp The Component to provide dragging for.
+ * @param {object} config The config object
+ */
+Ext.define('Ext.util.ComponentDragger', {
+
+ /**
+ * @cfg {Boolean} constrain
+ * Specify as <code>true</code> to constrain the Component to within the bounds of the {@link #constrainTo} region.
+ */
+
+ /**
+ * @cfg {String/Element} delegate
+ * Optional. <p>A {@link Ext.DomQuery DomQuery} selector which identifies child elements within the Component's encapsulating
+ * Element which are the drag handles. This limits dragging to only begin when the matching elements are mousedowned.</p>
+ * <p>This may also be a specific child element within the Component's encapsulating element to use as the drag handle.</p>
+ */
+
+ /**
+ * @cfg {Boolean} constrainDelegate
+ * Specify as <code>true</code> to constrain the drag handles within the {@link constrainTo} region.
+ */
+
+ extend: 'Ext.dd.DragTracker',
+
+ autoStart: 500,
+
+ constructor: function(comp, config) {
+ this.comp = comp;
+ this.initialConstrainTo = config.constrainTo;
+ this.callParent([ config ]);
+ },
+
+ onStart: function(e) {
+ var me = this,
+ comp = me.comp;
+
+ // Cache the start [X, Y] array
+ this.startPosition = comp.getPosition();
+
+ // If client Component has a ghost method to show a lightweight version of itself
+ // then use that as a drag proxy unless configured to liveDrag.
+ if (comp.ghost && !comp.liveDrag) {
+ me.proxy = comp.ghost();
+ me.dragTarget = me.proxy.header.el;
+ }
+
+ // Set the constrainTo Region before we start dragging.
+ if (me.constrain || me.constrainDelegate) {
+ me.constrainTo = me.calculateConstrainRegion();
+ }
+ },
+
+ calculateConstrainRegion: function() {
+ var me = this,
+ comp = me.comp,
+ c = me.initialConstrainTo,
+ delegateRegion,
+ elRegion,
+ shadowSize = comp.el.shadow ? comp.el.shadow.offset : 0;
+
+ // The configured constrainTo might be a Region or an element
+ if (!(c instanceof Ext.util.Region)) {
+ c = Ext.fly(c).getViewRegion();
+ }
+
+ // Reduce the constrain region to allow for shadow
+ if (shadowSize) {
+ c.adjust(0, -shadowSize, -shadowSize, shadowSize);
+ }
+
+ // If they only want to constrain the *delegate* to within the constrain region,
+ // adjust the region to be larger based on the insets of the delegate from the outer
+ // edges of the Component.
+ if (!me.constrainDelegate) {
+ delegateRegion = Ext.fly(me.dragTarget).getRegion();
+ elRegion = me.proxy ? me.proxy.el.getRegion() : comp.el.getRegion();
+
+ c.adjust(
+ delegateRegion.top - elRegion.top,
+ delegateRegion.right - elRegion.right,
+ delegateRegion.bottom - elRegion.bottom,
+ delegateRegion.left - elRegion.left
+ );
+ }
+ return c;
+ },
+
+ // Move either the ghost Component or the target Component to its new position on drag
+ onDrag: function(e) {
+ var me = this,
+ comp = (me.proxy && !me.comp.liveDrag) ? me.proxy : me.comp,
+ offset = me.getOffset(me.constrain || me.constrainDelegate ? 'dragTarget' : null);
+
+ comp.setPosition.apply(comp, [me.startPosition[0] + offset[0], me.startPosition[1] + offset[1]]);
+ },
+
+ onEnd: function(e) {
+ if (this.proxy && !this.comp.liveDrag) {
+ this.comp.unghost();
+ }
+ }
+});