/**
+ * The Drag & Drop Utility allows you to create a draggable interface efficiently, buffering you from browser-level abnormalities and enabling you to focus on the interesting logic surrounding your particular implementation. This component enables you to create a variety of standard draggable objects with just a few lines of code and then, using its extensive API, add your own specific implementation logic.
+ * @module dd
+ * @submodule dd-constrain
+ */
+ /**
+ * This is a plugin for the dd-drag module to add the constraining methods to it. It supports constraining to a renodenode or viewport. It anode* supports tick based moves and XY axis constraints.
+ * @class DragConstrained
+ * @extends Base
+ * @constructor
+ * @namespace Plugin
+ */
+
+ var DRAG_NODE = 'dragNode',
+ OFFSET_HEIGHT = 'offsetHeight',
+ OFFSET_WIDTH = 'offsetWidth',
+ HOST = 'host',
+ CON_2_REGION = 'constrain2region',
+ CON_2_NODE = 'constrain2node',
+ TICK_X_ARRAY = 'tickXArray',
+ TICK_Y_ARRAY = 'tickYArray',
+ DDM = Y.DD.DDM,
+ TOP = 'top',
+ RIGHT = 'right',
+ BOTTOM = 'bottom',
+ LEFT = 'left',
+ proto = null;
+
+ var C = function(config) {
+ C.superclass.constructor.apply(this, arguments);
+ };
+
+ C.NAME = 'DragConstrained';
+ /**
+ * @property con
+ * @description The Constrained instance will be placed on the Drag instance under the con namespace.
+ * @type {String}
+ */
+ C.NS = 'con';
+
+ C.ATTRS = {
+ host: {
+ },
+ /**
+ * @attribute stickX
+ * @description Stick the drag movement to the X-Axis. Default: false
+ * @type Boolean
+ */
+ stickX: {
+ value: false
+ },
+ /**
+ * @attribute stickY
+ * @description Stick the drag movement to the Y-Axis
+ * @type Boolean
+ */
+ stickY: {
+ value: false
+ },
+ /**
+ * @attribute tickX
+ * @description The X tick offset the drag node should snap to on each drag move. False for no ticks. Default: false
+ * @type Number/false
+ */
+ tickX: {
+ value: false
+ },
+ /**
+ * @attribute tickY
+ * @description The Y tick offset the drag node should snap to on each drag move. False for no ticks. Default: false
+ * @type Number/false
+ */
+ tickY: {
+ value: false
+ },
+ /**
+ * @attribute tickXArray
+ * @description An array of page coordinates to use as X ticks for drag movement.
+ * @type Array
+ */
+ tickXArray: {
+ value: false
+ },
+ /**
+ * @attribute tickYArray
+ * @description An array of page coordinates to use as Y ticks for drag movement.
+ * @type Array
+ */
+ tickYArray: {
+ value: false
+ },
+ /**
+ * @attribute constrain2region
+ * @description An Object Literal containing a valid region (top, right, bottom, left) of page positions to constrain the drag node to.
+ * @type Object
+ */
+ constrain2region: {
+ value: false,
+ getter: function(r) {
+ if (Y.Lang.isObject(r)) {
+ var o = {};
+ Y.mix(o, r);
+ return o;
+ } else {
+ return false;
+ }
+ },
+ setter: function (r) {
+ if (Y.Lang.isObject(r)) {
+ if (Y.Lang.isNumber(r[TOP]) && Y.Lang.isNumber(r[RIGHT]) && Y.Lang.isNumber(r[LEFT]) && Y.Lang.isNumber(r[BOTTOM])) {
+ var o = {};
+ Y.mix(o, r);
+ return o;
+ } else {
+ return false;
+ }
+ } else if (r !== false) {
+ return false;
+ }
+ return r;
+ }
+ },
+ /**
+ * @attribute gutter
+ * @description CSS style string for the gutter of a region (supports negative values): '5 0' (sets top and bottom to 5px, left and right to 0px), '1 2 3 4' (top 1px, right 2px, bottom 3px, left 4px)
+ * @type String
+ */
+ gutter: {
+ value: '0',
+ setter: function(gutter) {
+ return Y.DD.DDM.cssSizestoObject(gutter);
+ }
+ },
+ /**
+ * @attribute constrain2node
+ * @description Will attempt to constrain the drag node to the bounderies of this node.
+ * @type Object
+ */
+ constrain2node: {
+ value: false,
+ setter: function(n) {
+ if (!this.get(CON_2_REGION)) {
+ var node = Y.Node.get(n);
+ if (node) {
+ return node;
+ }
+ } else if (this.get(CON_2_REGION) !== false) {
+ }
+ return false;
+ }
+ },
+ /**
+ * @attribute constrain2view
+ * @description Will attempt to constrain the drag node to the bounderies of the viewport region.
+ * @type Object
+ */
+ constrain2view: {
+ value: false
+ }
+ };
+
+ proto = {
+ initializer: function() {
+ this.get(HOST).on('drag:start', Y.bind(this._handleStart, this));
+ this.get(HOST).after('drag:align', Y.bind(this.align, this));
+ },
+ /**
+ * @private
+ * @method _handleStart
+ * @description Fires on drag:start and clears the _regionCache
+ */
+ _handleStart: function() {
+ this._regionCache = null;
+ },
+ /**
+ * @private
+ * @property _regionCache
+ * @description Store a cache of the region that we are constraining to
+ * @type Object
+ */
+ _regionCache: null,
+ /**
+ * @private
+ * @method _cacheRegion
+ * @description Get's the region and caches it, called from window.resize and when the cache is null
+ */
+ _cacheRegion: function() {
+ this._regionCache = this.get(CON_2_NODE).get('region');
+ },
+ /**
+ * @method getRegion
+ * @description Get the active region: viewport, node, custom region
+ * @param {Boolean} inc Include the node's height and width
+ * @return {Object}
+ */
+ getRegion: function(inc) {
+ var r = {}, oh = null, ow = null,
+ g = this.get('gutter'),
+ host = this.get(HOST);
+
+ if (this.get(CON_2_NODE)) {
+ if (!this._regionCache) {
+ Y.on('resize', Y.bind(this._cacheRegion, this), window);
+ this._cacheRegion();
+ }
+ r = Y.clone(this._regionCache);
+ } else if (this.get(CON_2_REGION)) {
+ r = this.get(CON_2_REGION);
+ } else if (this.get('constrain2view')) {
+ r = host.get(DRAG_NODE).get('viewportRegion');
+ } else {
+ return false;
+ }
+
+ Y.each(g, function(i, n) {
+ if ((n == RIGHT) || (n == BOTTOM)) {
+ r[n] -= i;
+ } else {
+ r[n] += i;
+ }
+ });
+ if (inc) {
+ oh = host.get(DRAG_NODE).get(OFFSET_HEIGHT);
+ ow = host.get(DRAG_NODE).get(OFFSET_WIDTH);
+ r[RIGHT] = r[RIGHT] - ow;
+ r[BOTTOM] = r[BOTTOM] - oh;
+ }
+ return r;
+ },
+ /**
+ * @private
+ * @method _checkRegion
+ * @description Check if xy is inside a given region, if not change to it be inside.
+ * @param {Array} _xy The XY to check if it's in the current region, if it isn't inside the region, it will reset the xy array to be inside the region.
+ * @return {Array} The new XY that is inside the region
+ */
+ _checkRegion: function(_xy) {
+ var oxy = _xy,
+ r = this.getRegion(),
+ host = this.get(HOST),
+ oh = host.get(DRAG_NODE).get(OFFSET_HEIGHT),
+ ow = host.get(DRAG_NODE).get(OFFSET_WIDTH);
+
+ if (oxy[1] > (r[BOTTOM] - oh)) {
+ _xy[1] = (r[BOTTOM] - oh);
+ }
+ if (r[TOP] > oxy[1]) {
+ _xy[1] = r[TOP];
+
+ }
+ if (oxy[0] > (r[RIGHT] - ow)) {
+ _xy[0] = (r[RIGHT] - ow);
+ }
+ if (r[LEFT] > oxy[0]) {
+ _xy[0] = r[LEFT];
+ }
+
+ return _xy;
+ },
+ /**
+ * @method inRegion
+ * @description Checks if the XY passed or the dragNode is inside the active region.
+ * @param {Array} xy Optional XY to check, if not supplied this.get('dragNode').getXY() is used.
+ * @return {Boolean} True if the XY is inside the region, false otherwise.
+ */
+ inRegion: function(xy) {
+ xy = xy || this.get(HOST).get(DRAG_NODE).getXY();
+
+ var _xy = this._checkRegion([xy[0], xy[1]]),
+ inside = false;
+ if ((xy[0] === _xy[0]) && (xy[1] === _xy[1])) {
+ inside = true;
+ }
+ return inside;
+ },
+ /**
+ * @method align
+ * @description Modifies the Drag.actXY method from the after drag:align event. This is where the constraining happens.
+ */
+ align: function() {
+ var host = this.get(HOST),
+ _xy = host.actXY,
+ r = this.getRegion(true);
+
+ if (this.get('stickX')) {
+ _xy[1] = (host.startXY[1] - host.deltaXY[1]);
+ }
+ if (this.get('stickY')) {
+ _xy[0] = (host.startXY[0] - host.deltaXY[0]);
+ }
+
+ if (r) {
+ _xy = this._checkRegion(_xy);
+ }
+
+ _xy = this._checkTicks(_xy, r);
+ host.actXY = _xy;
+ },
+ /**
+ * @private
+ * @method _checkTicks
+ * @description This method delegates the proper helper method for tick calculations
+ * @param {Array} xy The XY coords for the Drag
+ * @param {Object} r The optional region that we are bound to.
+ * @return {Array} The calced XY coords
+ */
+ _checkTicks: function(xy, r) {
+ var host = this.get(HOST),
+ lx = (host.startXY[0] - host.deltaXY[0]),
+ ly = (host.startXY[1] - host.deltaXY[1]),
+ xt = this.get('tickX'),
+ yt = this.get('tickY');
+ if (xt && !this.get(TICK_X_ARRAY)) {
+ xy[0] = DDM._calcTicks(xy[0], lx, xt, r[LEFT], r[RIGHT]);
+ }
+ if (yt && !this.get(TICK_Y_ARRAY)) {
+ xy[1] = DDM._calcTicks(xy[1], ly, yt, r[TOP], r[BOTTOM]);
+ }
+ if (this.get(TICK_X_ARRAY)) {
+ xy[0] = DDM._calcTickArray(xy[0], this.get(TICK_X_ARRAY), r[LEFT], r[RIGHT]);
+ }
+ if (this.get(TICK_Y_ARRAY)) {
+ xy[1] = DDM._calcTickArray(xy[1], this.get(TICK_Y_ARRAY), r[TOP], r[BOTTOM]);
+ }
+
+ return xy;
+ }
+ };
+
+ Y.namespace('Plugin');
+ Y.extend(C, Y.Base, proto);
+ Y.Plugin.DDConstrained = C;
+
+ Y.mix(DDM, {
+ /**
+ * @for DDM
+ * @namespace DD
+ * @private
+ * @method _calcTicks
+ * @description Helper method to calculate the tick offsets for a given position
+ * @param {Number} pos The current X or Y position
+ * @param {Number} start The start X or Y position
+ * @param {Number} tick The X or Y tick increment
+ * @param {Number} off1 The min offset that we can't pass (region)
+ * @param {Number} off2 The max offset that we can't pass (region)
+ * @return {Number} The new position based on the tick calculation
+ */
+ _calcTicks: function(pos, start, tick, off1, off2) {
+ var ix = ((pos - start) / tick),
+ min = Math.floor(ix),
+ max = Math.ceil(ix);
+ if ((min !== 0) || (max !== 0)) {
+ if ((ix >= min) && (ix <= max)) {
+ pos = (start + (tick * min));
+ if (off1 && off2) {
+ if (pos < off1) {
+ pos = (start + (tick * (min + 1)));
+ }
+ if (pos > off2) {
+ pos = (start + (tick * (min - 1)));
+ }
+ }
+ }
+ }
+ return pos;
+ },
+ /**
+ * @for DDM
+ * @namespace DD
+ * @private
+ * @method _calcTickArray
+ * @description This method is used with the tickXArray and tickYArray config options
+ * @param {Number} pos The current X or Y position
+ * @param {Number} ticks The array containing our custom tick positions.
+ * @param {Number} off1 The min offset that we can't pass (region)
+ * @param {Number} off2 The max offset that we can't pass (region)
+ * @return The tick position
+ */
+ _calcTickArray: function(pos, ticks, off1, off2) {
+ var i = 0, len = ticks.length, next = 0,
+ diff1, diff2, ret;
+
+ if (!ticks || (ticks.length === 0)) {
+ return pos;
+ } else if (ticks[0] >= pos) {
+ return ticks[0];
+ } else {
+ for (i = 0; i < len; i++) {
+ next = (i + 1);
+ if (ticks[next] && ticks[next] >= pos) {
+ diff1 = pos - ticks[i];
+ diff2 = ticks[next] - pos;
+ ret = (diff2 > diff1) ? ticks[i] : ticks[next];
+ if (off1 && off2) {
+ if (ret > off2) {
+ if (ticks[i]) {
+ ret = ticks[i];
+ } else {
+ ret = ticks[len - 1];
+ }
+ }
+ }
+ return ret;
+ }
+
+ }
+ return ticks[ticks.length - 1];
+ }
+ }
+ });
+