File: slider/js/clickable-rail.js
/**
* Adds support for mouse interaction with the Slider rail triggering thumb
* movement.
*
* @module slider
* @submodule clickable-rail
*/
/**
* Slider extension that allows clicking on the Slider's rail element,
* triggering the thumb to align with the location of the click.
*
* @class ClickableRail
*/
function ClickableRail() {
this._initClickableRail();
}
Y.ClickableRail = Y.mix(ClickableRail, {
// Prototype methods added to host class
prototype: {
/**
* Initializes the internal state and sets up events.
*
* @method _initClickableRail
* @protected
*/
_initClickableRail: function () {
this._evtGuid = this._evtGuid || (Y.guid() + '|');
/**
* Broadcasts when the rail has received a mousedown event and
* triggers the thumb positioning. Use
* <code>e.preventDefault()</code> or
* <code>set("clickableRail", false)</code> to prevent
* the thumb positioning.
*
* @event railMouseDown
* @preventable _defRailMouseDownFn
*/
this.publish('railMouseDown', {
defaultFn: this._defRailMouseDownFn
});
this.after('render', this._bindClickableRail);
this.on('destroy', this._unbindClickableRail);
},
/**
* Attaches DOM event subscribers to support rail interaction.
*
* @method _bindClickableRail
* @protected
*/
_bindClickableRail: function () {
this._dd.addHandle(this.rail);
this.rail.on(this._evtGuid + Y.DD.Drag.START_EVENT,
Y.bind(this._onRailMouseDown, this));
},
/**
* Detaches DOM event subscribers for cleanup/destruction cycle.
*
* @method _unbindClickableRail
* @protected
*/
_unbindClickableRail: function () {
if (this.get('rendered')) {
var contentBox = this.get('contentBox'),
rail = contentBox.one('.' + this.getClassName('rail'));
rail.detach(this.evtGuid + '*');
}
},
/**
* Dispatches the railMouseDown event.
*
* @method _onRailMouseDown
* @param e {DOMEvent} the mousedown event object
* @protected
*/
_onRailMouseDown: function (e) {
if (this.get('clickableRail') && !this.get('disabled')) {
this.fire('railMouseDown', { ev: e });
this.thumb.focus();
}
},
/**
* Default behavior for the railMouseDown event. Centers the thumb at
* the click location and passes control to the DDM to behave as though
* the thumb itself were clicked in preparation for a drag operation.
*
* @method _defRailMouseDownFn
* @param e {Event} the EventFacade for the railMouseDown custom event
* @protected
*/
_defRailMouseDownFn: function (e) {
e = e.ev;
// Logic that determines which thumb should be used is abstracted
// to someday support multi-thumb sliders
var dd = this._resolveThumb(e),
i = this._key.xyIndex,
length = parseFloat(this.get('length'), 10),
thumb,
thumbSize,
xy;
if (dd) {
thumb = dd.get('dragNode');
thumbSize = parseFloat(thumb.getStyle(this._key.dim), 10);
// Step 1. Allow for aligning to thumb center or edge, etc
xy = this._getThumbDestination(e, thumb);
// Step 2. Remove page offsets to give just top/left style val
xy = xy[ i ] - this.rail.getXY()[i];
// Step 3. Constrain within the rail in case of attempt to
// center the thumb when clicking on the end of the rail
xy = Math.min(
Math.max(xy, 0),
(length - thumbSize));
this._uiMoveThumb(xy, { source: 'rail' });
// Set e.target for DD's IE9 patch which calls
// e.target._node.setCapture() to allow imgs to be dragged.
// Without this, setCapture is called from the rail and rail
// clicks on other Sliders may have their thumb movements
// overridden by a different Slider (the thumb on the wrong
// Slider moves).
e.target = this.thumb.one('img') || this.thumb;
// Delegate to DD's natural behavior
dd._handleMouseDownEvent(e);
// TODO: this won't trigger a slideEnd if the rail is clicked
// check if dd._move(e); dd._dragThreshMet = true; dd.start();
// will do the trick. Is that even a good idea?
}
},
/**
* Resolves which thumb to actuate if any. Override this if you want to
* support multiple thumbs. By default, returns the Drag instance for
* the thumb stored by the Slider.
*
* @method _resolveThumb
* @param e {DOMEvent} the mousedown event object
* @return {DD.Drag} the Drag instance that should be moved
* @protected
*/
_resolveThumb: function (e) {
/* Temporary workaround
var primaryOnly = this._dd.get('primaryButtonOnly'),
validClick = !primaryOnly || e.button <= 1;
return (validClick) ? this._dd : null;
*/
return this._dd;
},
/**
* Calculates the top left position the thumb should be moved to to
* align the click XY with the center of the specified node.
*
* @method _getThumbDestination
* @param e {DOMEvent} The mousedown event object
* @param node {Node} The node to position
* @return {Array} the [top, left] pixel position of the destination
* @protected
*/
_getThumbDestination: function (e, node) {
var offsetWidth = node.get('offsetWidth'),
offsetHeight = node.get('offsetHeight');
// center
return [
(e.pageX - Math.round((offsetWidth / 2))),
(e.pageY - Math.round((offsetHeight / 2)))
];
}
},
// Static properties added onto host class
ATTRS: {
/**
* Enable or disable clickable rail support.
*
* @attribute clickableRail
* @type {Boolean}
* @default true
*/
clickableRail: {
value: true,
validator: Y.Lang.isBoolean
}
}
}, true);