In addition to the set of attributes supported by WidgetParent, the constructor
* configuration object can also contain a children which can be used
* to add child widgets to the parent during construction. The children
* property is an array of either child widget instances or child widget configuration
* objects, and is sugar for the add method. See the
* add for details on the structure of the child widget
* configuration object.
* @class WidgetParent
* @constructor
* @uses ArrayList
* @param {Object} config User configuration object.
*/
function Parent(config) {
/**
* Fires when a Widget is add as a child. The event object will have a
* 'child' property that returns a reference to the child Widget, as well
* as an 'index' property that returns a reference to the index specified
* when the add() method was called.
*
* Subscribers to the "on" moment of this event, will be notified * before a child is added. *
** Subscribers to the "after" moment of this event, will be notified * after a child is added. *
* * @event addChild * @preventable _defAddChildFn * @param {EventFacade} e The Event Facade */ this.publish("addChild", { defaultTargetOnly: true, defaultFn: this._defAddChildFn }); /** * Fires when a child Widget is removed. The event object will have a * 'child' property that returns a reference to the child Widget, as well * as an 'index' property that returns a reference child's ordinal position. ** Subscribers to the "on" moment of this event, will be notified * before a child is removed. *
** Subscribers to the "after" moment of this event, will be notified * after a child is removed. *
* * @event removeChild * @preventable _defRemoveChildFn * @param {EventFacade} e The Event Facade */ this.publish("removeChild", { defaultTargetOnly: true, defaultFn: this._defRemoveChildFn }); this._items = []; var children, handle; if (config && config.children) { children = config.children; handle = this.after("initializedChange", function (e) { this._add(children); handle.detach(); }); } // Widget method overlap Y.after(this._renderChildren, this, "renderUI"); Y.after(this._bindUIParent, this, "bindUI"); Y.before(this._destroyChildren, this, "destructor"); this.after("selectionChange", this._afterSelectionChange); this.after("selectedChange", this._afterParentSelectedChange); this.after("activeDescendantChange", this._afterActiveDescendantChange); this._hDestroyChild = this.after("*:destroy", this._afterDestroyChild); this.after("*:focusedChange", this._updateActiveDescendant); } Parent.ATTRS = { /** * @attribute defaultChildType * @type {String|Object} * * @description String representing the default type of the children * managed by this Widget. Can also supply default type as a constructor * reference. */ defaultChildType: { setter: function (val) { var returnVal = Y.Attribute.INVALID_VALUE, FnConstructor = Lang.isString(val) ? Y[val] : val; if (Lang.isFunction(FnConstructor)) { returnVal = FnConstructor; } return returnVal; } }, /** * @attribute activeDescendant * @type Widget * @readOnly * * @description Returns the Widget's currently focused descendant Widget. */ activeDescendant: { readOnly: true }, /** * @attribute multiple * @type Boolean * @default false * @writeOnce * * @description Boolean indicating if multiple children can be selected at * once. Whether or not multiple selection is enabled is always delegated * to the value of themultiple attribute of the root widget
* in the object hierarchy.
*/
multiple: {
value: false,
validator: Lang.isBoolean,
writeOnce: true,
getter: function (value) {
var root = this.get("root");
return (root && root != this) ? root.get("multiple") : value;
}
},
/**
* @attribute selection
* @type {Y.ArrayList|Widget}
* @readOnly
*
* @description Returns the currently selected child Widget. If the
* mulitple attribte is set to true will
* return an Y.ArrayList instance containing the currently selected
* children. If no children are selected, will return null.
*/
selection: {
readOnly: true,
setter: "_setSelection",
getter: function (value) {
var selection = Lang.isArray(value) ?
(new Y.ArrayList(value)) : value;
return selection;
}
},
selected: {
setter: function (value) {
// Enforces selection behavior on for parent Widgets. Parent's
// selected attribute can be set to the following:
// 0 - Not selected
// 1 - Fully selected (all children are selected). In order for
// all children to be selected, multiple selection must be
// enabled. Therefore, you cannot set the "selected" attribute
// on a parent Widget to 1 unless multiple selection is enabled.
// 2 - Partially selected, meaning one ore more (but not all)
// children are selected.
var returnVal = value;
if (value === 1 && !this.get("multiple")) {
returnVal = Y.Attribute.INVALID_VALUE;
}
return returnVal;
}
}
};
Parent.prototype = {
/**
* Destroy event listener for each child Widget, responsible for removing
* the destroyed child Widget from the parent's internal array of children
* (_items property).
*
* @method _afterDestroyChild
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_afterDestroyChild: function (event) {
var child = event.target;
if (child.get("parent") == this) {
child.remove();
}
},
/**
* Attribute change listener for the selection
* attribute, responsible for setting the value of the
* parent's selected attribute.
*
* @method _afterSelectionChange
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_afterSelectionChange: function (event) {
if (event.target == this && event.src != this) {
var selection = event.newVal,
selectedVal = 0; // Not selected
if (selection) {
selectedVal = 2; // Assume partially selected, confirm otherwise
if (Y.instanceOf(selection, Y.ArrayList) &&
(selection.size() === this.size())) {
selectedVal = 1; // Fully selected
}
}
this.set("selected", selectedVal, { src: this });
}
},
/**
* Attribute change listener for the activeDescendant
* attribute, responsible for setting the value of the
* parent's activeDescendant attribute.
*
* @method _afterActiveDescendantChange
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_afterActiveDescendantChange: function (event) {
var parent = this.get("parent");
if (parent) {
parent._set("activeDescendant", event.newVal);
}
},
/**
* Attribute change listener for the selected
* attribute, responsible for syncing the selected state of all children to
* match that of their parent Widget.
*
*
* @method _afterParentSelectedChange
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_afterParentSelectedChange: function (event) {
var value = event.newVal;
if (this == event.target && event.src != this &&
(value === 0 || value === 1)) {
this.each(function (child) {
// Specify the source of this change as the parent so that
// value of the parent's "selection" attribute isn't
// recalculated
child.set("selected", value, { src: this });
}, this);
}
},
/**
* Default setter for selection attribute changes.
*
* @method _setSelection
* @protected
* @param child {Widget|Array} Widget or Array of Widget instances.
* @return {Widget|Array} Widget or Array of Widget instances.
*/
_setSelection: function (child) {
var selection = null,
selected;
if (this.get("multiple") && !this.isEmpty()) {
selected = [];
this.each(function (v) {
if (v.get("selected") > 0) {
selected.push(v);
}
});
if (selected.length > 0) {
selection = selected;
}
}
else {
if (child.get("selected") > 0) {
selection = child;
}
}
return selection;
},
/**
* Attribute change listener for the selected
* attribute of child Widgets, responsible for setting the value of the
* parent's selection attribute.
*
* @method _updateSelection
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_updateSelection: function (event) {
var child = event.target,
selection;
if (child.get("parent") == this) {
if (event.src != "_updateSelection") {
selection = this.get("selection");
if (!this.get("multiple") && selection && event.newVal > 0) {
// Deselect the previously selected child.
// Set src equal to the current context to prevent
// unnecessary re-calculation of the selection.
selection.set("selected", 0, { src: "_updateSelection" });
}
this._set("selection", child);
}
if (event.src == this) {
this._set("selection", child, { src: this });
}
}
},
/**
* Attribute change listener for the focused
* attribute of child Widgets, responsible for setting the value of the
* parent's activeDescendant attribute.
*
* @method _updateActiveDescendant
* @protected
* @param {EventFacade} event The event facade for the attribute change.
*/
_updateActiveDescendant: function (event) {
var activeDescendant = (event.newVal === true) ? event.target : null;
this._set("activeDescendant", activeDescendant);
},
/**
* Creates an instance of a child Widget using the specified configuration.
* By default Widget instances will be created of the type specified
* by the defaultChildType attribute. Types can be explicitly
* defined via the childType property of the configuration object
* literal. The use of the type property has been deprecated, but
* will still be used as a fallback, if childType is not defined,
* for backwards compatibility.
*
* @method _createChild
* @protected
* @param config {Object} Object literal representing the configuration
* used to create an instance of a Widget.
*/
_createChild: function (config) {
var defaultType = this.get("defaultChildType"),
altType = config.childType || config.type,
child,
Fn,
FnConstructor;
if (altType) {
Fn = Lang.isString(altType) ? Y[altType] : altType;
}
if (Lang.isFunction(Fn)) {
FnConstructor = Fn;
} else if (defaultType) {
// defaultType is normalized to a function in it's setter
FnConstructor = defaultType;
}
if (FnConstructor) {
child = new FnConstructor(config);
} else {
Y.error("Could not create a child instance because its constructor is either undefined or invalid.");
}
return child;
},
/**
* Default addChild handler
*
* @method _defAddChildFn
* @protected
* @param event {EventFacade} The Event object
* @param child {Widget} The Widget instance, or configuration
* object for the Widget to be added as a child.
* @param index {Number} Number representing the position at
* which the child will be inserted.
*/
_defAddChildFn: function (event) {
var child = event.child,
index = event.index,
children = this._items;
if (child.get("parent")) {
child.remove();
}
if (Lang.isNumber(index)) {
children.splice(index, 0, child);
}
else {
children.push(child);
}
child._set("parent", this);
child.addTarget(this);
// Update index in case it got normalized after addition
// (e.g. user passed in 10, and there are only 3 items, the actual index would be 3. We don't want to pass 10 around in the event facade).
event.index = child.get("index");
// TO DO: Remove in favor of using event bubbling
child.after("selectedChange", Y.bind(this._updateSelection, this));
},
/**
* Default removeChild handler
*
* @method _defRemoveChildFn
* @protected
* @param event {EventFacade} The Event object
* @param child {Widget} The Widget instance to be removed.
* @param index {Number} Number representing the index of the Widget to
* be removed.
*/
_defRemoveChildFn: function (event) {
var child = event.child,
index = event.index,
children = this._items;
if (child.get("focused")) {
child.set("focused", false);
}
if (child.get("selected")) {
child.set("selected", 0);
}
children.splice(index, 1);
child.removeTarget(this);
child._oldParent = child.get("parent");
child._set("parent", null);
},
/**
* @method _add
* @protected
* @param child {Widget|Object} The Widget instance, or configuration
* object for the Widget to be added as a child.
* @param child {Array} Array of Widget instances, or configuration
* objects for the Widgets to be added as a children.
* @param index {Number} (Optional.) Number representing the position at
* which the child should be inserted.
* @description Adds a Widget as a child. If the specified Widget already
* has a parent it will be removed from its current parent before
* being added as a child.
* @return {Widget|Array} Successfully added Widget or Array containing the
* successfully added Widget instance(s). If no children where added, will
* will return undefined.
*/
_add: function (child, index) {
var children,
oChild,
returnVal;
if (Lang.isArray(child)) {
children = [];
Y.each(child, function (v, k) {
oChild = this._add(v, (index + k));
if (oChild) {
children.push(oChild);
}
}, this);
if (children.length > 0) {
returnVal = children;
}
}
else {
if (Y.instanceOf(child, Y.Widget)) {
oChild = child;
}
else {
oChild = this._createChild(child);
}
if (oChild && this.fire("addChild", { child: oChild, index: index })) {
returnVal = oChild;
}
}
return returnVal;
},
/**
* @method add
* @param child {Widget|Object} The Widget instance, or configuration
* object for the Widget to be added as a child. The configuration object
* for the child can include a childType property, which is either
* a constructor function or a string which names a constructor function on the
* Y instance (e.g. "Tab" would refer to Y.Tab) (childType used to be
* named type, support for which has been deprecated, but is still
* maintained for backward compatibility. childType takes precedence
* over type if both are defined.
* @param child {Array} Array of Widget instances, or configuration
* objects for the Widgets to be added as a children.
* @param index {Number} (Optional.) Number representing the position at
* which the child should be inserted.
* @description Adds a Widget as a child. If the specified Widget already
* has a parent it will be removed from its current parent before
* being added as a child.
* @return {Y.ArrayList} Y.ArrayList containing the successfully added
* Widget instance(s). If no children where added, will return an empty
* Y.ArrayList instance.
*/
add: function () {
var added = this._add.apply(this, arguments),
children = added ? (Lang.isArray(added) ? added : [added]) : [];
return (new Y.ArrayList(children));
},
/**
* @method remove
* @param index {Number} (Optional.) Number representing the index of the
* child to be removed.
* @description Removes the Widget from its parent. Optionally, can remove
* a child by specifying its index.
* @return {Widget} Widget instance that was successfully removed, otherwise
* undefined.
*/
remove: function (index) {
var child = this._items[index],
returnVal;
if (child && this.fire("removeChild", { child: child, index: index })) {
returnVal = child;
}
return returnVal;
},
/**
* @method removeAll
* @description Removes all of the children from the Widget.
* @return {Y.ArrayList} Y.ArrayList instance containing Widgets that were
* successfully removed. If no children where removed, will return an empty
* Y.ArrayList instance.
*/
removeAll: function () {
var removed = [],
child;
Y.each(this._items.concat(), function () {
child = this.remove(0);
if (child) {
removed.push(child);
}
}, this);
return (new Y.ArrayList(removed));
},
/**
* Selects the child at the given index (zero-based).
*
* @method selectChild
* @param {Number} i the index of the child to be selected
*/
selectChild: function(i) {
this.item(i).set('selected', 1);
},
/**
* Selects all children.
*
* @method selectAll
*/
selectAll: function () {
this.set("selected", 1);
},
/**
* Deselects all children.
*
* @method deselectAll
*/
deselectAll: function () {
this.set("selected", 0);
},
/**
* Updates the UI in response to a child being added.
*
* @method _uiAddChild
* @protected
* @param child {Widget} The child Widget instance to render.
* @param parentNode {Object} The Node under which the
* child Widget is to be rendered.
*/
_uiAddChild: function (child, parentNode) {
child.render(parentNode);
// TODO: Ideally this should be in Child's render UI.
var childBB = child.get("boundingBox"),
siblingBB,
nextSibling = child.next(false),
prevSibling;
// Insert or Append to last child.
// Avoiding index, and using the current sibling
// state (which should be accurate), means we don't have
// to worry about decorator elements which may be added
// to the _childContainer node.
if (nextSibling) {
siblingBB = nextSibling.get("boundingBox");
siblingBB.insert(childBB, "before");
} else {
prevSibling = child.previous(false);
if (prevSibling) {
siblingBB = prevSibling.get("boundingBox");
siblingBB.insert(childBB, "after");
}
}
},
/**
* Updates the UI in response to a child being removed.
*
* @method _uiRemoveChild
* @protected
* @param child {Widget} The child Widget instance to render.
*/
_uiRemoveChild: function (child) {
child.get("boundingBox").remove();
},
_afterAddChild: function (event) {
var child = event.child;
if (child.get("parent") == this) {
this._uiAddChild(child, this._childrenContainer);
}
},
_afterRemoveChild: function (event) {
var child = event.child;
if (child._oldParent == this) {
this._uiRemoveChild(child);
}
},
/**
* Sets up DOM and CustomEvent listeners for the parent widget.
* * This method in invoked after bindUI is invoked for the Widget class * using YUI's aop infrastructure. *
* * @method _bindUIParent * @protected */ _bindUIParent: function () { this.after("addChild", this._afterAddChild); this.after("removeChild", this._afterRemoveChild); }, /** * Renders all child Widgets for the parent. ** This method in invoked after renderUI is invoked for the Widget class * using YUI's aop infrastructure. *
* @method _renderChildren * @protected */ _renderChildren: function () { /** *By default WidgetParent will render it's children to the parent's content box.
* *If the children need to be rendered somewhere else, the _childrenContainer property * can be set to the Node which the children should be rendered to. This property should be * set before the _renderChildren method is invoked, ideally in your renderUI method, * as soon as you create the element to be rendered to.
* * @protected * @property _childrenContainer * @value The content box * @type Node */ var renderTo = this._childrenContainer || this.get("contentBox"); this._childrenContainer = renderTo; this.each(function (child) { child.render(renderTo); }); }, /** * Destroys all child Widgets for the parent. ** This method is invoked before the destructor is invoked for the Widget * class using YUI's aop infrastructure. *
* @method _destroyChildren * @protected */ _destroyChildren: function () { // Detach the handler responsible for removing children in // response to destroying them since: // 1) It is unnecessary/inefficient at this point since we are doing // a batch destroy of all children. // 2) Removing each child will affect our ability to iterate the // children since the size of _items will be changing as we // iterate. this._hDestroyChild.detach(); // Need to clone the _items array since this.each(function (child) { child.destroy(); }); } }; Y.augment(Parent, Y.ArrayList); Y.WidgetParent = Parent; }, '3.3.0' ,{requires:['base-build', 'arraylist', 'widget']});