// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Copyright 2008 Google Inc. All Rights Reserved.
/**
* @fileoverview Renderer for {@link goog.ui.MenuItem}s.
*
*/
goog.provide('goog.ui.MenuItemRenderer');
goog.require('goog.dom');
goog.require('goog.dom.a11y');
goog.require('goog.dom.a11y.Role');
goog.require('goog.dom.classes');
goog.require('goog.ui.Component.State');
goog.require('goog.ui.ControlContent');
goog.require('goog.ui.ControlRenderer');
/**
* Default renderer for {@link goog.ui.MenuItem}s. Each item has the following
* structure:
* <pre>
* <div class="goog-menuitem">
* <div class="goog-menuitem-content">
* ...(menu item contents)...
* </div>
* </div>
* </pre>
* @constructor
* @extends {goog.ui.ControlRenderer}
*/
goog.ui.MenuItemRenderer = function() {
goog.ui.ControlRenderer.call(this);
/**
* Commonly used CSS class names, cached here for convenience (and to avoid
* unnecessary string concatenation).
* @type {!Array.<string>}
* @private
*/
this.classNameCache_ = [];
};
goog.inherits(goog.ui.MenuItemRenderer, goog.ui.ControlRenderer);
goog.addSingletonGetter(goog.ui.MenuItemRenderer);
/**
* CSS class name the renderer applies to menu item elements.
* @type {string}
*/
goog.ui.MenuItemRenderer.CSS_CLASS = goog.getCssName('goog-menuitem');
/**
* Constants for referencing composite CSS classes.
* @enum {number}
* @private
*/
goog.ui.MenuItemRenderer.CompositeCssClassIndex_ = {
HOVER: 0,
CHECKBOX: 1,
CONTENT: 2
};
/**
* Returns the composite CSS class by using the cached value or by constructing
* the value from the base CSS class and the passed index.
* @param {goog.ui.MenuItemRenderer.CompositeCssClassIndex_} index Index for the
* CSS class - could be highlight, checkbox or content in usual cases.
* @return {string} The composite CSS class.
* @private
*/
goog.ui.MenuItemRenderer.prototype.getCompositeCssClass_ = function(index) {
var result = this.classNameCache_[index];
if (!result) {
switch (index) {
case goog.ui.MenuItemRenderer.CompositeCssClassIndex_.HOVER:
result = goog.getCssName(this.getStructuralCssClass(), 'highlight');
break;
case goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CHECKBOX:
result = goog.getCssName(this.getStructuralCssClass(), 'checkbox');
break;
case goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CONTENT:
result = goog.getCssName(this.getStructuralCssClass(), 'content');
break;
}
this.classNameCache_[index] = result;
}
return result;
};
/** @return {goog.dom.a11y.Role} The ARIA role. */
goog.ui.MenuItemRenderer.prototype.getAriaRole = function() {
return goog.dom.a11y.Role.MENU_ITEM;
};
/**
* Overrides {@link goog.ui.ControlRenderer#createDom} by adding extra markup
* and stying to the menu item's element if it is selectable or checkable.
* @param {goog.ui.Control} item Menu item to render.
* @return {Element} Root element for the item.
* @override
*/
goog.ui.MenuItemRenderer.prototype.createDom = function(item) {
var element = item.getDomHelper().createDom(
'div', this.getClassNames(item).join(' '),
this.createContent(item.getContent(), item.getDomHelper()));
this.setEnableCheckBoxStructure(item, element,
item.isSupportedState(goog.ui.Component.State.SELECTED) ||
item.isSupportedState(goog.ui.Component.State.CHECKED));
return element;
};
/** @inheritDoc */
goog.ui.MenuItemRenderer.prototype.getContentElement = function(element) {
return /** @type {Element} */ (element && element.firstChild);
};
/**
* Overrides {@link goog.ui.ControlRenderer#decorate} by initializing the
* menu item to checkable based on whether the element to be decorated has
* extra stying indicating that it should be.
* @param {goog.ui.Control} item Menu item instance to decorate the element.
* @param {Element} element Element to decorate.
* @return {Element} Decorated element.
* @override
*/
goog.ui.MenuItemRenderer.prototype.decorate = function(item, element) {
if (!this.hasContentStructure(element)) {
element.appendChild(
this.createContent(element.childNodes, item.getDomHelper()));
}
if (goog.dom.classes.has(element, goog.getCssName('goog-option'))) {
item.setCheckable(true);
this.setCheckable(item, element, true);
}
return goog.ui.MenuItemRenderer.superClass_.decorate.call(this, item,
element);
};
/**
* Takes a menu item's root element, and sets its content to the given text
* caption or DOM structure. Overrides the superclass immplementation by
* making sure that the checkbox structure (for selectable/checkable menu
* items) is preserved.
* @param {Element} element The item's root element.
* @param {goog.ui.ControlContent} content Text caption or DOM structure to be
* set as the item's content.
* @override
*/
goog.ui.MenuItemRenderer.prototype.setContent = function(element, content) {
// Save the checkbox element, if present.
var contentElement = this.getContentElement(element);
var checkBoxElement = this.hasCheckBoxStructure(element) ?
contentElement.firstChild : null;
goog.ui.MenuItemRenderer.superClass_.setContent.call(this, element, content);
if (checkBoxElement && !this.hasCheckBoxStructure(element)) {
// The call to setContent() blew away the checkbox element; reattach it.
contentElement.insertBefore(checkBoxElement,
contentElement.firstChild || null);
}
};
/**
* Returns true if the element appears to have a proper menu item structure by
* checking whether its first child has the appropriate structural class name.
* @param {Element} element Element to check.
* @return {boolean} Whether the element appears to have a proper menu item DOM.
* @protected
*/
goog.ui.MenuItemRenderer.prototype.hasContentStructure = function(element) {
var child = goog.dom.getFirstElementChild(element);
var contentClassName = this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CONTENT);
return !!child && child.className.indexOf(contentClassName) != -1;
};
/**
* Wraps the given text caption or existing DOM node(s) in a structural element
* containing the menu item's contents.
* @param {goog.ui.ControlContent} content Menu item contents.
* @param {goog.dom.DomHelper} dom DOM helper for document interaction.
* @return {Element} Menu item content element.
* @protected
*/
goog.ui.MenuItemRenderer.prototype.createContent = function(content, dom) {
var contentClassName = this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CONTENT);
return dom.createDom('div', contentClassName, content);
};
/**
* Enables/disables radio button semantics on the menu item.
* @param {goog.ui.Control} item Menu item to update.
* @param {Element?} element Menu item element to update (may be null if the
* item hasn't been rendered yet).
* @param {boolean} selectable Whether the item should be selectable.
*/
goog.ui.MenuItemRenderer.prototype.setSelectable = function(item, element,
selectable) {
if (element) {
goog.dom.a11y.setRole(element, selectable ?
goog.dom.a11y.Role.MENU_ITEM_RADIO : this.getAriaRole());
this.setEnableCheckBoxStructure(item, element, selectable);
}
};
/**
* Enables/disables checkbox semantics on the menu item.
* @param {goog.ui.Control} item Menu item to update.
* @param {Element?} element Menu item element to update (may be null if the
* item hasn't been rendered yet).
* @param {boolean} checkable Whether the item should be checkable.
*/
goog.ui.MenuItemRenderer.prototype.setCheckable = function(item, element,
checkable) {
if (element) {
goog.dom.a11y.setRole(element, checkable ?
goog.dom.a11y.Role.MENU_ITEM_CHECKBOX : this.getAriaRole());
this.setEnableCheckBoxStructure(item, element, checkable);
}
};
/**
* Determines whether the item contains a checkbox element.
* @param {Element} element Menu item root element.
* @return {boolean} Whether the element contains a checkbox element.
* @protected
*/
goog.ui.MenuItemRenderer.prototype.hasCheckBoxStructure = function(element) {
var contentElement = this.getContentElement(element);
if (contentElement) {
var child = contentElement.firstChild;
var checkboxClassName = this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CHECKBOX);
return !!child && !!child.className &&
child.className.indexOf(checkboxClassName) != -1;
}
return false;
};
/**
* Adds or removes extra markup and CSS styling to the menu item to make it
* selectable or non-selectable, depending on the value of the
* {@code selectable} argument.
* @param {goog.ui.Control} item Menu item to update.
* @param {Element} element Menu item element to update.
* @param {boolean} enable Whether to add or remove the checkbox structure.
* @protected
*/
goog.ui.MenuItemRenderer.prototype.setEnableCheckBoxStructure = function(item,
element, enable) {
if (enable != this.hasCheckBoxStructure(element)) {
goog.dom.classes.enable(element, goog.getCssName('goog-option'), enable);
var contentElement = this.getContentElement(element);
if (enable) {
// Insert checkbox structure.
var checkboxClassName = this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.CHECKBOX);
contentElement.insertBefore(
item.getDomHelper().createDom('div', checkboxClassName),
contentElement.firstChild || null);
} else {
// Remove checkbox structure.
contentElement.removeChild(contentElement.firstChild);
}
}
};
/**
* Takes a single {@link goog.ui.Component.State}, and returns the
* corresponding CSS class name (null if none). Overrides the superclass
* implementation by using 'highlight' as opposed to 'hover' as the CSS
* class name suffix for the HOVER state, for backwards compatibility.
* @param {goog.ui.Component.State} state Component state.
* @return {string|undefined} CSS class representing the given state
* (undefined if none).
* @override
*/
goog.ui.MenuItemRenderer.prototype.getClassForState = function(state) {
switch (state) {
case goog.ui.Component.State.HOVER:
// We use 'highlight' as the suffix, for backwards compatibility.
return this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.HOVER);
case goog.ui.Component.State.CHECKED:
case goog.ui.Component.State.SELECTED:
// We use 'goog-option-selected' as the class, for backwards compatibility.
return goog.getCssName('goog-option-selected');
default:
return goog.ui.MenuItemRenderer.superClass_.getClassForState.call(this,
state);
}
};
/**
* Takes a single CSS class name which may represent a component state, and
* returns the corresponding component state (0x00 if none). Overrides the
* superclass implementation by treating 'goog-option-selected' as special,
* for backwards compatibility.
* @param {string} className CSS class name, possibly representing a component
* state.
* @return {goog.ui.Component.State} state Component state corresponding
* to the given CSS class (0x00 if none).
* @override
*/
goog.ui.MenuItemRenderer.prototype.getStateFromClass = function(className) {
var hoverClassName = this.getCompositeCssClass_(
goog.ui.MenuItemRenderer.CompositeCssClassIndex_.HOVER);
switch (className) {
case goog.getCssName('goog-option-selected'):
return goog.ui.Component.State.CHECKED;
case hoverClassName:
return goog.ui.Component.State.HOVER;
default:
return goog.ui.MenuItemRenderer.superClass_.getStateFromClass.call(this,
className);
}
};
/** @inheritDoc */
goog.ui.MenuItemRenderer.prototype.getCssClass = function() {
return goog.ui.MenuItemRenderer.CSS_CLASS;
};