// 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 2007 Google Inc. All Rights Reserved.
/**
* @fileoverview Abstract class for all UI components. This defines the standard
* design pattern that all UI components should follow.
*
*/
goog.provide('goog.ui.Component');
goog.provide('goog.ui.Component.Error');
goog.provide('goog.ui.Component.EventType');
goog.provide('goog.ui.Component.State');
goog.require('goog.array');
goog.require('goog.dom');
goog.require('goog.dom.DomHelper');
goog.require('goog.events');
goog.require('goog.events.Event');
goog.require('goog.events.EventHandler');
goog.require('goog.events.EventTarget');
goog.require('goog.object');
goog.require('goog.style');
goog.require('goog.ui.IdGenerator');
/**
* Default implementation of UI component.
*
* @param {goog.dom.DomHelper} opt_domHelper Optional DOM helper.
* @constructor
* @extends {goog.events.EventTarget}
*/
goog.ui.Component = function(opt_domHelper) {
goog.events.EventTarget.call(this);
this.dom_ = opt_domHelper || goog.dom.getDomHelper();
// Set the defalt right to left value.
this.rightToLeft_ = goog.ui.Component.defaultRightToLeft_;
};
goog.inherits(goog.ui.Component, goog.events.EventTarget);
/**
* Generator for unique IDs.
* @type {goog.ui.IdGenerator}
* @private
*/
goog.ui.Component.prototype.idGenerator_ = goog.ui.IdGenerator.getInstance();
/**
* The default right to left value.
* @type {boolean?}
* @private
*/
goog.ui.Component.defaultRightToLeft_ = null;
/**
* Common events fired by components so that event propagation is useful. Not
* all components are expected to dispatch or listen for all event types.
* Events dispatched before a state transition should be cancelable to prevent
* the corresponding state change.
* @enum {string}
*/
goog.ui.Component.EventType = {
/** Dispatched before the component becomes visible. */
BEFORE_SHOW: 'beforeshow',
/**
* Dispatched after the component becomes visible.
* NOTE: For goog.ui.Container, this actually fires before containers
* are shown. Use goog.ui.Container.EventType.AFTER_SHOW if you want an event
* that fires after a goog.ui.Container is shown.
*/
SHOW: 'show',
/** Dispatched before the component becomes hidden. */
HIDE: 'hide',
/** Dispatched before the component becomes disabled. */
DISABLE: 'disable',
/** Dispatched before the component becomes enabled. */
ENABLE: 'enable',
/** Dispatched before the component becomes highlighted. */
HIGHLIGHT: 'highlight',
/** Dispatched before the component becomes un-highlighted. */
UNHIGHLIGHT: 'unhighlight',
/** Dispatched before the component becomes activated. */
ACTIVATE: 'activate',
/** Dispatched before the component becomes deactivated. */
DEACTIVATE: 'deactivate',
/** Dispatched before the component becomes selected. */
SELECT: 'select',
/** Dispatched before the component becomes un-selected. */
UNSELECT: 'unselect',
/** Dispatched before a component becomes checked. */
CHECK: 'check',
/** Dispatched before a component becomes un-checked. */
UNCHECK: 'uncheck',
/** Dispatched before a component becomes focused. */
FOCUS: 'focus',
/** Dispatched before a component becomes blurred. */
BLUR: 'blur',
/** Dispatched before a component is opened (expanded). */
OPEN: 'open',
/** Dispatched before a component is closed (collapsed). */
CLOSE: 'close',
/** Dispatched after a component is moused over. */
ENTER: 'enter',
/** Dispatched after a component is moused out of. */
LEAVE: 'leave',
/** Dispatched after the user activates the component. */
ACTION: 'action',
/** Dispatched after the external-facing state of a component is changed. */
CHANGE: 'change'
};
/**
* Errors thrown by the component.
* @enum {string}
*/
goog.ui.Component.Error = {
/**
* Error when a method is not supported.
*/
NOT_SUPPORTED: 'Method not supported',
/**
* Error when the given element can not be decorated.
*/
DECORATE_INVALID: 'Invalid element to decorate',
/**
* Error when the component is already rendered and another render attempt is
* made.
*/
ALREADY_RENDERED: 'Component already rendered',
/**
* Error when an attempt is made to set the parent of a component in a way
* that would result in an inconsistent object graph.
*/
PARENT_UNABLE_TO_BE_SET: 'Unable to set parent component',
/**
* Error when an attempt is made to add a child component at an out-of-bounds
* index. We don't support sparse child arrays.
*/
CHILD_INDEX_OUT_OF_BOUNDS: 'Child component index out of bounds',
/**
* Error when an attempt is made to remove a child component from a component
* other than its parent.
*/
NOT_OUR_CHILD: 'Child is not in parent component',
/**
* Error when an operation requiring DOM interaction is made when the
* component is not in the document
*/
NOT_IN_DOCUMENT: 'Operation not supported while component is not in document',
/**
* Error when an invalid component state is encountered.
*/
STATE_INVALID: 'Invalid component state'
};
/**
* Common component states. Components may have distinct appearance depending
* on what state(s) apply to them. Not all components are expected to support
* all states.
* @enum {number}
*/
goog.ui.Component.State = {
/**
* Union of all supported component states.
*/
ALL: 0xFF,
/**
* Component is disabled.
* @see goog.ui.Component.EventType.DISABLE
* @see goog.ui.Component.EventType.ENABLE
*/
DISABLED: 0x01,
/**
* Component is highlighted.
* @see goog.ui.Component.EventType.HIGHLIGHT
* @see goog.ui.Component.EventType.UNHIGHLIGHT
*/
HOVER: 0x02,
/**
* Component is active (or "pressed").
* @see goog.ui.Component.EventType.ACTIVATE
* @see goog.ui.Component.EventType.DEACTIVATE
*/
ACTIVE: 0x04,
/**
* Component is selected.
* @see goog.ui.Component.EventType.SELECT
* @see goog.ui.Component.EventType.UNSELECT
*/
SELECTED: 0x08,
/**
* Component is checked.
* @see goog.ui.Component.EventType.CHECK
* @see goog.ui.Component.EventType.UNCHECK
*/
CHECKED: 0x10,
/**
* Component has focus.
* @see goog.ui.Component.EventType.FOCUS
* @see goog.ui.Component.EventType.BLUR
*/
FOCUSED: 0x20,
/**
* Component is opened (expanded). Applies to tree nodes, menu buttons,
* submenus, zippys (zippies?), etc.
* @see goog.ui.Component.EventType.OPEN
* @see goog.ui.Component.EventType.CLOSE
*/
OPENED: 0x40
};
/**
* Static helper method; returns the type of event components are expected to
* dispatch when transitioning to or from the given state.
* @param {goog.ui.Component.State} state State to/from which the component
* is transitioning.
* @param {boolean} isEntering Whether the component is entering or leaving the
* state.
* @return {goog.ui.Component.EventType} Event type to dispatch.
*/
goog.ui.Component.getStateTransitionEvent = function(state, isEntering) {
switch (state) {
case goog.ui.Component.State.DISABLED:
return isEntering ? goog.ui.Component.EventType.DISABLE :
goog.ui.Component.EventType.ENABLE;
case goog.ui.Component.State.HOVER:
return isEntering ? goog.ui.Component.EventType.HIGHLIGHT :
goog.ui.Component.EventType.UNHIGHLIGHT;
case goog.ui.Component.State.ACTIVE:
return isEntering ? goog.ui.Component.EventType.ACTIVATE :
goog.ui.Component.EventType.DEACTIVATE;
case goog.ui.Component.State.SELECTED:
return isEntering ? goog.ui.Component.EventType.SELECT :
goog.ui.Component.EventType.UNSELECT;
case goog.ui.Component.State.CHECKED:
return isEntering ? goog.ui.Component.EventType.CHECK :
goog.ui.Component.EventType.UNCHECK;
case goog.ui.Component.State.FOCUSED:
return isEntering ? goog.ui.Component.EventType.FOCUS :
goog.ui.Component.EventType.BLUR;
case goog.ui.Component.State.OPENED:
return isEntering ? goog.ui.Component.EventType.OPEN :
goog.ui.Component.EventType.CLOSE;
default:
// Fall through.
}
// Invalid state.
throw Error(goog.ui.Component.Error.STATE_INVALID);
};
/**
* Set the default right-to-left value. This causes all component's created from
* this point foward to have the given value. This is useful for cases where
* a given page is always in one directionality, avoiding unnecessary
* right to left determinations.
* @param {boolean?} rightToLeft Whether the components should be rendered
* right-to-left. Null iff components should determine their directionality.
*/
goog.ui.Component.setDefaultRightToLeft = function(rightToLeft) {
goog.ui.Component.defaultRightToLeft_ = rightToLeft;
};
/**
* Unique ID of the component, lazily initialized in {@link
* goog.ui.Component#getId} if needed. This property is strictly private and
* must not be accessed directly outside of this class!
* @type {string?}
* @private
*/
goog.ui.Component.prototype.id_ = null;
/**
* DomHelper used to interact with the document, allowing components to be
* created in a different window.
* @type {goog.dom.DomHelper?}
* @protected
* @suppress {underscore}
*/
goog.ui.Component.prototype.dom_ = null;
/**
* Whether the component is in the document.
* @type {boolean}
* @private
*/
goog.ui.Component.prototype.inDocument_ = false;
// TODO: Stop referring to this private field in subclasses.
/**
* The DOM element for the component.
* @type {Element?}
* @private
*/
goog.ui.Component.prototype.element_ = null;
/**
* Event handler.
* TODO: rename it to handler_ after all component subclasses in
* inside Google have been cleaned up.
* Code search: http://go/component_code_search
* @type {goog.events.EventHandler}
* @private
*/
goog.ui.Component.prototype.googUiComponentHandler_;
/**
* Whether the component is rendered right-to-left. Right-to-left is set
* lazily when {@link #isRightToLeft} is called the first time, unless it has
* been set by calling {@link #setRightToLeft} explicitly.
* @type {boolean?}
* @private
*/
goog.ui.Component.prototype.rightToLeft_ = null;
/**
* Arbitrary data object associated with the component. Such as meta-data.
* @type {*}
* @private
*/
goog.ui.Component.prototype.model_ = null;
/**
* Parent component to which events will be propagated. This property is
* strictly private and must not be accessed directly outside of this class!
* @type {goog.ui.Component?}
* @private
*/
goog.ui.Component.prototype.parent_ = null;
/**
* Array of child components. Lazily initialized on first use. Must be kept in
* sync with {@code childIndex_}. This property is strictly private and must
* not be accessed directly outside of this class!
* @type {Array.<goog.ui.Component>?}
* @private
*/
goog.ui.Component.prototype.children_ = null;
/**
* Map of child component IDs to child components. Used for constant-time
* random access to child components by ID. Lazily initialized on first use.
* Must be kept in sync with {@code children_}. This property is strictly
* private and must not be accessed directly outside of this class!
*
* We use a plain Object, not a {@link goog.structs.Map}, for simplicity.
* This means components can't have children with IDs such as 'constructor' or
* 'valueOf', but this shouldn't really be an issue in practice, and if it is,
* we can always fix it later without changing the API.
*
* @type {Object?}
* @private
*/
goog.ui.Component.prototype.childIndex_ = null;
/**
* Flag used to keep track of whether a component decorated an already existing
* element or whether it created the DOM itself. If an element was decorated
* dispose will remove the node from the document, it is left up to the app.
* @type {boolean}
* @private
*/
goog.ui.Component.prototype.wasDecorated_ = false;
/**
* Gets the unique ID for the instance of this component. If the instance
* doesn't already have an ID, generates one on the fly.
* @return {string} Unique component ID.
*/
goog.ui.Component.prototype.getId = function() {
return this.id_ || (this.id_ = this.idGenerator_.getNextUniqueId());
};
/**
* Assigns an ID to this component instance. It is the caller's responsibility
* to guarantee that the ID is unique. If the component is a child of a parent
* component, then the parent component's child index is updated to reflect the
* new ID; this may throw an error if the parent already has a child with an ID
* that conflicts with the new ID.
* @param {string} id Unique component ID.
*/
goog.ui.Component.prototype.setId = function(id) {
if (this.parent_ && this.parent_.childIndex_) {
// Update the parent's child index.
goog.object.remove(this.parent_.childIndex_, this.id_);
goog.object.add(this.parent_.childIndex_, id, this);
}
// Update the component ID.
this.id_ = id;
};
/**
* Gets the component's element.
* @return {Element?} The element for the component.
*/
goog.ui.Component.prototype.getElement = function() {
return this.element_;
};
/**
* Sets the component's root element to the given element. Considered
* protected and final.
* @param {Element} element Root element for the component.
* @protected
*/
goog.ui.Component.prototype.setElementInternal = function(element) {
this.element_ = element;
};
/**
* Returns the event handler for this component, lazily created the first time
* this method is called.
* @return {!goog.events.EventHandler} Event handler for this component.
* @protected
*/
goog.ui.Component.prototype.getHandler = function() {
return this.googUiComponentHandler_ ||
(this.googUiComponentHandler_ = new goog.events.EventHandler(this));
};
/**
* Sets the parent of this component to use for event bubbling. Throws an error
* if the component already has a parent or if an attempt is made to add a
* component to itself as a child. Callers must use {@code removeChild}
* or {@code removeChildAt} to remove components from their containers before
* calling this method.
* @see goog.ui.Component#removeChild
* @see goog.ui.Component#removeChildAt
* @param {goog.ui.Component} parent The parent component.
*/
goog.ui.Component.prototype.setParent = function(parent) {
if (this == parent) {
// Attempting to add a child to itself is an error.
throw Error(goog.ui.Component.Error.PARENT_UNABLE_TO_BE_SET);
}
if (parent && this.parent_ && this.id_ && this.parent_.getChild(this.id_) &&
this.parent_ != parent) {
// This component is already the child of some parent, so it should be
// removed using removeChild/removeChildAt first.
throw Error(goog.ui.Component.Error.PARENT_UNABLE_TO_BE_SET);
}
this.parent_ = parent;
goog.ui.Component.superClass_.setParentEventTarget.call(this, parent);
};
/**
* Returns the component's parent, if any.
* @return {goog.ui.Component?} The parent component.
*/
goog.ui.Component.prototype.getParent = function() {
return this.parent_;
};
/**
* Overrides {@link goog.events.EventTarget#setParentEventTarget} to throw an
* error if the parent component is set, and the argument is not the parent.
*
* @param {goog.events.EventTarget} parent Parent EventTarget (null if none).
*/
goog.ui.Component.prototype.setParentEventTarget = function(parent) {
if (this.parent_ && this.parent_ != parent) {
throw Error(goog.ui.Component.Error.NOT_SUPPORTED);
}
goog.ui.Component.superClass_.setParentEventTarget.call(this, parent);
};
/**
* Returns the dom helper that is being used on this component.
* @return {goog.dom.DomHelper} The dom helper used on this component.
*/
goog.ui.Component.prototype.getDomHelper = function() {
return this.dom_;
};
/**
* Determines whether the component has been added to the document.
* @return {boolean} TRUE if rendered. Otherwise, FALSE.
*/
goog.ui.Component.prototype.isInDocument = function() {
return this.inDocument_;
};
/**
* Creates the initial DOM representation for the component. The default
* implementation is to set this.element_ = div.
*/
goog.ui.Component.prototype.createDom = function() {
this.element_ = this.dom_.createElement('div');
};
/**
* Renders the component. If a parent element is supplied, it should already be
* in the document and then the component's element will be appended to it. If
* there is no optional parent element and the element doesn't have a parentNode
* then it will be appended to the document body.
*
* Throws an Error if the component is already rendered.
*
* @param {Element} opt_parentElement Optional parent element to render the
* component into.
*/
goog.ui.Component.prototype.render = function(opt_parentElement) {
this.render_(opt_parentElement);
};
/**
* Renders the component before another element. The other element should be in
* the document already.
*
* Throws an Error if the component is already rendered.
*
* @param {Element} siblingElement Element to render the component before.
*/
goog.ui.Component.prototype.renderBefore = function(siblingElement) {
this.render_(/** @type {Element} */(siblingElement.parentNode),
siblingElement);
};
/**
* Renders the component. If a parent element is supplied, it should already be
* in the document and then the component's element will be appended to it. If
* there is no optional parent element and the element doesn't have a parentNode
* then it will be appended to the document body.
*
* Throws an Error if the component is already rendered.
*
* @param {Element} opt_parentElement Optional parent element to render the
* component into.
* @param {Element} opt_beforeElement Element before which the component is to
* be rendered. If left out the node is appended to the parent element.
* @private
*/
goog.ui.Component.prototype.render_ = function(opt_parentElement,
opt_beforeElement) {
if (this.inDocument_) {
throw Error(goog.ui.Component.Error.ALREADY_RENDERED);
}
if (!this.element_) {
this.createDom();
}
if (opt_parentElement) {
opt_parentElement.insertBefore(this.element_, opt_beforeElement || null);
} else {
this.dom_.getDocument().body.appendChild(this.element_);
}
// If this component has a parent component that isn't in the document yet,
// we don't call enterDocument() here. Instead, when the parent component
// enters the document, the enterDocument() call will propagate to its
// children, including this one. If the component doesn't have a parent
// or if the parent is already in the document, we call enterDocument().
if (!this.parent_ || this.parent_.isInDocument()) {
this.enterDocument();
}
};
/**
* Decorates the element for the UI component.
* @param {Element} element Element to decorate.
*/
goog.ui.Component.prototype.decorate = function(element) {
if (this.inDocument_) {
throw Error(goog.ui.Component.Error.ALREADY_RENDERED);
} else if (element && this.canDecorate(element)) {
this.wasDecorated_ = true;
// Set the DOM helper of the component to match the decorated element.
if (!this.dom_ ||
this.dom_.getDocument() != goog.dom.getOwnerDocument(element)) {
this.dom_ = goog.dom.getDomHelper(element);
}
// Call specific component decorate logic.
this.decorateInternal(element);
this.enterDocument();
} else {
throw Error(goog.ui.Component.Error.DECORATE_INVALID);
}
};
/**
* Determines if a given element can be decorated by this type of component.
* This method should be overridden by inheriting objects.
* @param {Element} element Element to decorate.
* @return {boolean} True if the element can be decorated, false otherwise.
*/
goog.ui.Component.prototype.canDecorate = function(element) {
return true;
};
/**
* @return {boolean} Whether the component was decorated.
*/
goog.ui.Component.prototype.wasDecorated = function() {
return this.wasDecorated_;
};
/**
* Actually decorates the element. Should be overridden by inheriting objects.
* This method can assume there are checks to ensure the component has not
* already been rendered have occurred and that enter document will be called
* afterwards. This method is considered protected.
* @param {Element} element Element to decorate.
* @protected
*/
goog.ui.Component.prototype.decorateInternal = function(element) {
this.element_ = element;
};
/**
* Called when the component's element is known to be in the document. Anything
* using document.getElementById etc. should be done at this stage.
*
* If the component contains child components, this call is propagated to its
* children.
*/
goog.ui.Component.prototype.enterDocument = function() {
this.inDocument_ = true;
// Propagate enterDocument to child components that have a DOM, if any.
this.forEachChild(function(child) {
if (!child.isInDocument() && child.getElement()) {
child.enterDocument();
}
});
};
/**
* Called by dispose to clean up the elements and listeners created by a
* component, or by a parent component/application who has removed the
* component from the document but wants to reuse it later.
*
* If the component contains child components, this call is propagated to its
* children.
*
* It should be possible for the component to be rendered again once this method
* has been called.
*/
goog.ui.Component.prototype.exitDocument = function() {
// Propagate exitDocument to child components that have been rendered, if any.
this.forEachChild(function(child) {
if (child.isInDocument()) {
child.exitDocument();
}
});
if (this.googUiComponentHandler_) {
this.googUiComponentHandler_.removeAll();
}
this.inDocument_ = false;
};
/**
* Disposes of the component. Calls {@code exitDocument}, which is expected to
* remove event handlers and clean up the component. Propagates the call to
* the component's children, if any. Removes the component's DOM from the
* document unless it was decorated.
* @override
*/
goog.ui.Component.prototype.disposeInternal = function() {
goog.ui.Component.superClass_.disposeInternal.call(this);
if (this.inDocument_) {
this.exitDocument();
}
if (this.googUiComponentHandler_) {
this.googUiComponentHandler_.dispose();
delete this.googUiComponentHandler_;
}
// Disposes of the component's children, if any.
this.forEachChild(function(child) {
child.dispose();
});
// Detach the component's element from the DOM, unless it was decorated.
if (!this.wasDecorated_ && this.element_) {
goog.dom.removeNode(this.element_);
}
this.children_ = null;
this.childIndex_ = null;
this.element_ = null;
this.model_ = null;
this.parent_ = null;
};
/**
* Helper function for subclasses that gets a unique id for a given fragment,
* this can be used by components to
* generate unique string ids for DOM elements
* @param {string} idFragment A partial id.
* @return {string} Unique element id.
*/
goog.ui.Component.prototype.makeId = function(idFragment) {
return this.getId() + '.' + idFragment;
};
/**
* Returns the model associated with the UI component.
* @return {*} The model.
*/
goog.ui.Component.prototype.getModel = function() {
return this.model_;
};
/**
* Sets the model associated with the UI component.
* @param {*} obj The model.
*/
goog.ui.Component.prototype.setModel = function(obj) {
this.model_ = obj;
};
/**
* Helper function for returning the fragment portion of an id generated using
* makeId().
* @param {string} id Id generated with makeId().
* @return {string} Fragment.
*/
goog.ui.Component.prototype.getFragmentFromId = function(id) {
return id.substring(this.getId().length + 1);
};
/**
* Helper function for returning an element in the document with a unique id
* generated using makeId().
* @param {string} idFragment The partial id.
* @return {Element?} The element with the unique id, or null if it cannot be
* found.
*/
goog.ui.Component.prototype.getElementByFragment = function(idFragment) {
if (!this.inDocument_) {
throw Error(goog.ui.Component.Error.NOT_IN_DOCUMENT);
}
return this.dom_.getElement(this.makeId(idFragment));
};
/**
* Adds the specified component as the last child of this component. See
* {@link goog.ui.Component#addChildAt} for detailed semantics.
*
* @see goog.ui.Component#addChildAt
* @param {goog.ui.Component} child The new child component.
* @param {boolean} opt_render If true, the child component will be rendered
* into the parent.
*/
goog.ui.Component.prototype.addChild = function(child, opt_render) {
this.addChildAt(child, this.getChildCount(), opt_render);
};
/**
* Adds the specified component as a child of this component at the given
* 0-based index.
*
* Both {@code addChild} and {@code addChildAt} assume the following contract
* between parent and child components:
* <ul>
* <li>the child component's element must be a descendant of the parent
* component's element, and
* <li>the DOM state of the child component must be consistent with the DOM
* state of the parent component (see {@code isInDocument}).
* </ul>
*
* In particular, {@code parent.addChild(child)} will throw an error if the
* child component is already in the document, but the parent isn't.
*
* Clients of this API may call {@code addChild} and {@code addChildAt} with
* {@code opt_render} set to true. If {@code opt_render} is true, calling these
* methods will automatically render the child component's element into the
* parent component's element. However, {@code parent.addChild(child, true)}
* will throw an error if:
* <ul>
* <li>the parent component has no DOM (i.e. {@code parent.getElement()} is
* null), or
* <li>the child component is already in the document, regardless of the
* parent's DOM state.
* </ul>
*
* Finally, this method also throws an error if the new child already has a
* different parent, or the given index is out of bounds.
*
* @see goog.ui.Component#addChild
* @param {goog.ui.Component} child The new child component.
* @param {number} index 0-based index at which the new child component is to be
* added; must be between 0 and the current child count (inclusive).
* @param {boolean} opt_render If true, the child component will be rendered
* into the parent.
*/
goog.ui.Component.prototype.addChildAt = function(child, index, opt_render) {
if (child.inDocument_ && (opt_render || !this.inDocument_)) {
// Adding a child that's already in the document is an error, except if the
// parent is also in the document and opt_render is false (e.g. decorate()).
throw Error(goog.ui.Component.Error.ALREADY_RENDERED);
}
if (index < 0 || index > this.getChildCount()) {
// Allowing sparse child arrays would lead to strange behavior, so we don't.
throw Error(goog.ui.Component.Error.CHILD_INDEX_OUT_OF_BOUNDS);
}
// Create the index and the child array on first use.
if (!this.childIndex_ || !this.children_) {
this.childIndex_ = {};
this.children_ = [];
}
// Moving child within component, remove old reference.
if (child.getParent() == this) {
goog.object.set(this.childIndex_, child.getId(), child);
goog.array.remove(this.children_, child);
// Add the child to this component. goog.object.add() throws an error if
// a child with the same ID already exists.
} else {
goog.object.add(this.childIndex_, child.getId(), child);
}
// Set the parent of the child to this component. This throws an error if
// the child is already contained by another component.
child.setParent(this);
goog.array.insertAt(this.children_, child, index);
if (child.inDocument_ && this.inDocument_ && child.getParent() == this) {
// Changing the position of an existing child, move the DOM node.
var contentElement = this.getContentElement();
contentElement.insertBefore(child.getElement(),
(contentElement.childNodes[index + 1] || null));
} else if (opt_render) {
// If this (parent) component doesn't have a DOM yet, call createDom now
// to make sure we render the child component's element into the correct
// parent element (otherwise render_ with a null first argument would
// render the child into the document body, which is almost certainly not
// what we want).
if (!this.element_) {
this.createDom();
}
// Render the child into the parent at the appropriate location. Note that
// getChildAt(index + 1) returns undefined if inserting at the end.
// TODO: We should have a renderer with a renderChildAt API.
var sibling = this.getChildAt(index + 1);
// render_() calls enterDocument() if the parent is already in the document.
child.render_(this.getContentElement(), sibling ? sibling.element_ : null);
} else {
// We don't touch the DOM, but if the parent is in the document, the child
// isn't, and the child has a DOM, then we call enterDocument on the child.
if (this.inDocument_ && !child.inDocument_ && child.element_) {
child.enterDocument();
}
}
};
/**
* Returns the DOM element into which child components are to be rendered,
* or null if the component itself hasn't been rendered yet. This default
* implementation returns the component's root element. Subclasses with
* complex DOM structures must override this method.
* @return {Element?} Element to contain child elements (null if none).
*/
goog.ui.Component.prototype.getContentElement = function() {
return this.element_;
};
/**
* Returns true if the component is rendered right-to-left, false otherwise.
* The first time this function is invoked, the right-to-left rendering property
* is set if it has not been already.
* @return {boolean} Whether the control is rendered right-to-left.
*/
goog.ui.Component.prototype.isRightToLeft = function() {
if (this.rightToLeft_ == null) {
this.rightToLeft_ = goog.style.isRightToLeft(this.inDocument_ ?
this.element_ : this.dom_.getDocument().body);
}
return /** @type {boolean} */(this.rightToLeft_);
};
/**
* Set is right-to-left. This function should be used if the component needs
* to know the rendering direction during dom creation (i.e. before
* {@link #enterDocument} is called and is right-to-left is set).
* @param {boolean} rightToLeft Whether the component is rendered
* right-to-left.
*/
goog.ui.Component.prototype.setRightToLeft = function(rightToLeft) {
if (this.inDocument_) {
throw Error(goog.ui.Component.Error.ALREADY_RENDERED);
}
this.rightToLeft_ = rightToLeft;
};
/**
* Returns true if the component has children.
* @return {boolean} True if the component has children.
*/
goog.ui.Component.prototype.hasChildren = function() {
return !!this.children_ && this.children_.length != 0;
};
/**
* Returns the number of children of this component.
* @return {number} The number of children.
*/
goog.ui.Component.prototype.getChildCount = function() {
return this.children_ ? this.children_.length : 0;
};
/**
* Returns an array containing the IDs of the children of this component, or an
* empty array if the component has no children.
* @return {Array.<string>} Child component IDs.
*/
goog.ui.Component.prototype.getChildIds = function() {
var ids = [];
// We don't use goog.object.getKeys(this.childIndex_) because we want to
// return the IDs in the correct order as determined by this.children_.
this.forEachChild(function(child) {
// addChild()/addChildAt() guarantee that the child array isn't sparse.
ids.push(child.getId());
});
return ids;
};
/**
* Returns the child with the given ID, or null if no such child exists.
* @param {string} id Child component ID.
* @return {goog.ui.Component?} The child with the given ID; null if none.
*/
goog.ui.Component.prototype.getChild = function(id) {
// Use childIndex_ for O(1) access by ID.
return (this.childIndex_ && id) ? (/** @type {goog.ui.Component} */
goog.object.get(this.childIndex_, id)) || null : null;
};
/**
* Returns the child at the given index, or null if the index is out of bounds.
* @param {number} index 0-based index.
* @return {goog.ui.Component?} The child at the given index; null if none.
*/
goog.ui.Component.prototype.getChildAt = function(index) {
// Use children_ for access by index.
return this.children_ ? this.children_[index] || null : null;
};
/**
* Calls the given function on each of this component's children in order. If
* {@code opt_obj} is provided, it will be used as the 'this' object in the
* function when called. The function should take two arguments: the child
* component and its 0-based index. The return value is ignored.
* @param {Function} f The function to call for every child component; should
* take 2 arguments (the child and its index).
* @param {Object} opt_obj Used as the 'this' object in f when called.
*/
goog.ui.Component.prototype.forEachChild = function(f, opt_obj) {
if (this.children_) {
goog.array.forEach(this.children_, f, opt_obj);
}
};
/**
* Returns the 0-based index of the given child component, or -1 if no such
* child is found.
* @param {goog.ui.Component?} child The child component.
* @return {number} 0-based index of the child component; -1 if not found.
*/
goog.ui.Component.prototype.indexOfChild = function(child) {
return (this.children_ && child) ? goog.array.indexOf(this.children_, child) :
-1;
};
/**
* Removes the given child from this component, and returns it. Throws an error
* if the argument is invalid or if the specified child isn't found in the
* parent component. The argument can either be a string (interpreted as the
* ID of the child component to remove) or the child component itself.
*
* If {@code opt_unrender} is true, calls {@link goog.ui.component#exitDocument}
* on the removed child, and subsequently detaches the child's DOM from the
* document. Otherwise it is the caller's responsibility to clean up the child
* component's DOM.
*
* @see goog.ui.Component#removeChildAt
* @param {string|goog.ui.Component|null} child The ID of the child to remove,
* or the child component itself.
* @param {boolean} opt_unrender If true, calls {@code exitDocument} on the
* removed child component, and detaches its DOM from the document.
* @return {goog.ui.Component} The removed component, if any.
*/
goog.ui.Component.prototype.removeChild = function(child, opt_unrender) {
if (child) {
// Normalize child to be the object and id to be the ID string. This also
// ensures that the child is really ours.
var id = goog.isString(child) ? child : child.getId();
child = this.getChild(id);
if (id && child) {
goog.object.remove(this.childIndex_, id);
goog.array.remove(this.children_, child);
if (opt_unrender) {
// Remove the child component's DOM from the document. We have to call
// exitDocument first (see documentation).
child.exitDocument();
if (child.element_) {
goog.dom.removeNode(child.element_);
}
}
// Child's parent must be set to null after exitDocument is called
// so that the child can unlisten to its parent if required.
child.setParent(null);
}
}
if (!child) {
throw Error(goog.ui.Component.Error.NOT_OUR_CHILD);
}
return /** @type {goog.ui.Component} */(child);
};
/**
* Removes the child at the given index from this component, and returns it.
* Throws an error if the argument is out of bounds, or if the specified child
* isn't found in the parent. See {@link goog.ui.Component#removeChild} for
* detailed semantics.
*
* @see goog.ui.Component#removeChild
* @param {number} index 0-based index of the child to remove.
* @param {boolean} opt_unrender If true, calls {@code exitDocument} on the
* removed child component, and detaches its DOM from the document.
* @return {goog.ui.Component} The removed component, if any.
*/
goog.ui.Component.prototype.removeChildAt = function(index, opt_unrender) {
// removeChild(null) will throw error.
return this.removeChild(this.getChildAt(index), opt_unrender);
};
/**
* Removes every child component attached to this one.
*
* @see goog.ui.Component#removeChild
* @param {boolean} opt_unrender If true, calls {@link #exitDocument} on the
* removed child components, and detaches their DOM from the document.
*/
goog.ui.Component.prototype.removeChildren = function(opt_unrender) {
while (this.hasChildren()) {
this.removeChildAt(0, opt_unrender);
}
};