// 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 Base class for containers that host {@link goog.ui.Control}s, * such as menus and toolbars. Provides default keyboard and mouse event * handling and child management, based on a generalized version of * {@link goog.ui.Menu}. * * @see ../demos/container.html */ // TODO: Fix code/logic duplication between this and goog.ui.Control. // TODO: Maybe pull common stuff all the way up into Component...? goog.provide('goog.ui.Container'); goog.provide('goog.ui.Container.Orientation'); goog.require('goog.dom'); goog.require('goog.dom.a11y'); goog.require('goog.dom.a11y.State'); goog.require('goog.events.EventType'); goog.require('goog.events.KeyCodes'); goog.require('goog.events.KeyHandler'); goog.require('goog.events.KeyHandler.EventType'); goog.require('goog.style'); goog.require('goog.ui.Component'); goog.require('goog.ui.Component.Error'); goog.require('goog.ui.Component.EventType'); goog.require('goog.ui.Component.State'); goog.require('goog.ui.ContainerRenderer'); goog.require('goog.userAgent'); /** * Base class for containers. Extends {@link goog.ui.Component} by adding * the following: * <ul> * <li>a {@link goog.events.KeyHandler}, to simplify keyboard handling, * <li>a pluggable <em>renderer</em> framework, to simplify the creation of * containers without the need to subclass this class, * <li>methods to manage child controls hosted in the container, * <li>default mouse and keyboard event handling methods. * </ul> * @param {?goog.ui.Container.Orientation} opt_orientation Container * orientation; defaults to {@code VERTICAL}. * @param {?goog.ui.ContainerRenderer} opt_renderer Renderer used to render or * decorate the container; defaults to {@link goog.ui.ContainerRenderer}. * @param {?goog.dom.DomHelper} opt_domHelper DOM helper, used for document * interaction. * @extends {goog.ui.Component} * @constructor */ goog.ui.Container = function(opt_orientation, opt_renderer, opt_domHelper) { goog.ui.Component.call(this, opt_domHelper); this.renderer_ = opt_renderer || goog.ui.ContainerRenderer.getInstance(); this.orientation_ = opt_orientation || this.renderer_.getDefaultOrientation(); }; goog.inherits(goog.ui.Container, goog.ui.Component); /** * Container-specific events. * @enum {string} */ goog.ui.Container.EventType = { /** * Dispatched after a goog.ui.Container becomes visible. Non-cancellable. * NOTE: This event really shouldn't exist, because the * goog.ui.Component.EventType.SHOW event should behave like this one. But the * SHOW event for containers has been behaving as other components' * BEFORE_SHOW event for a long time, and too much code relies on that old * behavior to fix it now. */ AFTER_SHOW: 'aftershow' }; /** * Container orientation constants. * @enum {string} */ goog.ui.Container.Orientation = { HORIZONTAL: 'horizontal', VERTICAL: 'vertical' }; /** * Allows an alternative element to be set to recieve key events, otherwise * defers to the renderer's element choice. * @type {Element|undefined} * @private */ goog.ui.Container.prototype.keyEventTarget_ = null; /** * Keyboard event handler. * @type {goog.events.KeyHandler?} * @private */ goog.ui.Container.prototype.keyHandler_ = null; /** * Renderer for the container. Defaults to {@link goog.ui.ContainerRenderer}. * @type {goog.ui.ContainerRenderer?} * @private */ goog.ui.Container.prototype.renderer_ = null; /** * Container orientation; determines layout and default keyboard navigation. * @type {?goog.ui.Container.Orientation} * @private */ goog.ui.Container.prototype.orientation_ = null; /** * Whether the container is set to be visible. Defaults to true. * @type {boolean} * @private */ goog.ui.Container.prototype.visible_ = true; /** * Whether the container is enabled and reacting to keyboard and mouse events. * Defaults to true. * @type {boolean} * @private */ goog.ui.Container.prototype.enabled_ = true; /** * Whether the container supports keyboard focus. Defaults to true. Focusable * containers have a {@code tabIndex} and can be navigated to via the keyboard. * @type {boolean} * @private */ goog.ui.Container.prototype.focusable_ = true; /** * The 0-based index of the currently highlighted control in the container * (-1 if none). * @type {number} * @private */ goog.ui.Container.prototype.highlightedIndex_ = -1; /** * The currently open (expanded) control in the container (null if none). * @type {goog.ui.Control?} * @private */ goog.ui.Container.prototype.openItem_ = null; /** * Whether the mouse button is held down. Defaults to false. This flag is set * when the user mouses down over the container, and remains set until they * release the mouse button. * @type {boolean} * @private */ goog.ui.Container.prototype.mouseButtonPressed_ = false; /** * Whether focus of child componenets should be allowed. Only effective if * focusable_ is set to false. * @type {boolean} * @private */ goog.ui.Container.prototype.allowFocusableChildren_ = false; /** * Map of DOM IDs to child controls. Each key is the DOM ID of a child * control's root element; each value is a reference to the child control * itself. Used for looking up the child control corresponding to a DOM * node in O(1) time. * @type {Object?} * @private */ goog.ui.Container.prototype.childElementIdMap_ = null; // Event handler and renderer management. /** * Returns the DOM element on which the container is listening for keyboard * events (null if none). * @return {Element?} Element on which the container is listening for key * events. */ goog.ui.Container.prototype.getKeyEventTarget = function() { // Delegate to renderer, unless we've set an explicit target. return this.keyEventTarget_ || this.renderer_.getKeyEventTarget(this); }; /** * Attaches an element on which to listen for key events. * @param {Element|undefined} element The element to attach, or null/undefined * to attach to the default element. */ goog.ui.Container.prototype.setKeyEventTarget = function(element) { if (this.focusable_) { var oldTarget = this.getKeyEventTarget(); var inDocument = this.isInDocument(); this.keyEventTarget_ = element; var newTarget = this.getKeyEventTarget(); if (inDocument) { // Unlisten for events on the old key target. Requires us to reset // key target state temporarily. this.keyEventTarget_ = oldTarget; this.enableFocusHandling_(false); this.keyEventTarget_ = element; // Listen for events on the new key target. this.getKeyHandler().attach(newTarget); this.enableFocusHandling_(true); } } else { throw Error('Can\'t set key event target for container ' + 'that doesn\'t support keyboard focus!'); } }; /** * Returns the keyboard event handler for this container, lazily created the * first time this method is called. The keyboard event handler listens for * keyboard events on the container's key event target, as determined by its * renderer. * @return {goog.events.KeyHandler} Keyboard event handler for this container. */ goog.ui.Container.prototype.getKeyHandler = function() { return this.keyHandler_ || (this.keyHandler_ = new goog.events.KeyHandler(this.getKeyEventTarget())); }; /** * Returns the renderer used by this container to render itself or to decorate * an existing element. * @return {goog.ui.ContainerRenderer} Renderer used by the container. */ goog.ui.Container.prototype.getRenderer = function() { return this.renderer_; }; /** * Registers the given renderer with the container. Changing renderers after * the container has already been rendered or decorated is an error. * @param {goog.ui.ContainerRenderer} renderer Renderer used by the container. */ goog.ui.Container.prototype.setRenderer = function(renderer) { if (this.getElement()) { // Too late. throw Error(goog.ui.Component.Error.ALREADY_RENDERED); } this.renderer_ = renderer; }; // Standard goog.ui.Component implementation. /** * Creates the container's DOM. Overrides {@link goog.ui.Component#createDom}. */ goog.ui.Container.prototype.createDom = function() { // Delegate to renderer. this.setElementInternal(this.renderer_.createDom(this)); }; /** * Returns the DOM element into which child components are to be rendered, * or null if the container itself hasn't been rendered yet. Overrides * {@link goog.ui.Component#getContentElement} by delegating to the renderer. * @return {Element?} Element to contain child elements (null if none). */ goog.ui.Container.prototype.getContentElement = function() { // Delegate to renderer. return this.renderer_.getContentElement(this.getElement()); }; /** * Returns true if the given element can be decorated by this container. * Overrides {@link goog.ui.Component#canDecorate}. * @param {Element} element Element to decorate. * @return {boolean} True iff the element can be decorated. */ goog.ui.Container.prototype.canDecorate = function(element) { // Delegate to renderer. return this.renderer_.canDecorate(element); }; /** * Decorates the given element with this container. Overrides {@link * goog.ui.Component#decorateInternal}. Considered protected. * @param {Element} element Element to decorate. */ goog.ui.Container.prototype.decorateInternal = function(element) { // Delegate to renderer. this.setElementInternal(this.renderer_.decorate(this, element)); // Check whether the decorated element is explicitly styled to be invisible. if (element.style.display == 'none') { this.visible_ = false; } }; /** * Configures the container after its DOM has been rendered, and sets up event * handling. Overrides {@link goog.ui.Component#enterDocument}. */ goog.ui.Container.prototype.enterDocument = function() { goog.ui.Container.superClass_.enterDocument.call(this); this.forEachChild(function(child) { if (child.isInDocument()) { this.registerChildId_(child); } }, this); // Detect right-to-left direction. var elem = this.getElement(); // Call the renderer's initializeDom method to initialize the container's DOM. this.renderer_.initializeDom(this); // Initialize visibility (opt_force = true, so we don't dispatch events). this.setVisible(this.visible_, true); // Handle events dispatched by child controls. this.getHandler(). listen(this, goog.ui.Component.EventType.ENTER, this.handleEnterItem). listen(this, goog.ui.Component.EventType.HIGHLIGHT, this.handleHighlightItem). listen(this, goog.ui.Component.EventType.UNHIGHLIGHT, this.handleUnHighlightItem). listen(this, goog.ui.Component.EventType.OPEN, this.handleOpenItem). listen(this, goog.ui.Component.EventType.CLOSE, this.handleCloseItem). // Handle mouse events. listen(elem, goog.events.EventType.MOUSEDOWN, this.handleMouseDown). listen(goog.dom.getOwnerDocument(elem), goog.events.EventType.MOUSEUP, this.handleDocumentMouseUp). // Handle mouse events on behalf of cpresently2ontrols in the container. listen(elem, [ goog.events.EventType.MOUSEDOWN, goog.events.EventType.MOUSEUP, goog.events.EventType.MOUSEOVER, goog.events.EventType.MOUSEOUT ], this.handleChildMouseEvents); // If the container is focusable, set up keyboard event handling. if (this.isFocusable()) { this.enableFocusHandling_(true); } }; /** * Sets up listening for events applicable to focusable containers. * @param {boolean} enable Whether to enable or disable focus handling. * @private */ goog.ui.Container.prototype.enableFocusHandling_ = function(enable) { var handler = this.getHandler(); var keyTarget = this.getKeyEventTarget(); if (enable) { handler. listen(keyTarget, goog.events.EventType.FOCUS, this.handleFocus). listen(keyTarget, goog.events.EventType.BLUR, this.handleBlur). listen(this.getKeyHandler(), goog.events.KeyHandler.EventType.KEY, this.handleKeyEvent); } else { handler. unlisten(keyTarget, goog.events.EventType.FOCUS, this.handleFocus). unlisten(keyTarget, goog.events.EventType.BLUR, this.handleBlur). unlisten(this.getKeyHandler(), goog.events.KeyHandler.EventType.KEY, this.handleKeyEvent); } }; /** * Cleans up the container before its DOM is removed from the document, and * removes event handlers. Overrides {@link goog.ui.Component#exitDocument}. */ goog.ui.Container.prototype.exitDocument = function() { // {@link #setHighlightedIndex} has to be called before // {@link goog.ui.Component#exitDocument}, otherwise it has no effect. this.setHighlightedIndex(-1); if (this.openItem_) { this.openItem_.setOpen(false); } this.mouseButtonPressed_ = false; goog.ui.Container.superClass_.exitDocument.call(this); }; /** @inheritDoc */ goog.ui.Container.prototype.disposeInternal = function() { goog.ui.Container.superClass_.disposeInternal.call(this); if (this.keyHandler_) { this.keyHandler_.dispose(); this.keyHandler_ = null; } this.childElementIdMap_ = null; this.openItem_ = null; this.renderer_ = null; }; // Default event handlers. /** * Handles ENTER events raised by child controls when they are navigated to. * @param {goog.events.Event} e ENTER event to handle. * @return {boolean} Whether to prevent handleMouseOver from handling * the event. */ goog.ui.Container.prototype.handleEnterItem = function(e) { // Allow the Control to highlight itself. return true; }; /** * Handles HIGHLIGHT events dispatched by items in the container when * they are highlighted. * @param {goog.events.Event} e Highlight event to handle. */ goog.ui.Container.prototype.handleHighlightItem = function(e) { var index = this.indexOfChild(/** @type {goog.ui.Control} */ (e.target)); if (index > -1 && index != this.highlightedIndex_) { var item = this.getHighlighted(); if (item) { // Un-highlight previously highlighted item. item.setHighlighted(false); } this.highlightedIndex_ = index; item = this.getHighlighted(); if (this.isMouseButtonPressed()) { // Activate item when mouse button is pressed, to allow MacOS-style // dragging to choose menu items. Although this should only truly // happen if the highlight is due to mouse movements, there is little // harm in doing it for keyboard or programmatic highlights. item.setActive(true); } // Open follows highlight. if (this.openItem_ && item != this.openItem_) { if (item.isSupportedState(goog.ui.Component.State.OPENED)) { item.setOpen(true); } else { this.openItem_.setOpen(false); } } } goog.dom.a11y.setState(this.getElement(), goog.dom.a11y.State.ACTIVEDESCENDANT, e.target.getElement().id); }; /** * Handles UNHIGHLIGHT events dispatched by items in the container when * they are unhighlighted. * @param {goog.events.Event} e Unhighlight event to handle. */ goog.ui.Container.prototype.handleUnHighlightItem = function(e) { if (e.target == this.getHighlighted()) { this.highlightedIndex_ = -1; } goog.dom.a11y.setState(this.getElement(), goog.dom.a11y.State.ACTIVEDESCENDANT, ''); }; /** * Handles OPEN events dispatched by items in the container when they are * opened. * @param {goog.events.Event} e Open event to handle. */ goog.ui.Container.prototype.handleOpenItem = function(e) { var item = /** @type {goog.ui.Control} */ (e.target); if (item && item != this.openItem_ && item.getParent() == this) { if (this.openItem_) { this.openItem_.setOpen(false); } this.openItem_ = item; } }; /** * Handles CLOSE events dispatched by items in the container when they are * closed. * @param {goog.events.Event} e Close event to handle. */ goog.ui.Container.prototype.handleCloseItem = function(e) { if (e.target == this.openItem_) { this.openItem_ = null; } }; /** * Handles mousedown events over the container. The default implementation * sets the "mouse button pressed" flag and, if the container is focusable, * grabs keyboard focus. * @param {goog.events.BrowserEvent} e Mousedown event to handle. */ goog.ui.Container.prototype.handleMouseDown = function(e) { if (this.enabled_) { this.setMouseButtonPressed(true); } var keyTarget = this.getKeyEventTarget(); if (this.renderer_.hasTabIndex(keyTarget)) { // The container is configured to receive keyboard focus. keyTarget.focus(); } else { // The control isn't configured to receive keyboard focus; prevent it // from stealing focus or destroying the selection. e.preventDefault(); } }; /** * Handles mouseup events over the document. The default implementation * clears the "mouse button pressed" flag. * @param {goog.events.BrowserEvent} e Mouseup event to handle. */ goog.ui.Container.prototype.handleDocumentMouseUp = function(e) { this.setMouseButtonPressed(false); }; /** * Handles mouse events originating from nodes belonging to the controls hosted * in the container. Locates the child control based on the DOM node that * dispatched the event, and forwards the event to the control for handling. * @param {goog.events.BrowserEvent} e Mouse event to handle. */ goog.ui.Container.prototype.handleChildMouseEvents = function(e) { var control = this.getOwnerControl(/** @type {Node} */ (e.target)); if (control) { // Child control identified; forward the event. switch (e.type) { case goog.events.EventType.MOUSEDOWN: control.handleMouseDown(e); break; case goog.events.EventType.MOUSEUP: control.handleMouseUp(e); break; case goog.events.EventType.MOUSEOVER: control.handleMouseOver(e); break; case goog.events.EventType.MOUSEOUT: control.handleMouseOut(e); break; } } }; /** * Returns the child control that owns the given DOM node, or null if no such * control is found. * @param {Node} node DOM node whose owner is to be returned. * @return {goog.ui.Control?} Control hosted in the container to which the node * belongs (if found). * @protected */ goog.ui.Container.prototype.getOwnerControl = function(node) { // Ensure that this container actually has child controls before // looking up the owner. if (this.childElementIdMap_) { var elem = this.getElement(); while (node && node.parentNode && node != elem) { var id = node.id; if (id in this.childElementIdMap_) { return this.childElementIdMap_[id]; } node = node.parentNode; } } return null; }; /** * Handles focus events raised when the container's key event target receives * keyboard focus. * @param {goog.events.BrowserEvent} e Focus event to handle. */ goog.ui.Container.prototype.handleFocus = function(e) { // No-op in the base class. }; /** * Handles blur events raised when the container's key event target loses * keyboard focus. The default implementation clears the highlight index. * @param {goog.events.BrowserEvent} e Blur event to handle. */ goog.ui.Container.prototype.handleBlur = function(e) { this.setHighlightedIndex(-1); this.setMouseButtonPressed(false); // If the container loses focus, and one of its children is open, close it. if (this.openItem_) { this.openItem_.setOpen(false); } }; /** * Attempts to handle a keyboard event, if the control is enabled, by calling * {@link handleKeyEventInternal}. Considered protected; should only be used * within this package and by subclasses. * @param {goog.events.KeyEvent} e Key event to handle. * @return {boolean} Whether the key event was handled. */ goog.ui.Container.prototype.handleKeyEvent = function(e) { if (this.isEnabled() && this.getChildCount() != 0 && this.handleKeyEventInternal(e)) { e.preventDefault(); e.stopPropagation(); return true; } return false; }; /** * Attempts to handle a keyboard event; returns true if the event was handled, * false otherwise. If the container is enabled, and a child is highlighted, * calls the child control's {@code handleKeyEvent} method to give the control * a chance to handle the event first. * @param {goog.events.KeyEvent} e Key event to handle. * @return {boolean} Whether the event was handled by the container (or one of * its children). */ goog.ui.Container.prototype.handleKeyEventInternal = function(e) { // Give the highlighted control the chance to handle the key event. var highlighted = this.getHighlighted(); if (highlighted && typeof highlighted.handleKeyEvent == 'function' && highlighted.handleKeyEvent(e)) { return true; } // Give the open control the chance to handle the key event. if (this.openItem_ && this.openItem_ != highlighted && typeof this.openItem_.handleKeyEvent == 'function' && this.openItem_.handleKeyEvent(e)) { return true; } // Either nothing is highlighted, or the highlighted control didn't handle // the key event, so attempt to handle it here. switch (e.keyCode) { case goog.events.KeyCodes.ESC: if (this.isFocusable()) { this.getKeyEventTarget().blur(); } else { return false; } break; case goog.events.KeyCodes.HOME: this.highlightFirst(); break; case goog.events.KeyCodes.END: this.highlightLast(); break; case goog.events.KeyCodes.UP: if (this.orientation_ == goog.ui.Container.Orientation.VERTICAL) { this.highlightPrevious(); } else { return false; } break; case goog.events.KeyCodes.LEFT: if (this.orientation_ == goog.ui.Container.Orientation.HORIZONTAL) { if (this.isRightToLeft()) { this.highlightNext(); } else { this.highlightPrevious(); } } else { return false; } break; case goog.events.KeyCodes.DOWN: if (this.orientation_ == goog.ui.Container.Orientation.VERTICAL) { this.highlightNext(); } else { return false; } break; case goog.events.KeyCodes.RIGHT: if (this.orientation_ == goog.ui.Container.Orientation.HORIZONTAL) { if (this.isRightToLeft()) { this.highlightPrevious(); } else { this.highlightNext(); } } else { return false; } break; default: return false; } return true; }; // Child component management. /** * Creates a DOM ID for the child control and registers it to an internal * hash table to be able to find it fast by id. * @param {goog.ui.Control} child The child control. Its root element has * to be created yet. * @private */ goog.ui.Container.prototype.registerChildId_ = function(child) { // Map the DOM ID of the control's root element to the control itself. var childElem = child.getElement(); // If the control's root element doesn't have a DOM ID assign one. var id = childElem.id || (childElem.id = child.getId()); // Lazily create the child element ID map on first use. if (!this.childElementIdMap_) { this.childElementIdMap_ = {}; } this.childElementIdMap_[id] = child; }; /** * Adds the specified control as the last child of this container. See * {@link goog.ui.Container#addChildAt} for detailed semantics. * @param {goog.ui.Control} child The new child control. * @param {boolean} opt_render Whether the new child should be rendered * immediately after being added (defaults to false). */ goog.ui.Container.prototype.addChild = function(child, opt_render) { goog.ui.Container.superClass_.addChild.call(this, child, opt_render); }; /** * Adds the control as a child of this container at the given 0-based index. * Overrides {@link goog.ui.Component#addChildAt} by also updating the * container's highlight index. Since {@link goog.ui.Component#addChild} uses * {@link #addChildAt} internally, we only need to override this method. * @param {goog.ui.Control} control New child. * @param {number} index Index at which the new child is to be added. * @param {boolean} opt_render Whether the new child should be rendered * immediately after being added (defaults to false). */ goog.ui.Container.prototype.addChildAt = function(control, index, opt_render) { // Make sure the child control dispatches HIGHLIGHT, UNHIGHLIGHT, OPEN, and // CLOSE events, and that it doesn't steal keyboard focus. control.setDispatchTransitionEvents(goog.ui.Component.State.HOVER, true); control.setDispatchTransitionEvents(goog.ui.Component.State.OPENED, true); if (this.isFocusable() || !this.isFocusableChildrenAllowed()) { control.setSupportedState(goog.ui.Component.State.FOCUSED, false); } // Disable mouse event handling by child controls. control.setHandleMouseEvents(false); // Let the superclass implementation do the work. goog.ui.Container.superClass_.addChildAt.call(this, control, index, opt_render); if (opt_render && this.isInDocument()) { this.registerChildId_(control); } // Update the highlight index, if needed. if (index <= this.highlightedIndex_) { this.highlightedIndex_++; } }; /** * Removes a child control. Overrides {@link goog.ui.Component#removeChild} by * updating the highlight index. Since {@link goog.ui.Component#removeChildAt} * uses {@link #removeChild} internally, we only need to override this method. * @param {string|goog.ui.Control} control The ID of the child to remove, or * the control itself. * @param {boolean} opt_unrender Whether to call {@code exitDocument} on the * removed control, and detach its DOM from the document (defaults to * false). * @return {goog.ui.Control} The removed control, if any. */ goog.ui.Container.prototype.removeChild = function(control, opt_unrender) { // TODO: Fix implementation so that it works if control is a string. var index = this.indexOfChild(/** @type {goog.ui.Control} */ (control)); if (index != -1) { if (index == this.highlightedIndex_) { control.setHighlighted(false); } else if (index < this.highlightedIndex_) { this.highlightedIndex_--; } } // Remove the mapping from the child element ID map. var childElem = control.getElement(); if (childElem && childElem.id) { goog.object.remove(this.childElementIdMap_, childElem.id); } control = /** @type {goog.ui.Control} */ ( goog.ui.Container.superClass_.removeChild.call(this, control, opt_unrender)); // Re-enable mouse event handling (in case the control is reused elsewhere). control.setHandleMouseEvents(true); return control; }; // Container state management. /** * Returns the container's orientation. * @return {?goog.ui.Container.Orientation} Container orientation. */ goog.ui.Container.prototype.getOrientation = function() { return this.orientation_; }; /** * Sets the container's orientation. * @param {goog.ui.Container.Orientation} orientation Container orientation. */ // TODO: Do we need to support containers with dynamic orientation? goog.ui.Container.prototype.setOrientation = function(orientation) { if (this.getElement()) { // Too late. throw Error(goog.ui.Component.Error.ALREADY_RENDERED); } this.orientation_ = orientation; }; /** * Returns true if the container's visibility is set to visible, false if * it is set to hidden. A container that is set to hidden is guaranteed * to be hidden from the user, but the reverse isn't necessarily true. * A container may be set to visible but can otherwise be obscured by another * element, rendered off-screen, or hidden using direct CSS manipulation. * @return {boolean} Whether the container is set to be visible. */ goog.ui.Container.prototype.isVisible = function() { return this.visible_; }; /** * Shows or hides the container. Does nothing if the container already has * the requested visibility. Otherwise, dispatches a SHOW or HIDE event as * appropriate, giving listeners a chance to prevent the visibility change. * @param {boolean} visible Whether to show or hide the container. * @param {boolean} opt_force If true, doesn't check whether the container * already has the requested visibility, and doesn't dispatch any events. * @return {boolean} Whether the visibility was changed. */ goog.ui.Container.prototype.setVisible = function(visible, opt_force) { if (opt_force || (this.visible_ != visible && this.dispatchEvent(visible ? goog.ui.Component.EventType.SHOW : goog.ui.Component.EventType.HIDE))) { this.visible_ = visible; var elem = this.getElement(); if (elem) { goog.style.showElement(elem, visible); if (this.isFocusable()) { // Enable keyboard access only for enabled & visible containers. this.renderer_.enableTabIndex(this.getKeyEventTarget(), this.enabled_ && this.visible_); } if (this.visible_ && !opt_force) { this.dispatchEvent(goog.ui.Container.EventType.AFTER_SHOW); } } return true; } return false; }; /** * Returns true if the container is enabled, false otherwise. * @return {boolean} Whether the container is enabled. */ goog.ui.Container.prototype.isEnabled = function() { return this.enabled_; }; /** * Enables/disables the container based on the {@code enable} argument. * Dispatches an {@code ENABLED} or {@code DISABLED} event prior to changing * the container's state, which may be caught and canceled to prevent the * container from changing state. Also enables/disables child controls. * @param {boolean} enable Whether to enable or disable the container. */ goog.ui.Container.prototype.setEnabled = function(enable) { if (this.enabled_ != enable && this.dispatchEvent(enable ? goog.ui.Component.EventType.ENABLE : goog.ui.Component.EventType.DISABLE)) { if (enable) { // Flag the container as enabled first, then update children. This is // because controls can't be enabled if their parent is disabled. this.enabled_ = true; this.forEachChild(function(child) { // Enable child control unless it is flagged. if (child.wasDisabled) { delete child.wasDisabled; } else { child.setEnabled(true); } }); } else { // Disable children first, then flag the container as disabled. This is // because controls can't be disabled if their parent is already disabled. this.forEachChild(function(child) { // Disable child control, or flag it if it's already disabled. if (child.isEnabled()) { child.setEnabled(false); } else { child.wasDisabled = true; } }); this.enabled_ = false; this.setMouseButtonPressed(false); } if (this.isFocusable()) { // Enable keyboard access only for enabled & visible components. this.renderer_.enableTabIndex(this.getKeyEventTarget(), enable && this.visible_); } } }; /** * Returns true if the container is focusable, false otherwise. The default * is true. Focusable containers always have a tab index and allocate a key * handler to handle keyboard events while focused. * @return {boolean} Whether the component is focusable. */ goog.ui.Container.prototype.isFocusable = function() { return this.focusable_; }; /** * Sets whether the container is focusable. The default is true. Focusable * containers always have a tab index and allocate a key handler to handle * keyboard events while focused. * @param {boolean} focusable Whether the component is to be focusable. */ goog.ui.Container.prototype.setFocusable = function(focusable) { if (focusable != this.focusable_ && this.isInDocument()) { this.enableFocusHandling_(focusable); } this.focusable_ = focusable; if (this.enabled_ && this.visible_) { this.renderer_.enableTabIndex(this.getKeyEventTarget(), focusable); } }; /** * Returns true if the container allows children to be focusable, false * otherwise. Only effective if the container is not focusable. * @return {boolean} Whether children should be focusable. */ goog.ui.Container.prototype.isFocusableChildrenAllowed = function() { return this.allowFocusableChildren_; }; /** * Sets whether the container allows children to be focusable, false * otherwise. Only effective if the container is not focusable. * @param {boolean} focusable Whether the children should be focusable. */ goog.ui.Container.prototype.setFocusableChildrenAllowed = function(focusable) { this.allowFocusableChildren_ = focusable; }; // Highlight management. /** * Returns the index of the currently highlighted item (-1 if none). * @return {number} Index of the currently highlighted item. */ goog.ui.Container.prototype.getHighlightedIndex = function() { return this.highlightedIndex_; }; /** * Highlights the item at the given 0-based index (if any). If another item * was previously highlighted, it is un-highlighted. * @param {number} index Index of item to highlight (-1 removes the current * highlight). */ goog.ui.Container.prototype.setHighlightedIndex = function(index) { var child = this.getChildAt(index); if (child) { child.setHighlighted(true); } else if (this.highlightedIndex_ > -1) { this.getHighlighted().setHighlighted(false); } }; /** * Highlights the given item if it exists and is a child of the container; * otherwise un-highlights the currently highlighted item. * @param {goog.ui.Control} item Item to highlight. */ goog.ui.Container.prototype.setHighlighted = function(item) { this.setHighlightedIndex(this.indexOfChild(item)); }; /** * Returns the currently highlighted item (if any). * @return {goog.ui.Control?} Highlighted item (null if none). */ goog.ui.Container.prototype.getHighlighted = function() { return /** @type {goog.ui.Control} */ ( this.getChildAt(this.highlightedIndex_)); }; /** * Highlights the first highlightable item in the container */ goog.ui.Container.prototype.highlightFirst = function() { this.highlightHelper(function(index, max) { return (index + 1) % max; }, this.getChildCount() - 1); }; /** * Highlights the last highlightable item in the container. */ goog.ui.Container.prototype.highlightLast = function() { this.highlightHelper(function(index, max) { index--; return index < 0 ? max - 1 : index; }, 0); }; /** * Highlights the next highlightable item (or the first if nothing is currently * highlighted). */ goog.ui.Container.prototype.highlightNext = function() { this.highlightHelper(function(index, max) { return (index + 1) % max; }, this.highlightedIndex_); }; /** * Highlights the previous highlightable item (or the last if nothing is * currently highlighted). */ goog.ui.Container.prototype.highlightPrevious = function() { this.highlightHelper(function(index, max) { index--; return index < 0 ? max - 1 : index; }, this.highlightedIndex_); }; /** * Helper function that manages the details of moving the highlight among * child controls in response to keyboard events. * @param {function(number, number) : number} fn Function that accepts the * current and maximum indices, and returns the next index to check. * @param {number} startIndex Start index. * @return {boolean} Whether the highlight has changed. * @protected */ goog.ui.Container.prototype.highlightHelper = function(fn, startIndex) { // If the start index is -1 (meaning there's nothing currently highlighted), // try starting from the currently open item, if any. var curIndex = startIndex < 0 ? this.indexOfChild(this.openItem_) : startIndex; var numItems = this.getChildCount(); curIndex = fn(curIndex, numItems); var visited = 0; while (visited <= numItems) { var control = /** @type {goog.ui.Control} */ (this.getChildAt(curIndex)); if (control && this.canHighlightItem(control)) { this.setHighlightedIndexFromKeyEvent(curIndex); return true; } visited++; curIndex = fn(curIndex, numItems); } return false; }; /** * Returns whether the given item can be highlighted. * @param {goog.ui.Control} item The item to check. * @return {boolean} Whether the item can be highlighted. * @protected */ goog.ui.Container.prototype.canHighlightItem = function(item) { return item.isVisible() && item.isEnabled() && item.isSupportedState(goog.ui.Component.State.HOVER); }; /** * Helper method that sets the highlighted index to the given index in response * to a keyboard event. The base class implementation simply calls the * {@link #setHighlightedIndex} method, but subclasses can override this * behavior as needed. * @param {number} index Index of item to highlight. * @protected */ goog.ui.Container.prototype.setHighlightedIndexFromKeyEvent = function(index) { this.setHighlightedIndex(index); }; /** * Returns true if the mouse button is pressed, false otherwise. * @return {boolean} Whether the mouse button is pressed. */ goog.ui.Container.prototype.isMouseButtonPressed = function() { return this.mouseButtonPressed_; }; /** * Sets or clears the "mouse button pressed" flag. * @param {boolean} pressed Whether the mouse button is presed. */ goog.ui.Container.prototype.setMouseButtonPressed = function(pressed) { this.mouseButtonPressed_ = pressed; };