Source/WebInspectorUI/UserInterface/Views/TabBrowser.js - WebKit - Git at Google

 /*
  * Copyright (C) 2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 WI.TabBrowser = class TabBrowser extends WI.View
 {
     constructor(element, tabBar, navigationSidebar, detailsSidebar)
     {
         console.assert(tabBar, "Must provide a TabBar.");

         super(element);

         this.element.classList.add("tab-browser");

         this._tabBar = tabBar;
         this._navigationSidebar = navigationSidebar || null;
         this._detailsSidebar = detailsSidebar || null;

         if (this._navigationSidebar) {
             this._navigationSidebar.addEventListener(WI.Sidebar.Event.CollapsedStateDidChange, this._sidebarCollapsedStateDidChange, this);
             this._navigationSidebar.addEventListener(WI.Sidebar.Event.WidthDidChange, this._sidebarWidthDidChange, this);
         }

         if (this._detailsSidebar) {
             this._detailsSidebar.addEventListener(WI.Sidebar.Event.CollapsedStateDidChange, this._sidebarCollapsedStateDidChange, this);
             this._detailsSidebar.addEventListener(WI.Sidebar.Event.SidebarPanelSelected, this._sidebarPanelSelected, this);
             this._detailsSidebar.addEventListener(WI.Sidebar.Event.WidthDidChange, this._sidebarWidthDidChange, this);
         }

         this._contentViewContainer = new WI.ContentViewContainer;
         this.addSubview(this._contentViewContainer);

         let showNextTab = () => { this._showNextTab(); };
         let showPreviousTab = () => { this._showPreviousTab(); };

         let isRTL = WI.resolvedLayoutDirection() === WI.LayoutDirection.RTL;

         let nextKey1 = isRTL ? WI.KeyboardShortcut.Key.LeftCurlyBrace : WI.KeyboardShortcut.Key.RightCurlyBrace;
         let previousKey1 = isRTL ? WI.KeyboardShortcut.Key.RightCurlyBrace : WI.KeyboardShortcut.Key.LeftCurlyBrace;

         this._showNextTabKeyboardShortcut1 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl | WI.KeyboardShortcut.Modifier.Shift, nextKey1, showNextTab);
         this._showPreviousTabKeyboardShortcut1 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl | WI.KeyboardShortcut.Modifier.Shift, previousKey1, showPreviousTab);

         let nextModifier2 = isRTL ? WI.KeyboardShortcut.Modifier.Shift : 0;
         let previousModifier2 = isRTL ? 0 : WI.KeyboardShortcut.Modifier.Shift;

         this._showNextTabKeyboardShortcut2 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.Control | nextModifier2, WI.KeyboardShortcut.Key.Tab, showNextTab);
         this._showPreviousTabKeyboardShortcut2 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.Control | previousModifier2, WI.KeyboardShortcut.Key.Tab, showPreviousTab);

         let previousTabKey = isRTL ? WI.KeyboardShortcut.Key.Right : WI.KeyboardShortcut.Key.Left;
         let nextTabKey = isRTL ? WI.KeyboardShortcut.Key.Left : WI.KeyboardShortcut.Key.Right;
         this._previousTabKeyboardShortcut = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl | WI.KeyboardShortcut.Modifier.Shift, previousTabKey, this._showPreviousTabCheckingForEditableField.bind(this));
         this._previousTabKeyboardShortcut.implicitlyPreventsDefault = false;
         this._nextTabKeyboardShortcut = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl | WI.KeyboardShortcut.Modifier.Shift, nextTabKey, this._showNextTabCheckingForEditableField.bind(this));
         this._nextTabKeyboardShortcut.implicitlyPreventsDefault = false;

         this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemSelected, this._tabBarItemSelected, this);
         this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemAdded, this._tabBarItemAdded, this);
         this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemRemoved, this._tabBarItemRemoved, this);

         this._recentTabContentViews = [];
         this._closedTabClasses = new Set;
     }

     // Public

     get tabBar()
     {
         return this._tabBar;
     }

     get navigationSidebar()
     {
         return this._navigationSidebar;
     }

     get detailsSidebar()
     {
         return this._detailsSidebar;
     }

     get selectedTabContentView()
     {
         return this._contentViewContainer.currentContentView;
     }

     bestTabContentViewForClass(constructor)
     {
         console.assert(!this.selectedTabContentView || this.selectedTabContentView === this._recentTabContentViews[0]);

         for (var tabContentView of this._recentTabContentViews) {
             if (tabContentView instanceof constructor)
                 return tabContentView;
         }

         return null;
     }

     bestTabContentViewForRepresentedObject(representedObject, options = {})
     {
         console.assert(!this.selectedTabContentView || this.selectedTabContentView === this._recentTabContentViews[0]);

         let tabContentView = this._recentTabContentViews.find((tabContentView) => tabContentView.type === options.preferredTabType);
         if (tabContentView && tabContentView.canShowRepresentedObject(representedObject))
             return tabContentView;

         for (let tabContentView of this._recentTabContentViews) {
             if (options.ignoreSearchTab && tabContentView instanceof WI.SearchTabContentView)
                 continue;
             if (options.ignoreNetworkTab && tabContentView instanceof WI.NetworkTabContentView)
                 continue;

             if (tabContentView.canShowRepresentedObject(representedObject))
                 return tabContentView;
         }

         return null;
     }

     addTabForContentView(tabContentView, options = {})
     {
         console.assert(tabContentView instanceof WI.TabContentView);
         if (!(tabContentView instanceof WI.TabContentView))
             return false;

         let tabBarItem = tabContentView.tabBarItem;

         console.assert(tabBarItem instanceof WI.TabBarItem);
         if (!(tabBarItem instanceof WI.TabBarItem))
             return false;

         if (tabBarItem.representedObject !== tabContentView)
             tabBarItem.representedObject = tabContentView;

         if (tabBarItem.parentTabBar === this._tabBar)
             return true;

         // Add the tab after the first tab content view, since the first
         // tab content view is the currently selected one.
         if (this._recentTabContentViews.length && this.selectedTabContentView)
             this._recentTabContentViews.splice(1, 0, tabContentView);
         else
             this._recentTabContentViews.push(tabContentView);

         if (typeof options.insertionIndex === "number")
             this._tabBar.insertTabBarItem(tabBarItem, options.insertionIndex, options);
         else
             this._tabBar.addTabBarItem(tabBarItem, options);

         console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
         console.assert(!this.selectedTabContentView || this.selectedTabContentView === this._recentTabContentViews[0]);

         return true;
     }

     showTabForContentView(tabContentView, options = {})
     {
         if (!this.addTabForContentView(tabContentView, options))
             return false;

         this._tabBar.selectedTabBarItem = tabContentView.tabBarItem;

         // FIXME: this is a workaround for <https://webkit.org/b/151876>.
         // Without this extra call, we might never lay out the child tab
         // if it has already marked itself as dirty in the same run loop
         // as it is attached. It will schedule a layout, but when the rAF
         // fires the parent will abort the layout because the counter is
         // out of sync.
         this.needsLayout();
         return true;
     }

     closeTabForContentView(tabContentView, options = {})
     {
         console.assert(tabContentView instanceof WI.TabContentView);
         if (!(tabContentView instanceof WI.TabContentView))
             return false;

         console.assert(tabContentView.tabBarItem instanceof WI.TabBarItem);
         if (!(tabContentView.tabBarItem instanceof WI.TabBarItem))
             return false;

         if (tabContentView.tabBarItem.parentTabBar !== this._tabBar)
             return false;

         this._tabBar.removeTabBarItem(tabContentView.tabBarItem, options);

         console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
         console.assert(!this.selectedTabContentView || this.selectedTabContentView === this._recentTabContentViews[0]);

         return true;
     }

     // Protected

     sizeDidChange()
     {
         super.sizeDidChange();

         for (let tabContentView of this._recentTabContentViews)
             tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol] = tabContentView !== this.selectedTabContentView;
     }

     // Private

     _tabBarItemSelected(event)
     {
         this._saveFocusedNodeForTabContentView(event.data.previousTabBarItem ? event.data.previousTabBarItem.representedObject : null);

         let tabContentView = this._tabBar.selectedTabBarItem ? this._tabBar.selectedTabBarItem.representedObject : null;

         if (tabContentView) {
             let shouldSaveTab = tabContentView.constructor.shouldSaveTab();
             if (shouldSaveTab) {
                 this._recentTabContentViews.remove(tabContentView);
                 this._recentTabContentViews.unshift(tabContentView);
             }

             this._contentViewContainer.showContentView(tabContentView);

             console.assert(this.selectedTabContentView);
             console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
             console.assert(this.selectedTabContentView === this._recentTabContentViews[0] || !shouldSaveTab);
         } else {
             this._contentViewContainer.closeAllContentViews();

             console.assert(!this.selectedTabContentView);
         }

         this._showNavigationSidebarPanelForTabContentView(tabContentView);
         this._showDetailsSidebarPanelsForTabContentView(tabContentView);

         // If the tab browser was resized prior to showing the tab, the new tab needs to perform a resize layout.
         if (tabContentView && tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol]) {
             tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol] = false;
             tabContentView.updateLayout(WI.View.LayoutReason.Resize);
         }

         this.dispatchEventToListeners(WI.TabBrowser.Event.SelectedTabContentViewDidChange);

         this._restoreFocusedNodeForTabContentView(tabContentView);
     }

     _tabBarItemAdded(event)
     {
         let tabContentView = event.data.tabBarItem.representedObject;

         console.assert(tabContentView);
         if (!tabContentView)
             return;

         this._closedTabClasses.delete(tabContentView.constructor);
     }

     _tabBarItemRemoved(event)
     {
         let tabContentView = event.data.tabBarItem.representedObject;

         console.assert(tabContentView);
         if (!tabContentView)
             return;

         this._recentTabContentViews.remove(tabContentView);

         if (!tabContentView.constructor.tabInfo().isEphemeral)
             this._closedTabClasses.add(tabContentView.constructor);

         this._contentViewContainer.closeContentView(tabContentView);

         console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
         console.assert(!this.selectedTabContentView || this.selectedTabContentView === this._recentTabContentViews[0]);
     }

     _sidebarPanelSelected(event)
     {
         if (this._ignoreSidebarEvents)
             return;

         var tabContentView = this.selectedTabContentView;
         if (!tabContentView)
             return;

         console.assert(event.target === this._detailsSidebar);

         if (tabContentView.managesDetailsSidebarPanels)
             return;

         var selectedSidebarPanel = this._detailsSidebar.selectedSidebarPanel;
         tabContentView.detailsSidebarSelectedPanelSetting.value = selectedSidebarPanel ? selectedSidebarPanel.identifier : null;
     }

     _sidebarCollapsedStateDidChange(event)
     {
         if (this._ignoreSidebarEvents)
             return;

         var tabContentView = this.selectedTabContentView;
         if (!tabContentView)
             return;

         if (event.target === this._navigationSidebar && !tabContentView.managesNavigationSidebarPanel)
             tabContentView.navigationSidebarCollapsedSetting.value = this._navigationSidebar.collapsed;
         else if (event.target === this._detailsSidebar && !tabContentView.managesDetailsSidebarPanels)
             tabContentView.detailsSidebarCollapsedSetting.value = this._detailsSidebar.collapsed;
     }

     _sidebarWidthDidChange(event)
     {
         if (this._ignoreSidebarEvents || !event.data)
             return;

         let tabContentView = this.selectedTabContentView;
         if (!tabContentView)
             return;

         switch (event.target) {
         case this._navigationSidebar:
             tabContentView.navigationSidebarWidthSetting.value = event.data.newWidth;
             break;

         case this._detailsSidebar:
             tabContentView.detailsSidebarWidthSetting.value = event.data.newWidth;
             break;
         }
     }

     _saveFocusedNodeForTabContentView(tabContentView)
     {
         if (!tabContentView)
             return;

         if (!WI.isContentAreaFocused())
             return;

         tabContentView[WI.TabBrowser.FocusedNodeSymbol] = document.activeElement;
     }

     _restoreFocusedNodeForTabContentView(tabContentView)
     {
         if (!tabContentView)
             return;

         let node = tabContentView[WI.TabBrowser.FocusedNodeSymbol];
         if (node && !WI.isContentAreaFocused())
             node.focus();

         tabContentView[WI.TabBrowser.FocusedNodeSymbol] = null;
     }

     _showNavigationSidebarPanelForTabContentView(tabContentView)
     {
         if (!this._navigationSidebar)
             return;

         this._ignoreSidebarEvents = true;

         this._navigationSidebar.removeSidebarPanel(0);

         console.assert(!this._navigationSidebar.sidebarPanels.length);

         if (!tabContentView) {
             this._ignoreSidebarEvents = false;
             return;
         }

         if (tabContentView.navigationSidebarWidthSetting.value)
             this._navigationSidebar.width = tabContentView.navigationSidebarWidthSetting.value;

         var navigationSidebarPanel = tabContentView.navigationSidebarPanel;
         if (!navigationSidebarPanel) {
             this._navigationSidebar.collapsed = true;
             this._ignoreSidebarEvents = false;
             return;
         }

         if (tabContentView.managesNavigationSidebarPanel) {
             tabContentView.showNavigationSidebarPanel();
             this._ignoreSidebarEvents = false;
             return;
         }

         this._navigationSidebar.addSidebarPanel(navigationSidebarPanel);
         this._navigationSidebar.selectedSidebarPanel = navigationSidebarPanel;

         this._navigationSidebar.collapsed = tabContentView.navigationSidebarCollapsedSetting.value;

         this._ignoreSidebarEvents = false;
     }

     _showDetailsSidebarPanelsForTabContentView(tabContentView)
     {
         if (!this._detailsSidebar)
             return;

         this._ignoreSidebarEvents = true;

         for (var i = this._detailsSidebar.sidebarPanels.length - 1; i >= 0; --i)
             this._detailsSidebar.removeSidebarPanel(i);

         console.assert(!this._detailsSidebar.sidebarPanels.length);

         if (!tabContentView) {
             this._ignoreSidebarEvents = false;
             return;
         }

         if (tabContentView.detailsSidebarWidthSetting.value)
             this._detailsSidebar.width = tabContentView.detailsSidebarWidthSetting.value;

         if (tabContentView.managesDetailsSidebarPanels) {
             tabContentView.showDetailsSidebarPanels();
             this._ignoreSidebarEvents = false;
             return;
         }

         var detailsSidebarPanels = tabContentView.detailsSidebarPanels;
         if (!detailsSidebarPanels) {
             this._detailsSidebar.collapsed = true;
             this._ignoreSidebarEvents = false;
             return;
         }

         for (var detailsSidebarPanel of detailsSidebarPanels)
             this._detailsSidebar.addSidebarPanel(detailsSidebarPanel);

         this._detailsSidebar.selectedSidebarPanel = tabContentView.detailsSidebarSelectedPanelSetting.value || detailsSidebarPanels[0];

         this._detailsSidebar.collapsed = tabContentView.detailsSidebarCollapsedSetting.value || !detailsSidebarPanels.length;

         this._ignoreSidebarEvents = false;
     }

     _showPreviousTab(event)
     {
         this._tabBar.selectPreviousTab();
     }

     _showNextTab(event)
     {
         this._tabBar.selectNextTab();
     }

     _showNextTabCheckingForEditableField(event)
     {
         if (WI.isEventTargetAnEditableField(event))
             return;

         this._showNextTab(event);

         event.preventDefault();
     }

     _showPreviousTabCheckingForEditableField(event)
     {
         if (WI.isEventTargetAnEditableField(event))
             return;

         this._showPreviousTab(event);

         event.preventDefault();
     }
 };

 WI.TabBrowser.NeedsResizeLayoutSymbol = Symbol("needs-resize-layout");
 WI.TabBrowser.FocusedNodeSymbol = Symbol("focused-node");

 WI.TabBrowser.Event = {
     SelectedTabContentViewDidChange: "tab-browser-selected-tab-content-view-did-change"
 };
	/*
	* Copyright (C) 2015 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	WI.TabBrowser = class TabBrowser extends WI.View
	{
	constructor(element, tabBar, navigationSidebar, detailsSidebar)
	{
	console.assert(tabBar, "Must provide a TabBar.");

	super(element);

	this.element.classList.add("tab-browser");

	this._tabBar = tabBar;
	this._navigationSidebar = navigationSidebar \|\| null;
	this._detailsSidebar = detailsSidebar \|\| null;

	if (this._navigationSidebar) {
	this._navigationSidebar.addEventListener(WI.Sidebar.Event.CollapsedStateDidChange, this._sidebarCollapsedStateDidChange, this);
	this._navigationSidebar.addEventListener(WI.Sidebar.Event.WidthDidChange, this._sidebarWidthDidChange, this);
	}

	if (this._detailsSidebar) {
	this._detailsSidebar.addEventListener(WI.Sidebar.Event.CollapsedStateDidChange, this._sidebarCollapsedStateDidChange, this);
	this._detailsSidebar.addEventListener(WI.Sidebar.Event.SidebarPanelSelected, this._sidebarPanelSelected, this);
	this._detailsSidebar.addEventListener(WI.Sidebar.Event.WidthDidChange, this._sidebarWidthDidChange, this);
	}

	this._contentViewContainer = new WI.ContentViewContainer;
	this.addSubview(this._contentViewContainer);

	let showNextTab = () => { this._showNextTab(); };
	let showPreviousTab = () => { this._showPreviousTab(); };

	let isRTL = WI.resolvedLayoutDirection() === WI.LayoutDirection.RTL;

	let nextKey1 = isRTL ? WI.KeyboardShortcut.Key.LeftCurlyBrace : WI.KeyboardShortcut.Key.RightCurlyBrace;
	let previousKey1 = isRTL ? WI.KeyboardShortcut.Key.RightCurlyBrace : WI.KeyboardShortcut.Key.LeftCurlyBrace;

	this._showNextTabKeyboardShortcut1 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl \| WI.KeyboardShortcut.Modifier.Shift, nextKey1, showNextTab);
	this._showPreviousTabKeyboardShortcut1 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl \| WI.KeyboardShortcut.Modifier.Shift, previousKey1, showPreviousTab);

	let nextModifier2 = isRTL ? WI.KeyboardShortcut.Modifier.Shift : 0;
	let previousModifier2 = isRTL ? 0 : WI.KeyboardShortcut.Modifier.Shift;

	this._showNextTabKeyboardShortcut2 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.Control \| nextModifier2, WI.KeyboardShortcut.Key.Tab, showNextTab);
	this._showPreviousTabKeyboardShortcut2 = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.Control \| previousModifier2, WI.KeyboardShortcut.Key.Tab, showPreviousTab);

	let previousTabKey = isRTL ? WI.KeyboardShortcut.Key.Right : WI.KeyboardShortcut.Key.Left;
	let nextTabKey = isRTL ? WI.KeyboardShortcut.Key.Left : WI.KeyboardShortcut.Key.Right;
	this._previousTabKeyboardShortcut = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl \| WI.KeyboardShortcut.Modifier.Shift, previousTabKey, this._showPreviousTabCheckingForEditableField.bind(this));
	this._previousTabKeyboardShortcut.implicitlyPreventsDefault = false;
	this._nextTabKeyboardShortcut = new WI.KeyboardShortcut(WI.KeyboardShortcut.Modifier.CommandOrControl \| WI.KeyboardShortcut.Modifier.Shift, nextTabKey, this._showNextTabCheckingForEditableField.bind(this));
	this._nextTabKeyboardShortcut.implicitlyPreventsDefault = false;

	this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemSelected, this._tabBarItemSelected, this);
	this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemAdded, this._tabBarItemAdded, this);
	this._tabBar.addEventListener(WI.TabBar.Event.TabBarItemRemoved, this._tabBarItemRemoved, this);

	this._recentTabContentViews = [];
	this._closedTabClasses = new Set;
	}

	// Public

	get tabBar()
	{
	return this._tabBar;
	}

	get navigationSidebar()
	{
	return this._navigationSidebar;
	}

	get detailsSidebar()
	{
	return this._detailsSidebar;
	}

	get selectedTabContentView()
	{
	return this._contentViewContainer.currentContentView;
	}

	bestTabContentViewForClass(constructor)
	{
	console.assert(!this.selectedTabContentView \|\| this.selectedTabContentView === this._recentTabContentViews[0]);

	for (var tabContentView of this._recentTabContentViews) {
	if (tabContentView instanceof constructor)
	return tabContentView;
	}

	return null;
	}

	bestTabContentViewForRepresentedObject(representedObject, options = {})
	{
	console.assert(!this.selectedTabContentView \|\| this.selectedTabContentView === this._recentTabContentViews[0]);

	let tabContentView = this._recentTabContentViews.find((tabContentView) => tabContentView.type === options.preferredTabType);
	if (tabContentView && tabContentView.canShowRepresentedObject(representedObject))
	return tabContentView;

	for (let tabContentView of this._recentTabContentViews) {
	if (options.ignoreSearchTab && tabContentView instanceof WI.SearchTabContentView)
	continue;
	if (options.ignoreNetworkTab && tabContentView instanceof WI.NetworkTabContentView)
	continue;

	if (tabContentView.canShowRepresentedObject(representedObject))
	return tabContentView;
	}

	return null;
	}

	addTabForContentView(tabContentView, options = {})
	{
	console.assert(tabContentView instanceof WI.TabContentView);
	if (!(tabContentView instanceof WI.TabContentView))
	return false;

	let tabBarItem = tabContentView.tabBarItem;

	console.assert(tabBarItem instanceof WI.TabBarItem);
	if (!(tabBarItem instanceof WI.TabBarItem))
	return false;

	if (tabBarItem.representedObject !== tabContentView)
	tabBarItem.representedObject = tabContentView;

	if (tabBarItem.parentTabBar === this._tabBar)
	return true;

	// Add the tab after the first tab content view, since the first
	// tab content view is the currently selected one.
	if (this._recentTabContentViews.length && this.selectedTabContentView)
	this._recentTabContentViews.splice(1, 0, tabContentView);
	else
	this._recentTabContentViews.push(tabContentView);

	if (typeof options.insertionIndex === "number")
	this._tabBar.insertTabBarItem(tabBarItem, options.insertionIndex, options);
	else
	this._tabBar.addTabBarItem(tabBarItem, options);

	console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
	console.assert(!this.selectedTabContentView \|\| this.selectedTabContentView === this._recentTabContentViews[0]);

	return true;
	}

	showTabForContentView(tabContentView, options = {})
	{
	if (!this.addTabForContentView(tabContentView, options))
	return false;

	this._tabBar.selectedTabBarItem = tabContentView.tabBarItem;

	// FIXME: this is a workaround for <https://webkit.org/b/151876>.
	// Without this extra call, we might never lay out the child tab
	// if it has already marked itself as dirty in the same run loop
	// as it is attached. It will schedule a layout, but when the rAF
	// fires the parent will abort the layout because the counter is
	// out of sync.
	this.needsLayout();
	return true;
	}

	closeTabForContentView(tabContentView, options = {})
	{
	console.assert(tabContentView instanceof WI.TabContentView);
	if (!(tabContentView instanceof WI.TabContentView))
	return false;

	console.assert(tabContentView.tabBarItem instanceof WI.TabBarItem);
	if (!(tabContentView.tabBarItem instanceof WI.TabBarItem))
	return false;

	if (tabContentView.tabBarItem.parentTabBar !== this._tabBar)
	return false;

	this._tabBar.removeTabBarItem(tabContentView.tabBarItem, options);

	console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
	console.assert(!this.selectedTabContentView \|\| this.selectedTabContentView === this._recentTabContentViews[0]);

	return true;
	}

	// Protected

	sizeDidChange()
	{
	super.sizeDidChange();

	for (let tabContentView of this._recentTabContentViews)
	tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol] = tabContentView !== this.selectedTabContentView;
	}

	// Private

	_tabBarItemSelected(event)
	{
	this._saveFocusedNodeForTabContentView(event.data.previousTabBarItem ? event.data.previousTabBarItem.representedObject : null);

	let tabContentView = this._tabBar.selectedTabBarItem ? this._tabBar.selectedTabBarItem.representedObject : null;

	if (tabContentView) {
	let shouldSaveTab = tabContentView.constructor.shouldSaveTab();
	if (shouldSaveTab) {
	this._recentTabContentViews.remove(tabContentView);
	this._recentTabContentViews.unshift(tabContentView);
	}

	this._contentViewContainer.showContentView(tabContentView);

	console.assert(this.selectedTabContentView);
	console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
	console.assert(this.selectedTabContentView === this._recentTabContentViews[0] \|\| !shouldSaveTab);
	} else {
	this._contentViewContainer.closeAllContentViews();

	console.assert(!this.selectedTabContentView);
	}

	this._showNavigationSidebarPanelForTabContentView(tabContentView);
	this._showDetailsSidebarPanelsForTabContentView(tabContentView);

	// If the tab browser was resized prior to showing the tab, the new tab needs to perform a resize layout.
	if (tabContentView && tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol]) {
	tabContentView[WI.TabBrowser.NeedsResizeLayoutSymbol] = false;
	tabContentView.updateLayout(WI.View.LayoutReason.Resize);
	}

	this.dispatchEventToListeners(WI.TabBrowser.Event.SelectedTabContentViewDidChange);

	this._restoreFocusedNodeForTabContentView(tabContentView);
	}

	_tabBarItemAdded(event)
	{
	let tabContentView = event.data.tabBarItem.representedObject;

	console.assert(tabContentView);
	if (!tabContentView)
	return;

	this._closedTabClasses.delete(tabContentView.constructor);
	}

	_tabBarItemRemoved(event)
	{
	let tabContentView = event.data.tabBarItem.representedObject;

	console.assert(tabContentView);
	if (!tabContentView)
	return;

	this._recentTabContentViews.remove(tabContentView);

	if (!tabContentView.constructor.tabInfo().isEphemeral)
	this._closedTabClasses.add(tabContentView.constructor);

	this._contentViewContainer.closeContentView(tabContentView);

	console.assert(this._recentTabContentViews.length === this._tabBar.saveableTabCount);
	console.assert(!this.selectedTabContentView \|\| this.selectedTabContentView === this._recentTabContentViews[0]);
	}

	_sidebarPanelSelected(event)
	{
	if (this._ignoreSidebarEvents)
	return;

	var tabContentView = this.selectedTabContentView;
	if (!tabContentView)
	return;

	console.assert(event.target === this._detailsSidebar);

	if (tabContentView.managesDetailsSidebarPanels)
	return;

	var selectedSidebarPanel = this._detailsSidebar.selectedSidebarPanel;
	tabContentView.detailsSidebarSelectedPanelSetting.value = selectedSidebarPanel ? selectedSidebarPanel.identifier : null;
	}

	_sidebarCollapsedStateDidChange(event)
	{
	if (this._ignoreSidebarEvents)
	return;

	var tabContentView = this.selectedTabContentView;
	if (!tabContentView)
	return;

	if (event.target === this._navigationSidebar && !tabContentView.managesNavigationSidebarPanel)
	tabContentView.navigationSidebarCollapsedSetting.value = this._navigationSidebar.collapsed;
	else if (event.target === this._detailsSidebar && !tabContentView.managesDetailsSidebarPanels)
	tabContentView.detailsSidebarCollapsedSetting.value = this._detailsSidebar.collapsed;
	}

	_sidebarWidthDidChange(event)
	{
	if (this._ignoreSidebarEvents \|\| !event.data)
	return;

	let tabContentView = this.selectedTabContentView;
	if (!tabContentView)
	return;

	switch (event.target) {
	case this._navigationSidebar:
	tabContentView.navigationSidebarWidthSetting.value = event.data.newWidth;
	break;

	case this._detailsSidebar:
	tabContentView.detailsSidebarWidthSetting.value = event.data.newWidth;
	break;
	}
	}

	_saveFocusedNodeForTabContentView(tabContentView)
	{
	if (!tabContentView)
	return;

	if (!WI.isContentAreaFocused())
	return;

	tabContentView[WI.TabBrowser.FocusedNodeSymbol] = document.activeElement;
	}

	_restoreFocusedNodeForTabContentView(tabContentView)
	{
	if (!tabContentView)
	return;

	let node = tabContentView[WI.TabBrowser.FocusedNodeSymbol];
	if (node && !WI.isContentAreaFocused())
	node.focus();

	tabContentView[WI.TabBrowser.FocusedNodeSymbol] = null;
	}

	_showNavigationSidebarPanelForTabContentView(tabContentView)
	{
	if (!this._navigationSidebar)
	return;

	this._ignoreSidebarEvents = true;

	this._navigationSidebar.removeSidebarPanel(0);

	console.assert(!this._navigationSidebar.sidebarPanels.length);

	if (!tabContentView) {
	this._ignoreSidebarEvents = false;
	return;
	}

	if (tabContentView.navigationSidebarWidthSetting.value)
	this._navigationSidebar.width = tabContentView.navigationSidebarWidthSetting.value;

	var navigationSidebarPanel = tabContentView.navigationSidebarPanel;
	if (!navigationSidebarPanel) {
	this._navigationSidebar.collapsed = true;
	this._ignoreSidebarEvents = false;
	return;
	}

	if (tabContentView.managesNavigationSidebarPanel) {
	tabContentView.showNavigationSidebarPanel();
	this._ignoreSidebarEvents = false;
	return;
	}

	this._navigationSidebar.addSidebarPanel(navigationSidebarPanel);
	this._navigationSidebar.selectedSidebarPanel = navigationSidebarPanel;

	this._navigationSidebar.collapsed = tabContentView.navigationSidebarCollapsedSetting.value;

	this._ignoreSidebarEvents = false;
	}

	_showDetailsSidebarPanelsForTabContentView(tabContentView)
	{
	if (!this._detailsSidebar)
	return;

	this._ignoreSidebarEvents = true;

	for (var i = this._detailsSidebar.sidebarPanels.length - 1; i >= 0; --i)
	this._detailsSidebar.removeSidebarPanel(i);

	console.assert(!this._detailsSidebar.sidebarPanels.length);

	if (!tabContentView) {
	this._ignoreSidebarEvents = false;
	return;
	}

	if (tabContentView.detailsSidebarWidthSetting.value)
	this._detailsSidebar.width = tabContentView.detailsSidebarWidthSetting.value;

	if (tabContentView.managesDetailsSidebarPanels) {
	tabContentView.showDetailsSidebarPanels();
	this._ignoreSidebarEvents = false;
	return;
	}

	var detailsSidebarPanels = tabContentView.detailsSidebarPanels;
	if (!detailsSidebarPanels) {
	this._detailsSidebar.collapsed = true;
	this._ignoreSidebarEvents = false;
	return;
	}

	for (var detailsSidebarPanel of detailsSidebarPanels)
	this._detailsSidebar.addSidebarPanel(detailsSidebarPanel);

	this._detailsSidebar.selectedSidebarPanel = tabContentView.detailsSidebarSelectedPanelSetting.value \|\| detailsSidebarPanels[0];

	this._detailsSidebar.collapsed = tabContentView.detailsSidebarCollapsedSetting.value \|\| !detailsSidebarPanels.length;

	this._ignoreSidebarEvents = false;
	}

	_showPreviousTab(event)
	{
	this._tabBar.selectPreviousTab();
	}

	_showNextTab(event)
	{
	this._tabBar.selectNextTab();
	}

	_showNextTabCheckingForEditableField(event)
	{
	if (WI.isEventTargetAnEditableField(event))
	return;

	this._showNextTab(event);

	event.preventDefault();
	}

	_showPreviousTabCheckingForEditableField(event)
	{
	if (WI.isEventTargetAnEditableField(event))
	return;

	this._showPreviousTab(event);

	event.preventDefault();
	}
	};

	WI.TabBrowser.NeedsResizeLayoutSymbol = Symbol("needs-resize-layout");
	WI.TabBrowser.FocusedNodeSymbol = Symbol("focused-node");

	WI.TabBrowser.Event = {
	SelectedTabContentViewDidChange: "tab-browser-selected-tab-content-view-did-change"
	};