chrome-devtools-frontend/front_end/sources/SourcesPanel.js

Chrome DevTools UI

/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 * Copyright (C) 2011 Google 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. ``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
 * 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.
 */

import * as Bindings from '../bindings/bindings.js';
import * as Common from '../common/common.js';
import * as Extensions from '../extensions/extensions.js';
import * as Host from '../host/host.js';
import * as i18n from '../i18n/i18n.js';
import * as ObjectUI from '../object_ui/object_ui.js';
import * as Recorder from '../recorder/recorder.js';
import * as Root from '../root/root.js';
import * as SDK from '../sdk/sdk.js';
import * as Snippets from '../snippets/snippets.js';
import * as UI from '../ui/ui.js';
import * as Workspace from '../workspace/workspace.js';

import {CallStackSidebarPane} from './CallStackSidebarPane.js';
import {DebuggerPausedMessage} from './DebuggerPausedMessage.js';
import {NavigatorView} from './NavigatorView.js';  // eslint-disable-line no-unused-vars
import {ContentScriptsNavigatorView, FilesNavigatorView, NetworkNavigatorView, OverridesNavigatorView, RecordingsNavigatorView, SnippetsNavigatorView} from './SourcesNavigator.js';
import {Events, SourcesView} from './SourcesView.js';
import {ThreadsSidebarPane} from './ThreadsSidebarPane.js';
import {UISourceCodeFrame} from './UISourceCodeFrame.js';

export const UIStrings = {
  /**
  *@description Text that appears when user drag and drop something (for example, a file) in Sources Panel of the Sources panel
  */
  dropWorkspaceFolderHere: 'Drop workspace folder here',
  /**
  *@description Text to show more options
  */
  moreOptions: 'More options',
  /**
  *@description Title of the file navigator sidebar in the Sources panel
  */
  navigator: 'navigator',
  /**
  *@description Title of the debugger sidebar in the Sources panel
  */
  debugger: 'debugger',
  /**
  *@description Text in Sources Panel of the Sources panel
  */
  groupByFolder: 'Group by folder',
  /**
  *@description Text for pausing the debugger on exceptions
  */
  pauseOnExceptions: 'Pause on exceptions',
  /**
  *@description Text in Sources Panel of the Sources panel
  */
  dontPauseOnExceptions: 'Don\'t pause on exceptions',
  /**
  *@description Tooltip text that appears when hovering over the largeicon play button in the Sources Panel of the Sources panel
  */
  resumeWithAllPausesBlockedForMs: 'Resume with all pauses blocked for 500 ms',
  /**
  *@description Tooltip text that appears when hovering over the largeicon terminate execution button in the Sources Panel of the Sources panel
  */
  terminateCurrentJavascriptCall: 'Terminate current JavaScript call',
  /**
  *@description Text in Sources Panel of the Sources panel
  */
  pauseOnCaughtExceptions: 'Pause on caught exceptions',
  /**
  *@description A context menu item in the Sources Panel of the Sources panel
  */
  revealInSidebar: 'Reveal in sidebar',
  /**
  *@description A context menu item in the Sources Panel of the Sources panel
  */
  continueToHere: 'Continue to here',
  /**
  *@description A context menu item in the Console that stores selection as a temporary global variable
  *@example {string} PH1
  */
  storeSAsGlobalVariable: 'Store {PH1} as global variable',
  /**
  *@description A context menu item in the Console, Sources, and Network panel
  *@example {string} PH1
  */
  copyS: 'Copy {PH1}',
  /**
  *@description A context menu item in the Sources Panel of the Sources panel
  */
  showFunctionDefinition: 'Show function definition',
  /**
  *@description Text in Sources Panel of the Sources panel
  */
  openInSourcesPanel: 'Open in Sources panel',
};
const str_ = i18n.i18n.registerUIStrings('sources/SourcesPanel.js', UIStrings);
const i18nString = i18n.i18n.getLocalizedString.bind(undefined, str_);
/** @type {!SourcesPanel} */
let sourcesPanelInstance;
/** @type {!WrapperView} */
let wrapperViewInstance;

/**
 * @implements {UI.ContextMenu.Provider}
 * @implements {SDK.SDKModel.Observer}
 * @implements {UI.View.ViewLocationResolver}
 */
export class SourcesPanel extends UI.Panel.Panel {
  constructor() {
    super('sources');
    this.registerRequiredCSS('sources/sourcesPanel.css', {enableLegacyPatching: false});
    new UI.DropTarget.DropTarget(
        this.element, [UI.DropTarget.Type.Folder], i18nString(UIStrings.dropWorkspaceFolderHere),
        this._handleDrop.bind(this));

    this._workspace = Workspace.Workspace.WorkspaceImpl.instance();
    /** @type {!UI.ActionRegistration.Action }*/
    this._togglePauseAction = (UI.ActionRegistry.ActionRegistry.instance().action('debugger.toggle-pause'));
    /** @type {!UI.ActionRegistration.Action }*/
    this._stepOverAction = (UI.ActionRegistry.ActionRegistry.instance().action('debugger.step-over'));
    /** @type {!UI.ActionRegistration.Action }*/
    this._stepIntoAction = (UI.ActionRegistry.ActionRegistry.instance().action('debugger.step-into'));
    /** @type {!UI.ActionRegistration.Action }*/
    this._stepOutAction = (UI.ActionRegistry.ActionRegistry.instance().action('debugger.step-out'));
    /** @type {!UI.ActionRegistration.Action }*/
    this._stepAction = (UI.ActionRegistry.ActionRegistry.instance().action('debugger.step'));
    /** @type {!UI.ActionRegistration.Action }*/
    this._toggleBreakpointsActiveAction =
        (UI.ActionRegistry.ActionRegistry.instance().action('debugger.toggle-breakpoints-active'));

    this._debugToolbar = this._createDebugToolbar();
    this._debugToolbarDrawer = this._createDebugToolbarDrawer();
    this._debuggerPausedMessage = new DebuggerPausedMessage();

    const initialDebugSidebarWidth = 225;
    this._splitWidget =
        new UI.SplitWidget.SplitWidget(true, true, 'sourcesPanelSplitViewState', initialDebugSidebarWidth);
    this._splitWidget.enableShowModeSaving();
    this._splitWidget.show(this.element);

    // Create scripts navigator
    const initialNavigatorWidth = 225;
    this.editorView =
        new UI.SplitWidget.SplitWidget(true, false, 'sourcesPanelNavigatorSplitViewState', initialNavigatorWidth);
    this.editorView.enableShowModeSaving();
    this._splitWidget.setMainWidget(this.editorView);

    // Create navigator tabbed pane with toolbar.
    this._navigatorTabbedLocation = UI.ViewManager.ViewManager.instance().createTabbedLocation(
        this._revealNavigatorSidebar.bind(this), 'navigator-view', true);
    const tabbedPane = this._navigatorTabbedLocation.tabbedPane();
    tabbedPane.setMinimumSize(100, 25);
    tabbedPane.element.classList.add('navigator-tabbed-pane');
    const navigatorMenuButton = new UI.Toolbar.ToolbarMenuButton(this._populateNavigatorMenu.bind(this), true);
    navigatorMenuButton.setTitle(i18nString(UIStrings.moreOptions));
    tabbedPane.rightToolbar().appendToolbarItem(navigatorMenuButton);

    if (UI.ViewManager.ViewManager.instance().hasViewsForLocation('run-view-sidebar')) {
      const navigatorSplitWidget =
          new UI.SplitWidget.SplitWidget(false, true, 'sourcePanelNavigatorSidebarSplitViewState');
      navigatorSplitWidget.setMainWidget(tabbedPane);
      const runViewTabbedPane = UI.ViewManager.ViewManager.instance()
                                    .createTabbedLocation(this._revealNavigatorSidebar.bind(this), 'run-view-sidebar')
                                    .tabbedPane();
      navigatorSplitWidget.setSidebarWidget(runViewTabbedPane);
      navigatorSplitWidget.installResizer(runViewTabbedPane.headerElement());
      this.editorView.setSidebarWidget(navigatorSplitWidget);
    } else {
      this.editorView.setSidebarWidget(tabbedPane);
    }

    this._sourcesView = new SourcesView();
    this._sourcesView.addEventListener(Events.EditorSelected, this._editorSelected.bind(this));

    this._toggleNavigatorSidebarButton = this.editorView.createShowHideSidebarButton(i18nString(UIStrings.navigator));
    this._toggleDebuggerSidebarButton = this._splitWidget.createShowHideSidebarButton(i18nString(UIStrings.debugger));
    this.editorView.setMainWidget(this._sourcesView);

    this._threadsSidebarPane = null;
    /** @type {!UI.View.View} */
    this._watchSidebarPane = (UI.ViewManager.ViewManager.instance().view('sources.watch'));
    this._callstackPane = CallStackSidebarPane.instance();

    Common.Settings.Settings.instance()
        .moduleSetting('sidebarPosition')
        .addChangeListener(this._updateSidebarPosition.bind(this));
    this._updateSidebarPosition();

    this._updateDebuggerButtonsAndStatus();
    this._pauseOnExceptionEnabledChanged();
    Common.Settings.Settings.instance()
        .moduleSetting('pauseOnExceptionEnabled')
        .addChangeListener(this._pauseOnExceptionEnabledChanged, this);

    this._liveLocationPool = new Bindings.LiveLocation.LiveLocationPool();

    this._setTarget(UI.Context.Context.instance().flavor(SDK.SDKModel.Target));
    Common.Settings.Settings.instance()
        .moduleSetting('breakpointsActive')
        .addChangeListener(this._breakpointsActiveStateChanged, this);
    UI.Context.Context.instance().addFlavorChangeListener(SDK.SDKModel.Target, this._onCurrentTargetChanged, this);
    UI.Context.Context.instance().addFlavorChangeListener(SDK.DebuggerModel.CallFrame, this._callFrameChanged, this);
    SDK.SDKModel.TargetManager.instance().addModelListener(
        SDK.DebuggerModel.DebuggerModel, SDK.DebuggerModel.Events.DebuggerWasEnabled, this._debuggerWasEnabled, this);
    SDK.SDKModel.TargetManager.instance().addModelListener(
        SDK.DebuggerModel.DebuggerModel, SDK.DebuggerModel.Events.DebuggerPaused, this._debuggerPaused, this);
    SDK.SDKModel.TargetManager.instance().addModelListener(
        SDK.DebuggerModel.DebuggerModel, SDK.DebuggerModel.Events.DebuggerResumed,
        event => this._debuggerResumed(/** @type {!SDK.DebuggerModel.DebuggerModel} */ (event.data)));
    SDK.SDKModel.TargetManager.instance().addModelListener(
        SDK.DebuggerModel.DebuggerModel, SDK.DebuggerModel.Events.GlobalObjectCleared,
        event => this._debuggerResumed(/** @type {!SDK.DebuggerModel.DebuggerModel} */ (event.data)));
    Extensions.ExtensionServer.ExtensionServer.instance().addEventListener(
        Extensions.ExtensionServer.Events.SidebarPaneAdded, this._extensionSidebarPaneAdded, this);
    SDK.SDKModel.TargetManager.instance().observeTargets(this);
    this._lastModificationTime = window.performance.now();
  }

  /**
   * @param {{forceNew: ?boolean}=} opts
   * @return {!SourcesPanel}
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!sourcesPanelInstance || forceNew) {
      sourcesPanelInstance = new SourcesPanel();
    }

    return sourcesPanelInstance;
  }

  /**
   * @param {!SourcesPanel} panel
   */
  static updateResizerAndSidebarButtons(panel) {
    panel._sourcesView.leftToolbar().removeToolbarItems();
    panel._sourcesView.rightToolbar().removeToolbarItems();
    panel._sourcesView.bottomToolbar().removeToolbarItems();
    const isInWrapper = WrapperView.isShowing() && !UI.InspectorView.InspectorView.instance().isDrawerMinimized();
    if (panel._splitWidget.isVertical() || isInWrapper) {
      panel._splitWidget.uninstallResizer(panel._sourcesView.toolbarContainerElement());
    } else {
      panel._splitWidget.installResizer(panel._sourcesView.toolbarContainerElement());
    }
    if (!isInWrapper) {
      panel._sourcesView.leftToolbar().appendToolbarItem(panel._toggleNavigatorSidebarButton);
      if (panel._splitWidget.isVertical()) {
        panel._sourcesView.rightToolbar().appendToolbarItem(panel._toggleDebuggerSidebarButton);
      } else {
        panel._sourcesView.bottomToolbar().appendToolbarItem(panel._toggleDebuggerSidebarButton);
      }
    }
  }

  /**
   * @override
   * @param {!SDK.SDKModel.Target} target
   */
  targetAdded(target) {
    this._showThreadsIfNeeded();
  }

  /**
   * @override
   * @param {!SDK.SDKModel.Target} target
   */
  targetRemoved(target) {
  }

  _showThreadsIfNeeded() {
    if (ThreadsSidebarPane.shouldBeShown() && !this._threadsSidebarPane) {
      this._threadsSidebarPane =
          /** @type {!UI.View.View} */ (UI.ViewManager.ViewManager.instance().view('sources.threads'));
      if (this._sidebarPaneStack && this._threadsSidebarPane) {
        this._sidebarPaneStack.showView(
            this._threadsSidebarPane, this._splitWidget.isVertical() ? this._watchSidebarPane : this._callstackPane);
      }
    }
  }

  /**
   * @param {?SDK.SDKModel.Target} target
   */
  _setTarget(target) {
    if (!target) {
      return;
    }
    const debuggerModel = target.model(SDK.DebuggerModel.DebuggerModel);
    if (!debuggerModel) {
      return;
    }

    if (debuggerModel.isPaused()) {
      this._showDebuggerPausedDetails(
          /** @type {!SDK.DebuggerModel.DebuggerPausedDetails} */ (debuggerModel.debuggerPausedDetails()));
    } else {
      this._paused = false;
      this._clearInterface();
      this._toggleDebuggerSidebarButton.setEnabled(true);
    }
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _onCurrentTargetChanged(event) {
    const target = /** @type {?SDK.SDKModel.Target} */ (event.data);
    this._setTarget(target);
  }
  /**
   * @return {boolean}
   */
  paused() {
    return this._paused || false;
  }

  /**
   * @override
   */
  wasShown() {
    UI.Context.Context.instance().setFlavor(SourcesPanel, this);
    super.wasShown();
    const wrapper = WrapperView.instance();
    if (wrapper && wrapper.isShowing()) {
      UI.InspectorView.InspectorView.instance().setDrawerMinimized(true);
      SourcesPanel.updateResizerAndSidebarButtons(this);
    }
    this.editorView.setMainWidget(this._sourcesView);
  }

  /**
   * @override
   */
  willHide() {
    super.willHide();
    UI.Context.Context.instance().setFlavor(SourcesPanel, null);
    if (WrapperView.isShowing()) {
      WrapperView.instance()._showViewInWrapper();
      UI.InspectorView.InspectorView.instance().setDrawerMinimized(false);
      SourcesPanel.updateResizerAndSidebarButtons(this);
    }
  }

  /**
   * @override
   * @param {string} locationName
   * @return {?UI.View.ViewLocation}
   */
  resolveLocation(locationName) {
    if (locationName === 'sources.sidebar-top' || locationName === 'sources.sidebar-bottom' ||
        locationName === 'sources.sidebar-tabs') {
      return this._sidebarPaneStack || null;
    }
    return this._navigatorTabbedLocation;
  }

  /**
   * @return {boolean}
   */
  _ensureSourcesViewVisible() {
    if (WrapperView.isShowing()) {
      return true;
    }
    if (!UI.InspectorView.InspectorView.instance().canSelectPanel('sources')) {
      return false;
    }
    UI.ViewManager.ViewManager.instance().showView('sources');
    return true;
  }

  /**
   * @override
   */
  onResize() {
    if (Common.Settings.Settings.instance().moduleSetting('sidebarPosition').get() === 'auto') {
      this.element.window().requestAnimationFrame(this._updateSidebarPosition.bind(this));
    }  // Do not force layout.
  }

  /**
   * @override
   * @return {!UI.SearchableView.SearchableView}
   */
  searchableView() {
    return this._sourcesView.searchableView();
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _debuggerPaused(event) {
    const debuggerModel = /** @type {!SDK.DebuggerModel.DebuggerModel} */ (event.data);
    const details = debuggerModel.debuggerPausedDetails();
    if (!this._paused) {
      this._setAsCurrentPanel();
    }

    if (UI.Context.Context.instance().flavor(SDK.SDKModel.Target) === debuggerModel.target()) {
      this._showDebuggerPausedDetails(/** @type {!SDK.DebuggerModel.DebuggerPausedDetails} */ (details));
    } else if (!this._paused) {
      UI.Context.Context.instance().setFlavor(SDK.SDKModel.Target, debuggerModel.target());
    }
  }

  /**
   * @param {!SDK.DebuggerModel.DebuggerPausedDetails} details
   */
  _showDebuggerPausedDetails(details) {
    this._paused = true;
    this._updateDebuggerButtonsAndStatus();
    UI.Context.Context.instance().setFlavor(SDK.DebuggerModel.DebuggerPausedDetails, details);
    this._toggleDebuggerSidebarButton.setEnabled(false);
    this._revealDebuggerSidebar();
    window.focus();
    Host.InspectorFrontendHost.InspectorFrontendHostInstance.bringToFront();
  }

  /**
   * @param {!SDK.DebuggerModel.DebuggerModel} debuggerModel
   */
  _debuggerResumed(debuggerModel) {
    const target = debuggerModel.target();
    if (UI.Context.Context.instance().flavor(SDK.SDKModel.Target) !== target) {
      return;
    }
    this._paused = false;
    this._clearInterface();
    this._toggleDebuggerSidebarButton.setEnabled(true);
    this._switchToPausedTargetTimeout = setTimeout(this._switchToPausedTarget.bind(this, debuggerModel), 500);
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _debuggerWasEnabled(event) {
    const debuggerModel = /** @type {!SDK.DebuggerModel.DebuggerModel} */ (event.data);
    if (UI.Context.Context.instance().flavor(SDK.SDKModel.Target) !== debuggerModel.target()) {
      return;
    }

    this._updateDebuggerButtonsAndStatus();
  }

  /**
   * @return {?UI.Widget.Widget}
   */
  get visibleView() {
    return this._sourcesView.visibleView();
  }

  /**
   * @param {!Workspace.UISourceCode.UISourceCode} uiSourceCode
   * @param {number=} lineNumber 0-based
   * @param {number=} columnNumber
   * @param {boolean=} omitFocus
   */
  showUISourceCode(uiSourceCode, lineNumber, columnNumber, omitFocus) {
    if (omitFocus) {
      const wrapperShowing = WrapperView.isShowing();
      if (!this.isShowing() && !wrapperShowing) {
        return;
      }
    } else {
      this._showEditor();
    }
    this._sourcesView.showSourceLocation(uiSourceCode, lineNumber, columnNumber, omitFocus);
  }

  _showEditor() {
    if (WrapperView.isShowing()) {
      return;
    }
    this._setAsCurrentPanel();
  }

  /**
   * @param {!Workspace.UISourceCode.UILocation} uiLocation
   * @param {boolean=} omitFocus
   */
  showUILocation(uiLocation, omitFocus) {
    this.showUISourceCode(uiLocation.uiSourceCode, uiLocation.lineNumber, uiLocation.columnNumber, omitFocus);
  }

  /**
   * @param {!Workspace.UISourceCode.UISourceCode} uiSourceCode
   * @param {boolean=} skipReveal
   */
  _revealInNavigator(uiSourceCode, skipReveal) {
    for (const navigator of registeredNavigatorViews) {
      const navigatorView = navigator.navigatorView();
      const viewId = navigator.viewId;
      if (viewId && navigatorView.acceptProject(uiSourceCode.project())) {
        navigatorView.revealUISourceCode(uiSourceCode, true);
        if (skipReveal) {
          this._navigatorTabbedLocation.tabbedPane().selectTab(viewId);
        } else {
          UI.ViewManager.ViewManager.instance().showView(viewId);
        }
      }
    }
  }

  /**
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   */
  _populateNavigatorMenu(contextMenu) {
    const groupByFolderSetting = Common.Settings.Settings.instance().moduleSetting('navigatorGroupByFolder');
    contextMenu.appendItemsAtLocation('navigatorMenu');
    contextMenu.viewSection().appendCheckboxItem(
        i18nString(UIStrings.groupByFolder), () => groupByFolderSetting.set(!groupByFolderSetting.get()),
        groupByFolderSetting.get());
  }

  /**
   * @param {boolean} ignoreExecutionLineEvents
   */
  setIgnoreExecutionLineEvents(ignoreExecutionLineEvents) {
    this._ignoreExecutionLineEvents = ignoreExecutionLineEvents;
  }

  updateLastModificationTime() {
    this._lastModificationTime = window.performance.now();
  }

  /**
   * @param {!Bindings.LiveLocation.LiveLocation} liveLocation
   */
  async _executionLineChanged(liveLocation) {
    const uiLocation = await liveLocation.uiLocation();
    if (!uiLocation) {
      return;
    }
    if (window.performance.now() - this._lastModificationTime < lastModificationTimeout) {
      return;
    }
    this._sourcesView.showSourceLocation(
        uiLocation.uiSourceCode, uiLocation.lineNumber, uiLocation.columnNumber, undefined, true);
  }

  _lastModificationTimeoutPassedForTest() {
    lastModificationTimeout = Number.MIN_VALUE;
  }

  _updateLastModificationTimeForTest() {
    lastModificationTimeout = Number.MAX_VALUE;
  }

  async _callFrameChanged() {
    const callFrame = UI.Context.Context.instance().flavor(SDK.DebuggerModel.CallFrame);
    if (!callFrame) {
      return;
    }
    if (this._executionLineLocation) {
      this._executionLineLocation.dispose();
    }
    this._executionLineLocation =
        await Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance().createCallFrameLiveLocation(
            callFrame.location(), this._executionLineChanged.bind(this), this._liveLocationPool);
  }

  _pauseOnExceptionEnabledChanged() {
    const enabled = Common.Settings.Settings.instance().moduleSetting('pauseOnExceptionEnabled').get();
    const button = /** @type {!UI.Toolbar.ToolbarToggle} */ (this._pauseOnExceptionButton);
    button.setToggled(enabled);
    button.setTitle(enabled ? i18nString(UIStrings.pauseOnExceptions) : i18nString(UIStrings.dontPauseOnExceptions));
    this._debugToolbarDrawer.classList.toggle('expanded', enabled);
  }

  async _updateDebuggerButtonsAndStatus() {
    const currentTarget = UI.Context.Context.instance().flavor(SDK.SDKModel.Target);
    const currentDebuggerModel = currentTarget ? currentTarget.model(SDK.DebuggerModel.DebuggerModel) : null;
    if (!currentDebuggerModel) {
      this._togglePauseAction.setEnabled(false);
      this._stepOverAction.setEnabled(false);
      this._stepIntoAction.setEnabled(false);
      this._stepOutAction.setEnabled(false);
      this._stepAction.setEnabled(false);
    } else if (this._paused) {
      this._togglePauseAction.setToggled(true);
      this._togglePauseAction.setEnabled(true);
      this._stepOverAction.setEnabled(true);
      this._stepIntoAction.setEnabled(true);
      this._stepOutAction.setEnabled(true);
      this._stepAction.setEnabled(true);
    } else {
      this._togglePauseAction.setToggled(false);
      this._togglePauseAction.setEnabled(!currentDebuggerModel.isPausing());
      this._stepOverAction.setEnabled(false);
      this._stepIntoAction.setEnabled(false);
      this._stepOutAction.setEnabled(false);
      this._stepAction.setEnabled(false);
    }

    const details = currentDebuggerModel ? currentDebuggerModel.debuggerPausedDetails() : null;
    await this._debuggerPausedMessage.render(
        details, Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance(),
        Bindings.BreakpointManager.BreakpointManager.instance());
    if (details) {
      this._updateDebuggerButtonsAndStatusForTest();
    }
  }

  _updateDebuggerButtonsAndStatusForTest() {
  }

  _clearInterface() {
    this._updateDebuggerButtonsAndStatus();
    UI.Context.Context.instance().setFlavor(SDK.DebuggerModel.DebuggerPausedDetails, null);

    if (this._switchToPausedTargetTimeout) {
      clearTimeout(this._switchToPausedTargetTimeout);
    }
    this._liveLocationPool.disposeAll();
  }

  /**
   * @param {!SDK.DebuggerModel.DebuggerModel} debuggerModel
   */
  _switchToPausedTarget(debuggerModel) {
    delete this._switchToPausedTargetTimeout;
    if (this._paused || debuggerModel.isPaused()) {
      return;
    }

    for (const debuggerModel of SDK.SDKModel.TargetManager.instance().models(SDK.DebuggerModel.DebuggerModel)) {
      if (debuggerModel.isPaused()) {
        UI.Context.Context.instance().setFlavor(SDK.SDKModel.Target, debuggerModel.target());
        break;
      }
    }
  }

  _togglePauseOnExceptions() {
    Common.Settings.Settings.instance()
        .moduleSetting('pauseOnExceptionEnabled')
        .set(!/** @type {!UI.Toolbar.ToolbarToggle} */ (this._pauseOnExceptionButton).toggled());
  }

  _runSnippet() {
    const uiSourceCode = this._sourcesView.currentUISourceCode();
    if (uiSourceCode) {
      Snippets.ScriptSnippetFileSystem.evaluateScriptSnippet(uiSourceCode);
    }
  }

  _toggleRecording() {
    const uiSourceCode = this._sourcesView.currentUISourceCode();
    if (!uiSourceCode) {
      return;
    }
    const target = UI.Context.Context.instance().flavor(SDK.SDKModel.Target);
    if (!target) {
      return;
    }
    const recorderModel = target.model(Recorder.RecorderModel.RecorderModel);
    if (!recorderModel) {
      return;
    }
    recorderModel.toggleRecording(uiSourceCode);
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _editorSelected(event) {
    const uiSourceCode = /** @type {!Workspace.UISourceCode.UISourceCode} */ (event.data);
    if (this.editorView.mainWidget() &&
        Common.Settings.Settings.instance().moduleSetting('autoRevealInNavigator').get()) {
      this._revealInNavigator(uiSourceCode, true);
    }
  }

  /**
   * @return {boolean}
   */
  _togglePause() {
    const target = UI.Context.Context.instance().flavor(SDK.SDKModel.Target);
    if (!target) {
      return true;
    }
    const debuggerModel = target.model(SDK.DebuggerModel.DebuggerModel);
    if (!debuggerModel) {
      return true;
    }

    if (this._paused) {
      this._paused = false;
      debuggerModel.resume();
    } else {
      // Make sure pauses didn't stick skipped.
      debuggerModel.pause();
    }

    this._clearInterface();
    return true;
  }

  /**
   * @return {?SDK.DebuggerModel.DebuggerModel}
   */
  _prepareToResume() {
    if (!this._paused) {
      return null;
    }

    this._paused = false;

    this._clearInterface();
    const target = UI.Context.Context.instance().flavor(SDK.SDKModel.Target);
    return target ? target.model(SDK.DebuggerModel.DebuggerModel) : null;
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _longResume(event) {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.skipAllPausesUntilReloadOrTimeout(500);
      debuggerModel.resume();
    }
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _terminateExecution(event) {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.runtimeModel().terminateExecution();
      debuggerModel.resume();
    }
  }

  /**
   * @return {boolean}
   */
  _stepOver() {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.stepOver();
    }
    return true;
  }

  /**
   * @return {boolean}
   */
  _stepInto() {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.stepInto();
    }
    return true;
  }

  /**
   * @return {boolean}
   */
  _stepIntoAsync() {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.scheduleStepIntoAsync();
    }
    return true;
  }

  /**
   * @return {boolean}
   */
  _stepOut() {
    const debuggerModel = this._prepareToResume();
    if (debuggerModel) {
      debuggerModel.stepOut();
    }
    return true;
  }

  /**
   * @param {!Workspace.UISourceCode.UILocation} uiLocation
   */
  async _continueToLocation(uiLocation) {
    const executionContext = UI.Context.Context.instance().flavor(SDK.RuntimeModel.ExecutionContext);
    if (!executionContext) {
      return;
    }
    // Always use 0 column.
    const rawLocations =
        await Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance().uiLocationToRawLocations(
            uiLocation.uiSourceCode, uiLocation.lineNumber, 0);
    const rawLocation = rawLocations.find(location => location.debuggerModel === executionContext.debuggerModel);
    if (rawLocation && this._prepareToResume()) {
      rawLocation.continueToLocation();
    }
  }

  _toggleBreakpointsActive() {
    Common.Settings.Settings.instance()
        .moduleSetting('breakpointsActive')
        .set(!Common.Settings.Settings.instance().moduleSetting('breakpointsActive').get());
  }

  _breakpointsActiveStateChanged() {
    const active = Common.Settings.Settings.instance().moduleSetting('breakpointsActive').get();
    this._toggleBreakpointsActiveAction.setToggled(!active);
    this._sourcesView.toggleBreakpointsActiveState(active);
  }

  /**
   * @return {!UI.Toolbar.Toolbar}
   */
  _createDebugToolbar() {
    const debugToolbar = new UI.Toolbar.Toolbar('scripts-debug-toolbar');

    const longResumeButton =
        new UI.Toolbar.ToolbarButton(i18nString(UIStrings.resumeWithAllPausesBlockedForMs), 'largeicon-play');
    longResumeButton.addEventListener(UI.Toolbar.ToolbarButton.Events.Click, this._longResume, this);
    const terminateExecutionButton = new UI.Toolbar.ToolbarButton(
        i18nString(UIStrings.terminateCurrentJavascriptCall), 'largeicon-terminate-execution');
    terminateExecutionButton.addEventListener(UI.Toolbar.ToolbarButton.Events.Click, this._terminateExecution, this);
    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createLongPressActionButton(
        this._togglePauseAction, [terminateExecutionButton, longResumeButton], []));

    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createActionButton(this._stepOverAction));
    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createActionButton(this._stepIntoAction));
    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createActionButton(this._stepOutAction));
    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createActionButton(this._stepAction));

    debugToolbar.appendSeparator();
    debugToolbar.appendToolbarItem(UI.Toolbar.Toolbar.createActionButton(this._toggleBreakpointsActiveAction));

    this._pauseOnExceptionButton = new UI.Toolbar.ToolbarToggle('', 'largeicon-pause-on-exceptions');
    this._pauseOnExceptionButton.addEventListener(
        UI.Toolbar.ToolbarButton.Events.Click, this._togglePauseOnExceptions, this);
    debugToolbar.appendToolbarItem(this._pauseOnExceptionButton);

    return debugToolbar;
  }

  _createDebugToolbarDrawer() {
    const debugToolbarDrawer = document.createElement('div');
    debugToolbarDrawer.classList.add('scripts-debug-toolbar-drawer');

    const label = i18nString(UIStrings.pauseOnCaughtExceptions);
    const setting = Common.Settings.Settings.instance().moduleSetting('pauseOnCaughtException');
    debugToolbarDrawer.appendChild(UI.SettingsUI.createSettingCheckbox(label, setting, true));

    return debugToolbarDrawer;
  }

  /**
   * @override
   * @param {!Event} event
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} target
   */
  appendApplicableItems(event, contextMenu, target) {
    this._appendUISourceCodeItems(event, contextMenu, target);
    this._appendUISourceCodeFrameItems(event, contextMenu, target);
    this.appendUILocationItems(contextMenu, target);
    this._appendRemoteObjectItems(contextMenu, target);
    this._appendNetworkRequestItems(contextMenu, target);
  }

  /**
   * @param {!Event} event
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} target
   */
  _appendUISourceCodeItems(event, contextMenu, target) {
    if (!(target instanceof Workspace.UISourceCode.UISourceCode) || !event.target) {
      return;
    }

    const uiSourceCode = /** @type {!Workspace.UISourceCode.UISourceCode} */ (target);
    const eventTarget = /** @type {!Node} */ (event.target);
    if (!uiSourceCode.project().isServiceProject() &&
        !eventTarget.isSelfOrDescendant(this._navigatorTabbedLocation.widget().element)) {
      contextMenu.revealSection().appendItem(
          i18nString(UIStrings.revealInSidebar), this._handleContextMenuReveal.bind(this, uiSourceCode));
    }
  }

  /**
   * @param {!Event} event
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} target
   */
  _appendUISourceCodeFrameItems(event, contextMenu, target) {
    if (!(target instanceof UISourceCodeFrame)) {
      return;
    }
    if (target.uiSourceCode().contentType().isFromSourceMap() || target.textEditor.selection().isEmpty()) {
      return;
    }
    contextMenu.debugSection().appendAction('debugger.evaluate-selection');
  }

  /**
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} object
   */
  appendUILocationItems(contextMenu, object) {
    if (!(object instanceof Workspace.UISourceCode.UILocation)) {
      return;
    }
    const uiLocation = /** @type {!Workspace.UISourceCode.UILocation} */ (object);
    const uiSourceCode = uiLocation.uiSourceCode;

    if (!Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance()
             .scriptsForUISourceCode(uiSourceCode)
             .every(script => script.isJavaScript())) {
      // Ignore List and 'Continue to here' currently only works for JavaScript debugging.
      return;
    }
    const contentType = uiSourceCode.contentType();
    if (contentType.hasScripts()) {
      const target = UI.Context.Context.instance().flavor(SDK.SDKModel.Target);
      const debuggerModel = target ? target.model(SDK.DebuggerModel.DebuggerModel) : null;
      if (debuggerModel && debuggerModel.isPaused()) {
        contextMenu.debugSection().appendItem(
            i18nString(UIStrings.continueToHere), this._continueToLocation.bind(this, uiLocation));
      }

      this._callstackPane.appendIgnoreListURLContextMenuItems(contextMenu, uiSourceCode);
    }
  }

  /**
   * @param {!Workspace.UISourceCode.UISourceCode} uiSourceCode
   */
  _handleContextMenuReveal(uiSourceCode) {
    this.editorView.showBoth();
    this._revealInNavigator(uiSourceCode);
  }

  /**
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} target
   */
  _appendRemoteObjectItems(contextMenu, target) {
    if (!(target instanceof SDK.RemoteObject.RemoteObject)) {
      return;
    }
    const indent = Common.Settings.Settings.instance().moduleSetting('textEditorIndent').get();
    const remoteObject = /** @type {!SDK.RemoteObject.RemoteObject} */ (target);
    const executionContext = UI.Context.Context.instance().flavor(SDK.RuntimeModel.ExecutionContext);

    function getObjectTitle() {
      if (remoteObject.type === 'wasm') {
        return remoteObject.subtype;
      }
      if (remoteObject.subtype === 'node') {
        return 'outerHTML';
      }
      return remoteObject.type;
    }
    const copyContextMenuTitle = getObjectTitle();

    contextMenu.debugSection().appendItem(
        i18nString(UIStrings.storeSAsGlobalVariable, {PH1: copyContextMenuTitle}),
        () => SDK.ConsoleModel.ConsoleModel.instance().saveToTempVariable(executionContext, remoteObject));

    // Copy object context menu.
    if (remoteObject.type !== 'function') {
      const copyDecodedValueHandler = async () => {
        const result = await remoteObject.callFunctionJSON(toStringForClipboard, [{
                                                             value: {
                                                               subtype: remoteObject.subtype,
                                                               indent: indent,
                                                             }
                                                           }]);
        Host.InspectorFrontendHost.InspectorFrontendHostInstance.copyText(result);
      };

      contextMenu.clipboardSection().appendItem(
          i18nString(UIStrings.copyS, {PH1: copyContextMenuTitle}), copyDecodedValueHandler);
    }

    if (remoteObject.type === 'function') {
      contextMenu.debugSection().appendItem(
          i18nString(UIStrings.showFunctionDefinition), this._showFunctionDefinition.bind(this, remoteObject));
    }

    /**
     * @param {*} data
     * @this {Object}
     */
    function toStringForClipboard(data) {
      const subtype = data.subtype;
      const indent = data.indent;

      if (subtype === 'node') {
        return this instanceof Element ? this.outerHTML : undefined;
      }
      if (subtype && typeof this === 'undefined') {
        return String(subtype);
      }
      try {
        return JSON.stringify(this, null, indent);
      } catch (error) {
        return String(this);
      }
    }
  }

  /**
   * @param {!UI.ContextMenu.ContextMenu} contextMenu
   * @param {!Object} target
   */
  _appendNetworkRequestItems(contextMenu, target) {
    if (!(target instanceof SDK.NetworkRequest.NetworkRequest)) {
      return;
    }
    const request = /** @type {!SDK.NetworkRequest.NetworkRequest} */ (target);
    const uiSourceCode = this._workspace.uiSourceCodeForURL(request.url());
    if (!uiSourceCode) {
      return;
    }
    const openText = i18nString(UIStrings.openInSourcesPanel);
    /** @type {function():*} */
    const callback = this.showUILocation.bind(this, uiSourceCode.uiLocation(0, 0));
    contextMenu.revealSection().appendItem(openText, callback);
  }

  /**
   * @param {!SDK.RemoteObject.RemoteObject} remoteObject
   */
  _showFunctionDefinition(remoteObject) {
    remoteObject.debuggerModel().functionDetailsPromise(remoteObject).then(this._didGetFunctionDetails.bind(this));
  }

  /**
   * @param {?{location: ?SDK.DebuggerModel.Location}} response
   */
  async _didGetFunctionDetails(response) {
    if (!response || !response.location) {
      return;
    }

    const uiLocation =
        await Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance().rawLocationToUILocation(
            response.location);
    if (uiLocation) {
      this.showUILocation(uiLocation);
    }
  }

  _revealNavigatorSidebar() {
    this._setAsCurrentPanel();
    this.editorView.showBoth(true);
  }

  _revealDebuggerSidebar() {
    this._setAsCurrentPanel();
    this._splitWidget.showBoth(true);
  }

  _updateSidebarPosition() {
    let vertically;
    const position = Common.Settings.Settings.instance().moduleSetting('sidebarPosition').get();
    if (position === 'right') {
      vertically = false;
    } else if (position === 'bottom') {
      vertically = true;
    } else {
      vertically = UI.InspectorView.InspectorView.instance().element.offsetWidth < 680;
    }

    if (this.sidebarPaneView && vertically === !this._splitWidget.isVertical()) {
      return;
    }

    if (this.sidebarPaneView && this.sidebarPaneView.shouldHideOnDetach()) {
      return;
    }  // We can't reparent extension iframes.

    if (this.sidebarPaneView) {
      this.sidebarPaneView.detach();
    }

    this._splitWidget.setVertical(!vertically);
    this._splitWidget.element.classList.toggle('sources-split-view-vertical', vertically);

    SourcesPanel.updateResizerAndSidebarButtons(this);

    // Create vertical box with stack.
    const vbox = new UI.Widget.VBox();
    vbox.element.appendChild(this._debugToolbar.element);
    vbox.element.appendChild(this._debugToolbarDrawer);

    vbox.setMinimumAndPreferredSizes(minToolbarWidth, 25, minToolbarWidth, 100);
    this._sidebarPaneStack =
        UI.ViewManager.ViewManager.instance().createStackLocation(this._revealDebuggerSidebar.bind(this));
    this._sidebarPaneStack.widget().element.classList.add('overflow-auto');
    this._sidebarPaneStack.widget().show(vbox.element);
    this._sidebarPaneStack.widget().element.appendChild(this._debuggerPausedMessage.element());
    this._sidebarPaneStack.appendApplicableItems('sources.sidebar-top');

    if (this._threadsSidebarPane) {
      this._sidebarPaneStack.showView(this._threadsSidebarPane);
    }

    const jsBreakpoints =
        /** @type {!UI.View.View} */ (UI.ViewManager.ViewManager.instance().view('sources.jsBreakpoints'));
    const scopeChainView =
        /** @type {!UI.View.View} */ (UI.ViewManager.ViewManager.instance().view('sources.scopeChain'));

    if (this._tabbedLocationHeader) {
      this._splitWidget.uninstallResizer(this._tabbedLocationHeader);
      this._tabbedLocationHeader = null;
    }

    if (!vertically) {
      // Populate the rest of the stack.
      this._sidebarPaneStack.appendView(this._watchSidebarPane);
      this._sidebarPaneStack.showView(jsBreakpoints);
      this._sidebarPaneStack.showView(scopeChainView);
      this._sidebarPaneStack.showView(this._callstackPane);
      this._extensionSidebarPanesContainer = this._sidebarPaneStack;
      this.sidebarPaneView = vbox;
      this._splitWidget.uninstallResizer(this._debugToolbar.gripElementForResize());
    } else {
      const splitWidget = new UI.SplitWidget.SplitWidget(true, true, 'sourcesPanelDebuggerSidebarSplitViewState', 0.5);
      splitWidget.setMainWidget(vbox);

      // Populate the left stack.
      this._sidebarPaneStack.showView(jsBreakpoints);
      this._sidebarPaneStack.showView(this._callstackPane);

      const tabbedLocation =
          UI.ViewManager.ViewManager.instance().createTabbedLocation(this._revealDebuggerSidebar.bind(this));
      splitWidget.setSidebarWidget(tabbedLocation.tabbedPane());
      this._tabbedLocationHeader = tabbedLocation.tabbedPane().headerElement();
      this._splitWidget.installResizer(this._tabbedLocationHeader);
      this._splitWidget.installResizer(this._debugToolbar.gripElementForResize());
      tabbedLocation.appendView(scopeChainView);
      tabbedLocation.appendView(this._watchSidebarPane);
      tabbedLocation.appendApplicableItems('sources.sidebar-tabs');
      this._extensionSidebarPanesContainer = tabbedLocation;
      this.sidebarPaneView = splitWidget;
    }

    this._sidebarPaneStack.appendApplicableItems('sources.sidebar-bottom');
    const extensionSidebarPanes = Extensions.ExtensionServer.ExtensionServer.instance().sidebarPanes();
    for (let i = 0; i < extensionSidebarPanes.length; ++i) {
      this._addExtensionSidebarPane(extensionSidebarPanes[i]);
    }

    this._splitWidget.setSidebarWidget(this.sidebarPaneView);
  }

  /**
   * @return {!Promise<void>}
   */
  _setAsCurrentPanel() {
    return UI.ViewManager.ViewManager.instance().showView('sources');
  }

  /**
   * @param {!Common.EventTarget.EventTargetEvent} event
   */
  _extensionSidebarPaneAdded(event) {
    const pane = /** @type {!Extensions.ExtensionPanel.ExtensionSidebarPane} */ (event.data);
    this._addExtensionSidebarPane(pane);
  }

  /**
   * @param {!Extensions.ExtensionPanel.ExtensionSidebarPane} pane
   */
  _addExtensionSidebarPane(pane) {
    if (pane.panelName() === this.name) {
      /** @type {!UI.View.ViewLocation} */ (this._extensionSidebarPanesContainer).appendView(pane);
    }
  }

  /**
   * @return {!SourcesView}
   */
  sourcesView() {
    return this._sourcesView;
  }

  /**
   * @param {!DataTransfer} dataTransfer
   */
  _handleDrop(dataTransfer) {
    const items = dataTransfer.items;
    if (!items.length) {
      return;
    }
    const entry = items[0].webkitGetAsEntry();
    if (!entry.isDirectory) {
      return;
    }
    Host.InspectorFrontendHost.InspectorFrontendHostInstance.upgradeDraggedFileSystemPermissions(entry.filesystem);
  }
}

export let lastModificationTimeout = 200;
export const minToolbarWidth = 215;

/** @type {!UILocationRevealer} */
let uILocationRevealerInstance;

/**
 * @implements {Common.Revealer.Revealer}
 */
export class UILocationRevealer {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!uILocationRevealerInstance || forceNew) {
      uILocationRevealerInstance = new UILocationRevealer();
    }

    return uILocationRevealerInstance;
  }

  /**
   * @override
   * @param {!Object} uiLocation
   * @param {boolean=} omitFocus
   * @return {!Promise<void>}
   */
  reveal(uiLocation, omitFocus) {
    if (!(uiLocation instanceof Workspace.UISourceCode.UILocation)) {
      return Promise.reject(new Error('Internal error: not a ui location'));
    }
    SourcesPanel.instance().showUILocation(uiLocation, omitFocus);
    return Promise.resolve();
  }
}

/** @type {!DebuggerLocationRevealer} */
let debuggerLocationRevealerInstance;

/**
 * @implements {Common.Revealer.Revealer}
 */
export class DebuggerLocationRevealer {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!debuggerLocationRevealerInstance || forceNew) {
      debuggerLocationRevealerInstance = new DebuggerLocationRevealer();
    }

    return debuggerLocationRevealerInstance;
  }

  /**
   * @override
   * @param {!Object} rawLocation
   * @param {boolean=} omitFocus
   * @return {!Promise<void>}
   */
  async reveal(rawLocation, omitFocus) {
    if (!(rawLocation instanceof SDK.DebuggerModel.Location)) {
      throw new Error('Internal error: not a debugger location');
    }
    const uiLocation =
        await Bindings.DebuggerWorkspaceBinding.DebuggerWorkspaceBinding.instance().rawLocationToUILocation(
            rawLocation);
    if (uiLocation) {
      SourcesPanel.instance().showUILocation(uiLocation, omitFocus);
    }
  }
}

/** @type {!UISourceCodeRevealer} */
let uISourceCodeRevealerInstance;

/**
 * @implements {Common.Revealer.Revealer}
 */
export class UISourceCodeRevealer {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!uISourceCodeRevealerInstance || forceNew) {
      uISourceCodeRevealerInstance = new UISourceCodeRevealer();
    }

    return uISourceCodeRevealerInstance;
  }

  /**
   * @override
   * @param {!Object} uiSourceCode
   * @param {boolean=} omitFocus
   * @return {!Promise<void>}
   */
  reveal(uiSourceCode, omitFocus) {
    if (!(uiSourceCode instanceof Workspace.UISourceCode.UISourceCode)) {
      return Promise.reject(new Error('Internal error: not a ui source code'));
    }
    SourcesPanel.instance().showUISourceCode(uiSourceCode, undefined, undefined, omitFocus);
    return Promise.resolve();
  }
}

/** @type {!DebuggerPausedDetailsRevealer} */
let debuggerPausedDetailsRevealerInstance;

/**
 * @implements {Common.Revealer.Revealer}
 */
export class DebuggerPausedDetailsRevealer {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!debuggerPausedDetailsRevealerInstance || forceNew) {
      debuggerPausedDetailsRevealerInstance = new DebuggerPausedDetailsRevealer();
    }

    return debuggerPausedDetailsRevealerInstance;
  }

  /**
   * @override
   * @param {!Object} object
   * @return {!Promise<void>}
   */
  reveal(object) {
    return SourcesPanel.instance()._setAsCurrentPanel();
  }
}

/** @type {!RevealingActionDelegate} */
let revealingActionDelegateInstance;

/**
 * @implements {UI.ActionRegistration.ActionDelegate}
 */
export class RevealingActionDelegate {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!revealingActionDelegateInstance || forceNew) {
      revealingActionDelegateInstance = new RevealingActionDelegate();
    }

    return revealingActionDelegateInstance;
  }
  /**
   * @override
   * @param {!UI.Context.Context} context
   * @param {string} actionId
   * @return {boolean}
   */
  handleAction(context, actionId) {
    const panel = SourcesPanel.instance();
    if (!panel._ensureSourcesViewVisible()) {
      return false;
    }
    switch (actionId) {
      case 'debugger.toggle-pause':
        panel._togglePause();
        return true;
    }
    return false;
  }
}

/** @type {!DebuggingActionDelegate} */
let debuggingActionDelegateInstance;

/**
 * @implements {UI.ActionRegistration.ActionDelegate}
 */
export class DebuggingActionDelegate {
  /**
   * @param {{forceNew: ?boolean}} opts
   */
  static instance(opts = {forceNew: null}) {
    const {forceNew} = opts;
    if (!debuggingActionDelegateInstance || forceNew) {
      debuggingActionDelegateInstance = new DebuggingActionDelegate();
    }

    return debuggingActionDelegateInstance;
  }
  /**
   * @override
   * @param {!UI.Context.Context} context
   * @param {string} actionId
   * @return {boolean}
   */
  handleAction(context, actionId) {
    const panel = SourcesPanel.instance();
    switch (actionId) {
      case 'debugger.step-over': {
        panel._stepOver();
        return true;
      }
      case 'debugger.step-into': {
        panel._stepIntoAsync();
        return true;
      }
      case 'debugger.step': {
        panel._stepInto();
        return true;
      }
      case 'debugger.step-out': {
        panel._stepOut();
        return true;
      }
      case 'debugger.run-snippet': {
        panel._runSnippet();
        return true;
      }
      case 'recorder.toggle-recording': {
        panel._toggleRecording();
        return true;
      }
      case 'debugger.toggle-breakpoints-active': {
        panel._toggleBreakpointsActive();
        return true;
      }
      case 'debugger.evaluate-selection': {
        const frame = UI.Context.Context.instance().flavor(UISourceCodeFrame);
        if (frame) {
          let text = frame.textEditor.text(frame.textEditor.selectio