DevTools: extract modules (with extensions)

third_party/WebKit/Source/devtools/front_end/components/ExecutionContextSelector.js

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-/**
- * @implements {SDK.TargetManager.Observer}
- * @unrestricted
- */
-Components.ExecutionContextSelector = class {
-  /**
-   * @param {!SDK.TargetManager} targetManager
-   * @param {!UI.Context} context
-   */
-  constructor(targetManager, context) {
-    targetManager.observeTargets(this, SDK.Target.Capability.JS);
-    context.addFlavorChangeListener(SDK.ExecutionContext, this._executionContextChanged, this);
-    context.addFlavorChangeListener(SDK.Target, this._targetChanged, this);
-
-    targetManager.addModelListener(
-        SDK.RuntimeModel, SDK.RuntimeModel.Events.ExecutionContextCreated, this._onExecutionContextCreated, this);
-    targetManager.addModelListener(
-        SDK.RuntimeModel, SDK.RuntimeModel.Events.ExecutionContextDestroyed, this._onExecutionContextDestroyed, this);
-    targetManager.addModelListener(
-        SDK.RuntimeModel, SDK.RuntimeModel.Events.ExecutionContextOrderChanged, this._onExecutionContextOrderChanged,
-        this);
-    this._targetManager = targetManager;
-    this._context = context;
-  }
-
-  /**
-   * @override
-   * @param {!SDK.Target} target
-   */
-  targetAdded(target) {
-    // Defer selecting default target since we need all clients to get their
-    // targetAdded notifications first.
-    setImmediate(deferred.bind(this));
-
-    /**
-     * @this {Components.ExecutionContextSelector}
-     */
-    function deferred() {
-      // We always want the second context for the service worker targets.
-      if (!this._context.flavor(SDK.Target))
-        this._context.setFlavor(SDK.Target, target);
-    }
-  }
-
-  /**
-   * @override
-   * @param {!SDK.Target} target
-   */
-  targetRemoved(target) {
-    var currentExecutionContext = this._context.flavor(SDK.ExecutionContext);
-    if (currentExecutionContext && currentExecutionContext.target() === target)
-      this._currentExecutionContextGone();
-
-    var targets = this._targetManager.targets(SDK.Target.Capability.JS);
-    if (this._context.flavor(SDK.Target) === target && targets.length)
-      this._context.setFlavor(SDK.Target, targets[0]);
-  }
-
-  /**
-   * @param {!Common.Event} event
-   */
-  _executionContextChanged(event) {
-    var newContext = /** @type {?SDK.ExecutionContext} */ (event.data);
-    if (newContext) {
-      this._context.setFlavor(SDK.Target, newContext.target());
-      if (!this._ignoreContextChanged)
-        this._lastSelectedContextId = this._contextPersistentId(newContext);
-    }
-  }
-
-  /**
-   * @param {!SDK.ExecutionContext} executionContext
-   * @return {string}
-   */
-  _contextPersistentId(executionContext) {
-    return executionContext.isDefault ? executionContext.target().name() + ':' + executionContext.frameId : '';
-  }
-
-  /**
-   * @param {!Common.Event} event
-   */
-  _targetChanged(event) {
-    var newTarget = /** @type {?SDK.Target} */ (event.data);
-    var currentContext = this._context.flavor(SDK.ExecutionContext);
-
-    if (!newTarget || (currentContext && currentContext.target() === newTarget))
-      return;
-
-    var executionContexts = newTarget.runtimeModel.executionContexts();
-    if (!executionContexts.length)
-      return;
-
-    var newContext = null;
-    for (var i = 0; i < executionContexts.length && !newContext; ++i) {
-      if (this._shouldSwitchToContext(executionContexts[i]))
-        newContext = executionContexts[i];
-    }
-    for (var i = 0; i < executionContexts.length && !newContext; ++i) {
-      if (this._isDefaultContext(executionContexts[i]))
-        newContext = executionContexts[i];
-    }
-    this._ignoreContextChanged = true;
-    this._context.setFlavor(SDK.ExecutionContext, newContext || executionContexts[0]);
-    this._ignoreContextChanged = false;
-  }
-
-  /**
-   * @param {!SDK.ExecutionContext} executionContext
-   * @return {boolean}
-   */
-  _shouldSwitchToContext(executionContext) {
-    if (this._lastSelectedContextId && this._lastSelectedContextId === this._contextPersistentId(executionContext))
-      return true;
-    if (!this._lastSelectedContextId && this._isDefaultContext(executionContext))
-      return true;
-    return false;
-  }
-
-  /**
-   * @param {!SDK.ExecutionContext} executionContext
-   * @return {boolean}
-   */
-  _isDefaultContext(executionContext) {
-    if (!executionContext.isDefault || !executionContext.frameId)
-      return false;
-    if (executionContext.target().parentTarget())
-      return false;
-    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(executionContext.target());
-    var frame = resourceTreeModel && resourceTreeModel.frameForId(executionContext.frameId);
-    if (frame && frame.isMainFrame())
-      return true;
-    return false;
-  }
-
-  /**
-   * @param {!Common.Event} event
-   */
-  _onExecutionContextCreated(event) {
-    this._switchContextIfNecessary(/** @type {!SDK.ExecutionContext} */ (event.data));
-  }
-
-  /**
-   * @param {!Common.Event} event
-   */
-  _onExecutionContextDestroyed(event) {
-    var executionContext = /** @type {!SDK.ExecutionContext}*/ (event.data);
-    if (this._context.flavor(SDK.ExecutionContext) === executionContext)
-      this._currentExecutionContextGone();
-  }
-
-  /**
-   * @param {!Common.Event} event
-   */
-  _onExecutionContextOrderChanged(event) {
-    var runtimeModel = /** @type {!SDK.RuntimeModel} */ (event.data);
-    var executionContexts = runtimeModel.executionContexts();
-    for (var i = 0; i < executionContexts.length; i++) {
-      if (this._switchContextIfNecessary(executionContexts[i]))
-        break;
-    }
-  }
-
-  /**
-   * @param {!SDK.ExecutionContext} executionContext
-   * @return {boolean}
-   */
-  _switchContextIfNecessary(executionContext) {
-    if (!this._context.flavor(SDK.ExecutionContext) || this._shouldSwitchToContext(executionContext)) {
-      this._ignoreContextChanged = true;
-      this._context.setFlavor(SDK.ExecutionContext, executionContext);
-      this._ignoreContextChanged = false;
-      return true;
-    }
-    return false;
-  }
-
-  _currentExecutionContextGone() {
-    var targets = this._targetManager.targets(SDK.Target.Capability.JS);
-    var newContext = null;
-    for (var i = 0; i < targets.length && !newContext; ++i) {
-      var executionContexts = targets[i].runtimeModel.executionContexts();
-      for (var executionContext of executionContexts) {
-        if (this._isDefaultContext(executionContext)) {
-          newContext = executionContext;
-          break;
-        }
-      }
-    }
-    if (!newContext) {
-      for (var i = 0; i < targets.length && !newContext; ++i) {
-        var executionContexts = targets[i].runtimeModel.executionContexts();
-        if (executionContexts.length) {
-          newContext = executionContexts[0];
-          break;
-        }
-      }
-    }
-    this._ignoreContextChanged = true;
-    this._context.setFlavor(SDK.ExecutionContext, newContext);
-    this._ignoreContextChanged = false;
-  }
-};