[DevTools] Show an empty Manifest view if no manifest

third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js

Index: third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js b/third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js
index 948c20fa46b1c6f8250c1e88deab4409d3fe7085..79fc7658eeda58511a3f3921a89e86db51a922bc 100644
--- a/third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js
+++ b/third_party/WebKit/Source/devtools/front_end/resources/ResourcesPanel.js
@@ -159,6 +159,8 @@ Resources.ResourcesPanel = class extends UI.PanelWithSidebar {
     resourceTreeModel.addEventListener(SDK.ResourceTreeModel.Events.CachedResourcesLoaded, this._initialize, this);
     resourceTreeModel.addEventListener(
         SDK.ResourceTreeModel.Events.WillLoadCachedResources, this._resetWithFrames, this);
+
+    this._manifestTreeElement._startTracking(target);

[pfeldman, 2017/02/07 00:25:35]

We only show manifest for the main target, see below.

[eostroukhov, 2017/02/07 01:40:38]

Acknowledged.

   }
 
   /**
@@ -169,7 +171,7 @@ Resources.ResourcesPanel = class extends UI.PanelWithSidebar {
     if (target !== this._target)
       return;
     delete this._target;
-
+    this._manifestTreeElement._stopTracking(target);
     var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(target);
     if (resourceTreeModel) {
       resourceTreeModel.removeEventListener(SDK.ResourceTreeModel.Events.CachedResourcesLoaded, this._initialize, this);
@@ -640,6 +642,9 @@ Resources.ResourcesPanel = class extends UI.PanelWithSidebar {
     this._innerShowView(this._categoryView);
   }
 
+  /**
+   * @param {!UI.Widget} view
+   */
   _innerShowView(view) {
     if (this.visibleView === view)
       return;
@@ -1428,15 +1433,24 @@ Resources.ServiceWorkersTreeElement = class extends Resources.BaseStorageTreeEle
   }
 };
 
-/**
- * @unrestricted
- */
 Resources.AppManifestTreeElement = class extends Resources.BaseStorageTreeElement {
   /**
    * @param {!Resources.ResourcesPanel} storagePanel
    */
   constructor(storagePanel) {
     super(storagePanel, Common.UIString('Manifest'), false);
+    /** @type {?Resources.AppManifestView} */
+    this._view = null;
+    /** @type {?SDK.ResourceTreeModel} */
+    this._resourceTreeModel = null;
+    /** @type {string} */
+    this._manifestUrl = '';
+    /** @type {?string} */
+    this._manifestData = null;
+    /** @type {!Array<!Protocol.Page.AppManifestError>} */
+    this._manifestFetchErrors = [];
+    this.selectable = false;
+
     var icon = UI.Icon.create('mediumicon-manifest', 'resource-tree-item');
     this.setLeadingIcons([icon]);
   }
@@ -1450,15 +1464,76 @@ Resources.AppManifestTreeElement = class extends Resources.BaseStorageTreeElemen
 
   /**
    * @override
+   * @param {boolean=} selectedByUser
    * @return {boolean}
    */
   onselect(selectedByUser) {
+    if (!this.selectable)
+      return false;
     super.onselect(selectedByUser);
-    if (!this._view)
+    if (!this._view) {
       this._view = new Resources.AppManifestView();
+      this._view.renderManifest(this._manifestUrl, this._manifestData, this._manifestFetchErrors);
+    }
     this._storagePanel._innerShowView(this._view);
     return false;
   }
+
+  /**
+   * @param {!SDK.Target} target
+   */
+  _startTracking(target) {
+    if (this._resourceTreeModel)
+      return;
+    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(target);
+    if (!resourceTreeModel)
+      return;
+    this._resourceTreeModel = resourceTreeModel;
+    this._updateManifest();
+    resourceTreeModel.addEventListener(SDK.ResourceTreeModel.Events.MainFrameNavigated, this._updateManifest, this);

[pfeldman, 2017/02/07 00:25:35]

You should instead set this listener on the targetManager.

[eostroukhov, 2017/02/07 01:40:38]

Done. Thanks for reminding me!

+  }
+
+  /**
+   * @param {!SDK.Target} target
+   */
+  _stopTracking(target) {
+    var resourceTreeModel = SDK.ResourceTreeModel.fromTarget(target);
+    if (!this._resourceTreeModel || this._resourceTreeModel !== resourceTreeModel)
+      return;
+    resourceTreeModel.removeEventListener(SDK.ResourceTreeModel.Events.MainFrameNavigated, this._updateManifest, this);
+    delete this._resourceTreeModel;
+    this._onManifestFetched('', null, []);
+  }
+
+  _updateManifest() {
+    this._resourceTreeModel.fetchAppManifest(this._onManifestFetched.bind(this));
+  }
+
+  /**
+   * @param {string} url
+   * @param {?string} data
+   * @param {!Array<!Protocol.Page.AppManifestError>} errors
+   */
+  _onManifestFetched(url, data, errors) {
+    this._manifestUrl = url;
+    this._manifestData = data;
+    this._manifestFetchErrors = errors;
+
+    this._setEnabled(!!data || !!errors.length);
+
+    if (this._view)
+      this._view.renderManifest(url, data, errors);
+  }
+
+  /**
+   * @param {boolean} enabled
+   */
+  _setEnabled(enabled) {
+    this.selectable = enabled;
+    this.listItemElement.classList.toggle('resource-sidebar-item-disabled', !enabled);
+    if (!enabled && this._storagePanel.visibleView === this._view)
+      this._storagePanel.closeVisibleView();

[pfeldman, 2017/02/07 00:25:35]

You might end up resetting the view upon navigation through redirect, etc.

[eostroukhov, 2017/02/07 01:40:38]

I think it is ok to let the user see "broken" panel in some rare cases. I
changed the code.

+  }
 };
 
 /**