Bug 1521440: Avoid to move to about:blank after destroying. r=ochameau,jdescottes

Differential Revision: https://phabricator.services.mozilla.com/D17795

--HG--
extra : moz-landing-system : lando

devtools/client/framework/toolbox-host-manager.js

@@ -104,6 +104,7 @@ ToolboxHostManager.prototype = {
         this.hostType === Toolbox.HostType.RIGHT) {
       this.host.frame.minWidth = WIDTH_CHEVRON_AND_MEATBALL_AND_CLOSE * zoomValue;
     } else if (this.hostType === Toolbox.HostType.WINDOW ||
+               this.hostType === Toolbox.HostType.PAGE ||
                this.hostType === Toolbox.HostType.CUSTOM) {
       this.host.frame.minWidth = WIDTH_CHEVRON_AND_MEATBALL * zoomValue;
     }
@@ -215,7 +216,8 @@ ToolboxHostManager.prototype = {
 
     this.destroyHost();
 
-    if (this.hostType != Toolbox.HostType.CUSTOM) {
+    if (this.hostType !== Toolbox.HostType.CUSTOM &&
+        this.hostType !== Toolbox.HostType.PAGE) {
       Services.prefs.setCharPref(PREVIOUS_HOST, this.hostType);
     }
 
@@ -227,7 +229,8 @@ ToolboxHostManager.prototype = {
 
     this.setMinWidthWithZoom();
 
-    if (hostType != Toolbox.HostType.CUSTOM) {
+    if (hostType !== Toolbox.HostType.CUSTOM &&
+        hostType !== Toolbox.HostType.PAGE) {
       Services.prefs.setCharPref(LAST_HOST, hostType);
     }
 

devtools/client/framework/toolbox-hosts.js

@@ -370,6 +370,35 @@ CustomHost.prototype = {
   },
 };
 
+/**
+ * Host object for the toolbox as a page.
+ * This is typically used by `about:debugging`, when opening toolbox in a new tab,
+ * via `about:devtools-toolbox` URLs.
+ * The `iframe` ends up being the tab's browser element.
+ */
+function PageHost(hostTab, options) {
+  this.frame = options.customIframe;
+}
+
+PageHost.prototype = {
+  type: "page",
+
+  create: function() {
+    return promise.resolve(this.frame);
+  },
+
+  // Do nothing.
+  raise: function() {},
+
+  // Do nothing.
+  setTitle: function(title) {},
+
+  // Do nothing.
+  destroy: function() {
+    return promise.resolve(null);
+  },
+};
+
 /**
  *  Switch to the given tab in a browser and focus the browser window
  */
@@ -385,5 +414,5 @@ exports.Hosts = {
   "right": RightHost,
   "window": WindowHost,
   "custom": CustomHost,
+  "page": PageHost,
 };
-

devtools/client/framework/toolbox-init.js

@@ -77,7 +77,7 @@ if (url.search.length > 1) {
       target = await targetFromURL(url);
     }
     const options = { customIframe: host };
-    await gDevTools.showToolbox(target, tool, Toolbox.HostType.CUSTOM, options);
+    await gDevTools.showToolbox(target, tool, Toolbox.HostType.PAGE, options);
   })().catch(error => {
     console.error("Exception while loading the toolbox", error);
   });

devtools/client/framework/toolbox.js

@@ -220,6 +220,9 @@ Toolbox.HostType = {
   LEFT: "left",
   WINDOW: "window",
   CUSTOM: "custom",
+  // This is typically used by `about:debugging`, when opening toolbox in a new tab,
+  // via `about:devtools-toolbox` URLs.
+  PAGE: "page",
 };
 
 Toolbox.prototype = {
@@ -435,7 +438,9 @@ Toolbox.prototype = {
       if (isToolboxURL) {
         // Update the URL so that onceDOMReady watch for the right url.
         this._URL = this.win.location.href;
+      }
 
+      if (this.hostType === Toolbox.HostType.PAGE) {
         // Displays DebugTargetInfo which shows the basic information of debug target,
         // if `about:devtools-toolbox` URL opens directly.
         // DebugTargetInfo requires this._deviceDescription to be populated
@@ -727,6 +732,7 @@ Toolbox.prototype = {
       case Toolbox.HostType.WINDOW: return 2;
       case Toolbox.HostType.CUSTOM: return 3;
       case Toolbox.HostType.LEFT: return 4;
+      case Toolbox.HostType.PAGE: return 5;
       default: return 9;
     }
   },
@@ -738,6 +744,7 @@ Toolbox.prototype = {
       case Toolbox.HostType.LEFT: return "left";
       case Toolbox.HostType.RIGHT: return "right";
       case Toolbox.HostType.WINDOW: return "window";
+      case Toolbox.HostType.PAGE: return "page";
       case Toolbox.HostType.CUSTOM: return "other";
       default: return "bottom";
     }
@@ -1105,6 +1112,7 @@ Toolbox.prototype = {
     for (const type in Toolbox.HostType) {
       const position = Toolbox.HostType[type];
       if (position == Toolbox.HostType.CUSTOM ||
+          position == Toolbox.HostType.PAGE ||
           (!sideEnabled &&
             (position == Toolbox.HostType.LEFT || position == Toolbox.HostType.RIGHT))) {
         continue;
@@ -2981,7 +2989,13 @@ Toolbox.prototype = {
           // target attribute to be still
           // defined.
           try {
+            // If this toolbox displayed as a page, avoid to move to `about:blank`.
+            // For example in case of reloading, when the thread of processing of
+            // destroying the toolbox arrives at here after starting reloading process,
+            // although we should display same page, `about:blank` will display.
+            if (this.hostType !== Toolbox.HostType.PAGE) {
               win.location.replace("about:blank");
+            }
           } catch (e) {
             // Do nothing;
           }

toolkit/components/telemetry/Events.yaml

@@ -281,7 +281,7 @@ devtools.main:
     release_channel_collection: opt-out
     expiry_version: never
     extra_keys:
-      host: "Toolbox host (positioning): bottom, side, window or other."
+      host: "Toolbox host (positioning): bottom, left, right, window, page or other."
       width: Toolbox width rounded up to the nearest 50px.
       session_id: The start time of the session in milliseconds since epoch (Unix Timestamp) e.g. 1396381378123.
   add_breakpoint:

toolkit/components/telemetry/Histograms.json

@@ -10493,7 +10493,7 @@
     "bug_numbers": [1205845, 1389995],
     "n_values": 9,
     "releaseChannelCollection": "opt-out",
-    "description": "Records DevTools toolbox host each time the toolbox is opened and when the host is changed (0:Bottom, 1:Side, 2:Window, 3:Custom, 9:Unknown)."
+    "description": "Records DevTools toolbox host each time the toolbox is opened and when the host is changed (0:Bottom, 1:RIGHT, 2:WINDOW, 3:CUSTOM, 4:LEFT, 5:PAGE, 9:Unknown)."
   },
   "DEVTOOLS_NUMBER_OF_CSS_GRIDS_IN_A_PAGE": {
     "record_in_processes": ["main", "content"],