Bug 1409085 - Tell RDM when picking to stop simulating touch; r=mtigley,gl

Differential Revision: https://phabricator.services.mozilla.com/D25231

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

devtools/client/framework/toolbox.js

@@ -64,6 +64,8 @@ loader.lazyRequireGetter(this, "createEditContextMenu",
   "devtools/client/framework/toolbox-context-menu", true);
 loader.lazyRequireGetter(this, "remoteClientManager",
   "devtools/client/shared/remote-debugging/remote-client-manager.js", true);
+loader.lazyRequireGetter(this, "ResponsiveUIManager",
+  "devtools/client/responsive.html/manager", true);
 
 loader.lazyGetter(this, "domNodeConstants", () => {
   return require("devtools/shared/dom-node-constants");
@@ -1343,6 +1345,7 @@ Toolbox.prototype = {
   },
 
   _onPickerStarting: async function() {
+    this.tellRDMAboutPickerState(true);
     this.pickerButton.isChecked = true;
     await this.selectTool("inspector", "inspect_dom");
     this.on("select", this.inspector.nodePicker.stop);
@@ -1354,11 +1357,31 @@ Toolbox.prototype = {
   },
 
   _onPickerStopped: function() {
+    this.tellRDMAboutPickerState(false);
     this.off("select", this.inspector.nodePicker.stop);
     this.doc.removeEventListener("keypress", this._onPickerKeypress, true);
     this.pickerButton.isChecked = false;
   },
 
+  /**
+   * RDM sometimes simulates touch events. For this to work correctly at all times, it
+   * needs to know when the picker is active or not.
+   * This method communicates with the RDM Manager if it exists.
+   *
+   * @param {Boolean} state
+   */
+  tellRDMAboutPickerState: async function(state) {
+    const { tab } = this.target;
+
+    if (!ResponsiveUIManager.isActiveForTab(tab) ||
+        await !this.target.actorHasMethod("emulation", "setElementPickerState")) {
+      return;
+    }
+
+    const ui = ResponsiveUIManager.getResponsiveUIForTab(tab);
+    await ui.emulationFront.setElementPickerState(state);
+  },
+
   /**
    * When the picker is canceled, make sure the toolbox
    * gets the focus.

devtools/server/actors/emulation.js

@@ -177,6 +177,30 @@ const EmulationActor = protocol.ActorClassWithSpec(emulationSpec, {
 
   _previousTouchEventsOverride: undefined,
 
+  /**
+   * Set the current element picker state.
+   *
+   * True means the element picker is currently active and we should not be emulating
+   * touch events.
+   * False means the element picker is not active and it is ok to emulate touch events.
+   *
+   * This actor method is meant to be called by the DevTools front-end. The reason for
+   * this is the following:
+   * RDM is the only current consumer of the touch simulator. RDM instantiates this actor
+   * on its own, whether or not the Toolbox is opened. That means it does so in its own
+   * Debugger Server instance.
+   * When the Toolbox is running, it uses a different DebuggerServer. Therefore, it is not
+   * possible for the touch simulator to know whether the picker is active or not. This
+   * state has to be sent by the client code of the Toolbox to this actor.
+   * If a future use case arises where we want to use the touch simulator from the Toolbox
+   * too, then we could add code in here to detect the picker mode as described in
+   * https://bugzilla.mozilla.org/show_bug.cgi?id=1409085#c3
+   * @param {Boolean} state
+   */
+  setElementPickerState(state) {
+    this.touchSimulator.setElementPickerState(state);
+  },
+
   setTouchEventsOverride(flag) {
     if (this.getTouchEventsOverride() == flag) {
       return false;

devtools/server/actors/emulation/touch-simulator.js

@@ -73,7 +73,23 @@ TouchSimulator.prototype = {
     this.enabled = false;
   },
 
+  /**
+   * Set the current element picker state value.
+   * True means the element picker is currently active and we should not be emulating
+   * touch events.
+   * False means the element picker is not active and it is ok to emulate touch events.
+   * @param {Boolean} state
+   */
+  setElementPickerState(state) {
+    this._isPicking = state;
+  },
+
   handleEvent(evt) {
+    // Bail out if devtools is in pick mode in the same tab.
+    if (this._isPicking) {
+      return;
+    }
+
     // The gaia system window use an hybrid system even on the device which is
     // a mix of mouse/touch events. So let's not cancel *all* mouse events
     // if it is the current target.

devtools/shared/specs/emulation.js

@@ -123,6 +123,13 @@ const emulationSpec = generateActorSpec({
         valueChanged: RetVal("boolean"),
       },
     },
+
+    setElementPickerState: {
+      request: {
+        state: Arg(0, "boolean"),
+      },
+      response: {},
+    },
   },
 });