Change interface for cast system gesture handling.

New interface (with default stub implementations) with the following:

  * Pass the event location rather than the underlying event (so that
    touch events or other data sources can be used instead of gesture events)
  * Method to query the handler whether it can handle a given event origin
    so we can avoid detecting (or blocking) margin events unnecessarily.
  * Adds a method for continuation/drag events.

Bug: internal b/78462154
Bug: internal b/78461207
Change-Id: I1bba715e98b6458bf079cacd71b4ef3403ae7260
Tested: manual test
Reviewed-on: https://chromium-review.googlesource.com/1028656
Commit-Queue: Ryan Daum <rdaum@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Alex Sakhartchouk <alexst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553767}

chromecast/browser/cast_content_window_aura.cc

@@ -138,5 +138,18 @@ void CastContentWindowAura::OnSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
   }
 }
 
+bool CastContentWindowAura::CanHandleSwipe(CastSideSwipeOrigin swipe_origin) {
+  return swipe_origin == CastSideSwipeOrigin::LEFT &&
+         delegate_->CanHandleGesture(GestureType::GO_BACK);
+}
+
+void CastContentWindowAura::HandleSideSwipeBegin(
+    CastSideSwipeOrigin swipe_origin,
+    const gfx::Point& touch_location) {
+  if (swipe_origin == CastSideSwipeOrigin::LEFT) {
+    delegate_->ConsumeGesture(GestureType::GO_BACK);
+  }
+}
+
 }  // namespace shell
 }  // namespace chromecast

chromecast/browser/cast_content_window_aura.h

@@ -40,6 +40,10 @@ class CastContentWindowAura : public CastContentWindow,
   void OnSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
                       ui::GestureEvent* gesture_event) override;
 
+  bool CanHandleSwipe(CastSideSwipeOrigin swipe_origin) override;
+  void HandleSideSwipeBegin(CastSideSwipeOrigin swipe_origin,
+                            const gfx::Point& touch_location) override;
+
  private:
   friend class CastContentWindow;
 

chromecast/graphics/BUILD.gn

@@ -20,6 +20,7 @@ cast_source_set("graphics") {
     sources += [
       "cast_focus_client_aura.cc",
       "cast_focus_client_aura.h",
+      "cast_side_swipe_gesture_handler.cc",
       "cast_side_swipe_gesture_handler.h",
       "cast_system_gesture_event_handler.cc",
       "cast_system_gesture_event_handler.h",

chromecast/graphics/cast_side_swipe_gesture_handler.cc

+// Copyright 2018 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.
+
+#include "chromecast/graphics/cast_side_swipe_gesture_handler.h"
+
+namespace chromecast {
+
+bool CastSideSwipeGestureHandlerInterface::CanHandleSwipe(
+    CastSideSwipeOrigin swipe_origin) {
+  return false;
+}
+
+}  // namespace chromecast

chromecast/graphics/cast_side_swipe_gesture_handler.h

@@ -11,6 +11,10 @@ namespace ui {
 class GestureEvent;
 }  // namespace ui
 
+namespace gfx {
+class Point;
+}  // namespace gfx
+
 namespace chromecast {
 
 enum class CastSideSwipeOrigin { TOP, BOTTOM, LEFT, RIGHT, NONE };
@@ -22,15 +26,33 @@ class CastSideSwipeGestureHandlerInterface {
   CastSideSwipeGestureHandlerInterface() = default;
   virtual ~CastSideSwipeGestureHandlerInterface() = default;
 
+  // Return true if this handler can handle swipes from the given origin.
+  virtual bool CanHandleSwipe(CastSideSwipeOrigin swipe_origin);
+
+  // Triggered on the beginning of a swipe from edge.
+  virtual void HandleSideSwipeBegin(CastSideSwipeOrigin swipe_origin,
+                                    const gfx::Point& touch_location) {}
+
+  // Triggered on the continuance (finger drag) of a swipe from edge.
+  virtual void HandleSideSwipeContinue(CastSideSwipeOrigin swipe_origin,
+                                       const gfx::Point& touch_location) {}
+
+  // Triggered on the completion (finger up) of a swipe from edge.
+  virtual void HandleSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
+                                  const gfx::Point& touch_location) {}
+
+  // TODO(rdaum): DEPRECATED below, delete after all downstream users are
+  // migrated to the new implementations above.
+
   // Triggered on the beginning of a swipe.
   // Note: Consumers of the event should call SetHandled on it to prevent its
   // further propagation.
   virtual void OnSideSwipeBegin(CastSideSwipeOrigin swipe_origin,
-                                ui::GestureEvent* gesture_event) = 0;
+                                ui::GestureEvent* gesture_event) {}
 
   // Triggered on the completion (finger up) of a swipe.
   virtual void OnSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
-                              ui::GestureEvent* gesture_event) = 0;
+                              ui::GestureEvent* gesture_event) {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CastSideSwipeGestureHandlerInterface);