Mash: Handle events on browser frame.

This re-implements functionality Ash would normally provide via
WorkspaceEventHandler (double click/tap on frame for maximize) and
WmToplevelWindowEventHandler (drag).

Dragging by gesture is a TODO, and may be more complicated. (It doesn't
work for tab-initiated drags either.)

Change-Id: Ie9eff39915dd6ea68dcc69ac9b46d6edda78f23f
Reviewed-on: https://chromium-review.googlesource.com/1246417Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595828}

ash/public/interfaces/ash_window_manager.mojom

@@ -4,6 +4,8 @@
 
 module ash.mojom;
 
+import "ui/events/mojo/event_constants.mojom";
+
 // The previewed snap state for a window, corresponding to the use of a
 // PhantomWindowController.
 enum SnapDirection {
@@ -21,4 +23,8 @@ interface AshWindowManager {
   ShowSnapPreview(uint64 window_id, SnapDirection snap);
 
   CommitSnap(uint64 window_id, SnapDirection snap);
+
+  // Maximizes the window in response to a double click or tap on the HTCAPTION
+  // area.
+  MaximizeWindowByCaptionClick(uint64 window_id, ui.mojom.PointerKind pointer);
 };

ash/ws/ash_window_manager.cc

@@ -6,7 +6,10 @@
 
 #include "ash/shell.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "ash/wm/window_state.h"
+#include "ash/wm/wm_event.h"
 #include "base/logging.h"
+#include "base/metrics/user_metrics.h"
 #include "services/ws/window_tree.h"
 
 namespace ash {
@@ -49,4 +52,28 @@ void AshWindowManager::CommitSnap(ws::Id window_id, mojom::SnapDirection snap) {
   }
 }
 
+void AshWindowManager::MaximizeWindowByCaptionClick(
+    ws::Id window_id,
+    ui::mojom::PointerKind pointer) {
+  aura::Window* window = window_tree_->GetWindowByTransportId(window_id);
+  if (!window || !window_tree_->IsTopLevel(window)) {
+    DVLOG(1) << "MaximizeWindowByCaptionClick passed invalid window, id="
+             << window_id;
+    return;
+  }
+
+  if (pointer == ui::mojom::PointerKind::MOUSE) {
+    base::RecordAction(base::UserMetricsAction("Caption_ClickTogglesMaximize"));
+  } else if (pointer == ui::mojom::PointerKind::TOUCH) {
+    base::RecordAction(
+        base::UserMetricsAction("Caption_GestureTogglesMaximize"));
+  } else {
+    DVLOG(1) << "MaximizeWindowByCaptionClick passed invalid event";
+    return;
+  }
+
+  const wm::WMEvent wm_event(wm::WM_EVENT_TOGGLE_MAXIMIZE_CAPTION);
+  wm::GetWindowState(window)->OnWMEvent(&wm_event);
+}
+
 }  // namespace ash

ash/ws/ash_window_manager.h

@@ -33,6 +33,8 @@ class AshWindowManager : public mojom::AshWindowManager,
   void AddWindowToTabletMode(ws::Id window_id) override;
   void ShowSnapPreview(ws::Id window_id, mojom::SnapDirection snap) override;
   void CommitSnap(ws::Id window_id, mojom::SnapDirection snap) override;
+  void MaximizeWindowByCaptionClick(ws::Id window_id,
+                                    ui::mojom::PointerKind pointer) override;
 
  private:
   ws::WindowTree* window_tree_;

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.cc

@@ -55,6 +55,7 @@
 #include "ui/base/layout.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/ui_base_features.h"
+#include "ui/display/screen.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/scoped_canvas.h"
@@ -471,6 +472,80 @@ void BrowserNonClientFrameViewAsh::ChildPreferredSizeChanged(
   }
 }
 
+bool BrowserNonClientFrameViewAsh::OnMousePressed(const ui::MouseEvent& event) {
+  if (!features::IsUsingWindowService())
+    return false;
+
+  if (event.IsOnlyLeftMouseButton()) {
+    if (event.flags() & ui::EF_IS_DOUBLE_CLICK) {
+      ash_window_manager_->MaximizeWindowByCaptionClick(
+          GetServerWindowId(), ui::mojom::PointerKind::MOUSE);
+    }
+
+    // Return true for single clicks to receive subsequent drag events.
+    return true;
+  }
+
+  return false;
+}
+
+bool BrowserNonClientFrameViewAsh::OnMouseDragged(const ui::MouseEvent& event) {
+  if (!features::IsUsingWindowService())
+    return false;
+
+  // The client may receive multiple drag events before Ash has taken over the
+  // window move. In this case, ignore the extras.
+  if (performing_window_move_)
+    return true;
+
+  aura::WindowTreeHostMus* window_tree_host_mus =
+      static_cast<aura::WindowTreeHostMus*>(
+          GetWidget()->GetNativeWindow()->GetHost());
+  performing_window_move_ = true;
+  window_tree_host_mus->PerformWindowMove(
+      ws::mojom::MoveLoopSource::MOUSE,
+      display::Screen::GetScreen()->GetCursorScreenPoint(),
+      base::BindRepeating(&BrowserNonClientFrameViewAsh::OnWindowMoveDone,
+                          weak_ptr_factory_.GetWeakPtr()));
+  return true;
+}
+
+void BrowserNonClientFrameViewAsh::OnMouseReleased(
+    const ui::MouseEvent& event) {
+  // If a window move has already been triggered and OnMouseReleased() is
+  // called, it means the mouse was released before the Ash asserted mouse
+  // capture, and the move should be cancelled. Note that if something else
+  // grabs mouse capture right after PerformWindowMove(), Ash may re-assert that
+  // capture instead of cancelling the move.
+  if (performing_window_move_) {
+    aura::WindowTreeHostMus* window_tree_host_mus =
+        static_cast<aura::WindowTreeHostMus*>(
+            GetWidget()->GetNativeWindow()->GetHost());
+    window_tree_host_mus->CancelWindowMove();
+  }
+}
+
+void BrowserNonClientFrameViewAsh::OnGestureEvent(ui::GestureEvent* event) {
+  if (!features::IsUsingWindowService())
+    return;
+
+  switch (event->type()) {
+    case ui::ET_GESTURE_TAP:
+      if (event->details().tap_count() == 2) {
+        // TODO(estade): need to log TouchUMA for GESTURE_MAXIMIZE_DOUBLETAP and
+        // GESTURE_FRAMEVIEW_TAP, as in WorkspaceEventHandler.
+        ash_window_manager_->MaximizeWindowByCaptionClick(
+            GetServerWindowId(), ui::mojom::PointerKind::TOUCH);
+        event->StopPropagation();
+      }
+      break;
+
+    // TODO(estade): handle gestures that trigger drags.
+    default:
+      break;
+  }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // ash::BrowserFrameHeaderAsh::AppearanceProvider:
 
@@ -877,6 +952,10 @@ bool BrowserNonClientFrameViewAsh::IsInOverviewMode() const {
   return GetFrameWindow()->GetProperty(ash::kIsShowingInOverviewKey);
 }
 
+void BrowserNonClientFrameViewAsh::OnWindowMoveDone(bool success) {
+  performing_window_move_ = false;
+}
+
 const aura::Window* BrowserNonClientFrameViewAsh::GetFrameWindow() const {
   return const_cast<BrowserNonClientFrameViewAsh*>(this)->GetFrameWindow();
 }

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h

@@ -11,6 +11,7 @@
 #include "ash/public/interfaces/split_view.mojom.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/command_observer.h"
 #include "chrome/browser/ui/ash/tablet_mode_client_observer.h"
@@ -87,6 +88,10 @@ class BrowserNonClientFrameViewAsh
   gfx::Size GetMinimumSize() const override;
   void OnThemeChanged() override;
   void ChildPreferredSizeChanged(views::View* child) override;
+  bool OnMousePressed(const ui::MouseEvent& event) override;
+  bool OnMouseDragged(const ui::MouseEvent& event) override;
+  void OnMouseReleased(const ui::MouseEvent& event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
 
   // BrowserFrameHeaderAsh::AppearanceProvider:
   SkColor GetTitleColor() override;
@@ -216,6 +221,8 @@ class BrowserNonClientFrameViewAsh
   // Returns whether this window is currently in the overview list.
   bool IsInOverviewMode() const;
 
+  void OnWindowMoveDone(bool success);
+
   // Returns the top level aura::Window for this browser window.
   const aura::Window* GetFrameWindow() const;
   aura::Window* GetFrameWindow();
@@ -254,6 +261,8 @@ class BrowserNonClientFrameViewAsh
 
   ScopedObserver<aura::Window, aura::WindowObserver> window_observer_{this};
 
+  bool performing_window_move_ = false;
+
   // Maintains the current split view state.
   ash::mojom::SplitViewState split_view_state_ =
       ash::mojom::SplitViewState::NO_SNAP;
@@ -261,6 +270,8 @@ class BrowserNonClientFrameViewAsh
   // Only used in mash.
   ash::mojom::AshWindowManagerAssociatedPtr ash_window_manager_;
 
+  base::WeakPtrFactory<BrowserNonClientFrameViewAsh> weak_ptr_factory_{this};
+
   DISALLOW_COPY_AND_ASSIGN(BrowserNonClientFrameViewAsh);
 };