Reland "splitview: Grab app for splitscreen only happen on long press."

This is a reland of b9d68c49
Left the previously disabled test disabled in the reland. Will fix in a
seperate cl.

TBR=oshima@chromium.org

Original change's description:
> splitview: Grab app for splitscreen only happen on long press.
>
> The indicators and the item enlarging only happen after long press, or
> if the item has been dragged.
>
> This is preparation for fling to dismiss. It also removes a flicker of
> the indidcators when you tap to open a item.
>
> Also renables a previous flaky test. Tested locally and it is not flaky
> no more.
>
> Test: ash_unittests SplitViewWindowSelectorTest.*
> Bug: 817863
> Change-Id: I9c20f2fa9a3c0a9218b3072c5b3d25711ad9c655
> Reviewed-on: https://chromium-review.googlesource.com/996528
> Commit-Queue: Sammie Quon <sammiequon@chromium.org>
> Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
> Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#550884}

Bug: 817863
Change-Id: I0d6b255a89e69443af2e6509a0769622c8f64fb3
Reviewed-on: https://chromium-review.googlesource.com/1012735Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551036}

ash/wm/overview/overview_window_drag_controller.cc

@@ -14,12 +14,19 @@
 #include "ash/wm/splitview/split_view_constants.h"
 #include "ash/wm/splitview/split_view_drag_indicators.h"
 #include "ash/wm/window_positioning_utils.h"
-#include "ash/wm/wm_event.h"
 #include "ui/aura/window.h"
 #include "ui/wm/core/coordinate_conversion.h"
 
 namespace ash {
 
+namespace {
+
+// Before dragging an overview window, the window will scale up |kPreDragScale|
+// to indicate its selection.
+constexpr float kDragWindowScale = 0.04f;
+
+}  // namespace
+
 OverviewWindowDragController::OverviewWindowDragController(
     WindowSelector* window_selector)
     : window_selector_(window_selector),
@@ -39,12 +46,6 @@ void OverviewWindowDragController::InitiateDrag(
       GetSnapPosition(location_in_screen) == SplitViewController::NONE
           ? base::nullopt
           : base::make_optional(location_in_screen);
-
-  window_selector_->SetSplitViewDragIndicatorsIndicatorState(
-      split_view_controller_->CanSnap(item->GetWindow())
-          ? IndicatorState::kDragArea
-          : IndicatorState::kCannotSnap,
-      location_in_screen);
 }
 
 void OverviewWindowDragController::Drag(const gfx::Point& location_in_screen) {
@@ -56,8 +57,8 @@ void OverviewWindowDragController::Drag(const gfx::Point& location_in_screen) {
         std::abs(distance.y()) < kMinimumDragOffset) {
       return;
     }
+    StartSplitViewDragMode(location_in_screen);
   }
-  did_move_ = true;
 
   // Update the dragged |item_|'s bounds accordingly.
   gfx::Rect bounds(item_->target_bounds());
@@ -94,6 +95,23 @@ void OverviewWindowDragController::CompleteDrag(
   item_ = nullptr;
 }
 
+void OverviewWindowDragController::StartSplitViewDragMode(
+    const gfx::Point& location_in_screen) {
+  // Increase the bounds of the dragged item.
+  gfx::Rect scaled_bounds(item_->target_bounds());
+  scaled_bounds.Inset(-scaled_bounds.width() * kDragWindowScale,
+                      -scaled_bounds.height() * kDragWindowScale);
+  item_->SetBounds(scaled_bounds,
+                   OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
+
+  did_move_ = true;
+  window_selector_->SetSplitViewDragIndicatorsIndicatorState(
+      split_view_controller_->CanSnap(item_->GetWindow())
+          ? IndicatorState::kDragArea
+          : IndicatorState::kCannotSnap,
+      location_in_screen);
+}
+
 void OverviewWindowDragController::ActivateDraggedWindow() {
   // If no drag was initiated (e.g., a click/tap on the overview window),
   // activate the window. If the split view is active and has a left window,

ash/wm/overview/overview_window_drag_controller.h

@@ -38,6 +38,7 @@ class ASH_EXPORT OverviewWindowDragController {
                     const gfx::Point& location_in_screen);
   void Drag(const gfx::Point& location_in_screen);
   void CompleteDrag(const gfx::Point& location_in_screen);
+  void StartSplitViewDragMode(const gfx::Point& location_in_screen);
   void ActivateDraggedWindow();
   void ResetGesture();
 

ash/wm/overview/window_selector.cc

@@ -617,14 +617,14 @@ void WindowSelector::InitiateDrag(WindowSelectorItem* item,
 
 void WindowSelector::Drag(WindowSelectorItem* item,
                           const gfx::Point& location_in_screen) {
-  DCHECK(window_drag_controller_.get());
+  DCHECK(window_drag_controller_);
   DCHECK_EQ(item, window_drag_controller_->item());
   window_drag_controller_->Drag(location_in_screen);
 }
 
 void WindowSelector::CompleteDrag(WindowSelectorItem* item,
                                   const gfx::Point& location_in_screen) {
-  DCHECK(window_drag_controller_.get());
+  DCHECK(window_drag_controller_);
   DCHECK_EQ(item, window_drag_controller_->item());
   window_drag_controller_->CompleteDrag(location_in_screen);
 
@@ -632,13 +632,16 @@ void WindowSelector::CompleteDrag(WindowSelectorItem* item,
     grid->OnSelectorItemDragEnded();
 }
 
+void WindowSelector::StartSplitViewDragMode(
+    const gfx::Point& location_in_screen) {
+  window_drag_controller_->StartSplitViewDragMode(location_in_screen);
+}
+
 void WindowSelector::ActivateDraggedWindow() {
-  DCHECK(window_drag_controller_.get());
   window_drag_controller_->ActivateDraggedWindow();
 }
 
 void WindowSelector::ResetDraggedWindowGesture() {
-  DCHECK(window_drag_controller_.get());
   window_drag_controller_->ResetGesture();
 }
 

ash/wm/overview/window_selector.h

@@ -120,6 +120,7 @@ class ASH_EXPORT WindowSelector : public display::DisplayObserver,
   void Drag(WindowSelectorItem* item, const gfx::Point& location_in_screen);
   void CompleteDrag(WindowSelectorItem* item,
                     const gfx::Point& location_in_screen);
+  void StartSplitViewDragMode(const gfx::Point& location_in_screen);
   void ActivateDraggedWindow();
   void ResetDraggedWindowGesture();
 

ash/wm/overview/window_selector_item.cc

@@ -118,10 +118,6 @@ constexpr int kDragAnimationMs = 167;
 // this fraction of size.
 constexpr float kPreCloseScale = 0.02f;
 
-// Before dragging an overview window, the window will scale up |kPreDragScale|
-// to indicate its selection.
-constexpr float kDragWindowScale = 0.04f;
-
 // The size in dp of the window icon shown on the overview window next to the
 // title.
 constexpr gfx::Size kIconSize = gfx::Size(24, 24);
@@ -255,6 +251,9 @@ class ShieldButton : public views::Button {
         case ui::ET_GESTURE_SCROLL_END:
           listener()->HandleReleaseEvent(location);
           break;
+        case ui::ET_GESTURE_LONG_PRESS:
+          listener()->HandleLongPressEvent(location);
+          break;
         case ui::ET_GESTURE_TAP:
           listener()->ActivateDraggedWindow();
           break;
@@ -997,6 +996,11 @@ void WindowSelectorItem::HandleDragEvent(const gfx::Point& location_in_screen) {
   window_selector_->Drag(this, location_in_screen);
 }
 
+void WindowSelectorItem::HandleLongPressEvent(
+    const gfx::Point& location_in_screen) {
+  window_selector_->StartSplitViewDragMode(location_in_screen);
+}
+
 void WindowSelectorItem::ActivateDraggedWindow() {
   if (!IsDragItem())
     return;
@@ -1393,13 +1397,6 @@ void WindowSelectorItem::StartDrag() {
   // window is pressed while still animating.
   transform_window_.CancelAnimationsListener();
 
-  gfx::Rect scaled_bounds(target_bounds_);
-  scaled_bounds.Inset(-target_bounds_.width() * kDragWindowScale,
-                      -target_bounds_.height() * kDragWindowScale);
-  OverviewAnimationType animation_type =
-      OverviewAnimationType::OVERVIEW_ANIMATION_NONE;
-  SetBounds(scaled_bounds, animation_type);
-
   aura::Window* widget_window = item_widget_->GetNativeWindow();
   aura::Window* window = GetWindowForStacking();
   if (widget_window && widget_window->parent() == window->parent()) {

ash/wm/overview/window_selector_item.h

@@ -182,6 +182,7 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   void HandlePressEvent(const gfx::Point& location_in_screen);
   void HandleReleaseEvent(const gfx::Point& location_in_screen);
   void HandleDragEvent(const gfx::Point& location_in_screen);
+  void HandleLongPressEvent(const gfx::Point& location_in_screen);
   void ActivateDraggedWindow();
   void ResetDraggedWindowGesture();
 

ash/wm/overview/window_selector_unittest.cc

@@ -2960,6 +2960,7 @@ TEST_F(WindowSelectorTest, DISABLED_DraggingWithTwoFingers) {
   // Dragging is only allowed in tablet mode.
   RunAllPendingInMessageLoop();
   Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+  RunAllPendingInMessageLoop();
 
   ToggleOverview();
   RunAllPendingInMessageLoop();
@@ -2972,11 +2973,21 @@ TEST_F(WindowSelectorTest, DISABLED_DraggingWithTwoFingers) {
   constexpr int kTouchId1 = 1;
   constexpr int kTouchId2 = 2;
 
+  // Dispatches a long press event at the event generators current location.
+  // Long press is one way to start dragging in splitview.
+  auto dispatch_long_press = [this]() {
+    ui::TouchEvent long_press(
+        ui::ET_GESTURE_LONG_PRESS, GetEventGenerator().current_location(),
+        base::TimeTicks::Now(),
+        ui::PointerDetails(ui::EventPointerType::POINTER_TYPE_TOUCH));
+    GetEventGenerator().Dispatch(&long_press);
+  };
+
   // Verify that the bounds of the tapped window expand when touched.
   ui::test::EventGenerator& generator = GetEventGenerator();
   generator.set_current_location(original_bounds1.CenterPoint());
   generator.PressTouchId(kTouchId1);
-  RunAllPendingInMessageLoop();
+  dispatch_long_press();
   EXPECT_GT(item1->target_bounds().width(), original_bounds1.width());
   EXPECT_GT(item1->target_bounds().height(), original_bounds1.height());
 
@@ -2985,7 +2996,7 @@ TEST_F(WindowSelectorTest, DISABLED_DraggingWithTwoFingers) {
   // dragged.
   generator.set_current_location(original_bounds2.CenterPoint());
   generator.PressTouchId(kTouchId2);
-  RunAllPendingInMessageLoop();
+  dispatch_long_press();
   EXPECT_GT(item1->target_bounds().width(), original_bounds1.width());
   EXPECT_GT(item1->target_bounds().height(), original_bounds1.height());
   EXPECT_EQ(item2->target_bounds(), original_bounds2);
@@ -3002,8 +3013,8 @@ TEST_F(WindowSelectorTest, DISABLED_DraggingWithTwoFingers) {
   last_center_point = item1->target_bounds().CenterPoint();
   generator.ReleaseTouchId(kTouchId2);
   generator.PressTouchId(kTouchId2);
+  dispatch_long_press();
   generator.MoveTouchIdBy(kTouchId2, 40, 40);
-  RunAllPendingInMessageLoop();
   EXPECT_NE(last_center_point, item1->target_bounds().CenterPoint());
   EXPECT_EQ(original_bounds2.CenterPoint(),
             item2->target_bounds().CenterPoint());
@@ -3546,15 +3557,24 @@ TEST_F(SplitViewWindowSelectorTest, SplitViewDragIndicatorsState) {
       screen_util::GetDisplayWorkAreaBoundsInParent(window1.get()).width();
   const int edge_inset = GetEdgeInset(screen_width);
 
-  // Verify that when are no snapped windows, the indicator is visible when a
-  // drag is initiated and the left preview area appears when the drag reaches
-  // |edge_inset| from the edge of the screen.
+  // Verify that when are no snapped windows, the indicator is visible once
+  // there is a long press or after the drag has started.
   const int grid_index = 0;
   WindowSelectorItem* selector_item =
       GetWindowItemForWindow(grid_index, window1.get());
   gfx::Point start_location(selector_item->target_bounds().CenterPoint());
   window_selector()->InitiateDrag(selector_item, start_location);
+  EXPECT_EQ(IndicatorState::kNone, indicator_state());
+  window_selector()->StartSplitViewDragMode(start_location);
   EXPECT_EQ(IndicatorState::kDragArea, indicator_state());
+
+  // Reset the gesture so we stay in overview mode.
+  window_selector()->ResetDraggedWindowGesture();
+
+  // Verify the indicator is visible once the item starts moving, and becomes a
+  // preview area once we reach the left edge of the screen.
+  window_selector()->InitiateDrag(selector_item, start_location);
+  EXPECT_EQ(IndicatorState::kNone, indicator_state());
   window_selector()->Drag(selector_item, gfx::Point(edge_inset + 1, 0));
   EXPECT_EQ(IndicatorState::kDragArea, indicator_state());
   window_selector()->Drag(selector_item, gfx::Point(edge_inset, 0));
@@ -3571,7 +3591,7 @@ TEST_F(SplitViewWindowSelectorTest, SplitViewDragIndicatorsState) {
   selector_item = GetWindowItemForWindow(grid_index, window2.get());
   start_location = selector_item->target_bounds().CenterPoint();
   window_selector()->InitiateDrag(selector_item, start_location);
-  EXPECT_EQ(IndicatorState::kDragArea, indicator_state());
+  EXPECT_EQ(IndicatorState::kNone, indicator_state());
   window_selector()->Drag(selector_item, gfx::Point(screen_width - 1, 0));
   EXPECT_EQ(IndicatorState::kPreviewAreaRight, indicator_state());
   window_selector()->CompleteDrag(selector_item, start_location);
@@ -3591,6 +3611,7 @@ TEST_F(SplitViewWindowSelectorTest,
       GetWindowItemForWindow(grid_index, unsnappable_window.get());
   gfx::Point start_location(selector_item->target_bounds().CenterPoint());
   window_selector()->InitiateDrag(selector_item, start_location);
+  window_selector()->StartSplitViewDragMode(start_location);
   EXPECT_EQ(IndicatorState::kCannotSnap, indicator_state());
   const gfx::Point end_location1(0, 0);
   window_selector()->Drag(selector_item, end_location1);
@@ -3672,6 +3693,7 @@ TEST_F(SplitViewWindowSelectorTest, SplitViewDragIndicatorsWidgetReparenting) {
       GetWindowItemForWindow(0, primary_screen_window.get());
   gfx::Point start_location(selector_item->target_bounds().CenterPoint());
   window_selector()->InitiateDrag(selector_item, start_location);
+  window_selector()->Drag(selector_item, gfx::Point(100, 100));
   EXPECT_EQ(IndicatorState::kDragArea, indicator_state());
   EXPECT_EQ(root_windows[0], window_selector()
                                  ->split_view_drag_indicators()
@@ -3690,6 +3712,7 @@ TEST_F(SplitViewWindowSelectorTest, SplitViewDragIndicatorsWidgetReparenting) {
   selector_item = GetWindowItemForWindow(1, secondary_screen_window.get());
   start_location = gfx::Point(selector_item->target_bounds().CenterPoint());
   window_selector()->InitiateDrag(selector_item, start_location);
+  window_selector()->Drag(selector_item, gfx::Point(800, 200));
   EXPECT_EQ(IndicatorState::kDragArea, indicator_state());
   EXPECT_EQ(root_windows[1], window_selector()
                                  ->split_view_drag_indicators()