[ash-md] Adds support for gesture to move selection in overview mode

ash/wm/gestures/overview_gesture_handler_unittest.cc

Index: ash/wm/gestures/overview_gesture_handler_unittest.cc
diff --git a/ash/wm/gestures/overview_gesture_handler_unittest.cc b/ash/wm/gestures/overview_gesture_handler_unittest.cc
index bba37173b707c02e48fa75f01172a56895eecc61..90d2639bef07a651f2f08c1fcc2cb2e766364558 100644
--- a/ash/wm/gestures/overview_gesture_handler_unittest.cc
+++ b/ash/wm/gestures/overview_gesture_handler_unittest.cc
@@ -2,11 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "ash/wm/gestures/overview_gesture_handler.h"
+
 #include "ash/common/wm/overview/window_selector_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
+#include "ash/wm/window_util.h"
 #include "ui/aura/test/test_window_delegate.h"
 #include "ui/aura/test/test_windows.h"
 #include "ui/aura/window.h"
@@ -25,63 +28,119 @@ class OverviewGestureHandlerTest : public test::AshTestBase {
     return CreateTestWindowInShellWithDelegate(&delegate_, -1, bounds);
   }
 
+  void ToggleOverview() {
+    WmShell::Get()->window_selector_controller()->ToggleOverview();
+  }
+
   bool IsSelecting() {
     return WmShell::Get()->window_selector_controller()->IsSelecting();
   }
 
+  float vertical_threshold_pixels() const {
+    return OverviewGestureHandler::vertical_threshold_pixels_;
+  }
+
+  float horizontal_threshold_pixels() const {
+    return OverviewGestureHandler::horizontal_threshold_pixels_;
+  }
+
  private:
   aura::test::TestWindowDelegate delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(OverviewGestureHandlerTest);
 };
 
-// Tests a swipe up with three fingers to enter and a swipe down to exit
-// overview.
-TEST_F(OverviewGestureHandlerTest, VerticalSwipes) {
+// Tests a three fingers upwards scroll gesture to enter and a scroll down to
+// exit overview.
+TEST_F(OverviewGestureHandlerTest, VerticalScrolls) {
   gfx::Rect bounds(0, 0, 400, 400);
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   std::unique_ptr<aura::Window> window1(CreateWindow(bounds));
   std::unique_ptr<aura::Window> window2(CreateWindow(bounds));
   ui::test::EventGenerator generator(root_window, root_window);
+  const float long_scroll = 2 * vertical_threshold_pixels();
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           0, -500, 100, 3);
+                           0, -long_scroll, 100, 3);
   EXPECT_TRUE(IsSelecting());
 
   // Swiping up again does nothing.
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           0, -500, 100, 3);
+                           0, -long_scroll, 100, 3);
   EXPECT_TRUE(IsSelecting());
 
   // Swiping down exits.
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           0, 500, 100, 3);
+                           0, long_scroll, 100, 3);
   EXPECT_FALSE(IsSelecting());
 
   // Swiping down again does nothing.
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           0, 500, 100, 3);
+                           0, long_scroll, 100, 3);
+  EXPECT_FALSE(IsSelecting());
+}
+
+// Tests three finger horizontal scroll gesture to move selection left or right.
+TEST_F(OverviewGestureHandlerTest, HorizontalScrollInOverview) {
+  gfx::Rect bounds(0, 0, 400, 400);
+  aura::Window* root_window = Shell::GetPrimaryRootWindow();
+  std::unique_ptr<aura::Window> window1(CreateWindow(bounds));
+  std::unique_ptr<aura::Window> window2(CreateWindow(bounds));
+  std::unique_ptr<aura::Window> window3(CreateWindow(bounds));
+  std::unique_ptr<aura::Window> window4(CreateWindow(bounds));
+  std::unique_ptr<aura::Window> window5(CreateWindow(bounds));
+  ui::test::EventGenerator generator(root_window, root_window);
+  const float vertical_scroll = 2 * vertical_threshold_pixels();
+  const float horizontal_scroll = horizontal_threshold_pixels();
+  // Enter overview mode as if using an accelerator.
+  // Entering overview mode with an upwards three-finger scroll gesture would
+  // have the same result (allow selection using horizontal scroll).
+  ToggleOverview();
+  EXPECT_TRUE(IsSelecting());
+
+  // Long scroll right moves selection to the fourth window.
+  generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
+                           horizontal_scroll * 4, 0, 100, 3);
+  EXPECT_TRUE(IsSelecting());
+
+  // Short scroll left (3 fingers) moves selection to the third window.
+  generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
+                           -horizontal_scroll, 0, 100, 3);
+  EXPECT_TRUE(IsSelecting());
+
+  // Short scroll left (3 fingers) moves selection to the second window.
+  generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
+                           -horizontal_scroll, 0, 100, 3);
+  EXPECT_TRUE(IsSelecting());
+
+  // Swiping down exits and selects the currently-highlighted window.
+  generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
+                           0, vertical_scroll, 100, 3);
   EXPECT_FALSE(IsSelecting());
+
+  // Second MRU window is selected (i.e. |window4|).
+  EXPECT_EQ(window4.get(), wm::GetActiveWindow());
 }
 
-// Tests that a mostly horizontal swipe does not trigger overview.
-TEST_F(OverviewGestureHandlerTest, HorizontalSwipes) {
+// Tests that a mostly horizontal three-finger scroll does not trigger overview.
+TEST_F(OverviewGestureHandlerTest, HorizontalScrolls) {
   gfx::Rect bounds(0, 0, 400, 400);
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   std::unique_ptr<aura::Window> window1(CreateWindow(bounds));
   std::unique_ptr<aura::Window> window2(CreateWindow(bounds));
   ui::test::EventGenerator generator(root_window, root_window);
+  const float long_scroll = 2 * vertical_threshold_pixels();
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           600, -500, 100, 3);
+                           long_scroll + 100, -long_scroll, 100, 3);
   EXPECT_FALSE(IsSelecting());
 
   generator.ScrollSequence(gfx::Point(), base::TimeDelta::FromMilliseconds(5),
-                           -600, -500, 100, 3);
+                           -long_scroll - 100, -long_scroll, 100, 3);
   EXPECT_FALSE(IsSelecting());
 }
 
-// Tests a swipe up with three fingers without releasing followed by a swipe
+// Tests a scroll up with three fingers without releasing followed by a scroll
 // down by a lesser amount which should still be enough to exit.
-TEST_F(OverviewGestureHandlerTest, SwipeUpDownWithoutReleasing) {
+TEST_F(OverviewGestureHandlerTest, ScrollUpDownWithoutReleasing) {
   gfx::Rect bounds(0, 0, 400, 400);
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   std::unique_ptr<aura::Window> window1(CreateWindow(bounds));