Make sure the mouse pointer is always in one of displays

after display configuration change.

BUG=157658
TEST=covered by test. tested manually on the device.

Review URL: https://codereview.chromium.org/11263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@164452 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 116 insertions, 0 deletions

diff --git a/ash/display/multi_display_manager.cc b/ash/display/multi_display_manager.cc
index 4f200ee..3fc4ea5 100644
--- a/ash/display/multi_display_manager.cc
+++ b/ash/display/multi_display_manager.cc
@@ -16,6 +16,7 @@
 #include "base/utf_string_conversions.h"
 #include "grit/ash_strings.h"
 #include "ui/aura/aura_switches.h"
+#include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/root_window_host.h"
@@ -291,6 +292,7 @@ void MultiDisplayManager::OnNativeDisplaysChanged(
     NotifyDisplayRemoved(displays_.back());
     displays_.pop_back();
   }
+  EnsurePointerInDisplays();
 }
 
 RootWindow* MultiDisplayManager::CreateRootWindowForDisplay(
@@ -495,6 +497,42 @@ int64 MultiDisplayManager::SetFirstDisplayAsInternalDisplayForTest() {
   return internal_display_id_;
 }
 
+void MultiDisplayManager::EnsurePointerInDisplays() {
+  // Don't try to move the pointer during the boot/startup.
+  if (!Shell::HasInstance())
+    return;
+  gfx::Point location_in_screen = Shell::GetScreen()->GetCursorScreenPoint();
+  gfx::Point target_location;
+  int64 closest_distance = -1;
+
+  for (DisplayList::const_iterator iter = displays_.begin();
+       iter != displays_.end(); ++iter) {
+    const gfx::Rect& display_bounds = iter->bounds();
+
+    if (display_bounds.Contains(location_in_screen)) {
+      target_location = location_in_screen;
+      break;
+    }
+    gfx::Point center = display_bounds.CenterPoint();
+    gfx::Point diff = center.Subtract(location_in_screen);
+    // Use the distance from the center of the dislay. This is not
+    // exactly "closest" display, but good enough to pick one
+    // appropriate (and there are at most two displays).
+    int64 distance = diff.x() * diff.x() + diff.y() * diff.y();
+    if (closest_distance < 0 || closest_distance > distance) {
+      target_location = center;
+      closest_distance = distance;
+    }
+  }
+
+  aura::RootWindow* root_window = Shell::GetPrimaryRootWindow();
+  aura::client::ScreenPositionClient* client =
+      aura::client::GetScreenPositionClient(root_window);
+  client->ConvertPointFromScreen(root_window, &target_location);
+
+  root_window->MoveCursorTo(target_location);
+}
+
 void MultiDisplayManager::SetDisplayIdsForTest(DisplayList* to_update) const {
   DisplayList::iterator iter_to_update = to_update->begin();
   DisplayList::const_iterator iter = displays_.begin();
diff --git a/ash/display/multi_display_manager.h b/ash/display/multi_display_manager.h
index d82b0dd..0767e01 100644
--- a/ash/display/multi_display_manager.h
+++ b/ash/display/multi_display_manager.h
@@ -128,6 +128,10 @@ class ASH_EXPORT MultiDisplayManager : public aura::DisplayManager,
   // the internal display.
   int64 SetFirstDisplayAsInternalDisplayForTest();
 
+  // Checks if the mouse pointer is on one of displays, and moves to
+  // the center of the nearest display if it's outside of all displays.
+  void EnsurePointerInDisplays();
+
   // Update the display's id in the |display_list| to match the ones
   // stored in this display manager's |displays_|. This is used to
   // emulate display change behavior during the test byn creating the
diff --git a/ash/display/multi_display_manager_unittest.cc b/ash/display/multi_display_manager_unittest.cc
index b7e293a..8962bcb 100644
--- a/ash/display/multi_display_manager_unittest.cc
+++ b/ash/display/multi_display_manager_unittest.cc
@@ -5,6 +5,7 @@
 #include "ash/display/multi_display_manager.h"
 
 #include "ash/display/display_controller.h"
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "base/format_macros.h"
@@ -387,5 +388,78 @@ TEST_F(MultiDisplayManagerTest, MAYBE_TestNativeDisplaysChanged) {
             FindDisplayForId(internal_display_id).bounds().ToString());
 }
 
+TEST_F(MultiDisplayManagerTest, EnsurePointerInDisplays) {
+  UpdateDisplay("200x200,300x300");
+  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
+
+  aura::Env* env = aura::Env::GetInstance();
+
+  // Set the initial position.
+  root_windows[0]->MoveCursorTo(gfx::Point(350, 150));
+  EXPECT_EQ("350,150", env->last_mouse_location().ToString());
+
+  // A mouse pointer will be inside 2nd display.
+  UpdateDisplay("300x300,200x200");
+  EXPECT_EQ("350,150", env->last_mouse_location().ToString());
+
+  // A mouse pointer will be outside of displays and move to the
+  // center of 2nd display.
+  UpdateDisplay("300x300,100x100");
+  EXPECT_EQ("350,50", env->last_mouse_location().ToString());
+
+  // 2nd display was disconnected, but the mouse pointer says in the
+  // 1st display.
+  UpdateDisplay("400x400");
+  EXPECT_EQ("350,50", env->last_mouse_location().ToString());
+
+  // 1st display's resolution has changed, and the mouse pointer is
+  // now outside. Move the mouse pointer to the center of 1st display.
+  UpdateDisplay("300x300");
+  EXPECT_EQ("150,150", env->last_mouse_location().ToString());
+
+  // Move the mouse pointer to the bottom of 1st display.
+  root_windows[0]->MoveCursorTo(gfx::Point(150, 290));
+  EXPECT_EQ("150,290", env->last_mouse_location().ToString());
+
+  // The mouse pointer is outside and closest display is 1st one.
+  UpdateDisplay("300x280,200x200");
+  EXPECT_EQ("150,140", env->last_mouse_location().ToString());
+}
+
+TEST_F(MultiDisplayManagerTest, EnsurePointerInDisplays_2ndOnLeft) {
+  UpdateDisplay("200x200,300x300");
+  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
+
+  // Set the 2nd display on the left.
+  DisplayController* display_controller =
+      Shell::GetInstance()->display_controller();
+  DisplayLayout layout = display_controller->default_display_layout();
+  layout.position = DisplayLayout::LEFT;
+  display_controller->SetDefaultDisplayLayout(layout);
+
+  EXPECT_EQ("-300,0 300x300",
+            ScreenAsh::GetSecondaryDisplay().bounds().ToString());
+
+  aura::Env* env = aura::Env::GetInstance();
+
+  // Set the initial position.
+  root_windows[0]->MoveCursorTo(gfx::Point(-150, 150));
+  EXPECT_EQ("-150,150", env->last_mouse_location().ToString());
+
+  // A mouse pointer will be in 2nd display.
+  UpdateDisplay("300x300,200x200");
+  EXPECT_EQ("-150,150", env->last_mouse_location().ToString());
+
+  // A mouse pointer will be outside of displays and move to the
+  // center of 2nd display.
+  UpdateDisplay("300x300,200x100");
+  EXPECT_EQ("-100,50", env->last_mouse_location().ToString());
+
+  // 2nd display was disconnected. Mouse pointer should move to
+  // 1st display.
+  UpdateDisplay("300x300");
+  EXPECT_EQ("150,150", env->last_mouse_location().ToString());
+}
+
 }  // namespace internal
 }  // namespace ash