Cancel drag if display configuration changes.

ash/display/display_controller_unittest.cc

 // Copyright (c) 2012 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 "ash/display/display_controller.h"
 
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ui/aura/display_manager.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
 
 namespace ash {
 namespace test {
 namespace {
 
+class TestObserver : public DisplayController::Observer {
+ public:
+  TestObserver() : count_(0) {
+    Shell::GetInstance()->display_controller()->AddObserver(this);
+  }
+
+  virtual ~TestObserver() {
+    Shell::GetInstance()->display_controller()->RemoveObserver(this);
+  }
+
+  virtual void OnDisplayConfigurationChanging() OVERRIDE {
+    ++count_;
+  }
+
+  int CountAndReset() {
+    int c = count_;
+    count_ = 0;
+    return c;
+  }
+
+ private:
+  int count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestObserver);
+};
+
 gfx::Display GetPrimaryDisplay() {
   return gfx::Screen::GetDisplayNearestWindow(
       Shell::GetAllRootWindows()[0]);
 }
 
 gfx::Display GetSecondaryDisplay() {
   return gfx::Screen::GetDisplayNearestWindow(
       Shell::GetAllRootWindows()[1]);
 }
 
@@ skipping 13 matching lines @@
 // TOD(oshima): Windows creates a window with smaller client area.
 // Fix this and enable tests.
 #define MAYBE_SecondaryDisplayLayout DISABLED_SecondaryDisplayLayout
 #define MAYBE_BoundsUpdated DISABLED_BoundsUpdated
 #else
 #define MAYBE_SecondaryDisplayLayout SecondaryDisplayLayout
 #define MAYBE_BoundsUpdated BoundsUpdated
 #endif
 
 TEST_F(DisplayControllerTest, MAYBE_SecondaryDisplayLayout) {
+  TestObserver observer;
   UpdateDisplay("500x500,400x400");
+  EXPECT_EQ(2, observer.CountAndReset());  // resize and add
   gfx::Display* secondary_display =
       aura::Env::GetInstance()->display_manager()->GetDisplayAt(1);
   gfx::Insets insets(5, 5, 5, 5);
   secondary_display->UpdateWorkAreaFromInsets(insets);
 
   // Default layout is LEFT.
   EXPECT_EQ("0,0 500x500", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("500,0 400x400", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("505,5 390x390", GetSecondaryDisplay().work_area().ToString());
 
   // Layout the secondary display to the bottom of the primary.
   SetSecondaryDisplayLayout(DisplayLayout::BOTTOM);
+  EXPECT_EQ(1, observer.CountAndReset());
   EXPECT_EQ("0,0 500x500", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,500 400x400", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("5,505 390x390", GetSecondaryDisplay().work_area().ToString());
 
   // Layout the secondary display to the left of the primary.
   SetSecondaryDisplayLayout(DisplayLayout::LEFT);
+  EXPECT_EQ(1, observer.CountAndReset());
   EXPECT_EQ("0,0 500x500", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("-400,0 400x400", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("-395,5 390x390", GetSecondaryDisplay().work_area().ToString());
 
   // Layout the secondary display to the top of the primary.
   SetSecondaryDisplayLayout(DisplayLayout::TOP);
+  EXPECT_EQ(1, observer.CountAndReset());
   EXPECT_EQ("0,0 500x500", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,-400 400x400", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("5,-395 390x390", GetSecondaryDisplay().work_area().ToString());
 }
 
 TEST_F(DisplayControllerTest, MAYBE_BoundsUpdated) {
+  TestObserver observer;
   SetSecondaryDisplayLayout(DisplayLayout::BOTTOM);
-  UpdateDisplay("200x200,300x300");
+  UpdateDisplay("200x200,300x300");  // layout, resize and add.
+  EXPECT_EQ(3, observer.CountAndReset());
+
   gfx::Display* secondary_display =
       aura::Env::GetInstance()->display_manager()->GetDisplayAt(1);
   gfx::Insets insets(5, 5, 5, 5);
   secondary_display->UpdateWorkAreaFromInsets(insets);
 
   EXPECT_EQ("0,0 200x200", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,200 300x300", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("5,205 290x290", GetSecondaryDisplay().work_area().ToString());
 
   UpdateDisplay("400x400,200x200");
+  EXPECT_EQ(2, observer.CountAndReset());  // two resizes
   EXPECT_EQ("0,0 400x400", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,400 200x200", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("5,405 190x190", GetSecondaryDisplay().work_area().ToString());
 
   UpdateDisplay("400x400,300x300");
+  EXPECT_EQ(1, observer.CountAndReset());
   EXPECT_EQ("0,0 400x400", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,400 300x300", GetSecondaryDisplay().bounds().ToString());
   EXPECT_EQ("5,405 290x290", GetSecondaryDisplay().work_area().ToString());
 
   UpdateDisplay("400x400");
+  EXPECT_EQ(1, observer.CountAndReset());
   EXPECT_EQ("0,0 400x400", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ(1, gfx::Screen::GetNumDisplays());
 
   UpdateDisplay("500x500,700x700");
+  EXPECT_EQ(2, observer.CountAndReset());
   ASSERT_EQ(2, gfx::Screen::GetNumDisplays());
   EXPECT_EQ("0,0 500x500", GetPrimaryDisplay().bounds().ToString());
   EXPECT_EQ("0,500 700x700", GetSecondaryDisplay().bounds().ToString());
 }
 
 }  // namespace test
 }  // namespace ash