Correct scale for touch radius & scroll offset ordinal

In https://codereview.chromium.org/12983010/

reversed_root_transform is passed into event::UpdateForRootTransform.

Then for TouchEvent::UpdateForRootTransform(), the radius_x/y now
should times the inverted device scale factor instead of being
divided by it. The same in ScrollEvent::UpdateForRootTransform() for
scroll offset ordinal.

BUG=chromium:226169
TEST=On Link, visit http://www.rbyers.net/paint.html, make sure
     touch radius has normal range.

Review URL: https://chromiumcodereview.appspot.com/13594009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192490 0039d316-1c4b-4281-b951-d872f2087c98

ash/display/display_controller_unittest.cc

@@ -25,6 +25,8 @@ namespace ash {
 namespace test {
 namespace {
 
+const char kDesktopBackgroundView[] = "DesktopBackgroundView";
+
 class TestObserver : public DisplayController::Observer {
  public:
   TestObserver() : changing_count_(0), changed_count_(0) {
@@ -98,20 +100,53 @@ class DisplayControllerShutdownTest : public test::AshTestBase {
 
 class TestEventHandler : public ui::EventHandler {
  public:
-  TestEventHandler() : target_root_(NULL) {}
+  TestEventHandler() : target_root_(NULL),
+                       touch_radius_x_(0.0),
+                       touch_radius_y_(0.0),
+                       scroll_x_offset_(0.0),
+                       scroll_y_offset_(0.0),
+                       scroll_x_offset_ordinal_(0.0),
+                       scroll_y_offset_ordinal_(0.0) {}
   virtual ~TestEventHandler() {}
 
   virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE {
     aura::Window* target = static_cast<aura::Window*>(event->target());
     // Only record when the target is the background which covers
     // entire root window.
-    if (target->name() != "DesktopBackgroundView")
+    if (target->name() != kDesktopBackgroundView)
       return;
     mouse_location_ = event->location();
     target_root_ = target->GetRootWindow();
     event->StopPropagation();
   }
 
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE {
+    aura::Window* target = static_cast<aura::Window*>(event->target());
+    // Only record when the target is the background which covers
+    // entire root window.
+    if (target->name() != kDesktopBackgroundView)
+      return;
+    touch_radius_x_ = event->radius_x();
+    touch_radius_y_ = event->radius_y();
+    event->StopPropagation();
+  }
+
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE {
+    aura::Window* target = static_cast<aura::Window*>(event->target());
+    // Only record when the target is the background which covers
+    // entire root window.
+    if (target->name() != kDesktopBackgroundView)
+      return;
+
+    if (event->type() == ui::ET_SCROLL) {
+      scroll_x_offset_ = event->x_offset();
+      scroll_y_offset_ = event->y_offset();
+      scroll_x_offset_ordinal_ = event->x_offset_ordinal();
+      scroll_y_offset_ordinal_ = event->y_offset_ordinal();
+    }
+    event->StopPropagation();
+  }
+
   std::string GetLocationAndReset() {
     std::string result = mouse_location_.ToString();
     mouse_location_.SetPoint(0, 0);
@@ -119,10 +154,24 @@ class TestEventHandler : public ui::EventHandler {
     return result;
   }
 
+  float touch_radius_x() { return touch_radius_x_; }
+  float touch_radius_y() { return touch_radius_y_; }
+  float scroll_x_offset() { return scroll_x_offset_; }
+  float scroll_y_offset() { return scroll_y_offset_; }
+  float scroll_x_offset_ordinal() { return scroll_x_offset_ordinal_; }
+  float scroll_y_offset_ordinal() { return scroll_y_offset_ordinal_; }
+
  private:
   gfx::Point mouse_location_;
   aura::RootWindow* target_root_;
 
+  float touch_radius_x_;
+  float touch_radius_y_;
+  float scroll_x_offset_;
+  float scroll_y_offset_;
+  float scroll_x_offset_ordinal_;
+  float scroll_y_offset_ordinal_;
+
   DISALLOW_COPY_AND_ASSIGN(TestEventHandler);
 };
 
@@ -791,5 +840,44 @@ TEST_F(DisplayControllerTest, MAYBE_ScaleRootWindow) {
   Shell::GetInstance()->RemovePreTargetHandler(&event_handler);
 }
 
+
+#if defined(OS_WIN)
+// On Win8 bots, the host window can't be resized and
+// SetTransform updates the window using the orignal host window
+// size.
+#define MAYBE_TouchScale DISABLED_TouchScale
+#else
+#define MAYBE_TouchScale TouchScale
+#endif
+
+TEST_F(DisplayControllerTest, MAYBE_TouchScale) {
+  TestEventHandler event_handler;
+  Shell::GetInstance()->AddPreTargetHandler(&event_handler);
+
+  UpdateDisplay("200x200*2");
+  gfx::Display display = Shell::GetScreen()->GetPrimaryDisplay();
+  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
+  aura::RootWindow* root_window = root_windows[0];
+  aura::test::EventGenerator generator(root_window);
+
+  generator.PressMoveAndReleaseTouchTo(50, 50);
+  // Default test touches have radius_x/y = 1.0, with device scale
+  // factor = 2, the scaled radius_x/y should be 0.5.
+  EXPECT_EQ(0.5, event_handler.touch_radius_x());
+  EXPECT_EQ(0.5, event_handler.touch_radius_y());
+
+  generator.ScrollSequence(gfx::Point(0,0),
+                           base::TimeDelta::FromMilliseconds(100),
+                           10.0, 1.0, 5, 1);
+
+  // With device scale factor = 2, ordinal_offset * 2 = offset.
+  EXPECT_EQ(event_handler.scroll_x_offset(),
+            event_handler.scroll_x_offset_ordinal() * 2);
+  EXPECT_EQ(event_handler.scroll_y_offset(),
+            event_handler.scroll_y_offset_ordinal() * 2);
+
+  Shell::GetInstance()->RemovePreTargetHandler(&event_handler);
+}
+
 }  // namespace test
 }  // namespace ash

ui/aura/test/event_generator.cc

@@ -61,8 +61,8 @@ class TestTouchEvent : public ui::TouchEvent {
   TestTouchEvent(ui::EventType type,
                  const gfx::Point& root_location,
                  int flags)
-      : TouchEvent(type, root_location, 0, ui::EventTimeForNow()) {
-    set_flags(flags);
+      : TouchEvent(type, root_location, flags, 0, ui::EventTimeForNow(),
+                   1.0f, 1.0f, 1.0f, 1.0f) {
   }
 
  private:

ui/base/events/event.cc

@@ -462,15 +462,16 @@ void TouchEvent::Relocate(const gfx::Point& origin) {
   root_location_ -= origin.OffsetFromOrigin();
 }
 
-void TouchEvent::UpdateForRootTransform(const gfx::Transform& root_transform) {
-  LocatedEvent::UpdateForRootTransform(root_transform);
+void TouchEvent::UpdateForRootTransform(
+    const gfx::Transform& inverted_root_transform) {
+  LocatedEvent::UpdateForRootTransform(inverted_root_transform);
   gfx::DecomposedTransform decomp;
-  bool success = gfx::DecomposeTransform(&decomp, root_transform);
+  bool success = gfx::DecomposeTransform(&decomp, inverted_root_transform);
   DCHECK(success);
   if (decomp.scale[0])
-    radius_x_ /= decomp.scale[0];
+    radius_x_ *= decomp.scale[0];
   if (decomp.scale[1])
-    radius_y_ /= decomp.scale[1];
+    radius_y_ *= decomp.scale[1];
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -690,15 +691,16 @@ void ScrollEvent::Scale(const float factor) {
   y_offset_ordinal_ *= factor;
 }
 
-void ScrollEvent::UpdateForRootTransform(const gfx::Transform& root_transform) {
-  LocatedEvent::UpdateForRootTransform(root_transform);
+void ScrollEvent::UpdateForRootTransform(
+    const gfx::Transform& inverted_root_transform) {
+  LocatedEvent::UpdateForRootTransform(inverted_root_transform);
   gfx::DecomposedTransform decomp;
-  bool success = gfx::DecomposeTransform(&decomp, root_transform);
+  bool success = gfx::DecomposeTransform(&decomp, inverted_root_transform);
   DCHECK(success);
   if (decomp.scale[0])
-    x_offset_ordinal_ /= decomp.scale[0];
+    x_offset_ordinal_ *= decomp.scale[0];
   if (decomp.scale[1])
-    y_offset_ordinal_ /= decomp.scale[1];
+    y_offset_ordinal_ *= decomp.scale[1];
 }
 
 ////////////////////////////////////////////////////////////////////////////////

ui/base/events/event.h

@@ -495,7 +495,7 @@ class UI_EXPORT TouchEvent : public LocatedEvent {
 
   // Overridden from LocatedEvent.
   virtual void UpdateForRootTransform(
-      const gfx::Transform& root_transform) OVERRIDE;
+      const gfx::Transform& inverted_root_transform) OVERRIDE;
 
  protected:
   void set_radius(float radius_x, float radius_y) {
@@ -661,7 +661,7 @@ class UI_EXPORT ScrollEvent : public MouseEvent {
 
   // Overridden from LocatedEvent.
   virtual void UpdateForRootTransform(
-      const gfx::Transform& root_transform) OVERRIDE;
+      const gfx::Transform& inverted_root_transform) OVERRIDE;
 
  private:
   // Potential accelerated offsets.