Don't move cursor location when rotation /ui scaling has changed

ash/display/display_controller.cc

Index: ash/display/display_controller.cc
diff --git a/ash/display/display_controller.cc b/ash/display/display_controller.cc
index a7343c9eccadbb55a62cc90081371710e9712f03..30b3797e577bbe69c9bc0f663bc5cb40f7cbe0a1 100644
--- a/ash/display/display_controller.cc
+++ b/ash/display/display_controller.cc
@@ -24,6 +24,7 @@
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
+#include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
@@ -722,6 +723,76 @@ gfx::Display* DisplayController::GetSecondaryDisplay() {
       display_manager->GetDisplayAt(1) : display_manager->GetDisplayAt(0);
 }
 
+void DisplayController::EnsurePointerInDisplays() {
+  // Don't try to move the pointer during the boot/startup.
+  if (!HasPrimaryDisplay())
+    return;
+  gfx::Point location_in_screen = Shell::GetScreen()->GetCursorScreenPoint();
+  gfx::Point target_location;
+  int64 closest_distance_squared = -1;
+  internal::DisplayManager* display_manager = GetDisplayManager();
+
+  aura::RootWindow* dst_root_window = NULL;
+  for (size_t i = 0; i < display_manager->GetNumDisplays(); ++i) {
+    const gfx::Display* display = display_manager->GetDisplayAt(i);
+    aura::RootWindow* root_window = GetRootWindowForDisplayId(display->id());
+    if (display->bounds().Contains(location_in_screen)) {
+      dst_root_window = root_window;
+      target_location = location_in_screen;

[Jun Mukai, 2013/04/06 03:13:39]

in which case do we still need to call MoveCursorTo? Can we just return here?

[oshima, 2013/04/08 18:00:40]

Yes, we need to update the cursor when screen was rotated.

+      break;
+    }
+    gfx::Point center = display->bounds().CenterPoint();
+    // Use the distance squared 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).
+    // We don't care about actual distance, only relative to other displays, so
+    // using the LengthSquared() is cheaper than Length().
+
+    int64 distance_squared = (center - location_in_screen).LengthSquared();
+    if (closest_distance_squared < 0 ||
+        closest_distance_squared > distance_squared) {
+      dst_root_window = root_window;
+      target_location = center;
+      closest_distance_squared = distance_squared;
+    }
+  }

[Jun Mukai, 2013/04/06 03:13:39]

It seems that this method doesn't ensure it if dst_root_window is NULL, but it
also seems that dst_root_window never becomes NULL. Why not
DCHECK(dst_root_window != NULL) instead?

[oshima, 2013/04/08 18:00:40]

good point. done.

+  if (dst_root_window) {
+    aura::client::ScreenPositionClient* client =
+        aura::client::GetScreenPositionClient(dst_root_window);
+    client->ConvertPointFromScreen(dst_root_window, &target_location);
+    dst_root_window->MoveCursorTo(target_location);
+  }
+}
+
+gfx::Point DisplayController::GetNativeMouseCursorLocation() const {
+  gfx::Point location = Shell::GetScreen()->GetCursorScreenPoint();
+  const gfx::Display& display =
+      Shell::GetScreen()->GetDisplayNearestPoint(location);
+  const aura::RootWindow* root_window =
+      root_windows_.find(display.id())->second;
+  aura::client::ScreenPositionClient* client =
+      aura::client::GetScreenPositionClient(root_window);
+  client->ConvertPointFromScreen(root_window, &location);
+  root_window->ConvertPointToNativeScreen(&location);
+  return location;
+}
+
+void DisplayController::UpdateMouseCursor(const gfx::Point& point_in_native) {
+  std::vector<aura::RootWindow*> root_windows = GetAllRootWindows();
+  for (std::vector<aura::RootWindow*>::iterator iter = root_windows.begin();
+       iter != root_windows.end();
+       ++iter) {
+    aura::RootWindow* root_window = *iter;
+    gfx::Rect bounds(root_window->GetHostOrigin(), root_window->GetHostSize());

[Jun Mukai, 2013/04/06 03:13:39]

bounds_in_native?

[oshima, 2013/04/08 18:00:40]

Done.

+    if (bounds.Contains(point_in_native)) {
+      gfx::Point point(point_in_native);
+      root_window->ConvertPointFromNativeScreen(&point);
+      root_window->MoveCursorTo(point);
+      break;
+    }
+  }
+}
+
 void DisplayController::OnDisplayBoundsChanged(const gfx::Display& display) {
   if (limiter_.get())
     limiter_->SetThrottleTimeout(kAfterDisplayChangeThrottleTimeoutMs);