Scale TouchEvent's radius when touchscreen is in mirror mode

chromeos/display/output_configurator.h

Index: chromeos/display/output_configurator.h
diff --git a/chromeos/display/output_configurator.h b/chromeos/display/output_configurator.h
index 34e9384e21b560704a40285a649d5648cab40352..faef729ae69f26b1cc06c96895a15d4dbe193ad9 100644
--- a/chromeos/display/output_configurator.h
+++ b/chromeos/display/output_configurator.h
@@ -5,6 +5,7 @@
 #ifndef CHROMEOS_DISPLAY_OUTPUT_CONFIGURATOR_H_
 #define CHROMEOS_DISPLAY_OUTPUT_CONFIGURATOR_H_
 
+#include <map>
 #include <vector>
 
 #include "base/basictypes.h"
@@ -283,6 +284,10 @@ class CHROMEOS_EXPORT OutputConfigurator : public MessageLoop::Dispatcher {
   // suspended.
   void ResumeDisplays();
 
+  const std::map<int, float>& GetMirroredDisplayAreaRatioMap() {
+    return mirrored_display_area_ratio_map_;
+  }
+
  private:
   // Configure outputs.
   void ConfigureOutputs();
@@ -307,9 +312,22 @@ class CHROMEOS_EXPORT OutputConfigurator : public MessageLoop::Dispatcher {
   CoordinateTransformation GetMirrorModeCTM(
       const OutputConfigurator::OutputSnapshot* output);
 
+  // Returns the ratio between mirrored mode area and native mode area:
+  // (mirror_mode_width * mirrow_mode_height) / (native_width * native_height)
+  float GetMirroredDisplayAreaRatio(
+      const OutputConfigurator::OutputSnapshot* output);
+
   StateController* state_controller_;
   scoped_ptr<Delegate> delegate_;
 
+  // Key of the map is the touch display's id, and the value of the map is the
+  // touch display's area ratio in mirror mode defined as :
+  // mirror_mode_area / native_mode_area.
+  // This is used for scaling touch event's radius when the touch display is in
+  // mirror mode :
+  // new_touch_radius = sqrt(area_ratio) * old_touch_radius
+  std::map<int, float> mirrored_display_area_ratio_map_;
+
   // This is detected by the constructor to determine whether or not we should
   // be enabled.  If we aren't running on ChromeOS, we can't assume that the
   // Xrandr X11 extension is supported.