Scale TouchEvent's radius when touchscreen is in mirror mode

chromeos/display/output_configurator.h

 // 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.
 
 #ifndef CHROMEOS_DISPLAY_OUTPUT_CONFIGURATOR_H_
 #define CHROMEOS_DISPLAY_OUTPUT_CONFIGURATOR_H_
 
+#include <map>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/event_types.h"
 #include "base/observer_list.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/timer.h"
 #include "chromeos/chromeos_export.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
@@ skipping 258 matching lines @@
 
   // Sets all the displays into pre-suspend mode; usually this means
   // configure them for their resume state. This allows faster resume on
   // machines where display configuration is slow.
   void SuspendDisplays();
 
   // Reprobes displays to handle changes made while the system was
   // suspended.
   void ResumeDisplays();
 
+  const std::map<int, float>& GetMirroredDisplayAreaRatioMap() {
+    return mirrored_display_area_ratio_map_;
+  }
+
  private:
   // Configure outputs.
   void ConfigureOutputs();
 
   // Fires OnDisplayModeChanged() event to the observers.
   void NotifyOnDisplayChanged();
 
   // Switches to the state specified in |output_state| and |power_state|.
   // On success, updates |output_state_| and |power_state_| and returns true.
   bool EnterState(OutputState output_state,
                   DisplayPowerState power_state,
                   const std::vector<OutputSnapshot>& outputs);
 
   // Returns the output state that should be used with |outputs| connected
   // while in |power_state|.
   OutputState GetOutputState(const std::vector<OutputSnapshot>& outputs,
                              DisplayPowerState power_state) const;
 
   // Computes the relevant transformation for mirror mode.
   // |output| is the output on which mirror mode is being applied.
   // Returns the transformation or identity if computations fail.
   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.
   // If this flag is set to false, any attempts to change the output
   // configuration to immediately fail without changing the state.
   bool configure_display_;
 
   // The base of the event numbers used to represent XRandr events used in
   // decoding events regarding output add/remove.
   int xrandr_event_base_;
 
   // The current display state.
   OutputState output_state_;
 
   // The current power state.
   DisplayPowerState power_state_;
 
   ObserverList<Observer> observers_;
 
   // The timer to delay configuring outputs. See also the comments in
   // Dispatch().
   scoped_ptr<base::OneShotTimer<OutputConfigurator> > configure_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(OutputConfigurator);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DISPLAY_OUTPUT_CONFIGURATOR_H_