Scale TouchEvent's radius when touchscreen is in mirror mode

chromeos/display/output_configurator.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 "chromeos/display/output_configurator.h"
 
 #include <X11/Xlib.h>
 #include <X11/extensions/Xrandr.h>
 
 #include "base/bind.h"
@@ skipping 410 matching lines @@
 
       for (size_t i = 0; i < outputs.size(); ++i) {
         delegate_->ConfigureCrtc(&configs[i]);
         if (outputs[i].touch_device_id) {
           CoordinateTransformation ctm;
           // CTM needs to be calculated if aspect preserving scaling is used.
           // Otherwise, assume it is full screen, and use identity CTM.
           if (outputs[i].mirror_mode != outputs[i].native_mode &&
               outputs[i].is_aspect_preserving_scaling) {
             ctm = GetMirrorModeCTM(&outputs[i]);
+            mirrored_display_area_ratio_map_[outputs[i].touch_device_id] =
+              GetMirroredDisplayAreaRatio(&outputs[i]);
           }
           delegate_->ConfigureCTM(outputs[i].touch_device_id, ctm);
         }
       }
       break;
     }
     case STATE_DUAL_EXTENDED: {
       if (outputs.size() != 2 || (num_on_outputs != 0 && num_on_outputs != 2)) {
         LOG(WARNING) << "Ignoring request to enter extended mode with "
                      << outputs.size() << " connected output(s) and "
@@ skipping 114 matching lines @@
     ctm.y_scale = 1.0;
     ctm.y_offset = 0.0;
     ctm.x_scale = native_mode_ar / mirror_mode_ar;
     ctm.x_offset = (mirror_mode_ar / native_mode_ar - 1.0) * 0.5;
     return ctm;
   }
 
   return ctm;  // Same aspect ratio - return identity
 }
 
+float OutputConfigurator::GetMirroredDisplayAreaRatio(
+    const OutputConfigurator::OutputSnapshot* output) {
+  float area_ratio = 1.0f;
+  int native_mode_width = 0, native_mode_height = 0;
+  int mirror_mode_width = 0, mirror_mode_height = 0;
+  if (!delegate_->GetModeDetails(output->native_mode,
+          &native_mode_width, &native_mode_height, NULL) ||
+      !delegate_->GetModeDetails(output->mirror_mode,
+          &mirror_mode_width, &mirror_mode_height, NULL))
+    return area_ratio;
+
+  if (native_mode_height == 0 || mirror_mode_height == 0 ||
+      native_mode_width == 0 || mirror_mode_width == 0)
+    return area_ratio;
+
+  float width_ratio = static_cast<float>(mirror_mode_width) /
+      static_cast<float>(native_mode_width);
+  float height_ratio = static_cast<float>(mirror_mode_height) /
+      static_cast<float>(native_mode_height);
+
+  area_ratio = width_ratio * height_ratio;
+  return area_ratio;
+}
+
 }  // namespace chromeos