Refactor monitor_reconfigure to stop using system("xrandr").

monitor_reconfigure_main.h

 // Copyright (c) 2010 The Chromium OS 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 MONITOR_RECONFIGURE_MONITOR_RECONFIGURE_MAIN_H_
 #define MONITOR_RECONFIGURE_MONITOR_RECONFIGURE_MAIN_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include <X11/Xlib.h>
 #include <X11/extensions/Xrandr.h>
 
 #include "monitor_reconfig/resolution_selector.h"
 
 namespace monitor_reconfig {
 
 // MonitorReconfigureMain is the class responsible for setting the external
 // monitor to the max resolution based on the modes supported by the native
-// monitor and the external monitor
+// monitor and the external monitor.
 class MonitorReconfigureMain {
  public:
-  MonitorReconfigureMain(Display* display, XRRScreenResources* screen_info);
-  virtual ~MonitorReconfigureMain() {}
+  // |window| is the root window.
+  MonitorReconfigureMain(Display* display,
+                         Window window,
+                         XRRScreenResources* screen_info);
+  ~MonitorReconfigureMain() {
+    XRRFreeOutputInfo(lcd_output_info_);
+    XRRFreeOutputInfo(external_output_info_);
+  }
 
-  // Main entry point
+  // Main entry point.
   void Run();
 
  private:
   // Initializes the |lcd_output_| and |external_output_| members.
   void DetermineOutputs();
 
-  // Returns whether an external monitor is connected
+  // Returns whether an external monitor is connected.
   bool IsExternalMonitorConnected();
 
   // Sorts |output_info|'s modes by decreasing number of pixels, storing the
   // results in |modes_out|.
-  void SortModesByResolution(const XRROutputInfo& output_info,
+  void SortModesByResolution(RROutput output,
                              std::vector<ResolutionSelector::Mode>* modes_out);
 
   // Set the resolution for a particular device or for the screen.
-  bool SetDeviceResolution(const std::string& device_name,
-                           const std::string& resolution);
-  bool SetScreenResolution(const std::string& resolution);
+  bool SetDeviceResolution(RROutput output,
+                           const XRROutputInfo* output_info,
+                           const ResolutionSelector::Mode& resolution);
+  bool SetScreenResolution(const ResolutionSelector::Mode& resolution);
 
   // Disable output to a device.
-  bool DisableDevice(const std::string& device_name);
+  bool DisableDevice(RROutput output,
+                     const XRROutputInfo* output_info);
 
   // Mapping between mode XIDs and mode information structures.
   std::map<int, XRRModeInfo*> mode_map_;
 
-  // X Resources needed between functions
+  // X Resources needed between functions.
   Display* display_;
+  Window window_;
   XRRScreenResources* screen_info_;
-  XRROutputInfo* lcd_output_;
-  XRROutputInfo* external_output_;
+
+  RROutput lcd_output_;
+  XRROutputInfo* lcd_output_info_;
+
+  RROutput external_output_;
+  XRROutputInfo* external_output_info_;
 };
 
 }  // namespace monitor_reconfig
 
 #endif  // MONITOR_RECONFIGURE_MONITOR_RECONFIGURE_MAIN_H_