Fix display switching for extended displays.

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/dpms.h>
 #include <X11/extensions/Xrandr.h>
 
@@ skipping 641 matching lines @@
           // Primary is tiled first.
           state = STATE_DUAL_PRIMARY_ONLY;
         }
       }
     }
   }
 
   return state;
 }
 
-bool OutputConfigurator::CycleDisplayMode() {
+bool OutputConfigurator::CycleDisplayMode(bool extended_desktop_enabled) {
   VLOG(1) << "CycleDisplayMode";
   bool did_change = false;
+
+  // The next state to go into if the current state is dual primary.
+  State next_state_from_dual_primary = STATE_DUAL_SECONDARY_ONLY;
+  if (extended_desktop_enabled) {
+    if (mirror_supported_) {
+      next_state_from_dual_primary = STATE_DUAL_MIRROR;
+    } else {
+      // In case mirror is not supported, stay in the
+      // extended desktop primary display.
+      next_state_from_dual_primary = STATE_INVALID;
+    }
+  }

[Josh Horwich, 2012/07/26 00:18:26]

Would this be easier to follow if you just put it into the block for 'case
STATE_DUAL_PRIMARY_ONLY', e.g.
    case STATE_DUAL_PRIMARY_ONLY:
      new_state = extended_desktop_enabled ?
          (mirror_supported_ ? STATE_DUAL_MIRROR : STATE_INVALID) :
          STATE_DUAL_SECONDAY_ONLY;

[rkc, 2012/07/26 00:32:52]

The ?:'s seemed kinda ugly so I moved it in the switch but with if's.


On 2012/07/26 00:18:26, Josh Horwich wrote:

+
   if (is_running_on_chrome_os_) {
     // Rules:
     // - if there are 0 or 1 displays, do nothing and return false.
     // - use y-coord of CRTCs to determine if we are mirror, primary-first, or
     // secondary-first.  The cycle order is:
     //   mirror->primary->secondary->mirror.

[oshima, 2012/07/26 00:11:06]

can you update the comment?

[rkc, 2012/07/26 00:12:48]

Done.

     State new_state = STATE_INVALID;
     switch (output_state_) {
       case STATE_DUAL_MIRROR:
         new_state = STATE_DUAL_PRIMARY_ONLY;
         break;
       case STATE_DUAL_PRIMARY_ONLY:
-        new_state = STATE_DUAL_SECONDARY_ONLY;
+        new_state = next_state_from_dual_primary;
         break;
       case STATE_DUAL_SECONDARY_ONLY:
         new_state = mirror_supported_ ?
             STATE_DUAL_MIRROR :
             STATE_DUAL_PRIMARY_ONLY;
         break;
       default:
         // Do nothing - we aren't in a mode which we can rotate.
         break;
     }
@@ skipping 130 matching lines @@
       power_manager::kSetIsProjectingMethod);
   dbus::MessageWriter writer(&method_call);
   writer.AppendBool(is_projecting);
   power_manager_proxy->CallMethod(
       &method_call,
       dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
       dbus::ObjectProxy::EmptyResponseCallback());
 }
 
 }  // namespace chromeos