[Ozone-DRI] Add display observer

ui/ozone/platform/dri/screen_manager.cc

 // Copyright 2014 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 "ui/ozone/platform/dri/screen_manager.h"
 
 #include <xf86drmMode.h>
 
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 71 matching lines @@
 
   controllers_.push_back(new HardwareDisplayController(
       scoped_ptr<CrtcController>(new CrtcController(dri, crtc, connector))));
 }
 
 void ScreenManager::RemoveDisplayController(uint32_t crtc) {
   HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
   if (it != controllers_.end()) {
     bool is_mirrored = (*it)->IsMirrored();
     (*it)->RemoveCrtc(crtc);
-    if (!is_mirrored)
+    if (!is_mirrored) {
+      FOR_EACH_OBSERVER(DisplayChangeObserver, observers_,
+                        OnDisplayRemoved(*it));
       controllers_.erase(it);
+    }
   }
 }
 
 bool ScreenManager::ConfigureDisplayController(uint32_t crtc,
                                                uint32_t connector,
                                                const gfx::Point& origin,
                                                const drmModeModeInfo& mode) {
   gfx::Rect modeset_bounds(origin.x(), origin.y(), mode.hdisplay,
                            mode.vdisplay);
   HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
   DCHECK(controllers_.end() != it) << "Display controller (crtc=" << crtc
                                    << ") doesn't exist.";
 
   HardwareDisplayController* controller = *it;
-  controller = *it;
   // If nothing changed just enable the controller. Note, we perform an exact
   // comparison on the mode since the refresh rate may have changed.
   if (SameMode(mode, controller->get_mode()) &&
       origin == controller->origin()) {
     if (controller->IsDisabled()) {
       HardwareDisplayControllers::iterator mirror =
           FindActiveDisplayControllerByLocation(modeset_bounds);
       // If there is an active controller at the same location then start mirror
       // mode.
       if (mirror != controllers_.end())
         return HandleMirrorMode(it, mirror, crtc, connector);
     }
 
+    FOR_EACH_OBSERVER(DisplayChangeObserver, observers_,
+                      OnDisplayChanged(controller));
     // Just re-enable the controller to re-use the current state.
     return controller->Enable();
   }
 
   // Either the mode or the location of the display changed, so exit mirror
   // mode and configure the display independently. If the caller still wants
   // mirror mode, subsequent calls configuring the other controllers will
   // restore mirror mode.
   if (controller->IsMirrored()) {
     controller = new HardwareDisplayController(controller->RemoveCrtc(crtc));
@@ skipping 20 matching lines @@
     }
 
     (*it)->Disable();
     return true;
   }
 
   LOG(ERROR) << "Failed to find display controller crtc=" << crtc;
   return false;
 }
 
-base::WeakPtr<HardwareDisplayController> ScreenManager::GetDisplayController(
+HardwareDisplayController* ScreenManager::GetDisplayController(
     const gfx::Rect& bounds) {
   // TODO(dnicoara): Remove hack once TestScreen uses a simple Ozone display
   // configuration reader and ScreenManager is called from there to create the
   // one display needed by the content_shell target.
   if (controllers_.empty())
     ForceInitializationOfPrimaryDisplay();
 
   HardwareDisplayControllers::iterator it =
       FindActiveDisplayControllerByLocation(bounds);
   if (it != controllers_.end())
-    return (*it)->AsWeakPtr();
+    return *it;
 
-  return base::WeakPtr<HardwareDisplayController>();
+  return nullptr;
+}
+
+void ScreenManager::AddObserver(DisplayChangeObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ScreenManager::RemoveObserver(DisplayChangeObserver* observer) {
+  observers_.RemoveObserver(observer);
 }
 
 ScreenManager::HardwareDisplayControllers::iterator
 ScreenManager::FindDisplayController(uint32_t crtc) {
   for (HardwareDisplayControllers::iterator it = controllers_.begin();
        it != controllers_.end();
        ++it) {
     if ((*it)->HasCrtc(crtc))
       return it;
   }
@@ skipping 51 matching lines @@
     return false;
   }
 
   FillModesetBuffer(dri_, controller, buffer.get());
 
   if (!controller->Modeset(OverlayPlane(buffer), mode)) {
     LOG(ERROR) << "Failed to modeset controller";
     return false;
   }
 
+  FOR_EACH_OBSERVER(DisplayChangeObserver, observers_,
+                    OnDisplayChanged(controller));
   return true;
 }
 
 bool ScreenManager::HandleMirrorMode(
     HardwareDisplayControllers::iterator original,
     HardwareDisplayControllers::iterator mirror,
     uint32_t crtc,
     uint32_t connector) {
   (*mirror)->AddCrtc((*original)->RemoveCrtc(crtc));
   if ((*mirror)->Enable()) {
+    FOR_EACH_OBSERVER(DisplayChangeObserver, observers_,
+                      OnDisplayRemoved(*original));
+    FOR_EACH_OBSERVER(DisplayChangeObserver, observers_,
+                      OnDisplayChanged(*mirror));
     controllers_.erase(original);
     return true;
   }
 
   LOG(ERROR) << "Failed to switch to mirror mode";
 
   // When things go wrong revert back to the previous configuration since
   // it is expected that the configuration would not have changed if
   // things fail.
   (*original)->AddCrtc((*mirror)->RemoveCrtc(crtc));
   (*original)->Enable();
   return false;
 }
 
 }  // namespace ui