content/renderer/presentation/presentation_dispatcher.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/renderer/presentation/presentation_dispatcher.h"
   6
   7 #include "content/common/presentation/presentation_service.mojom.h"
   8 #include "content/public/common/service_registry.h"
   9 #include "content/public/renderer/render_frame.h"
  10 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationController.h"
  11
  12 namespace content {
  13
  14 PresentationDispatcher::PresentationDispatcher(RenderFrame* render_frame)
  15     : RenderFrameObserver(render_frame),
  16       controller_(nullptr) {
  17 }
  18
  19 PresentationDispatcher::~PresentationDispatcher() {
  20   // Controller should be destroyed before the dispatcher when frame is
  21   // destroyed.
  22   DCHECK(!controller_);
  23 }
  24
  25 void PresentationDispatcher::setController(
  26     blink::WebPresentationController* controller) {
  27   // There shouldn't be any swapping from one non-null controller to another.
  28   DCHECK(controller != controller_ && (!controller || !controller_));
  29   controller_ = controller;
  30   // The controller is set to null when the frame is about to be detached.
  31   // Nothing is listening for screen availability anymore but the Mojo service
  32   // will know about the frame being detached anyway.
  33 }
  34
  35 void PresentationDispatcher::updateAvailableChangeWatched(bool watched) {
  36   ConnectToPresentationServiceIfNeeded();
  37   if (watched) {
  38     presentation_service_->GetScreenAvailability(
  39         mojo::String(),
  40         base::Bind(&PresentationDispatcher::OnScreenAvailabilityChanged,
  41                  base::Unretained(this)));
  42   } else {
  43     presentation_service_->OnScreenAvailabilityListenerRemoved();
  44   }
  45 }
  46
  47 void PresentationDispatcher::OnScreenAvailabilityChanged(bool available) {
  48   if (!controller_)
  49     return;
  50
  51   // Reset the callback to get the next event.
  52   updateAvailableChangeWatched(controller_->isAvailableChangeWatched());
  53
  54   controller_->didChangeAvailability(available);
  55 }
  56
  57 void PresentationDispatcher::ConnectToPresentationServiceIfNeeded() {
  58   if (presentation_service_.get())
  59     return;
  60
  61   render_frame()->GetServiceRegistry()->ConnectToRemoteService(
  62       &presentation_service_);
  63 }
  64
  65 }  // namespace content