Implement WebVR presentation pausing for VR Shell Menu Mode

chrome/browser/android/vr_shell/vr_shell.cc

Index: chrome/browser/android/vr_shell/vr_shell.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell.cc b/chrome/browser/android/vr_shell/vr_shell.cc
index d14efcd68f02ea36aea729138e461273752b26ee..7f134358762c92b75bd118dbdbcef1be23dfeb48 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -21,6 +21,7 @@
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/referrer.h"
 #include "content/public/common/screen_info.h"
+#include "device/vr/android/gvr/gvr_device_provider.h"
 #include "jni/VrShellImpl_jni.h"
 #include "ui/android/view_android.h"
 #include "ui/android/window_android.h"
@@ -183,8 +184,7 @@ void VrShell::SetDelegate(JNIEnv* env,
   delegate_ = VrShellDelegate::getNativeDelegate(env, delegate);
 }
 
-enum class ViewerType
-{
+enum class ViewerType {
   UNKNOWN_TYPE = 0,
   CARDBOARD = 1,
   DAYDREAM = 2,
@@ -205,8 +205,7 @@ void VrShell::GvrInit(JNIEnv* env,
   ui_input_manager_ = new VrInputManager(ui_contents_);
 
   ViewerType viewerType;
-  switch (gvr_api_->GetViewerType())
-  {
+  switch (gvr_api_->GetViewerType()) {
     case gvr::ViewerType::GVR_VIEWER_TYPE_DAYDREAM:
       viewerType = ViewerType::DAYDREAM;
       break;
@@ -268,7 +267,31 @@ void VrShell::InitializeGl(JNIEnv* env,
 void VrShell::UpdateController(const gvr::Vec3f& forward_vector) {
   controller_->UpdateState();
   std::unique_ptr<WebGestureEvent> gesture = controller_->DetectGesture();
-
+#if defined(ENABLE_VR_SHELL)
+  // Note that button up/down state is transient, so IsButtonUp only returns
+  // true for a single frame (and we're guaranteed not to miss it).
+  if (controller_->IsButtonUp(
+      gvr::ControllerButton::GVR_CONTROLLER_BUTTON_APP)) {
+    if (html_interface_->GetMode() == UiInterface::Mode::MENU) {
+      // Temporary: Hit app button a second time to exit menu mode.
+      if (webvr_mode_) {
+        html_interface_->SetMode(UiInterface::Mode::WEB_VR);
+        delegate_->GetDeviceProvider()->ResumePresent();
+      } else {
+        html_interface_->SetMode(UiInterface::Mode::STANDARD);
+      }
+    } else {
+      if (html_interface_->GetMode() == UiInterface::Mode::WEB_VR) {
+        delegate_->GetDeviceProvider()->PausePresent();
+      }
+      html_interface_->SetMode(UiInterface::Mode::MENU);
+      // TODO(mthiesse): Also pause tracking for all webvr pages.

[bajones, 2016/11/01 18:11:31]

Is this comment accurate? Seems like we're already doing that?

[mthiesse, 2016/11/02 14:39:02]

As discussed offline, we're going to ignore the non-presenting WebVR case for
now as it's causing a lot of problems and we may not ship with it.

[bshe, 2016/11/02 14:58:40]

Does this mean magic window mode won't ship in normal 2d browser? Or do you mean
it won't be available in ChromeVR?

[mthiesse, 2016/11/02 15:03:32]

It doesn't mean either of those things. It means we haven't decided yet, so I'm
going to hold off on writing the code to pause WebVR for now. Right now we don't
even have a way to know which Device VR Shell is using, so we don't have a way
to find all of the WebVR pages using the same device.

+    }
+  }
+#endif
+  if (html_interface_->GetMode() == UiInterface::Mode::WEB_VR) {
+    return;
+  }
   // TODO(asimjour) for now, scroll is sent to the main content.
   if (gesture->type == WebInputEvent::GestureScrollBegin ||
       gesture->type == WebInputEvent::GestureScrollUpdate ||
@@ -408,7 +431,7 @@ uint32_t GetPixelEncodedPoseIndex() {
   // encodes the pose index, and device/vr/android/gvr/gvr_device.cc
   // which tracks poses.
   uint8_t pixels[4];
-  // Assume we're reading from the frambebuffer we just wrote to.
+  // Assume we're reading from the framebuffer we just wrote to.
   // That's true currently, we may need to use glReadBuffer(GL_BACK)
   // or equivalent if the rendering setup changes in the future.
   glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixels);