[vr] Clicking on the security icon should prompt the user to bail out of VR

chrome/browser/android/vr_shell/ui_scene_manager.cc

Index: chrome/browser/android/vr_shell/ui_scene_manager.cc
diff --git a/chrome/browser/android/vr_shell/ui_scene_manager.cc b/chrome/browser/android/vr_shell/ui_scene_manager.cc
index 4a6f45111f69e8ebe27183bd15d848582c585597..50545c84d2414ffe1e5ee321597c30c1f09a535f 100644
--- a/chrome/browser/android/vr_shell/ui_scene_manager.cc
+++ b/chrome/browser/android/vr_shell/ui_scene_manager.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/android/vr_shell/textures/ui_texture.h"
 #include "chrome/browser/android/vr_shell/ui_elements/audio_capture_indicator.h"
 #include "chrome/browser/android/vr_shell/ui_elements/button.h"
+#include "chrome/browser/android/vr_shell/ui_elements/exit_prompt.h"
 #include "chrome/browser/android/vr_shell/ui_elements/exit_warning.h"
 #include "chrome/browser/android/vr_shell/ui_elements/loading_indicator.h"
 #include "chrome/browser/android/vr_shell/ui_elements/permanent_security_warning.h"
@@ -46,6 +47,9 @@ static constexpr float kContentVerticalOffset = -0.1 * kContentDistance;
 static constexpr float kBackplaneSize = 1000.0;
 static constexpr float kBackgroundDistanceMultiplier = 1.414;
 
+static constexpr float kExitPromptWidth = 0.672 * kContentDistance;
+static constexpr float kExitPromptHeight = 0.2 * kContentDistance;
+
 static constexpr float kUrlBarDistance = 2.4;
 static constexpr float kUrlBarWidth = 0.672 * kUrlBarDistance;
 static constexpr float kUrlBarHeight = 0.088 * kUrlBarDistance;
@@ -211,9 +215,26 @@ void UiSceneManager::CreateContentQuad() {
   element->set_size({kBackplaneSize, kBackplaneSize, 1.0});
   element->set_translation({0.0, 0.0, -kTextureOffset});
   element->set_parent_id(main_content_->id());
+  main_content_backplane_ = element.get();
   content_elements_.push_back(element.get());
   scene_->AddUiElement(std::move(element));
 
+  element = base::MakeUnique<ExitPrompt>(
+      512,
+      base::Bind(&UiSceneManager::OnExitPromptPrimaryButtonClicked,
+                 base::Unretained(this)),
+      base::Bind(&UiSceneManager::OnExitPromptSecondaryButtonClicked,
+                 base::Unretained(this)));
+  element->set_debug_id(kExitPrompt);
+  element->set_id(AllocateId());
+  element->set_fill(vr_shell::Fill::NONE);
+  element->set_size({kExitPromptWidth, kExitPromptHeight, 1});
+  element->set_translation({0.0, 0.0, kTextureOffset});
+  element->set_parent_id(main_content_->id());
+  element->set_visible(false);
+  exit_prompt_ = element.get();
+  scene_->AddUiElement(std::move(element));
+
   // Limit reticle distance to a sphere based on content distance.
   scene_->SetBackgroundDistance(main_content_->translation().z() *
                                 -kBackgroundDistanceMultiplier);
@@ -233,7 +254,7 @@ void UiSceneManager::CreateBackground() {
   element->set_draw_phase(0);
   element->set_gridline_count(kFloorGridlineCount);
   floor_ = element.get();
-  content_elements_.push_back(element.get());
+  background_elements_.push_back(element.get());
   scene_->AddUiElement(std::move(element));
 
   // Ceiling.
@@ -246,7 +267,7 @@ void UiSceneManager::CreateBackground() {
   element->set_fill(vr_shell::Fill::OPAQUE_GRADIENT);
   element->set_draw_phase(0);
   ceiling_ = element.get();
-  content_elements_.push_back(element.get());
+  background_elements_.push_back(element.get());
   scene_->AddUiElement(std::move(element));
 
   UpdateBackgroundColor();
@@ -256,13 +277,14 @@ void UiSceneManager::CreateUrlBar() {
   // TODO(cjgrant): Incorporate final size and position.
   auto url_bar = base::MakeUnique<UrlBar>(
       512,
+      base::Bind(&UiSceneManager::OnBackButtonClicked, base::Unretained(this)),
+      base::Bind(&UiSceneManager::OnSecurityIconClicked,
+                 base::Unretained(this)),
       base::Bind(&UiSceneManager::OnUnsupportedMode, base::Unretained(this)));
   url_bar->set_debug_id(kUrlBar);
   url_bar->set_id(AllocateId());
   url_bar->set_translation({0, kUrlBarVerticalOffset, -kUrlBarDistance});
   url_bar->set_size({kUrlBarWidth, kUrlBarHeight, 1});
-  url_bar->SetBackButtonCallback(
-      base::Bind(&UiSceneManager::OnBackButtonClicked, base::Unretained(this)));
   url_bar_ = url_bar.get();
   control_elements_.push_back(url_bar.get());
   scene_->AddUiElement(std::move(url_bar));
@@ -311,16 +333,29 @@ void UiSceneManager::SetWebVrMode(bool web_vr) {
 
 void UiSceneManager::ConfigureScene() {
   exit_warning_->SetEnabled(scene_->is_exiting());
+  exit_prompt_->SetEnabled(scene_->is_prompting_to_exit());
   screen_dimmer_->SetEnabled(scene_->is_exiting());
 
   // Controls (URL bar, loading progress, etc).
   bool controls_visible = !web_vr_mode_ && !fullscreen_;
   for (UiElement* element : control_elements_) {
-    element->SetEnabled(controls_visible);
+    element->SetEnabled(controls_visible && !scene_->is_prompting_to_exit());
   }
 
   // Content elements.
   for (UiElement* element : content_elements_) {
+    // We don't want to show the content elements when the exit prompt is
+    // visible. The only content element visible in this case is the invisible
+    // backplane that we add right behind the content rect so that the reticle
+    // doesn't jump when it transitions between the content rect (and the exit
+    // prompt in this case) and the background.
+    bool disabled_for_exit_prompt =

[cjgrant, 2017/06/05 17:33:53]

It looks like we now have two content elements, and one of them is special-cased
here.  I think we should lose the loop for clarity.  I put the loops in only
because we had sets of elements that receive identical treatment.

[ymalik, 2017/06/05 20:02:42]

Totally, good catch.

+        element != main_content_backplane_ && scene_->is_prompting_to_exit();
+    element->SetEnabled(!web_vr_mode_ && !disabled_for_exit_prompt);
+  }
+
+  // Background elements.
+  for (UiElement* element : background_elements_) {
     element->SetEnabled(!web_vr_mode_);
   }
 
@@ -417,6 +452,24 @@ void UiSceneManager::OnBackButtonClicked() {
   browser_->NavigateBack();
 }
 
+void UiSceneManager::OnSecurityIconClicked() {
+  if (scene_->is_prompting_to_exit())

[cjgrant, 2017/06/05 17:33:53]

In this method and the next, why is the initial if() needed?  For example, when
will we be not prompting to exit, and handling an exit prompt button click?

[ymalik, 2017/06/05 20:02:42]

This is there for safety and you're right that this should never happen. Maybe
if we ever decide to show the url bar with the prompt.

+    return;
+  scene_->set_is_prompting_to_exit(true);
+  ConfigureScene();
+}
+
+void UiSceneManager::OnExitPromptPrimaryButtonClicked() {
+  if (!scene_->is_prompting_to_exit())
+    return;
+  scene_->set_is_prompting_to_exit(false);
+  ConfigureScene();
+}
+
+void UiSceneManager::OnExitPromptSecondaryButtonClicked() {
+  OnUnsupportedMode(UiUnsupportedMode::kUnhandledPageInfo);
+}
+
 void UiSceneManager::SetURL(const GURL& gurl) {
   url_bar_->SetURL(gurl);
 }