Update toast behavior and apperance according to UX requirement

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 a0507a63a625e4c67440520b15c315b198512d5a..595cf1239913d8679f40618247cb6fcd0eec78dc 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_browser_interface.h"
 #include "chrome/browser/android/vr_shell/ui_elements/button.h"
+#include "chrome/browser/android/vr_shell/ui_elements/exclusive_screen_toast.h"
 #include "chrome/browser/android/vr_shell/ui_elements/exit_prompt.h"
 #include "chrome/browser/android/vr_shell/ui_elements/exit_prompt_backplane.h"
 #include "chrome/browser/android/vr_shell/ui_elements/loading_indicator.h"
@@ -80,9 +81,14 @@ static constexpr float kTransientUrlBarVerticalOffset =
     -0.2 * kTransientUrlBarDistance;
 static constexpr int kTransientUrlBarTimeoutSeconds = 6;
 
-static constexpr float kToastDistance = 1.4;
-static constexpr float kToastWidth = 0.512 * kToastDistance;
-static constexpr float kToastHeight = 0.16 * kToastDistance;
+static constexpr float kWebVrToastDistance = 1.0;
+static constexpr float kFullscreenToastDistance = kFullscreenDistance;
+static constexpr float kToastWidthDMM = 0.512;
+static constexpr float kToastHeightDMM = 0.064;
+static constexpr float kToastOffsetDMM = 0.004;
+// When changing the value here, make sure it doesn't collide with
+// kWarningAngleRadians.
+static constexpr float kWebVrAngleRadians = 9.88 * M_PI / 180.0;
 static constexpr int kToastTimeoutSeconds = kTransientUrlBarTimeoutSeconds;
 
 static constexpr float kSplashScreenDistance = 1;
@@ -430,11 +436,9 @@ void UiSceneManager::CreateToasts() {
   element->set_debug_id(kExclusiveScreenToast);
   element->set_id(AllocateId());
   element->set_fill(vr_shell::Fill::NONE);
-  element->set_size({kToastWidth, kToastHeight, 1});
-  element->set_translation({0, 0, -kToastDistance});
+  element->set_size({kToastWidthDMM, kToastHeightDMM, 1});

[amp, 2017/06/28 16:47:21]

Don't the DMM need to be multiplied by the distance before being used?

Or is that what set_scale does below?  (in which case why don't we do that for
other elements?)

[bshe, 2017/06/28 20:01:58]

It is what set_scale does. It is unclear to me if we have a preference of one
over the other in each individual case. 
In my case, use set_scale makes much more sense. The real element size was
dynamically calculated based on the string length. And only the height of toast
stays the same. After calculation, I shouldn't change the size at all.

   element->set_visible(false);
   element->set_hit_testable(false);
-  element->set_lock_to_fov(true);
   exclusive_screen_toast_ = element.get();
   scene_->AddUiElement(std::move(element));
 }
@@ -520,6 +524,30 @@ void UiSceneManager::ConfigureScene() {
         gfx::Vector3dF(kCloseButtonWidth, kCloseButtonHeight, 1));
   }
 
+  if (fullscreen_ && !web_vr_mode_) {

[cjgrant, 2017/06/28 13:55:34]

Why not put this block into ConfigureExclusiveScreenToast, and call it here? 
IMO, that method's job is to do exactly what this code is doing.

[bshe, 2017/06/28 20:01:58]

I am trying to make rebase easier. Your refactor patch will get rid of
ConfigureExclusiveScreenToast, right?

[cjgrant, 2017/06/28 20:24:50]

Yes, it does, currently, but when there's this much code, it should continue to
exist.

[bshe, 2017/06/29 01:34:11]

Done.

+    // Do not set size again. The size might have been changed by the backing
+    // texture size in UpdateElementSize.
+    exclusive_screen_toast_->set_scale(
+        {kFullscreenToastDistance, kFullscreenToastDistance, 1});
+    exclusive_screen_toast_->set_translation(
+        {0,
+         kFullscreenVerticalOffset + kFullscreenHeight / 2 +
+             (kToastOffsetDMM + kToastHeightDMM) * kFullscreenToastDistance,
+         -kFullscreenToastDistance});
+    exclusive_screen_toast_->set_rotation(
+        gfx::Quaternion(gfx::Vector3dF(1, 0, 0), 0.0));
+    exclusive_screen_toast_->set_lock_to_fov(false);
+  } else if (web_vr_mode_ && web_vr_show_toast_) {
+    exclusive_screen_toast_->set_scale(
+        {kWebVrToastDistance, kWebVrToastDistance, 1});
+    exclusive_screen_toast_->set_translation(
+        gfx::Vector3dF(0, kWebVrToastDistance * sin(kWebVrAngleRadians),
+                       -kWebVrToastDistance * cos(kWebVrAngleRadians)));
+    exclusive_screen_toast_->set_rotation(
+        gfx::Quaternion(gfx::Vector3dF(1, 0, 0), kWebVrAngleRadians));
+    exclusive_screen_toast_->set_lock_to_fov(true);
+  }
+
   scene_->SetMode(mode());
   scene_->SetBackgroundDistance(main_content_->translation().z() *
                                 -kBackgroundDistanceMultiplier);