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

chrome/browser/android/vr_shell/textures/exit_prompt_texture.cc

+// Copyright 2017 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 "chrome/browser/android/vr_shell/textures/exit_prompt_texture.h"
+
+#include "cc/paint/skia_paint_canvas.h"
+#include "chrome/browser/android/vr_shell/color_scheme.h"
+#include "chrome/grit/generated_resources.h"
+#include "components/strings/grit/components_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/font_list.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/vector2d.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/gfx/render_text.h"
+#include "ui/gfx/vector_icon_types.h"
+#include "ui/vector_icons/vector_icons.h"
+
+#include "ui/gfx/color_palette.h"
+
+namespace vr_shell {
+
+namespace {
+
+constexpr float kWidth = 0.672;

[cjgrant, 2017/06/02 04:16:35]

Hmm, I'm used to these being static, but the codebase has both.  Seems like
there's a difference but I don't know what's better.

[ymalik, 2017/06/02 21:14:31]

There's no difference because things in anonymous namespace have static linkage.

+constexpr float kHeight = 0.2;
+constexpr float kButtonWidth = 0.162;
+constexpr float kButtonHeight = 0.066;
+constexpr float kPromptTextButtonSeperatorHeight = 0.04;
+constexpr float kButtonsSeperatorWidth = 0.01;
+constexpr float kButtonRadiusFactor = 0.006;
+constexpr float kFontSizeFactor = 0.048;
+
+}  // namespace
+
+ExitPromptTexture::ExitPromptTexture() = default;
+
+ExitPromptTexture::~ExitPromptTexture() = default;
+
+const ColorScheme& ExitPromptTexture::color_scheme() const {
+  return ColorScheme::GetColorScheme(mode());
+}
+
+void ExitPromptTexture::Draw(SkCanvas* sk_canvas,
+                             const gfx::Size& texture_size) {
+  size_.set_width(texture_size.width());
+  size_.set_height(texture_size.height());
+
+  cc::SkiaPaintCanvas paint_canvas(sk_canvas);
+  gfx::Canvas gfx_canvas(&paint_canvas, 1.0f);
+  gfx::Canvas* canvas = &gfx_canvas;
+
+  // Prompt text area

[cjgrant, 2017/06/02 04:16:35]

nit: Periods on comments. :)

[ymalik, 2017/06/02 21:14:31]

Done.

+  auto text = l10n_util::GetStringUTF16(IDS_VR_SHELL_EXIT_PROMPT_DESCRIPTION);
+  gfx::FontList fonts;
+  GetFontList(size_.width() * kFontSizeFactor, text, &fonts);
+  gfx::Rect prompt_text_size(size_.width(), 0);
+  std::vector<std::unique_ptr<gfx::RenderText>> lines = PrepareDrawStringRect(
+      text, fonts, color_scheme().prompt_text, &prompt_text_size,
+      kTextAlignmentCenter, kWrappingBehaviorWrap);
+  for (auto& render_text : lines)
+    render_text->Draw(canvas);
+
+  SkPaint paint;
+  gfx::Rect button_text_size(ToPixels(kButtonWidth), 0);
+  float radius = size_.width() * kButtonRadiusFactor;
+
+  // Secondary button area
+  text = l10n_util::GetStringUTF16(IDS_VR_SHELL_EXIT_PROMPT_EXIT_VR_BUTTON);
+  lines = PrepareDrawStringRect(
+      text, fonts, color_scheme().secondary_button_text, &button_text_size,
+      kTextAlignmentCenter, kWrappingBehaviorWrap);
+  secondary_button_rect_.SetRect(
+      ToPixels(kWidth) / 2 - ToPixels(kButtonsSeperatorWidth) -

[cjgrant, 2017/06/02 04:16:36]

Why 3 ToPixels calls instead of one, on the result of math on unconverted
constants?

[ymalik, 2017/06/02 21:14:31]

I was being silly :)

+          ToPixels(kButtonWidth),
+      prompt_text_size.height() + ToPixels(kPromptTextButtonSeperatorHeight),
+      ToPixels(kButtonWidth), ToPixels(kButtonHeight));
+  paint.setColor(secondary_hovered_
+                     ? color_scheme().button_background_hover
+                     : color_scheme().secondary_button_background);
+  canvas->Save();
+  canvas->Translate(
+      gfx::Vector2d(secondary_button_rect_.x(), secondary_button_rect_.y()));
+  sk_canvas->drawRoundRect(
+      SkRect::MakeXYWH(0, 0, ToPixels(kButtonWidth), ToPixels(kButtonHeight)),
+      radius, radius, paint);
+  canvas->Translate(gfx::Vector2d(
+      0, ToPixels(kButtonHeight) / 2 - button_text_size.height() / 2));
+  for (auto& render_text : lines)
+    render_text->Draw(canvas);
+  canvas->Restore();
+
+  // Primary button area
+  text = l10n_util::GetStringUTF16(IDS_OK);

[cjgrant, 2017/06/02 04:16:36]

This block is really similar to the one above. Do you think it's worth pulling
out a helper method, and calling it twice with primary and secondary parameters?

[ymalik, 2017/06/02 21:14:31]

We could, but we would either have to pass a lot of things as parameters, or
have "if(primary) else" blocks in the helper method. For example, the
differences are things like color, text, location.  I don't think it'll end up
looking much cleaner, so not worth it. 

+  button_text_size.set_size(ToPixels(kButtonWidth), 0);
+  lines = PrepareDrawStringRect(text, fonts, color_scheme().primary_button_text,
+                                &button_text_size, kTextAlignmentCenter,
+                                kWrappingBehaviorWrap);
+  primary_button_rect_.SetRect(
+      ToPixels(kWidth) / 2 + ToPixels(kButtonsSeperatorWidth),
+      prompt_text_size.height() + ToPixels(kPromptTextButtonSeperatorHeight),
+      ToPixels(kButtonWidth), ToPixels(kButtonHeight));
+  paint.setColor(primary_hovered_ ? color_scheme().button_background_hover
+                                  : color_scheme().primary_button_background);
+  canvas->Save();
+  canvas->Translate(
+      gfx::Vector2d(primary_button_rect_.x(), primary_button_rect_.y()));
+  sk_canvas->drawRoundRect(
+      SkRect::MakeXYWH(0, 0, ToPixels(kButtonWidth), ToPixels(kButtonHeight)),
+      radius, radius, paint);
+  canvas->Translate(gfx::Vector2d(
+      0, ToPixels(kButtonHeight) / 2 - button_text_size.height() / 2));
+  for (auto& render_text : lines)
+    render_text->Draw(canvas);
+  canvas->Restore();
+}
+
+float ExitPromptTexture::ToPixels(float meters) const {
+  return meters * size_.width() / kWidth;
+}
+
+gfx::PointF ExitPromptTexture::percentToPixels(
+    const gfx::PointF& percent) const {
+  return gfx::PointF(percent.x() * size_.width(), percent.y() * size_.height());
+}
+
+bool ExitPromptTexture::HitsSecondaryButton(const gfx::PointF& position) const {
+  return secondary_button_rect_.Contains(percentToPixels(position));
+}
+
+void ExitPromptTexture::SetPrimaryHovered(bool hovered) {
+  if (primary_hovered_ != hovered)
+    set_dirty();
+  primary_hovered_ = hovered;
+}
+
+void ExitPromptTexture::SetPrimaryPressed(bool pressed) {
+  if (primary_pressed_ != pressed)
+    set_dirty();
+  primary_pressed_ = pressed;
+}
+
+void ExitPromptTexture::SetSecondaryHovered(bool hovered) {
+  if (secondary_hovered_ != hovered)
+    set_dirty();
+  secondary_hovered_ = hovered;
+}
+
+void ExitPromptTexture::SetSecondaryPressed(bool pressed) {
+  if (secondary_pressed_ != pressed)
+    set_dirty();
+  secondary_pressed_ = pressed;
+}
+
+bool ExitPromptTexture::HitsPrimaryButton(const gfx::PointF& position) const {

[cjgrant, 2017/06/02 04:16:36]

nit: Should probably move this up with the other Hits method (ie. some kind of
sorting for readability).

[ymalik, 2017/06/02 21:14:31]

Done.

+  return primary_button_rect_.Contains(percentToPixels(position));
+}
+
+gfx::Size ExitPromptTexture::GetPreferredTextureSize(int maximum_width) const {
+  return gfx::Size(maximum_width, maximum_width * kHeight / kWidth);
+}
+
+gfx::SizeF ExitPromptTexture::GetDrawnSize() const {
+  return size_;
+}
+
+}  // namespace vr_shell