Views - draw omnibox popup shadows

chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc

 // Copyright (c) 2012 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/ui/views/omnibox/omnibox_popup_contents_view.h"
 
 #include <algorithm>
 
+#include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/layout_constants.h"
 #include "chrome/browser/ui/views/location_bar/location_bar_view.h"
 #include "chrome/browser/ui/views/omnibox/omnibox_result_view.h"
 #include "chrome/browser/ui/views/theme_copying_widget.h"
-#include "chrome/grit/theme_resources.h"
 #include "components/omnibox/browser/omnibox_view.h"
-#include "ui/base/material_design/material_design_controller.h"
-#include "ui/base/resource/resource_bundle.h"
+#include "third_party/skia/include/core/SkDrawLooper.h"
 #include "ui/base/theme_provider.h"
 #include "ui/compositor/clip_recorder.h"
 #include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/image/canvas_image_source.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/path.h"
+#include "ui/gfx/shadow_value.h"
+#include "ui/gfx/skia_util.h"
 #include "ui/views/controls/image_view.h"
-#include "ui/views/resources/grit/views_resources.h"
 #include "ui/views/view_targeter.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/non_client_view.h"
 
+namespace {
+
+// This creates a shadow image that is 1dp wide, suitable for tiling along the
+// top or bottom edge of the omnibox popup.
+class ShadowImageSource : public gfx::CanvasImageSource {
+ public:
+  ShadowImageSource(const std::vector<gfx::ShadowValue>& shadows, bool bottom)
+      : gfx::CanvasImageSource(gfx::Size(1, GetHeightForShadows(shadows)),
+                               false),
+        shadows_(shadows),
+        bottom_(bottom) {}
+  ~ShadowImageSource() override {}
+
+  void Draw(gfx::Canvas* canvas) override {
+    SkPaint paint;
+    paint.setLooper(gfx::CreateShadowDrawLooperCorrectBlur(shadows_));
+    canvas->DrawRect(gfx::RectF(0, bottom_ ? -1 : size().height(), 1, 1),
+                     paint);
+  }
+
+ private:
+  static int GetHeightForShadows(const std::vector<gfx::ShadowValue>& shadows) {
+    int height = 0;
+    for (const auto& shadow : shadows) {
+      height =
+          std::max(height, shadow.y() + static_cast<int>(shadow.blur()) / 2);

[Peter Kasting, 2016/09/23 19:38:44]

Functionally, shouldn't this be more like "ceil(blur() / 2)" to make sure we
cover all affected pixels?

Nit: Prefer gfx::ToRoundedInt() family of functions over direct static-casting,
to make the intent around rounding/flooring etc. clear.

[Evan Stade, 2016/09/26 18:11:42]

the blur value should always be even, but I've updated to use ToCeiledInt.

+    }
+    return height;
+  }
+
+  const std::vector<gfx::ShadowValue> shadows_;
+  bool bottom_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShadowImageSource);
+};
+
+// Cache the shadow images so that potentially expensive shadow drawing isn't
+// repeated.
+base::LazyInstance<gfx::ImageSkia> g_top_shadow = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<gfx::ImageSkia> g_bottom_shadow = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
 class OmniboxPopupContentsView::AutocompletePopupWidget
     : public ThemeCopyingWidget,
       public base::SupportsWeakPtr<AutocompletePopupWidget> {
  public:
   explicit AutocompletePopupWidget(views::Widget* role_model)
       : ThemeCopyingWidget(role_model) {}
   ~AutocompletePopupWidget() override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AutocompletePopupWidget);
@@ skipping 23 matching lines @@
       omnibox_view_(omnibox_view),
       location_bar_view_(location_bar_view),
       font_list_(font_list),
       ignore_mouse_drag_(false),
       size_animation_(this),
       start_margin_(0),
       end_margin_(0) {
   // The contents is owned by the LocationBarView.
   set_owned_by_client();
 
-  ui::ResourceBundle* rb = &ui::ResourceBundle::GetSharedInstance();
-  if (ui::MaterialDesignController::IsModeMaterial()) {
-    top_shadow_ = rb->GetImageSkiaNamed(IDR_OMNIBOX_DROPDOWN_SHADOW_TOP);
-    bottom_shadow_ = rb->GetImageSkiaNamed(IDR_OMNIBOX_DROPDOWN_SHADOW_BOTTOM);
-  } else {
-    bottom_shadow_ = rb->GetImageSkiaNamed(IDR_BUBBLE_B);
+  if (g_top_shadow.Get().isNull()) {
+    std::vector<gfx::ShadowValue> shadows;
+    // Blur by 1dp. See comment below about blur accounting.

[Peter Kasting, 2016/09/23 19:38:44]

Argument for another day: It sure is weird to me that we use a 1 dp blur atop
the omnibox instead of just making the toolbar bottom edge the omnibox top edge.
 Would love to kill the "top shadow" idea entirely.

[Evan Stade, 2016/09/26 18:11:42]

that works better when there's no bookmark bar --- with the bookmarks showing
there's not a horizontal rule to fall back on.

[Peter Kasting, 2016/09/26 19:57:34]

Yeah, we'd have to draw it ourselves, I just think the "shadow" effect looks
strange compared to the 1 px stroke, and it's weird it's not in the same
position as the no-bookmark-bar stroke.

Whatever.  Not for this CL.

+    shadows.emplace_back(gfx::Vector2d(), 2, SK_ColorBLACK);
+
+    auto source = new ShadowImageSource(shadows, false);
+    g_top_shadow.Get() = gfx::ImageSkia(source, source->size());

[Peter Kasting, 2016/09/23 19:38:44]

Musing: Wow, we really should fix
https://bugs.chromium.org/p/chromium/issues/detail?id=637898 .

All these .Get()s everywhere are sure ugly too.  Can't wait for C++20 to solve
the operator.() issue :P

+  }
+  if (g_bottom_shadow.Get().isNull()) {
+    const int kSmallShadowBlur = 3;
+    const int kLargeShadowBlur = 8;
+    const int kLargeShadowYOffset = 3;
+
+    std::vector<gfx::ShadowValue> shadows;
+    // gfx::ShadowValue counts blur pixels both inside and outside the shape,
+    // whereas these blur values only describe the outside portion, hence they
+    // must be doubled.
+    shadows.emplace_back(gfx::Vector2d(0, 0), 2 * kSmallShadowBlur,

[Peter Kasting, 2016/09/23 19:38:44]

Nit: Omit 0, 0

[Evan Stade, 2016/09/26 18:11:42]

Done.

+                         SK_ColorBLACK);
+    shadows.emplace_back(gfx::Vector2d(0, kLargeShadowYOffset),
+                         2 * kLargeShadowBlur, SK_ColorBLACK);
+
+    auto source = new ShadowImageSource(shadows, true);
+    g_bottom_shadow.Get() = gfx::ImageSkia(source, source->size());
   }
 
   SetEventTargeter(
       std::unique_ptr<views::ViewTargeter>(new views::ViewTargeter(this)));
 }
 
 void OmniboxPopupContentsView::Init() {
   // This can't be done in the constructor as at that point we aren't
   // necessarily our final class yet, and we may have subclasses
   // overriding CreateResultView.
@@ skipping 22 matching lines @@
   int current_height_delta = static_cast<int>(
       size_animation_.GetCurrentValue() * total_height_delta - 0.5);
   current_frame_bounds.set_height(
       current_frame_bounds.height() + current_height_delta);
   return current_frame_bounds;
 }
 
 void OmniboxPopupContentsView::LayoutChildren() {
   gfx::Rect contents_rect = GetContentsBounds();
   contents_rect.Inset(GetLayoutInsets(OMNIBOX_DROPDOWN));
-  contents_rect.Inset(start_margin_,
-                      views::NonClientFrameView::kClientEdgeThickness,
-                      end_margin_, 0);
+  contents_rect.Inset(start_margin_, g_top_shadow.Get().height(), end_margin_,
+                      0);
 
   int top = contents_rect.y();
   for (size_t i = 0; i < AutocompleteResult::kMaxMatches; ++i) {
     View* v = child_at(i);
     if (v->visible()) {
       v->SetBounds(contents_rect.x(), top, contents_rect.width(),
                    v->GetPreferredSize().height());
       top = v->bounds().bottom();
     }
   }
@@ skipping 53 matching lines @@
     }
     if (match.type == AutocompleteMatchType::SEARCH_SUGGEST_TAIL) {
       max_match_contents_width_ = std::max(
           max_match_contents_width_, view->GetMatchContentsWidth());
     }
   }
 
   for (size_t i = result_size; i < AutocompleteResult::kMaxMatches; ++i)
     child_at(i)->SetVisible(false);
 
-  // In non-material mode, we want the popup to appear as if it's overlaying
-  // the top of the page content, i.e., is flush against the client edge at the
-  // bottom of the toolbar. However, if the bookmarks bar is attached, we want
-  // to draw over it (so as not to push the results below it), but that means
-  // the toolbar won't be drawing a client edge separating itself from the
-  // popup. So we unconditionally overlap the toolbar by the thickness of the
-  // client edge and draw our own edge (see OnPaint()), which fixes the
-  // attached bookmark bar case without breaking the other case.
-  int top_edge_overlap = views::NonClientFrameView::kClientEdgeThickness;
-  if (ui::MaterialDesignController::IsModeMaterial()) {
-    // In material mode, we cover the bookmark bar similarly, but instead of
-    // appearing below the client edge, we want the popup to appear to overlay
-    // the bottom of the toolbar. So instead of drawing a client edge atop the
-    // popup, we shift the popup to completely cover the client edge, and then
-    // draw an additional semitransparent shadow above that. So the total
-    // overlap necessary is the client edge thickness plus the shadow height.
-    top_edge_overlap += top_shadow_->height();
-  }
+  // We want the popup to appear to overlay the bottom of the toolbar. So we
+  // shift the popup to completely cover the client edge, and then draw an
+  // additional semitransparent shadow above that. So the total overlap
+  // necessary is the client edge thickness plus the shadow height.

[Peter Kasting, 2016/09/23 19:38:44]

Nit: Wondering if the last sentence just restates the prior one + the code too
much

[Evan Stade, 2016/09/26 18:11:42]

Done.

+  int top_edge_overlap = views::NonClientFrameView::kClientEdgeThickness +
+                         g_top_shadow.Get().height();
 
   gfx::Point top_left_screen_coord;
   int width;
   location_bar_view_->GetOmniboxPopupPositioningInfo(
       &top_left_screen_coord, &width, &start_margin_,
       &end_margin_, top_edge_overlap);
   gfx::Rect new_target_bounds(top_left_screen_coord,
                               gfx::Size(width, CalculatePopupHeight()));
 
   // If we're animating and our target height changes, reset the animation.
@@ skipping 186 matching lines @@
 
 int OmniboxPopupContentsView::CalculatePopupHeight() {
   DCHECK_GE(static_cast<size_t>(child_count()), model_->result().size());
   int popup_height = 0;
   for (size_t i = 0; i < model_->result().size(); ++i)
     popup_height += child_at(i)->GetPreferredSize().height();
 
   // Add enough space on the top and bottom so it looks like there is the same
   // amount of space between the text and the popup border as there is in the
   // interior between each row of text.
-  return popup_height + views::NonClientFrameView::kClientEdgeThickness +
-      GetLayoutInsets(OMNIBOX_DROPDOWN).height() +
-      bottom_shadow_->height() -
-      GetLayoutConstant(OMNIBOX_DROPDOWN_BORDER_INTERIOR);
+  return popup_height + GetLayoutInsets(OMNIBOX_DROPDOWN).height() +
+         g_top_shadow.Get().height() + g_bottom_shadow.Get().height();
 }
 
 OmniboxResultView* OmniboxPopupContentsView::CreateResultView(
     int model_index,
     const gfx::FontList& font_list) {
   return new OmniboxResultView(this, model_index, location_bar_view_,
                                font_list);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // OmniboxPopupContentsView, views::View overrides, private:
 
 const char* OmniboxPopupContentsView::GetClassName() const {
   return "OmniboxPopupContentsView";
 }
 
 void OmniboxPopupContentsView::OnPaint(gfx::Canvas* canvas) {
-  // Top border.
-  if (ui::MaterialDesignController::IsModeMaterial()) {
-    canvas->TileImageInt(*top_shadow_, 0, 0, width(), top_shadow_->height());
-  } else {
-    canvas->FillRect(gfx::Rect(0, 0, width(),
-                               views::NonClientFrameView::kClientEdgeThickness),
-                     location_bar_view_->GetThemeProvider()->GetColor(
-                         ThemeProperties::COLOR_TOOLBAR_BOTTOM_SEPARATOR));
-  }
-
-  // Bottom border.
-  canvas->TileImageInt(*bottom_shadow_, 0, height() - bottom_shadow_->height(),
-                       width(), bottom_shadow_->height());
+  canvas->TileImageInt(g_top_shadow.Get(), 0, 0, width(),
+                       g_top_shadow.Get().height());
+  canvas->TileImageInt(g_bottom_shadow.Get(), 0,
+                       height() - g_bottom_shadow.Get().height(), width(),
+                       g_bottom_shadow.Get().height());
 }
 
 void OmniboxPopupContentsView::PaintChildren(const ui::PaintContext& context) {
   gfx::Rect contents_bounds = GetContentsBounds();
-  const int interior = GetLayoutConstant(OMNIBOX_DROPDOWN_BORDER_INTERIOR);
-  contents_bounds.Inset(0, views::NonClientFrameView::kClientEdgeThickness, 0,
-                        bottom_shadow_->height() - interior);
+  contents_bounds.Inset(0, g_top_shadow.Get().height(), 0,
+                        g_bottom_shadow.Get().height());
 
   ui::ClipRecorder clip_recorder(context);
   clip_recorder.ClipRect(contents_bounds);
   {
     ui::PaintRecorder recorder(context, size());
     SkColor background_color = result_view_at(0)->GetColor(
         OmniboxResultView::NORMAL, OmniboxResultView::BACKGROUND);
     recorder.canvas()->DrawColor(background_color);
   }
   View::PaintChildren(context);
@@ skipping 49 matching lines @@
   size_t index = GetIndexForPoint(event.location());
   if (!HasMatchAt(index))
     return;
   omnibox_view_->OpenMatch(model_->result().match_at(index), disposition,
                            GURL(), base::string16(), index);
 }
 
 OmniboxResultView* OmniboxPopupContentsView::result_view_at(size_t i) {
   return static_cast<OmniboxResultView*>(child_at(static_cast<int>(i)));
 }