MacViews: Overlay Scrollbars with Show/Hide Animations

ui/views/controls/scrollbar/native_scroll_bar_views.cc

Index: ui/views/controls/scrollbar/native_scroll_bar_views.cc
diff --git a/ui/views/controls/scrollbar/native_scroll_bar_views.cc b/ui/views/controls/scrollbar/native_scroll_bar_views.cc
index 3348b5bcbca041cc3e422722b685040a623e0c45..f9d2eb83ff002c7c8388525d32200ccbab7b90ce 100644
--- a/ui/views/controls/scrollbar/native_scroll_bar_views.cc
+++ b/ui/views/controls/scrollbar/native_scroll_bar_views.cc
@@ -29,7 +29,9 @@ class ScrollBarButton : public BaseScrollBarButton {
     RIGHT,
   };
 
-  ScrollBarButton(ButtonListener* listener, Type type);
+  ScrollBarButton(ButtonListener* listener,
+                  Type type,
+                  NativeScrollBarWrapper* wrapper);
   ~ScrollBarButton() override;
 
   gfx::Size GetPreferredSize() const override;
@@ -44,12 +46,14 @@ class ScrollBarButton : public BaseScrollBarButton {
   ui::NativeTheme::State GetNativeThemeState() const;
 
   Type type_;
+  NativeScrollBarWrapper* wrapper_;
 };
 
 // Wrapper for the scroll thumb
 class ScrollBarThumb : public BaseScrollBarThumb {
  public:
-  explicit ScrollBarThumb(BaseScrollBar* scroll_bar);
+  explicit ScrollBarThumb(BaseScrollBar* scroll_bar,

[tapted, 2016/02/08 00:31:15]

nit: explicit not needed

[spqchan, 2016/02/09 21:21:26]

Done.

+                          NativeScrollBarWrapper* wrapper);
   ~ScrollBarThumb() override;
 
   gfx::Size GetPreferredSize() const override;
@@ -64,14 +68,16 @@ class ScrollBarThumb : public BaseScrollBarThumb {
   ui::NativeTheme::State GetNativeThemeState() const;
 
   ScrollBar* scroll_bar_;
+  NativeScrollBarWrapper* wrapper_;

[tapted, 2016/02/08 00:31:15]

hm. I wonder if ScrollBar should expose a GetNativeWrapper virtual method. Or,
does anything other than NativeScrollBarViews call the constructor? (can you
just pass a NativeScrollBar, add a NativeScrollBar::native_wrapper() accessor,
and change the type of |scroll_bar_| to NativeScrollBar?

[spqchan, 2016/02/09 21:21:26]

ScrollBar doesn't contain the native_wrapper so that wouldn't work.
Changing it to NativeScrollBar would work though
Anyway, I just removed the wrapper since we no longer need it

 };
 
 /////////////////////////////////////////////////////////////////////////////
 // ScrollBarButton
 
-ScrollBarButton::ScrollBarButton(ButtonListener* listener, Type type)
-    : BaseScrollBarButton(listener),
-      type_(type) {
+ScrollBarButton::ScrollBarButton(ButtonListener* listener,
+                                 Type type,
+                                 NativeScrollBarWrapper* wrapper)
+    : BaseScrollBarButton(listener), type_(type), wrapper_(wrapper) {
   SetFocusable(false);
   SetAccessibilityFocusable(false);
 }
@@ -105,6 +111,8 @@ ui::NativeTheme::ExtraParams
       break;
   }
 
+  params.scrollbar_arrow.overlay = wrapper_->GetOverlayParams();

[tapted, 2016/02/08 00:31:15]

check for a null |wrapper_|?

[spqchan, 2016/02/09 21:21:26]

Acknowledged.

+
   return params;
 }
 
@@ -147,9 +155,11 @@ ui::NativeTheme::State
 /////////////////////////////////////////////////////////////////////////////
 // ScrollBarThumb
 
-ScrollBarThumb::ScrollBarThumb(BaseScrollBar* scroll_bar)
+ScrollBarThumb::ScrollBarThumb(BaseScrollBar* scroll_bar,
+                               NativeScrollBarWrapper* wrapper)
     : BaseScrollBarThumb(scroll_bar),
-      scroll_bar_(scroll_bar) {
+      scroll_bar_(scroll_bar),
+      wrapper_(wrapper) {
   SetFocusable(false);
   SetAccessibilityFocusable(false);
 }
@@ -184,6 +194,7 @@ ui::NativeTheme::ExtraParams ScrollBarThumb::GetNativeThemeParams() const {
   ui::NativeTheme::ExtraParams params;
   params.scrollbar_thumb.is_hovering =
       (GetState() != CustomButton::STATE_HOVERED);
+  params.scrollbar_thumb.overlay = wrapper_->GetOverlayParams();

[tapted, 2016/02/08 00:31:15]

null check?

[spqchan, 2016/02/09 21:21:26]

Acknowledged.

   return params;
 }
 
@@ -219,19 +230,18 @@ ui::NativeTheme::State ScrollBarThumb::GetNativeThemeState() const {
 const char NativeScrollBarViews::kViewClassName[] = "NativeScrollBarViews";
 
 NativeScrollBarViews::NativeScrollBarViews(NativeScrollBar* scroll_bar)
-    : BaseScrollBar(scroll_bar->IsHorizontal(),
-                    new ScrollBarThumb(this)),
+    : BaseScrollBar(scroll_bar->IsHorizontal(), new ScrollBarThumb(this, this)),
       native_scroll_bar_(scroll_bar) {
   set_controller(native_scroll_bar_->controller());
 
   if (native_scroll_bar_->IsHorizontal()) {
-    prev_button_ = new ScrollBarButton(this, ScrollBarButton::LEFT);
-    next_button_ = new ScrollBarButton(this, ScrollBarButton::RIGHT);
+    prev_button_ = new ScrollBarButton(this, ScrollBarButton::LEFT, this);
+    next_button_ = new ScrollBarButton(this, ScrollBarButton::RIGHT, this);
 
     part_ = ui::NativeTheme::kScrollbarHorizontalTrack;
   } else {
-    prev_button_ = new ScrollBarButton(this, ScrollBarButton::UP);
-    next_button_ = new ScrollBarButton(this, ScrollBarButton::DOWN);
+    prev_button_ = new ScrollBarButton(this, ScrollBarButton::UP, this);
+    next_button_ = new ScrollBarButton(this, ScrollBarButton::DOWN, this);
 
     part_ = ui::NativeTheme::kScrollbarVerticalTrack;
   }
@@ -406,4 +416,11 @@ int NativeScrollBarWrapper::GetVerticalScrollBarWidth(
   return std::max(track_size.width(), button_size.width());
 }
 
+ui::NativeTheme::OverlayParams NativeScrollBarWrapper::GetOverlayParams() {
+  ui::NativeTheme::OverlayParams params;
+  params.is_overlay = false;
+  params.alpha = 1.0;
+  return params;
+}
+
 }  // namespace views