Paint tab-loading throbbers into a ui::Layer.

chrome/browser/ui/views/tabs/tab.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/tabs/tab.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/debug/alias.h"
@@ skipping 119 matching lines @@
 // The minimum opacity (out of 1) when a tab (either active or inactive) is
 // throbbing in the immersive mode light strip.
 const double kImmersiveTabMinThrobOpacity = 0.66;
 
 // Number of steps in the immersive mode loading animation.
 const int kImmersiveLoadingStepCount = 32;
 
 const char kTabCloseButtonName[] = "TabCloseButton";
 const int kTabCloseButtonSize = 16;
 
+// Layer-backed view for updating a waiting or loading tab spinner.

[Peter Kasting, 2015/10/09 08:03:23]

Tiny nit: Please be consistent about using the word "throbber" (in the CL title
too), as mixing different terms is confusing.

[tapted, 2015/10/09 11:00:31]

Done.

+class ThrobberView : public views::View {
+ public:
+  explicit ThrobberView(Tab* owner) : owner_(owner) {

[Peter Kasting, 2015/10/09 08:03:24]

Don't define any of these class methods inline; define the methods separately
below the class definition.

[tapted, 2015/10/09 11:00:31]

Done.

+    // Since the throbber animates, paint to a separate layer do reduce repaint

[Peter Kasting, 2015/10/09 08:03:24]

Nit: do -> to ?

Maybe you want "can animate for a long time" instead of "animates" as well.

[tapted, 2015/10/09 11:00:31]

Done.

+    // overheads.

[Peter Kasting, 2015/10/09 08:03:23]

Nit: overheads -> overhead

[tapted, 2015/10/09 11:00:31]

Done.

+    SetPaintToLayer(true);
+    SetFillsBoundsOpaquely(false);
+  }
+
+  // views::View:
+  bool CanProcessEventsWithinSubtree() const override { return false; }
+
+  void OnPaint(gfx::Canvas* canvas) override {
+    const TabRendererData::NetworkState state = owner_->data().network_state;
+    if (state == TabRendererData::NETWORK_STATE_NONE)
+      return;
+
+    const gfx::Rect bounds = GetLocalBounds();

[Peter Kasting, 2015/10/09 08:03:23]

Nit: Might as well define this just below |tp|, there's no real reason to
separate it up here.

[tapted, 2015/10/09 11:00:31]

Done.

+
+    // Paint network activity (aka throbber) animation frame.

[Peter Kasting, 2015/10/09 08:03:24]

Nit: It's weird to say "aka throbber" in a class whose name is basically
"throbber".

I wonder if this comment should just go away entirely.  It doesn't seem to
really add to the code.

[tapted, 2015/10/09 11:00:31]

Done.

+    ui::ThemeProvider* tp = GetThemeProvider();
+    if (state == TabRendererData::NETWORK_STATE_WAITING) {
+      if (waiting_start_time_ == base::TimeTicks())
+        waiting_start_time_ = base::TimeTicks::Now();
+
+      waiting_state_.elapsed_time =
+          base::TimeTicks::Now() - waiting_start_time_;
+      gfx::PaintThrobberWaiting(
+          canvas, bounds, tp->GetColor(ThemeProperties::COLOR_THROBBER_WAITING),
+          waiting_state_.elapsed_time);
+    } else {
+      if (loading_start_time_ == base::TimeTicks())
+        loading_start_time_ = base::TimeTicks::Now();
+
+      waiting_state_.color =
+          tp->GetColor(ThemeProperties::COLOR_THROBBER_WAITING);
+      gfx::PaintThrobberSpinningAfterWaiting(
+          canvas, bounds,
+          tp->GetColor(ThemeProperties::COLOR_THROBBER_SPINNING),
+          base::TimeTicks::Now() - loading_start_time_, &waiting_state_);
+    }
+  }
+
+ private:
+  Tab* owner_;  // Weak. Owns |this|.
+
+  // The point in time when the tab icon was first painted in the waiting state.
+  base::TimeTicks waiting_start_time_;
+
+  // The point in time when the tab icon was first painted in the loading state.
+  base::TimeTicks loading_start_time_;
+
+  // Paint state for the throbber after the most recent waiting paint.
+  gfx::ThrobberWaitingState waiting_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThrobberView);
+};
+
 void DrawIconAtLocation(gfx::Canvas* canvas,
                         const gfx::ImageSkia& image,
                         int image_offset,
                         int dst_x,
                         int dst_y,
                         int icon_width,
                         int icon_height,
                         bool filter,
                         const SkPaint& paint) {
   // NOTE: the clipping is a work around for 69528, it shouldn't be necessary.
@@ skipping 255 matching lines @@
 // Tab, public:
 
 Tab::Tab(TabController* controller)
     : controller_(controller),
       closing_(false),
       dragging_(false),
       detached_(false),
       favicon_hiding_offset_(0),
       immersive_loading_step_(0),
       should_display_crashed_favicon_(false),
+      throbber_(nullptr),
       media_indicator_button_(nullptr),
       close_button_(nullptr),
       title_(new views::Label()),
       tab_activated_with_last_tap_down_(false),
       hover_controller_(this),
       showing_icon_(false),
       showing_media_indicator_(false),
       showing_close_button_(false),
       button_color_(SK_ColorTRANSPARENT) {
   DCHECK(controller);
   InitTabResources();
 
   // So we get don't get enter/exit on children and don't prematurely stop the
   // hover.
   set_notify_enter_exit_on_child(true);
 
   set_id(VIEW_ID_TAB);
 
   title_->SetHorizontalAlignment(gfx::ALIGN_TO_HEAD);
   title_->SetElideBehavior(gfx::FADE_TAIL);
   title_->SetHandlesTooltips(false);
   title_->SetAutoColorReadabilityEnabled(false);
   title_->SetText(CoreTabHelper::GetDefaultTitle());
   AddChildView(title_);
 
   SetEventTargeter(
       scoped_ptr<views::ViewTargeter>(new views::ViewTargeter(this)));
 
+  throbber_ = new ThrobberView(this);
+  AddChildView(throbber_);
+
   media_indicator_button_ = new MediaIndicatorButton(this);
   AddChildView(media_indicator_button_);
 
   close_button_ = new TabCloseButton(this);
   close_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_CLOSE));
   // The normal image is set by OnButtonColorMaybeChanged() because it depends
   // on the current theme and active state.  The hovered and pressed images
   // don't depend on the these, so we can set them here.
   const gfx::ImageSkia& hovered = gfx::CreateVectorIcon(
@@ skipping 34 matching lines @@
   return controller_->IsTabSelected(this);
 }
 
 void Tab::SetData(const TabRendererData& data) {
   DCHECK(GetWidget());
 
   if (data_.Equals(data))
     return;
 
   TabRendererData old(data_);
+  UpdateLoadingAnimation(data.network_state);

[tapted, 2015/10/09 06:39:02]

I noticed the throbber would hang around with some navigations (maybe those
involving pre-rendering). Without this line it's possible to "lose" a transition
from LOADING -> NONE and have both favicon and throbber get drawn.

   data_ = data;
 
   base::string16 title = data_.title;
   if (title.empty()) {
     title = data_.loading ?
         l10n_util::GetStringUTF16(IDS_TAB_LOADING_TITLE) :
         CoreTabHelper::GetDefaultTitle();
   } else {
     Browser::FormatTitleForDisplay(&title);
   }
@@ skipping 38 matching lines @@
 }
 
 void Tab::UpdateLoadingAnimation(TabRendererData::NetworkState state) {
   if (state == data_.network_state &&
       state == TabRendererData::NETWORK_STATE_NONE) {
     // If the network state is none and hasn't changed, do nothing. Otherwise we
     // need to advance the animation frame.
     return;
   }
 
-  TabRendererData::NetworkState old_state = data_.network_state;
   data_.network_state = state;
-  AdvanceLoadingAnimation(old_state, state);
+  AdvanceLoadingAnimation(state);
 }
 
 void Tab::StartPulse() {
   pulse_animation_.reset(new gfx::ThrobAnimation(this));
   pulse_animation_->SetSlideDuration(kPulseDurationMs);
   if (animation_container_.get())
     pulse_animation_->SetContainer(animation_container_.get());
   pulse_animation_->StartThrobbing(std::numeric_limits<int>::max());
 }
 
@@ skipping 212 matching lines @@
   const int extra_padding =
       (controller_->ShouldHideCloseButtonForInactiveTabs() ||
        (IconCapacity() < 3)) ? 0 : kExtraLeftPaddingToBalanceCloseButtonPadding;
   const int start = lb.x() + extra_padding;
   favicon_bounds_.SetRect(start, lb.y(), 0, 0);
   if (showing_icon_) {
     favicon_bounds_.set_size(gfx::Size(gfx::kFaviconSize, gfx::kFaviconSize));
     favicon_bounds_.set_y(lb.y() + (lb.height() - gfx::kFaviconSize + 1) / 2);
     MaybeAdjustLeftForPinnedTab(&favicon_bounds_);
   }
+  throbber_->SetBoundsRect(favicon_bounds_);
 
   showing_close_button_ = ShouldShowCloseBox();
   if (showing_close_button_) {
     // If the ratio of the close button size to tab width exceeds the maximum.
     // The close button should be as large as possible so that there is a larger
     // hit-target for touch events. So the close button bounds extends to the
     // edges of the tab. However, the larger hit-target should be active only
     // for mouse events, and the close-image should show up in the right place.
     // So a border is added to the button with necessary padding. The close
     // button (BaseTab::TabCloseButton) makes sure the padding is a hit-target
@@ skipping 540 matching lines @@
 }
 
 void Tab::PaintIcon(gfx::Canvas* canvas) {
   gfx::Rect bounds = favicon_bounds_;
   if (bounds.IsEmpty())
     return;
 
   bounds.set_x(GetMirroredXForRect(bounds));
 
   if (data().network_state != TabRendererData::NETWORK_STATE_NONE) {
-    // Paint network activity (aka throbber) animation frame.
-    ui::ThemeProvider* tp = GetThemeProvider();
-    if (data().network_state == TabRendererData::NETWORK_STATE_WAITING) {
-      if (waiting_start_time_ == base::TimeTicks())
-        waiting_start_time_ = base::TimeTicks::Now();
-
-      waiting_state_.elapsed_time =
-          base::TimeTicks::Now() - waiting_start_time_;
-      gfx::PaintThrobberWaiting(
-          canvas, bounds, tp->GetColor(ThemeProperties::COLOR_THROBBER_WAITING),
-          waiting_state_.elapsed_time);
-    } else {
-      if (loading_start_time_ == base::TimeTicks())
-        loading_start_time_ = base::TimeTicks::Now();
-
-      waiting_state_.color =
-          tp->GetColor(ThemeProperties::COLOR_THROBBER_WAITING);
-      gfx::PaintThrobberSpinningAfterWaiting(
-          canvas, bounds,
-          tp->GetColor(ThemeProperties::COLOR_THROBBER_SPINNING),
-          base::TimeTicks::Now() - loading_start_time_, &waiting_state_);
-    }
+    // Throbber will do its own painting.
   } else if (should_display_crashed_favicon_) {
     // Paint crash favicon.
     ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
     gfx::ImageSkia crashed_favicon(*rb.GetImageSkiaNamed(IDR_SAD_FAVICON));
     bounds.set_y(bounds.y() + favicon_hiding_offset_);
     DrawIconCenter(canvas, crashed_favicon, 0,
                    crashed_favicon.width(),
                    crashed_favicon.height(),
                    bounds, true, SkPaint());
   } else if (!data().favicon.isNull()) {
     // Paint the normal favicon.
     DrawIconCenter(canvas, data().favicon, 0,
                    data().favicon.width(),
                    data().favicon.height(),
                    bounds, true, SkPaint());
   }
 }
 
-void Tab::AdvanceLoadingAnimation(TabRendererData::NetworkState old_state,
-                                  TabRendererData::NetworkState state) {
-  if (state == TabRendererData::NETWORK_STATE_WAITING) {
-    // Waiting steps backwards.
-    immersive_loading_step_ =
-        (immersive_loading_step_ - 1 + kImmersiveLoadingStepCount) %
-            kImmersiveLoadingStepCount;
-  } else if (state == TabRendererData::NETWORK_STATE_LOADING) {
-    immersive_loading_step_ = (immersive_loading_step_ + 1) %
-        kImmersiveLoadingStepCount;
-  } else {
-    waiting_start_time_ = base::TimeTicks();
-    loading_start_time_ = base::TimeTicks();
-    waiting_state_ = gfx::ThrobberWaitingState();
-    immersive_loading_step_ = 0;
+void Tab::AdvanceLoadingAnimation(TabRendererData::NetworkState state) {
+  if (controller_->IsImmersiveStyle()) {
+    if (state == TabRendererData::NETWORK_STATE_WAITING) {
+      // Waiting steps backwards.
+      immersive_loading_step_ =
+          (immersive_loading_step_ - 1 + kImmersiveLoadingStepCount) %
+          kImmersiveLoadingStepCount;
+    } else if (state == TabRendererData::NETWORK_STATE_LOADING) {
+      immersive_loading_step_ =
+          (immersive_loading_step_ + 1) % kImmersiveLoadingStepCount;
+    } else {
+      immersive_loading_step_ = 0;
+    }
+
+    SchedulePaintInRect(GetImmersiveBarRect());
+    return;
   }
-  if (controller_->IsImmersiveStyle()) {
-    SchedulePaintInRect(GetImmersiveBarRect());
-  } else {
-    ScheduleIconPaint();
+
+  // To ensure the throbber layer does not paint over stacked or dragged tabs,
+  // hide it when the favicon would be clipped out. Check for any clipping on
+  // the left since the shoulder of a dragged tab can still paint over the icon.
+  gfx::Rect clip = GetLocalBounds();
+  const bool needs_throbber = state != TabRendererData::NETWORK_STATE_NONE &&
+                              controller_->ShouldPaintTab(this, &clip) &&
+                              clip.x() == 0 && clip.Contains(favicon_bounds_);
+
+  if (needs_throbber != throbber_->visible()) {
+    ScheduleIconPaint();  // Repaint the icon area to update favicon visibility.
+    throbber_->SetVisible(needs_throbber);

[Peter Kasting, 2015/10/09 08:03:23]

Nit: For clarity, you might want to reverse these two lines, so readers don't
wonder if the ScheduleIconPaint() call might synchronously paint before we've
changed the throbber visibility.

[tapted, 2015/10/09 11:00:31]

Done.

   }
+  throbber_->SchedulePaint();
 }
 
 int Tab::IconCapacity() const {
   const gfx::Size min_size(GetMinimumUnselectedSize());
   if (height() < min_size.height())
     return 0;
   const int available_width = std::max(0, width() - min_size.width());
   // All icons are the same size as the favicon.
   const int icon_width = gfx::kFaviconSize;
   // We need enough space to display the icons flush against each other.
@@ skipping 258 matching lines @@
                          const gfx::ImageSkia& image) {
   DCHECK_NE(scale_factor, ui::SCALE_FACTOR_NONE);
   ImageCacheEntry entry;
   entry.resource_id = resource_id;
   entry.scale_factor = scale_factor;
   entry.image = image;
   image_cache_->push_front(entry);
   if (image_cache_->size() > kMaxImageCacheSize)
     image_cache_->pop_back();
 }