Tab audio indicator tweaks

chrome/browser/ui/tabs/tab_audio_indicator.cc

 // Copyright (c) 2013 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/tabs/tab_audio_indicator.h"
 
 #include "grit/theme_resources.h"
 #include "ui/base/animation/animation_container.h"
 #include "ui/base/animation/linear_animation.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/rect.h"
+#include "ui/gfx/skia_util.h"
 
 namespace {
 
 // The number of columns to draw for the equalizer graphic.
-const size_t kEqualizerColumnCount = 3;
+const size_t kEqualizerColumnCount = 2;
 
 // The maximum level for the equalizer.
-const size_t kEqualizerMaxLevel = 8;
+const size_t kEqualizerMaxLevel = 4;
 
-// The equalizer cycles between these frames. An equalizer frame is 3 columns
+// The equalizer cycles between these frames. An equalizer frame is 2 columns
 // where each column ranges from 0 to |kEqualizerMaxLevel|. TODO(sail): Replace
 // this with levels from the actual audio source.
 const size_t kEqualizerFrames[][kEqualizerColumnCount] = {
-  { 7, 5, 3 },
-  { 4, 5, 7 },
-  { 4, 2, 5 },
-  { 3, 7, 4 },
-  { 2, 3, 2 },
-  { 3, 4, 3 },
+  { 2, 1 },
+  { 3, 2 },
+  { 2, 3 },
+  { 2, 2 },
+  { 2, 3 },
+  { 3, 4 },
+  { 2, 3 },
+  { 3, 2 },
+  { 2, 3 },
+  { 3, 2 },
 };
 
+// The space between equalizer levels.
+const int kEqualizerColumnPadding = 1;
+
 // The duration of each equalizer frame.
 const size_t kAnimationCycleDurationMs = 300;
 
 // The duration of the "ending" animation once audio stops playing.
 const size_t kAnimationEndingDurationMs = 1000;
 
 // Target frames per second. In reality fewer frames are drawn because the
 // equalizer levels change slowly.
 const int kFPS = 15;
 
@@ skipping 27 matching lines @@
     animation_->SetContainer(animation_container_);
     animation_->Start();
   }
 }
 
 bool TabAudioIndicator::IsAnimating() {
   return state_ != STATE_NOT_ANIMATING;
 }
 
 void TabAudioIndicator::Paint(gfx::Canvas* canvas, const gfx::Rect& rect) {
-  if (state_ == STATE_NOT_ANIMATING)
-    return;
-
   canvas->Save();
   canvas->ClipRect(rect);
 
-  // Draw 3 equalizer columns. |IDR_AUDIO_EQUALIZER_COLUMN| is a column of the
-  // equalizer with 8 levels. The current level is between 0 and 8 so the
+  // Draw 2 equalizer columns. |IDR_AUDIO_EQUALIZER_COLUMN| is a column of the
+  // equalizer with 4 levels. The current level is between 0 and 4 so the
   // image is shifted down and then drawn.
-  ui::ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-  gfx::ImageSkia* image(rb.GetImageSkiaNamed(IDR_AUDIO_EQUALIZER_COLUMN));
-  int x = rect.x();
-  std::vector<int> levels = GetCurrentEqualizerLevels();
-  for (size_t i = 0; i < levels.size(); ++i) {
-    // Shift the image down by the level. For example, for level 8 draw the
-    // image at rect.y(), For level 7, draw the image at rect.y() - 2, etc...
-    int y = rect.y() + (kEqualizerMaxLevel - levels[i]) * 2;
-    canvas->DrawImageInt(*image, x, y);
-    x += image->width() - 1;
+  if (state_ != STATE_NOT_ANIMATING) {
+    ui::ResourceBundle& rb = ResourceBundle::GetSharedInstance();
+    gfx::ImageSkia* image(rb.GetImageSkiaNamed(IDR_AUDIO_EQUALIZER_COLUMN));
+    int x = rect.right();
+    std::vector<int> levels = GetCurrentEqualizerLevels();
+    for (int i = levels.size() - 1; i >= 0; --i) {
+      // Shift the image down by the level.
+      int y = rect.bottom() - levels[i] * 2;
+      x -= image->width();
+      canvas->DrawImageInt(*image, x, y);
+
+      // Clip the equalizer column so the favicon doesn't obscure it.
+      gfx::Rect equalizer_rect(x, y, image->width(), image->height());
+      equalizer_rect.Inset(-kEqualizerColumnPadding, -kEqualizerColumnPadding);
+      canvas->sk_canvas()->clipRect(
+          gfx::RectToSkRect(equalizer_rect), SkRegion::kDifference_Op);
+
+      x -= kEqualizerColumnPadding;
+    }
+
+    // Cache the levels that were just drawn. This is used to prevent
+    // unnecessary drawing when animation progress doesn't result in equalizer
+    // levels changing.
+    last_displayed_equalizer_levels_ = levels;
+  }
+
+  if (!favicon_.isNull()) {
+    int dst_x = rect.x() - (favicon_.width() - rect.width()) / 2;
+    int dst_y = rect.y() - (favicon_.height()- rect.height()) / 2;
+    canvas->DrawImageInt(favicon_, dst_x, dst_y);
   }
 
   canvas->Restore();
-
-  // Cache the levels that were just drawn. This is used to prevent unnecessary
-  // drawing when animation progress doesn't result in equalizer levels
-  // changing.
-  last_displayed_equalizer_levels_ = levels;
 }
 
 void TabAudioIndicator::AnimationProgressed(const ui::Animation* animation) {
   std::vector<int> levels = GetCurrentEqualizerLevels();
   if (last_displayed_equalizer_levels_ != levels)
     delegate_->ScheduleAudioIndicatorPaint();
 }
 
 void TabAudioIndicator::AnimationEnded(const ui::Animation* animation) {
   if (state_ == STATE_ANIMATING) {
     // The current equalizer frame animation has finished. Start animating the
     // next frame.
     frame_index_ = (frame_index_ + 1) % arraysize(kEqualizerFrames);
     animation_->Start();
   } else if (state_ == STATE_ANIMATION_ENDING) {
     // The "ending" animation has stopped. Update the tab state so that the UI
     // can update the tab icon.
     state_ = STATE_NOT_ANIMATING;
     delegate_->ScheduleAudioIndicatorPaint();
   }
 }
 
 std::vector<int> TabAudioIndicator::GetCurrentEqualizerLevels() const {
   int next_frame_index = (frame_index_ + 1) % arraysize(kEqualizerFrames);
   std::vector<int> levels;
-  // For all 3 columsn of the equalizer, tween between the current equalizer
+  // For all 2 columsn of the equalizer, tween between the current equalizer
   // level and the target equalizer level.
   for (size_t i = 0; i < kEqualizerColumnCount; ++i) {
     int start = kEqualizerFrames[frame_index_][i];
     int end = state_ == STATE_ANIMATION_ENDING
               ? 0
               : kEqualizerFrames[next_frame_index][i];
     levels.push_back(animation_->CurrentValueBetween(start, end));
   }
   return levels;
 }