M20 Ash: Animate window header transition from active to inactive

ash/wm/frame_painter.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 "ash/wm/frame_painter.h"
 
 #include "base/logging.h"  // DCHECK
 #include "grit/ui_resources.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include "ui/aura/window.h"
+#include "ui/base/animation/slide_animation.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
 #include "ui/gfx/image/image.h"
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
 
@@ skipping 27 matching lines @@
 // Color for the title text.
 const SkColor kTitleColor = SkColorSetRGB(40, 40, 40);
 // Size of header/content separator line below the header image.
 const int kHeaderContentSeparatorSize = 1;
 // Color of header bottom edge line.
 const SkColor kHeaderContentSeparatorColor = SkColorSetRGB(128, 128, 128);
 // Space between close button and right edge of window.
 const int kCloseButtonOffsetX = 0;
 // Space between close button and top edge of window.
 const int kCloseButtonOffsetY = 0;
+// Duration of crossfade animation for activating and deactivating frame.
+const int kActivationCrossfadeDurationMS = 100;

[James Cook, 2012/03/19 19:25:58]

I think the shadow animation uses 200 ms.  Could you check and make sure they
match?  Also, I think we usually use the suffix "Ms" instead of "MS".

[pkotwicz, 2012/03/20 00:59:46]

Done.

 
 // Tiles an image into an area, rounding the top corners.
 void TileRoundRect(gfx::Canvas* canvas,
                    int x, int y, int w, int h,
+                   SkPaint paint,

[James Cook, 2012/03/19 19:25:58]

Are these cheap to copy?  If not, pass a pointer?

                    const SkBitmap& bitmap,
                    int corner_radius) {
   SkRect rect;
   rect.iset(x, y, x + w, y + h);
   const SkScalar kRadius = SkIntToScalar(corner_radius);
   SkScalar radii[8] = {
       kRadius, kRadius,  // top-left
       kRadius, kRadius,  // top-right
       0, 0,   // bottom-right
       0, 0};  // bottom-left
   SkPath path;
   path.addRoundRect(rect, radii, SkPath::kCW_Direction);
 
-  SkPaint paint;
   SkShader* shader = SkShader::CreateBitmapShader(bitmap,
                                                   SkShader::kRepeat_TileMode,
                                                   SkShader::kRepeat_TileMode);
   paint.setShader(shader);
-  paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
   // CreateBitmapShader returns a Shader with a reference count of one, we
   // need to unref after paint takes ownership of the shader.
   shader->unref();
   canvas->sk_canvas()->drawPath(path, paint);
 }
 }  // namespace
 
 namespace ash {
 
 ///////////////////////////////////////////////////////////////////////////////
 // FramePainter, public:
 
 FramePainter::FramePainter()
     : frame_(NULL),
       window_icon_(NULL),
       maximize_button_(NULL),
       close_button_(NULL),
       button_separator_(NULL),
       top_left_corner_(NULL),
       top_edge_(NULL),
       top_right_corner_(NULL),
       header_left_edge_(NULL),
-      header_right_edge_(NULL) {
+      header_right_edge_(NULL),
+      previous_theme_frame_(NULL),
+      crossfade_theme_frame_(NULL),
+      crossfade_animation_(NULL) {
 }
 
 FramePainter::~FramePainter() {
 }
 
 void FramePainter::Init(views::Widget* frame,
                         views::View* window_icon,
                         views::ImageButton* maximize_button,
                         views::ImageButton* close_button) {
   DCHECK(frame);
@@ skipping 100 matching lines @@
   if (title_width > min_size.width())
     min_size.set_width(title_width);
   return min_size;
 }
 
 void FramePainter::PaintHeader(views::NonClientFrameView* view,
                                gfx::Canvas* canvas,
                                const SkBitmap* theme_frame,
                                const SkBitmap* theme_frame_overlay) {
 
+  if (previous_theme_frame_ && previous_theme_frame_ != theme_frame) {
+    crossfade_animation_.reset(new ui::SlideAnimation(this));
+    crossfade_theme_frame_ = previous_theme_frame_;
+    crossfade_animation_->Reset();

[James Cook, 2012/03/19 19:25:58]

Does the animation have to be reset if it was just created?

[pkotwicz, 2012/03/20 00:59:46]

Done.

+    crossfade_animation_->SetSlideDuration(kActivationCrossfadeDurationMS);
+    crossfade_animation_->Show();
+  }
+
+  header_frame_bounds_ = gfx::Rect(0, 0, view->width(), theme_frame->height());
+  const int kCornerRadius = 2;
+
+  SkPaint paint;
+  if (crossfade_animation_.get() && crossfade_animation_->is_animating()) {
+    uint8 theme_alpha = crossfade_animation_->GetCurrentValue() * 255;
+
+    // Draw the old header background, clipping the corners to be rounded.
+    paint.setAlpha(255 - theme_alpha);
+    paint.setXfermodeMode(SkXfermode::kPlus_Mode);
+    TileRoundRect(canvas,
+                  0, 0, view->width(), theme_frame->height(),
+                  paint,
+                  *crossfade_theme_frame_,
+                  kCornerRadius);
+
+    paint.setAlpha(theme_alpha);
+  }
+
   // Draw the header background, clipping the corners to be rounded.
-  const int kCornerRadius = 2;
   TileRoundRect(canvas,
-                0, 0, view->width(), theme_frame->height(),
+                0, 0, view->width(), theme_frame->height(), paint,
                 *theme_frame,
                 kCornerRadius);
 
+  previous_theme_frame_ = theme_frame;
+
   // Draw the theme frame overlay, if available.
   if (theme_frame_overlay)
     canvas->DrawBitmapInt(*theme_frame_overlay, 0, 0);
 
   // Separator between the maximize and close buttons.
   canvas->DrawBitmapInt(*button_separator_,
                         close_button_->x() - button_separator_->width(),
                         close_button_->y());
 
   // Draw the top corners and edge.
@@ skipping 106 matching lines @@
       close_button_->y(),
       maximize_size.width(),
       maximize_size.height());
 
   if (window_icon_)
     window_icon_->SetBoundsRect(
         gfx::Rect(kIconOffsetX, kIconOffsetY, kIconSize, kIconSize));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
+// ui::AnimationDelegate overrides:
+
+void FramePainter::AnimationProgressed(const ui::Animation* animation) {
+  frame_->SchedulePaintInRect(gfx::Rect(header_frame_bounds_));
+}
+
+///////////////////////////////////////////////////////////////////////////////
 // FramePainter, private:
 
 void FramePainter::SetButtonImages(views::ImageButton* button,
                                    int normal_bitmap_id,
                                    int hot_bitmap_id,
                                    int pushed_bitmap_id) {
   ui::ThemeProvider* theme_provider = frame_->GetThemeProvider();
   button->SetImage(views::CustomButton::BS_NORMAL,
                    theme_provider->GetBitmapNamed(normal_bitmap_id));
   button->SetImage(views::CustomButton::BS_HOT,
                    theme_provider->GetBitmapNamed(hot_bitmap_id));
   button->SetImage(views::CustomButton::BS_PUSHED,
                    theme_provider->GetBitmapNamed(pushed_bitmap_id));
 }
 
 int FramePainter::GetTitleOffsetX() const {
   return window_icon_ ?
       window_icon_->bounds().right() + kTitleIconOffsetX :
       kTitleNoIconOffsetX;
 }
 
 }  // namespace ash