views/native_theme_painter.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "views/native_theme_painter.h"
   6
   7 #include "base/logging.h"
   8 #include "ui/base/animation/animation.h"
   9 #include "ui/gfx/canvas.h"
  10 #include "ui/gfx/canvas_skia.h"
  11 #include "ui/gfx/rect.h"
  12 #include "views/native_theme_delegate.h"
  13
  14 namespace views {
  15
  16 NativeThemePainter::NativeThemePainter(NativeThemeDelegate* delegate)
  17     : delegate_(delegate) {
  18   DCHECK(delegate_);
  19 }
  20
  21 gfx::Size NativeThemePainter::GetPreferredSize() {
  22   const gfx::NativeTheme* theme = gfx::NativeTheme::instance();
  23   gfx::NativeTheme::ExtraParams extra;
  24   gfx::NativeTheme::State state = delegate_->GetThemeState(&extra);
  25   return theme->GetPartSize(delegate_->GetThemePart(), state, extra);
  26 }
  27
  28 void NativeThemePainter::Paint(int w, int h, gfx::Canvas* canvas) {
  29   const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
  30   gfx::NativeTheme::Part part = delegate_->GetThemePart();
  31   gfx::Rect rect(0, 0, w, h);
  32
  33   if (delegate_->GetThemeAnimation() != NULL &&
  34       delegate_->GetThemeAnimation()->is_animating()) {
  35     // Paint background state.
  36     gfx::NativeTheme::ExtraParams prev_extra;
  37     gfx::NativeTheme::State prev_state =
  38         delegate_->GetBackgroundThemeState(&prev_extra);
  39     native_theme->Paint(
  40         canvas->GetSkCanvas(), part, prev_state, rect, prev_extra);
  41
  42     // Composite foreground state above it.
  43     gfx::NativeTheme::ExtraParams extra;
  44     gfx::NativeTheme::State state = delegate_->GetForegroundThemeState(&extra);
  45     int alpha = delegate_->GetThemeAnimation()->CurrentValueBetween(0, 255);
  46     canvas->SaveLayerAlpha(static_cast<uint8>(alpha));
  47     native_theme->Paint(canvas->GetSkCanvas(), part, state, rect, extra);
  48     canvas->Restore();
  49   } else {
  50     gfx::NativeTheme::ExtraParams extra;
  51     gfx::NativeTheme::State state = delegate_->GetThemeState(&extra);
  52     native_theme->Paint(canvas->GetSkCanvas(), part, state, rect, extra);
  53   }
  54 }
  55
  56 }  // namespace views