ui/views/native_theme_painter.cc

   1 // Copyright (c) 2012 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 "ui/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/rect.h"
  11 #include "ui/views/native_theme_delegate.h"
  12
  13 namespace views {
  14
  15 NativeThemePainter::NativeThemePainter(NativeThemeDelegate* delegate)
  16     : delegate_(delegate) {
  17   DCHECK(delegate_);
  18 }
  19
  20 gfx::Size NativeThemePainter::GetPreferredSize() {
  21   const ui::NativeTheme* theme = ui::NativeTheme::instance();
  22   ui::NativeTheme::ExtraParams extra;
  23   ui::NativeTheme::State state = delegate_->GetThemeState(&extra);
  24   return theme->GetPartSize(delegate_->GetThemePart(), state, extra);
  25 }
  26
  27 void NativeThemePainter::Paint(gfx::Canvas* canvas, const gfx::Size& size) {
  28   const ui::NativeTheme* native_theme = ui::NativeTheme::instance();
  29   ui::NativeTheme::Part part = delegate_->GetThemePart();
  30   gfx::Rect rect(size);
  31
  32   if (delegate_->GetThemeAnimation() != NULL &&
  33       delegate_->GetThemeAnimation()->is_animating()) {
  34     // Paint background state.
  35     ui::NativeTheme::ExtraParams prev_extra;
  36     ui::NativeTheme::State prev_state =
  37         delegate_->GetBackgroundThemeState(&prev_extra);
  38     native_theme->Paint(canvas->sk_canvas(), part, prev_state, rect,
  39                         prev_extra);
  40
  41     // Composite foreground state above it.
  42     ui::NativeTheme::ExtraParams extra;
  43     ui::NativeTheme::State state = delegate_->GetForegroundThemeState(&extra);
  44     int alpha = delegate_->GetThemeAnimation()->CurrentValueBetween(0, 255);
  45     canvas->SaveLayerAlpha(static_cast<uint8>(alpha));
  46     native_theme->Paint(canvas->sk_canvas(), part, state, rect, extra);
  47     canvas->Restore();
  48   } else {
  49     ui::NativeTheme::ExtraParams extra;
  50     ui::NativeTheme::State state = delegate_->GetThemeState(&extra);
  51     native_theme->Paint(canvas->sk_canvas(), part, state, rect, extra);
  52   }
  53 }
  54
  55 }  // namespace views