Adding a native theme painter, to allow Views to use NativeTheme to draw

their background.  Added example code to show it in use.  I still have not
hooked this into any existing View-based controls.

This CL depends on changes currently being made to native theme, see
http://codereview.chromium.org/6728029/ for details.

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/6771056

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80952 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 54 insertions, 0 deletions

diff --git a/views/native_theme_painter.cc b/views/native_theme_painter.cc
new file mode 100644
index 0000000..1d4ab21
--- /dev/null
+++ b/views/native_theme_painter.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2011 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 "views/native_theme_painter.h"
+
+#include "base/logging.h"
+#include "ui/base/animation/animation.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/rect.h"
+
+namespace views {
+
+NativeThemePainter::NativeThemePainter(Delegate* delegate)
+    : delegate_(delegate) {
+  DCHECK(delegate_);
+}
+
+gfx::Size NativeThemePainter::GetPreferredSize() {
+  const gfx::NativeTheme* theme = gfx::NativeTheme::instance();
+  return theme->GetPartSize(delegate_->GetThemePart());
+}
+
+void NativeThemePainter::Paint(int w, int h, gfx::Canvas* canvas) {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+  gfx::NativeTheme::Part part = delegate_->GetThemePart();
+  gfx::CanvasSkia* skia_canvas = canvas->AsCanvasSkia();
+  gfx::Rect rect(0, 0, w, h);
+
+  if (delegate_->GetThemeAnimation() != NULL &&
+      delegate_->GetThemeAnimation()->is_animating()) {
+
+    // Paint background state.
+    gfx::NativeTheme::ExtraParams prev_extra;
+    gfx::NativeTheme::State prev_state =
+        delegate_->GetBackgroundThemeState(&prev_extra);
+    native_theme->Paint(skia_canvas, part, prev_state, rect, prev_extra);
+
+    // Composite foreground state above it.
+    gfx::NativeTheme::ExtraParams extra;
+    gfx::NativeTheme::State state = delegate_->GetForegroundThemeState(&extra);
+    int alpha = delegate_->GetThemeAnimation()->CurrentValueBetween(0, 255);
+    skia_canvas->SaveLayerAlpha(static_cast<uint8>(alpha));
+    native_theme->Paint(skia_canvas, part, state, rect, extra);
+    skia_canvas->Restore();
+  } else {
+    gfx::NativeTheme::ExtraParams extra;
+    gfx::NativeTheme::State state = delegate_->GetThemeState(&extra);
+    native_theme->Paint(skia_canvas, part, state, rect, extra);
+  }
+}
+
+}  // namespace views