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, 79 insertions, 0 deletions

diff --git a/views/native_theme_painter.h b/views/native_theme_painter.h
new file mode 100644
index 0000000..75b8866
--- /dev/null
+++ b/views/native_theme_painter.h
@@ -0,0 +1,79 @@
+// 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.
+
+#ifndef VIEWS_NATIVE_THEME_PAINTER_H_
+#define VIEWS_NATIVE_THEME_PAINTER_H_
+#pragma once
+
+#include "base/compiler_specific.h"
+#include "ui/gfx/native_theme.h"
+#include "views/painter.h"
+
+namespace gfx {
+class Canvas;
+class Size;
+}
+
+namespace ui {
+class Animation;
+}
+
+namespace views {
+
+// A Painter that uses NativeTheme to implement painting and sizing.  A
+// theme delegate must be given at construction time so that the appropriate
+// painting and sizing can be done.
+class NativeThemePainter : public Painter {
+ public:
+  // A delagate that supports animating transtions between different native
+  // theme states.  If animation is onging, the native theme painter will
+  // composite the foreground state over the backgroud state using an alpha
+  // between 0 and 255 based on the current value of the animation.
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+
+    // Get the part that this native theme painter should draw.
+    virtual gfx::NativeTheme::Part GetThemePart() const = 0;
+
+    // Get the state of the part, along with any extra data needed for painting.
+    virtual gfx::NativeTheme::State GetThemeState(
+        gfx::NativeTheme::ExtraParams* params) const = 0;
+
+    // If the native theme painter is animated, return the Animation object
+    // that is controlling it.  If no animation is ongoing, NULL may be
+    // returned.
+    virtual ui::Animation* GetThemeAnimation() const = 0;
+
+    // If animation is onging, this returns the background native theme state.
+    virtual gfx::NativeTheme::State GetBackgroundThemeState(
+        gfx::NativeTheme::ExtraParams* params) const = 0;
+
+    // If animation is onging, this returns the foreground native theme state.
+    // This state will be composited over the background using an alpha value
+    // based on the current value of the animation.
+    virtual gfx::NativeTheme::State GetForegroundThemeState(
+        gfx::NativeTheme::ExtraParams* params) const = 0;
+  };
+
+  explicit NativeThemePainter(Delegate* delegate);
+
+  virtual ~NativeThemePainter() {}
+
+  // Returns the preferred size of the native part being painted.
+  gfx::Size GetPreferredSize();
+
+ private:
+  // The delegate the controls the appearance of this painter.
+  Delegate* delegate_;
+
+  // Overridden from Painter:
+  virtual void Paint(int w, int h, gfx::Canvas* canvas) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeThemePainter);
+};
+
+}  // namespace views
+
+#endif  // VIEWS_NATIVE_THEME_PAINTER_H_
\ No newline at end of file