Move more web widgets painting from webkit to chrome.

gfx/native_theme_linux.cc

 // Copyright (c) 2010 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 "gfx/native_theme_linux.h"
 
 #include "base/logging.h"
+#include "gfx/codec/png_codec.h"
+#include "gfx/color_utils.h"
+#include "gfx/gfx_module.h"
 #include "gfx/size.h"
 #include "gfx/rect.h"
+#include "grit/gfx_resources.h"
+#include "third_party/skia/include/effects/SkGradientShader.h"
 
 namespace gfx {
 
 unsigned int NativeThemeLinux::button_length_ = 14;
 unsigned int NativeThemeLinux::scrollbar_width_ = 15;
 unsigned int NativeThemeLinux::thumb_inactive_color_ = 0xeaeaea;
 unsigned int NativeThemeLinux::thumb_active_color_ = 0xf4f4f4;
 unsigned int NativeThemeLinux::track_color_ = 0xd3d3d3;
 
+// These are the default dimensions of radio buttons and checkboxes.
+const int NativeThemeLinux::kCheckboxAndRadioWidth = 13;
+const int NativeThemeLinux::kCheckboxAndRadioHeight = 13;
+
+static const SkColor kSliderTrackBackgroundColor =
+    SkColorSetRGB(0xe3, 0xdd, 0xd8);
+static const SkColor kSliderThumbLightGrey = SkColorSetRGB(0xf4, 0xf2, 0xef);
+static const SkColor kSliderThumbDarkGrey = SkColorSetRGB(0xea, 0xe5, 0xe0);
+static const SkColor kSliderThumbBorderDarkGrey =
+    SkColorSetRGB(0x9d, 0x96, 0x8e);
+
 #if !defined(OS_CHROMEOS)
 // Chromeos has a different look.
 // static
 NativeThemeLinux* NativeThemeLinux::instance() {
   // The global NativeThemeLinux instance.
   static NativeThemeLinux s_native_theme;
   return &s_native_theme;
 }
 #endif
 
+static SkBitmap* GfxGetBitmapNamed(int key) {
+  base::StringPiece data = GfxModule::GetResource(key);
+
+  SkBitmap bitmap;
+  gfx::PNGCodec::Decode(reinterpret_cast<const unsigned char*>(data.data()),
+      data.size(), &bitmap);

[tony, 2011/01/14 22:06:04]

Should we DCHECK the return value of Decode?  Maybe also DCHECK(data.length() >
0) << " Unable to load " << key; or something.

[xiyuan, 2011/01/18 21:30:49]

Done.

+  return new SkBitmap(bitmap);
+}
+
 NativeThemeLinux::NativeThemeLinux() {
 }
 
 NativeThemeLinux::~NativeThemeLinux() {
 }
 
 gfx::Size NativeThemeLinux::GetSize(Part part) const {
   switch (part) {
     case kScrollbarDownArrow:
     case kScrollbarUpArrow:
       return gfx::Size(scrollbar_width_, button_length_);
     case kScrollbarLeftArrow:
     case kScrollbarRightArrow:
       return gfx::Size(button_length_, scrollbar_width_);
     case kScrollbarHorizontalThumb:
       // This matches Firefox on Linux.
       return gfx::Size(2 * scrollbar_width_, scrollbar_width_);
     case kScrollbarVerticalThumb:
       // This matches Firefox on Linux.
       return gfx::Size(scrollbar_width_, 2 * scrollbar_width_);
       break;
     case kScrollbarHorizontalTrack:
       return gfx::Size(0, scrollbar_width_);
     case kScrollbarVerticalTrack:
       return gfx::Size(scrollbar_width_, 0);
+    case kCheckbox:
+    case kRadio:
+      return gfx::Size(kCheckboxAndRadioWidth, kCheckboxAndRadioHeight);
+    case kSliderThumb:
+      // These sizes match the sizes in Chromium Win.
+      return gfx::Size(11, 21);

[tony, 2011/01/14 22:06:04]

Can we convert 11 and 21 into constants?

[xiyuan, 2011/01/18 21:30:49]

Done.

+    case kInnerSpinButton:
+      return gfx::Size(scrollbar_width_, 0);
+    case kPushButton:
+    case kTextField:
+    case kMenuList:
+    case kSliderTrack:
+    case kProgressBar:
+      return gfx::Size();  // No default size.
   }
   return gfx::Size();
 }
 
 void NativeThemeLinux::PaintArrowButton(
     skia::PlatformCanvas* canvas,
     const gfx::Rect& rect, Part direction, State state) {
   int widthMiddle, lengthMiddle;
   SkPaint paint;
   if (direction == kScrollbarUpArrow || direction == kScrollbarDownArrow) {
@@ skipping 130 matching lines @@
       PaintArrowButton(canvas, rect, part, state);
       break;
     case kScrollbarHorizontalThumb:
     case kScrollbarVerticalThumb:
       PaintThumb(canvas, part, state, rect);
       break;
     case kScrollbarHorizontalTrack:
     case kScrollbarVerticalTrack:
       PaintTrack(canvas, part, state, extra.scrollbar_track, rect);
       break;
+    case kCheckbox:
+      PaintCheckbox(canvas, state, rect, extra.button);
+      break;
+    case kRadio:
+      PaintRadio(canvas, state, rect, extra.button);
+      break;
+    case kPushButton:
+      PaintButton(canvas, state, rect, extra.button);
+      break;
+    case kTextField:
+      PaintTextField(canvas, state, rect, extra.text_field);
+      break;
+    case kMenuList:
+      PaintMenuList(canvas, state, rect, extra.menu_list);
+      break;
+    case kSliderTrack:
+      PaintSliderTrack(canvas, state, rect, extra.slider);
+      break;
+    case kSliderThumb:
+      PaintSliderThumb(canvas, state, rect, extra.slider);
+      break;
+    case kInnerSpinButton:
+      PaintInnerSpinButton(canvas, state, rect, extra.inner_spin);
+      break;
+    case kProgressBar:
+      PaintProgressBar(canvas, state, rect, extra.progress_bar);
+      break;
   }
 }
 
 void NativeThemeLinux::PaintTrack(skia::PlatformCanvas* canvas,
                                   Part part,
                                   State state,
                                   const ScrollbarTrackExtraParams& extra_params,
                                   const gfx::Rect& rect) {
   SkPaint paint;
   SkIRect skrect;
@@ skipping 83 matching lines @@
                    paint);
       DrawVertLine(canvas,
                    midx + inter_grippy_offset,
                    midy - grippy_half_width,
                    midy + grippy_half_width,
                    paint);
     }
   }
 }
 
+void NativeThemeLinux::PaintCheckbox(skia::PlatformCanvas* canvas,
+                                     State state,
+                                     const gfx::Rect& rect,
+                                     const ButtonExtraParams& button) {
+  static SkBitmap* image_disabled_indeterminate = GfxGetBitmapNamed(
+      IDR_LINUX_CHECKBOX_DISABLED_INDETERMINATE);
+  static SkBitmap* image_indeterminate = GfxGetBitmapNamed(
+      IDR_LINUX_CHECKBOX_INDETERMINATE);
+  static SkBitmap* image_disabled_on = GfxGetBitmapNamed(
+      IDR_LINUX_CHECKBOX_DISABLED_ON);
+  static SkBitmap* image_on = GfxGetBitmapNamed(IDR_LINUX_CHECKBOX_ON);
+  static SkBitmap* image_disabled_off = GfxGetBitmapNamed(
+      IDR_LINUX_CHECKBOX_DISABLED_OFF);
+  static SkBitmap* image_off = GfxGetBitmapNamed(IDR_LINUX_CHECKBOX_OFF);
+
+  SkBitmap* image = NULL;
+  if (button.indeterminate) {
+    image = state == kDisabled ? image_disabled_indeterminate :

[tony, 2011/01/14 22:06:04]

Nit: I normally line up the : below the ?

[xiyuan, 2011/01/18 21:30:49]

Done.

+                                 image_indeterminate;
+  } else if (button.checked) {
+    image = state == kDisabled ? image_disabled_on : image_on;
+  } else {
+    image = state == kDisabled ? image_disabled_off : image_off;
+  }
+
+  gfx::Rect bounds = rect.Center(gfx::Size(image->width(), image->height()));
+  canvas->drawBitmap(*image, SkIntToScalar(bounds.x()),
+      SkIntToScalar(bounds.y()));
+}
+
+void NativeThemeLinux::PaintRadio(skia::PlatformCanvas* canvas,
+                                  State state,
+                                  const gfx::Rect& rect,
+                                  const ButtonExtraParams& button) {
+  static SkBitmap* image_disabled_on = GfxGetBitmapNamed(
+      IDR_LINUX_RADIO_DISABLED_ON);
+  static SkBitmap* image_on = GfxGetBitmapNamed(IDR_LINUX_RADIO_ON);
+  static SkBitmap* image_disabled_off = GfxGetBitmapNamed(
+      IDR_LINUX_RADIO_DISABLED_OFF);
+  static SkBitmap* image_off = GfxGetBitmapNamed(IDR_LINUX_RADIO_OFF);
+
+  SkBitmap* image = NULL;
+  if (state == kDisabled) {
+    image = button.checked ? image_disabled_on : image_disabled_off;
+  } else {
+    image = button.checked ? image_on : image_off;
+  }
+
+  gfx::Rect bounds = rect.Center(gfx::Size(image->width(), image->height()));
+  canvas->drawBitmap(*image, SkIntToScalar(bounds.x()),
+      SkIntToScalar(bounds.y()));
+}
+
+void NativeThemeLinux::PaintButton(skia::PlatformCanvas* canvas,
+                                   State state,
+                                   const gfx::Rect& rect,
+                                   const ButtonExtraParams& button) {
+  SkPaint paint;
+  SkRect skrect;
+  const int right = rect.right();

[tony, 2011/01/14 22:06:04]

Local consts should still be of the form kRight.
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Constant_Names

[xiyuan, 2011/01/18 21:30:49]

Done.

+  const int bottom = rect.bottom();
+  SkColor base_color = button.background_color;
+
+  color_utils::HSL base_hsl;
+  color_utils::SkColorToHSL(base_color, &base_hsl);
+
+  // Our standard gradient is from 0xdd to 0xf8. This is the amount of
+  // increased luminance between those values.
+  SkColor light_color(BrightenColor(base_hsl, SkColorGetA(base_color), 0.105));
+
+  // If the button is too small, fallback to drawing a single, solid color
+  if (rect.width() < 5 || rect.height() < 5) {
+    paint.setColor(base_color);
+    skrect.set(rect.x(), rect.y(), right, bottom);
+    canvas->drawRect(skrect, paint);
+    return;
+  }
+
+  const int border_alpha = state == kHover ? 0x80 : 0x55;

[tony, 2011/01/14 22:06:04]

const naming

[xiyuan, 2011/01/18 21:30:49]

Done.

+  paint.setARGB(border_alpha, 0, 0, 0);
+  canvas->drawLine(rect.x() + 1, rect.y(), right - 1, rect.y(), paint);
+  canvas->drawLine(right - 1, rect.y() + 1, right - 1, bottom - 1, paint);
+  canvas->drawLine(rect.x() + 1, bottom - 1, right - 1, bottom - 1, paint);
+  canvas->drawLine(rect.x(), rect.y() + 1, rect.x(), bottom - 1, paint);
+
+  paint.setColor(SK_ColorBLACK);
+  SkPoint p[2];

[tony, 2011/01/14 22:06:04]

Please use a variable name other than p.  Maybe gradient_bounds?

[xiyuan, 2011/01/18 21:30:49]

Done.

+  const int light_end = state == kPressed ? 1 : 0;
+  const int dark_end = !light_end;

[tony, 2011/01/14 22:06:04]

const naming

[xiyuan, 2011/01/18 21:30:49]

Done.

+  p[light_end].set(SkIntToScalar(rect.x()), SkIntToScalar(rect.y()));
+  p[dark_end].set(SkIntToScalar(rect.x()), SkIntToScalar(bottom - 1));
+  SkColor colors[2];
+  colors[0] = light_color;
+  colors[1] = base_color;
+
+  SkShader* shader = SkGradientShader::CreateLinear(
+      p, colors, NULL, 2, SkShader::kClamp_TileMode, NULL);
+  paint.setStyle(SkPaint::kFill_Style);
+  paint.setShader(shader);
+  shader->unref();
+
+  skrect.set(rect.x() + 1, rect.y() + 1, right - 1, bottom - 1);
+  canvas->drawRect(skrect, paint);
+
+  paint.setShader(NULL);
+  paint.setColor(BrightenColor(base_hsl, SkColorGetA(base_color), -0.0588));
+  canvas->drawPoint(rect.x() + 1, rect.y() + 1, paint);
+  canvas->drawPoint(right - 2, rect.y() + 1, paint);
+  canvas->drawPoint(rect.x() + 1, bottom - 2, paint);
+  canvas->drawPoint(right - 2, bottom - 2, paint);
+}
+
+void NativeThemeLinux::PaintTextField(skia::PlatformCanvas* canvas,
+                                      State state,
+                                      const gfx::Rect& rect,
+                                      const TextFieldExtraParams& text) {
+  // The following drawing code simulates the user-agent css border for
+  // text area and text input so that we do not break layout tests. Once we
+  // have decided the desired looks, we should update the code here and
+  // the layout test expectations.
+  SkRect bounds;
+  bounds.set(rect.x(), rect.y(), rect.right() - 1, rect.bottom() - 1);
+
+  SkPaint fill_paint;
+  fill_paint.setStyle(SkPaint::kFill_Style);
+  fill_paint.setColor(text.background_color);
+  canvas->drawRect(bounds, fill_paint);
+
+  if (text.is_text_area) {
+    // Draw text area border: 1px solid black
+    SkPaint stroke_paint;
+    fill_paint.setStyle(SkPaint::kStroke_Style);
+    fill_paint.setColor(SK_ColorBLACK);
+    canvas->drawRect(bounds, fill_paint);
+  } else {
+    // Draw text input and listbox inset border
+    //   Text Input: 2px inset #eee
+    //   Listbox: 1px inset #808080
+    const SkColor kLightColor = text.is_listbox ?

[tony, 2011/01/14 22:06:04]

const naming

[xiyuan, 2011/01/18 21:30:49]

Done. border_width -> kBorderWidth

+        SkColorSetRGB(0x80, 0x80, 0x80) : SkColorSetRGB(0xee, 0xee, 0xee);
+    const SkColor kDarkColor = text.is_listbox ?
+        SkColorSetRGB(0x2c, 0x2c, 0x2c) : SkColorSetRGB(0x9a, 0x9a, 0x9a);
+    const int border_width = text.is_listbox ? 1 : 2;
+
+    SkPaint dark_paint;
+    dark_paint.setAntiAlias(true);
+    dark_paint.setStyle(SkPaint::kFill_Style);
+    dark_paint.setColor(kDarkColor);
+
+    SkPaint light_paint;
+    light_paint.setAntiAlias(true);
+    light_paint.setStyle(SkPaint::kFill_Style);
+    light_paint.setColor(kLightColor);
+
+    int left = rect.x();
+    int top = rect.y();
+    int right = rect.right();
+    int bottom = rect.bottom();
+
+    SkPath path;
+    path.incReserve(4);
+
+    // Top
+    path.moveTo(SkIntToScalar(left), SkIntToScalar(top));
+    path.lineTo(SkIntToScalar(left + border_width),
+                SkIntToScalar(top + border_width));
+    path.lineTo(SkIntToScalar(right - border_width),
+                SkIntToScalar(top + border_width));
+    path.lineTo(SkIntToScalar(right), SkIntToScalar(top));
+    canvas->drawPath(path, dark_paint);
+
+    // Bottom
+    path.reset();
+    path.moveTo(SkIntToScalar(left + border_width),
+                SkIntToScalar(bottom - border_width));
+    path.lineTo(SkIntToScalar(left), SkIntToScalar(bottom));
+    path.lineTo(SkIntToScalar(right), SkIntToScalar(bottom));
+    path.lineTo(SkIntToScalar(right - border_width),
+                SkIntToScalar(bottom - border_width));
+    canvas->drawPath(path, light_paint);
+
+    // Left
+    path.reset();
+    path.moveTo(SkIntToScalar(left), SkIntToScalar(top));
+    path.lineTo(SkIntToScalar(left), SkIntToScalar(bottom));
+    path.lineTo(SkIntToScalar(left + border_width),
+                SkIntToScalar(bottom - border_width));
+    path.lineTo(SkIntToScalar(left + border_width),
+                SkIntToScalar(top + border_width));
+    canvas->drawPath(path, dark_paint);
+
+    // Right
+    path.reset();
+    path.moveTo(SkIntToScalar(right - border_width),
+                SkIntToScalar(top + border_width));
+    path.lineTo(SkIntToScalar(right - border_width), SkIntToScalar(bottom));
+    path.lineTo(SkIntToScalar(right), SkIntToScalar(bottom));
+    path.lineTo(SkIntToScalar(right), SkIntToScalar(top));
+    canvas->drawPath(path, light_paint);
+  }
+}
+
+void NativeThemeLinux::PaintMenuList(skia::PlatformCanvas* canvas,
+                                     State state,
+                                     const gfx::Rect& rect,
+                                     const MenuListExtraParams& menu_list) {
+  ButtonExtraParams button = { 0 };
+  button.background_color = menu_list.background_color;
+  PaintButton(canvas, state, rect, button);
+
+  SkPaint paint;
+  paint.setColor(SK_ColorBLACK);
+  paint.setAntiAlias(true);
+  paint.setStyle(SkPaint::kFill_Style);
+
+  SkPath path;
+  path.moveTo(menu_list.arrow_x, menu_list.arrow_y - 3);
+  path.rLineTo(6, 0);
+  path.rLineTo(-3, 6);
+  path.close();
+  canvas->drawPath(path, paint);
+}
+
+void NativeThemeLinux::PaintSliderTrack(skia::PlatformCanvas* canvas,
+                                        State state,
+                                        const gfx::Rect& rect,
+                                        const SliderExtraParams& slider) {
+  const int midx = rect.x() + rect.width() / 2;
+  const int midy = rect.y() + rect.height() / 2;

[tony, 2011/01/14 22:06:04]

const naming

[xiyuan, 2011/01/18 21:30:49]

Done.

+
+  SkPaint paint;
+  paint.setColor(kSliderTrackBackgroundColor);
+
+  SkRect skrect;
+  if (slider.vertical) {
+    skrect.set(std::max(rect.x(), midx - 2),
+               rect.y(),
+               std::min(rect.right(), midx + 2),
+               rect.bottom());
+  } else {
+    skrect.set(rect.x(),
+               std::max(rect.y(), midy - 2),
+               rect.right(),
+               std::min(rect.bottom(), midy + 2));
+  }
+  canvas->drawRect(skrect, paint);
+}
+
+void NativeThemeLinux::PaintSliderThumb(skia::PlatformCanvas* canvas,
+                                        State state,
+                                        const gfx::Rect& rect,
+                                        const SliderExtraParams& slider) {
+  const bool hovered = state == kHover || slider.in_drag;
+  const int midx = rect.x() + rect.width() / 2;
+  const int midy = rect.y() + rect.height() / 2;

[tony, 2011/01/14 22:06:04]

const naming

[xiyuan, 2011/01/18 21:30:49]

Done.

+
+  SkPaint paint;
+  paint.setColor(hovered ? SK_ColorWHITE : kSliderThumbLightGrey);
+
+  SkIRect skrect;
+  if (slider.vertical)
+    skrect.set(rect.x(), rect.y(), midx + 1, rect.bottom());
+  else
+    skrect.set(rect.x(), rect.y(), rect.right(), midy + 1);
+
+  canvas->drawIRect(skrect, paint);
+
+  paint.setColor(hovered ? kSliderThumbLightGrey : kSliderThumbDarkGrey);
+
+  if (slider.vertical)
+    skrect.set(midx + 1, rect.y(), rect.right(), rect.bottom());
+  else
+    skrect.set(rect.x(), midy + 1, rect.right(), rect.bottom());
+
+  canvas->drawIRect(skrect, paint);
+
+  paint.setColor(kSliderThumbBorderDarkGrey);
+  DrawBox(canvas, rect, paint);
+
+  if (rect.height() > 10 && rect.width() > 10) {
+    DrawHorizLine(canvas, midx - 2, midx + 2, midy, paint);
+    DrawHorizLine(canvas, midx - 2, midx + 2, midy - 3, paint);
+    DrawHorizLine(canvas, midx - 2, midx + 2, midy + 3, paint);
+  }
+}
+
+void NativeThemeLinux::PaintInnerSpinButton(skia::PlatformCanvas* canvas,
+    State state,

[tony, 2011/01/14 22:06:04]

Nit: I think we often put multiple params on the same line

[xiyuan, 2011/01/18 21:30:49]

The third param is long and could in. That's why I could not align all params
with the first param and give each a separate line.
Isn't this way more clear? :)

[tony, 2011/01/18 22:39:19]

*shrug* this is fine.  I don't have a strong feeling one way or another. :)

+    const gfx::Rect& rect,
+    const InnerSpinButtonExtraParams& spin_button) {
+  if (spin_button.read_only)
+    state = kDisabled;
+
+  State north_state = state;
+  State south_state = state;
+  if (spin_button.spin_up)
+    south_state = south_state != kDisabled ? kNormal : kDisabled;
+  else
+    north_state = north_state != kDisabled ? kNormal : kDisabled;
+
+  gfx::Rect half = rect;
+  half.set_height(rect.height() / 2);
+  PaintArrowButton(canvas, half, kScrollbarUpArrow, north_state);
+
+  half.set_y(rect.y() + rect.height() / 2);
+  PaintArrowButton(canvas, half, kScrollbarDownArrow, south_state);
+}
+
+void NativeThemeLinux::PaintProgressBar(skia::PlatformCanvas* canvas,
+    State state,
+    const gfx::Rect& rect,
+    const ProgressBarExtraParams& progress_bar) {
+  static SkBitmap* bar_image = GfxGetBitmapNamed(IDR_PROGRESS_BAR);
+  static SkBitmap* value_image = GfxGetBitmapNamed(IDR_PROGRESS_VALUE);
+  static SkBitmap* left_border_image = GfxGetBitmapNamed(
+      IDR_PROGRESS_BORDER_LEFT);
+  static SkBitmap* right_border_image = GfxGetBitmapNamed(
+      IDR_PROGRESS_BORDER_RIGHT);
+
+  double tile_scale = static_cast<double>(rect.height()) /
+      bar_image->height();
+
+  int new_tile_width = static_cast<int>(bar_image->width() * tile_scale);
+  double tile_scale_x = static_cast<double>(new_tile_width) /
+      bar_image->width();
+
+  DrawTiledImage(canvas, *bar_image, 0, 0, tile_scale_x, tile_scale,
+      rect.x(), rect.y(), rect.width(), rect.height());
+
+  if (progress_bar.value_rect_width) {
+
+    new_tile_width = static_cast<int>(value_image->width() * tile_scale);
+    tile_scale_x = static_cast<double>(new_tile_width) /
+        value_image->width();
+
+    DrawTiledImage(canvas, *value_image, 0, 0, tile_scale_x, tile_scale,
+        progress_bar.value_rect_x,
+        progress_bar.value_rect_y,
+        progress_bar.value_rect_width,
+        progress_bar.value_rect_height);
+  }
+
+  int dest_left_border_width = static_cast<int>(left_border_image->width() *
+      tile_scale);
+  SkRect dest_rect = {
+    SkIntToScalar(rect.x()),
+    SkIntToScalar(rect.y()),
+    SkIntToScalar(rect.x() + dest_left_border_width),
+    SkIntToScalar(rect.bottom())

[tony, 2011/01/14 22:06:04]

indent 2 spaces more

[xiyuan, 2011/01/18 21:30:49]

Done.

+  };
+  canvas->drawBitmapRect(*left_border_image, NULL, dest_rect);
+
+  int dest_right_border_width = static_cast<int>(right_border_image->width() *
+      tile_scale);
+  dest_rect.set(SkIntToScalar(rect.right() - dest_right_border_width),
+      SkIntToScalar(rect.y()),
+      SkIntToScalar(rect.right()),
+      SkIntToScalar(rect.bottom()));
+  canvas->drawBitmapRect(*right_border_image, NULL, dest_rect);
+}
+
 void NativeThemeLinux::DrawVertLine(SkCanvas* canvas,
                                     int x,
                                     int y1,
                                     int y2,
                                     const SkPaint& paint) const {
   SkIRect skrect;
   skrect.set(x, y1, x + 1, y2 + 1);
   canvas->drawIRect(skrect, paint);
 }
 
@@ skipping 11 matching lines @@
                                const gfx::Rect& rect,
                                const SkPaint& paint) const {
   const int right = rect.x() + rect.width() - 1;
   const int bottom = rect.y() + rect.height() - 1;
   DrawHorizLine(canvas, rect.x(), right, rect.y(), paint);
   DrawVertLine(canvas, right, rect.y(), bottom, paint);
   DrawHorizLine(canvas, rect.x(), right, bottom, paint);
   DrawVertLine(canvas, rect.x(), rect.y(), bottom, paint);
 }
 
+void NativeThemeLinux::DrawTiledImage(SkCanvas* canvas,
+   const SkBitmap& bitmap,
+   int src_x, int src_y, double tile_scale_x, double tile_scale_y,
+   int dest_x, int dest_y, int w, int h) const {
+  SkShader* shader = SkShader::CreateBitmapShader(bitmap,

[tony, 2011/01/14 22:06:04]

Is there a smart pointer we can use to auto-unref SkShaders?

[xiyuan, 2011/01/18 21:30:49]

I poked around in skia code and here are some findings:

We could not use SkRefPtr because it always increase ref count when attached to
an object and skia object is created with ref count 1. So assigning to a
SkRefPtr would leave ref count 1 when SkRefPtr is out of scope. I am not sure if
we should add a method that makes it able to attach to an object without add ref
count as this might be a bug load in the future.

There is a SkAutoUnref that we might be able to use but then we need a cast in
setShader call. It would be something like this:
SkAutoUnref shader(SkShader::CreateBitmapShader(...));
...
paint.setShader(static_cast<SkShader*>(shader.get()));
...

Skia code seems use this pattern when referencing newly create object.
paint.setShader(shader)->unref();

Which way is better? I personally like the skia pattern a bit.

[tony, 2011/01/18 22:39:19]

Ok, this seems fine.  I wasn't sure if there was a more common/better pattern,
but since this is what Skia code does, seems fine for us to continue to do this.

+                                                  SkShader::kRepeat_TileMode,
+                                                  SkShader::kRepeat_TileMode);
+  if (tile_scale_x != 1.0 || tile_scale_y != 1.0) {
+    SkMatrix shader_scale;
+    shader_scale.setScale(SkDoubleToScalar(tile_scale_x),
+                          SkDoubleToScalar(tile_scale_y));
+    shader->setLocalMatrix(shader_scale);
+  }
+
+  SkPaint paint;
+  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->save();
+  canvas->translate(SkIntToScalar(dest_x - src_x),
+                    SkIntToScalar(dest_y - src_y));
+  canvas->clipRect(SkRect::MakeXYWH(src_x, src_y, w, h));
+  canvas->drawPaint(paint);
+  canvas->restore();
+}
+
 SkScalar NativeThemeLinux::Clamp(SkScalar value,
                                  SkScalar min,
                                  SkScalar max) const {
   return std::min(std::max(value, min), max);
 }
 
 SkColor NativeThemeLinux::SaturateAndBrighten(SkScalar* hsv,
                                               SkScalar saturate_amount,
                                               SkScalar brighten_amount) const {
   SkScalar color[3];
@@ skipping 42 matching lines @@
 
 void NativeThemeLinux::SetScrollbarColors(unsigned inactive_color,
                                           unsigned active_color,
                                           unsigned track_color) const {
   thumb_inactive_color_ = inactive_color;
   thumb_active_color_ = active_color;
   track_color_ = track_color;
 }
 
 }  // namespace gfx