ui/views/shadow_border.cc

   1 // Copyright 2013 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/shadow_border.h"
   6
   7 #include "third_party/skia/include/core/SkDrawLooper.h"
   8 #include "ui/gfx/canvas.h"
   9 #include "ui/gfx/geometry/insets.h"
  10 #include "ui/gfx/geometry/rect.h"
  11 #include "ui/gfx/skia_util.h"
  12 #include "ui/views/view.h"
  13
  14 namespace views {
  15
  16 namespace {
  17
  18 gfx::Insets GetInsetsFromShadowValue(const gfx::ShadowValue& shadow) {
  19   std::vector<gfx::ShadowValue> shadows;
  20   shadows.push_back(shadow);
  21   return -gfx::ShadowValue::GetMargin(shadows);
  22 }
  23
  24 }  // namespace
  25
  26 ShadowBorder::ShadowBorder(const gfx::ShadowValue& shadow)
  27     : views::Border(),
  28       shadow_value_(shadow),
  29       insets_(GetInsetsFromShadowValue(shadow)) {
  30 }
  31
  32 ShadowBorder::~ShadowBorder() {
  33 }
  34
  35 // TODO(sidharthms): Re-painting a shadow looper on every paint call may yield
  36 // poor performance. Ideally we should be caching the border to bitmaps.
  37 void ShadowBorder::Paint(const views::View& view, gfx::Canvas* canvas) {
  38   SkPaint paint;
  39   std::vector<gfx::ShadowValue> shadows;
  40   shadows.push_back(shadow_value_);
  41   skia::RefPtr<SkDrawLooper> looper = gfx::CreateShadowDrawLooper(shadows);
  42   paint.setLooper(looper.get());
  43   paint.setColor(SK_ColorTRANSPARENT);
  44   paint.setStrokeJoin(SkPaint::kRound_Join);
  45   gfx::Rect bounds(view.size());
  46   bounds.Inset(-gfx::ShadowValue::GetMargin(shadows));
  47   canvas->DrawRect(bounds, paint);
  48 }
  49
  50 gfx::Insets ShadowBorder::GetInsets() const {
  51   return insets_;
  52 }
  53
  54 gfx::Size ShadowBorder::GetMinimumSize() const {
  55   return gfx::Size(shadow_value_.blur(), shadow_value_.blur());
  56 }
  57
  58 }  // namespace views