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 "chrome/common/badge_util.h"
6
7#include <cmath>
8
9#include "base/logging.h"
10#include "base/strings/utf_string_conversions.h"
11#include "third_party/skia/include/core/SkPaint.h"
12#include "third_party/skia/include/core/SkTypeface.h"
13#include "ui/base/resource/resource_bundle.h"
14#include "ui/gfx/canvas.h"
15#include "ui/gfx/font.h"
16#include "ui/gfx/rect.h"
17#include "ui/gfx/size.h"
18#include "ui/resources/grit/ui_resources.h"
19
20namespace {
21
22// Different platforms need slightly different constants to look good.
23#if defined(OS_WIN)
24const float kTextSize = 10;
25const int kBottomMarginBrowserAction = 0;
26const int kBottomMarginPageAction = 2;
27const int kPadding = 2;
28// The padding between the top of the badge and the top of the text.
29const int kTopTextPadding = -1;
30#elif defined(OS_MACOSX)
31const float kTextSize = 9.0;
32const int kBottomMarginBrowserAction = 5;
33const int kBottomMarginPageAction = 2;
34const int kPadding = 2;
35const int kTopTextPadding = 0;
36#elif defined(OS_CHROMEOS)
37const float kTextSize = 8.0;
38const int kBottomMarginBrowserAction = 0;
39const int kBottomMarginPageAction = 2;
40const int kPadding = 2;
41const int kTopTextPadding = 1;
42#elif defined(OS_POSIX)
43const float kTextSize = 9.0;
44const int kBottomMarginBrowserAction = 0;
45const int kBottomMarginPageAction = 2;
46const int kPadding = 2;
47const int kTopTextPadding = 0;
48#endif
49
50const int kBadgeHeight = 11;
51const int kMaxTextWidth = 23;
52
53// The minimum width for center-aligning the badge.
54const int kCenterAlignThreshold = 20;
55
56}  // namespace
57
58namespace badge_util {
59
60SkPaint* GetBadgeTextPaintSingleton() {
61#if defined(OS_MACOSX)
62  const char kPreferredTypeface[] = "Helvetica Bold";
63#else
64  const char kPreferredTypeface[] = "Arial";
65#endif
66
67  static SkPaint* text_paint = NULL;
68  if (!text_paint) {
69    text_paint = new SkPaint;
70    text_paint->setAntiAlias(true);
71    text_paint->setTextAlign(SkPaint::kLeft_Align);
72
73    skia::RefPtr<SkTypeface> typeface = skia::AdoptRef(
74        SkTypeface::CreateFromName(kPreferredTypeface, SkTypeface::kBold));
75    // Skia doesn't do any font fallback---if the user is missing the font then
76    // typeface will be NULL. If we don't do manual fallback then we'll crash.
77    if (typeface) {
78      text_paint->setFakeBoldText(true);
79    } else {
80      // Fall back to the system font. We don't bold it because we aren't sure
81      // how it will look.
82      // For the most part this code path will only be hit on Linux systems
83      // that don't have Arial.
84      ResourceBundle& rb = ResourceBundle::GetSharedInstance();
85      const gfx::Font& base_font = rb.GetFont(ResourceBundle::BaseFont);
86      typeface = skia::AdoptRef(SkTypeface::CreateFromName(
87          base_font.GetFontName().c_str(), SkTypeface::kNormal));
88      DCHECK(typeface);
89    }
90
91    text_paint->setTypeface(typeface.get());
92    // |text_paint| adds its own ref. Release the ref from CreateFontName.
93  }
94  return text_paint;
95}
96
97void PaintBadge(gfx::Canvas* canvas,
98                const gfx::Rect& bounds,
99                const std::string& text,
100                const SkColor& text_color_in,
101                const SkColor& background_color_in,
102                int icon_width,
103                extensions::ActionInfo::Type action_type) {
104  if (text.empty())
105    return;
106
107  SkColor text_color = text_color_in;
108  if (SkColorGetA(text_color_in) == 0x00)
109    text_color = SK_ColorWHITE;
110
111  SkColor background_color = background_color_in;
112  if (SkColorGetA(background_color_in) == 0x00)
113      background_color = SkColorSetARGB(255, 218, 0, 24);
114
115  canvas->Save();
116
117  SkPaint* text_paint = badge_util::GetBadgeTextPaintSingleton();
118  text_paint->setColor(text_color);
119  float scale = canvas->image_scale();
120
121  // Calculate text width. Font width may not be linear with respect to the
122  // scale factor (e.g. when hinting is applied), so we need to use the font
123  // size that canvas actually uses when drawing a text.
124  text_paint->setTextSize(SkFloatToScalar(kTextSize) * scale);
125  SkScalar sk_text_width_in_pixel =
126      text_paint->measureText(text.c_str(), text.size());
127  text_paint->setTextSize(SkFloatToScalar(kTextSize));
128
129  // We clamp the width to a max size. SkPaint::measureText returns the width in
130  // pixel (as a result of scale multiplier), so convert sk_text_width_in_pixel
131  // back to DIP (density independent pixel) first.
132  int text_width =
133      std::min(kMaxTextWidth,
134               static_cast<int>(
135                   std::ceil(SkScalarToFloat(sk_text_width_in_pixel) / scale)));
136
137  // Calculate badge size. It is clamped to a min width just because it looks
138  // silly if it is too skinny.
139  int badge_width = text_width + kPadding * 2;
140  // Force the pixel width of badge to be either odd (if the icon width is odd)
141  // or even otherwise. If there is a mismatch you get http://crbug.com/26400.
142  if (icon_width != 0 && (badge_width % 2 != icon_width % 2))
143    badge_width += 1;
144  badge_width = std::max(kBadgeHeight, badge_width);
145
146  // Paint the badge background color in the right location. It is usually
147  // right-aligned, but it can also be center-aligned if it is large.
148  int rect_height = kBadgeHeight;
149  int bottom_margin =
150      action_type == extensions::ActionInfo::TYPE_BROWSER ?
151      kBottomMarginBrowserAction : kBottomMarginPageAction;
152  int rect_y = bounds.bottom() - bottom_margin - kBadgeHeight;
153  int rect_width = badge_width;
154  int rect_x = (badge_width >= kCenterAlignThreshold) ?
155      bounds.x() + (bounds.width() - badge_width) / 2 :
156      bounds.right() - badge_width;
157  gfx::Rect rect(rect_x, rect_y, rect_width, rect_height);
158
159  SkPaint rect_paint;
160  rect_paint.setStyle(SkPaint::kFill_Style);
161  rect_paint.setAntiAlias(true);
162  rect_paint.setColor(background_color);
163  canvas->DrawRoundRect(rect, 2, rect_paint);
164
165  // Overlay the gradient. It is stretchy, so we do this in three parts.
166  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
167  gfx::ImageSkia* gradient_left = rb.GetImageSkiaNamed(
168      IDR_BROWSER_ACTION_BADGE_LEFT);
169  gfx::ImageSkia* gradient_right = rb.GetImageSkiaNamed(
170      IDR_BROWSER_ACTION_BADGE_RIGHT);
171  gfx::ImageSkia* gradient_center = rb.GetImageSkiaNamed(
172      IDR_BROWSER_ACTION_BADGE_CENTER);
173
174  canvas->DrawImageInt(*gradient_left, rect.x(), rect.y());
175  canvas->TileImageInt(*gradient_center,
176      rect.x() + gradient_left->width(),
177      rect.y(),
178      rect.width() - gradient_left->width() - gradient_right->width(),
179      rect.height());
180  canvas->DrawImageInt(*gradient_right,
181      rect.right() - gradient_right->width(), rect.y());
182
183  // Finally, draw the text centered within the badge. We set a clip in case the
184  // text was too large.
185  rect.Inset(kPadding, 0);
186  canvas->ClipRect(rect);
187  canvas->sk_canvas()->drawText(
188      text.c_str(), text.size(),
189      SkFloatToScalar(rect.x() +
190                      static_cast<float>(rect.width() - text_width) / 2),
191      SkFloatToScalar(rect.y() + kTextSize + kTopTextPadding),
192      *text_paint);
193  canvas->Restore();
194}
195
196}  // namespace badge_util
197