chrome/common/badge_util.cc

   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
  20 namespace {
  21
  22 // Different platforms need slightly different constants to look good.
  23 #if defined(OS_WIN)
  24 const float kTextSize = 10;
  25 const int kBottomMarginBrowserAction = 0;
  26 const int kBottomMarginPageAction = 2;
  27 const int kPadding = 2;
  28 // The padding between the top of the badge and the top of the text.
  29 const int kTopTextPadding = -1;
  30 #elif defined(OS_MACOSX)
  31 const float kTextSize = 9.0;
  32 const int kBottomMarginBrowserAction = 5;
  33 const int kBottomMarginPageAction = 2;
  34 const int kPadding = 2;
  35 const int kTopTextPadding = 0;
  36 #elif defined(OS_CHROMEOS)
  37 const float kTextSize = 8.0;
  38 const int kBottomMarginBrowserAction = 0;
  39 const int kBottomMarginPageAction = 2;
  40 const int kPadding = 2;
  41 const int kTopTextPadding = 1;
  42 #elif defined(OS_POSIX)
  43 const float kTextSize = 9.0;
  44 const int kBottomMarginBrowserAction = 0;
  45 const int kBottomMarginPageAction = 2;
  46 const int kPadding = 2;
  47 const int kTopTextPadding = 0;
  48 #endif
  49
  50 const int kBadgeHeight = 11;
  51 const int kMaxTextWidth = 23;
  52
  53 // The minimum width for center-aligning the badge.
  54 const int kCenterAlignThreshold = 20;
  55
  56 }  // namespace
  57
  58 namespace badge_util {
  59
  60 SkPaint* 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
  97 void 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