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 "base/logging.h"
   8 #include "base/strings/utf_string_conversions.h"
   9 #include "grit/ui_resources.h"
  10 #include "third_party/skia/include/core/SkPaint.h"
  11 #include "third_party/skia/include/core/SkTypeface.h"
  12 #include "ui/base/resource/resource_bundle.h"
  13 #include "ui/gfx/canvas.h"
  14 #include "ui/gfx/font.h"
  15 #include "ui/gfx/rect.h"
  16 #include "ui/gfx/size.h"
  17
  18 namespace {
  19
  20 // Different platforms need slightly different constants to look good.
  21 #if defined(OS_LINUX) && !defined(TOOLKIT_VIEWS)
  22 const float kTextSize = 9.0;
  23 const int kBottomMarginBrowserAction = 0;
  24 const int kBottomMarginPageAction = 2;
  25 const int kPadding = 2;
  26 const int kTopTextPadding = 0;
  27 #elif defined(OS_LINUX) && defined(TOOLKIT_VIEWS)
  28 const float kTextSize = 8.0;
  29 const int kBottomMarginBrowserAction = 5;
  30 const int kBottomMarginPageAction = 2;
  31 const int kPadding = 2;
  32 const int kTopTextPadding = 1;
  33 #elif defined(OS_MACOSX)
  34 const float kTextSize = 9.0;
  35 const int kBottomMarginBrowserAction = 5;
  36 const int kBottomMarginPageAction = 2;
  37 const int kPadding = 2;
  38 const int kTopTextPadding = 0;
  39 #else
  40 const float kTextSize = 10;
  41 const int kBottomMarginBrowserAction = 5;
  42 const int kBottomMarginPageAction = 2;
  43 const int kPadding = 2;
  44 // The padding between the top of the badge and the top of the text.
  45 const int kTopTextPadding = -1;
  46 #endif
  47
  48 const int kBadgeHeight = 11;
  49 const int kMaxTextWidth = 23;
  50
  51 // The minimum width for center-aligning the badge.
  52 const int kCenterAlignThreshold = 20;
  53
  54 }  // namespace
  55
  56 namespace badge_util {
  57
  58 SkPaint* GetBadgeTextPaintSingleton() {
  59 #if defined(OS_MACOSX)
  60   const char kPreferredTypeface[] = "Helvetica Bold";
  61 #else
  62   const char kPreferredTypeface[] = "Arial";
  63 #endif
  64
  65   static SkPaint* text_paint = NULL;
  66   if (!text_paint) {
  67     text_paint = new SkPaint;
  68     text_paint->setAntiAlias(true);
  69     text_paint->setTextAlign(SkPaint::kLeft_Align);
  70
  71     skia::RefPtr<SkTypeface> typeface = skia::AdoptRef(
  72         SkTypeface::CreateFromName(kPreferredTypeface, SkTypeface::kBold));
  73     // Skia doesn't do any font fallback---if the user is missing the font then
  74     // typeface will be NULL. If we don't do manual fallback then we'll crash.
  75     if (typeface) {
  76       text_paint->setFakeBoldText(true);
  77     } else {
  78       // Fall back to the system font. We don't bold it because we aren't sure
  79       // how it will look.
  80       // For the most part this code path will only be hit on Linux systems
  81       // that don't have Arial.
  82       ResourceBundle& rb = ResourceBundle::GetSharedInstance();
  83       const gfx::Font& base_font = rb.GetFont(ResourceBundle::BaseFont);
  84       typeface = skia::AdoptRef(SkTypeface::CreateFromName(
  85           base_font.GetFontName().c_str(), SkTypeface::kNormal));
  86       DCHECK(typeface);
  87     }
  88
  89     text_paint->setTypeface(typeface.get());
  90     // |text_paint| adds its own ref. Release the ref from CreateFontName.
  91   }
  92   return text_paint;
  93 }
  94
  95 SkBitmap DrawBadgeIconOverlay(const SkBitmap& icon,
  96                               float font_size,
  97                               const base::string16& text,
  98                               const base::string16& fallback) {
  99   const int kMinPadding = 1;
 100
 101   // Calculate the proper style/text overlay to render on the badge.
 102   SkPaint* paint = badge_util::GetBadgeTextPaintSingleton();
 103   paint->setTextSize(SkFloatToScalar(font_size));
 104   paint->setColor(SK_ColorWHITE);
 105
 106   std::string badge_text = base::UTF16ToUTF8(text);
 107
 108   // See if the text will fit - otherwise use a default.
 109   SkScalar text_width = paint->measureText(badge_text.c_str(),
 110                                            badge_text.size());
 111
 112   if (SkScalarRoundToInt(text_width) > (icon.width() - kMinPadding * 2)) {
 113     // String is too large - use the alternate text.
 114     badge_text = base::UTF16ToUTF8(fallback);
 115     text_width = paint->measureText(badge_text.c_str(), badge_text.size());
 116   }
 117
 118   // When centering the text, we need to make sure there are an equal number
 119   // of pixels on each side as otherwise the text looks off-center. So if the
 120   // padding would be uneven, clip one pixel off the right side.
 121   int badge_width = icon.width();
 122   if ((SkScalarRoundToInt(text_width) % 1) != (badge_width % 1))
 123     badge_width--;
 124
 125   // Render the badge bitmap and overlay into a canvas.
 126   scoped_ptr<gfx::Canvas> canvas(new gfx::Canvas(
 127       gfx::Size(badge_width, icon.height()), 1.0f, false));
 128   canvas->DrawImageInt(gfx::ImageSkia::CreateFrom1xBitmap(icon), 0, 0);
 129
 130   // Draw the text overlay centered horizontally and vertically. Skia expects
 131   // us to specify the lower left coordinate of the text box, which is why we
 132   // add 'font_size - 1' to the height.
 133   SkScalar x = (badge_width - text_width)/2;
 134   SkScalar y = (icon.height() - font_size)/2 + font_size - 1;
 135   canvas->sk_canvas()->drawText(
 136       badge_text.c_str(), badge_text.size(), x, y, *paint);
 137
 138   // Return the generated image.
 139   return canvas->ExtractImageRep().sk_bitmap();
 140 }
 141
 142 void PaintBadge(gfx::Canvas* canvas,
 143                 const gfx::Rect& bounds,
 144                 const std::string& text,
 145                 const SkColor& text_color_in,
 146                 const SkColor& background_color_in,
 147                 int icon_width,
 148                 extensions::ActionInfo::Type action_type) {
 149   if (text.empty())
 150     return;
 151
 152   SkColor text_color = text_color_in;
 153   if (SkColorGetA(text_color_in) == 0x00)
 154     text_color = SK_ColorWHITE;
 155
 156   SkColor background_color = background_color_in;
 157   if (SkColorGetA(background_color_in) == 0x00)
 158       background_color = SkColorSetARGB(255, 218, 0, 24);
 159
 160   canvas->Save();
 161
 162   SkPaint* text_paint = badge_util::GetBadgeTextPaintSingleton();
 163   text_paint->setTextSize(SkFloatToScalar(kTextSize));
 164   text_paint->setColor(text_color);
 165
 166   // Calculate text width. We clamp it to a max size.
 167   SkScalar sk_text_width = text_paint->measureText(text.c_str(), text.size());
 168   int text_width = std::min(kMaxTextWidth, SkScalarFloorToInt(sk_text_width));
 169
 170   // Calculate badge size. It is clamped to a min width just because it looks
 171   // silly if it is too skinny.
 172   int badge_width = text_width + kPadding * 2;
 173   // Force the pixel width of badge to be either odd (if the icon width is odd)
 174   // or even otherwise. If there is a mismatch you get http://crbug.com/26400.
 175   if (icon_width != 0 && (badge_width % 2 != icon_width % 2))
 176     badge_width += 1;
 177   badge_width = std::max(kBadgeHeight, badge_width);
 178
 179   // Paint the badge background color in the right location. It is usually
 180   // right-aligned, but it can also be center-aligned if it is large.
 181   int rect_height = kBadgeHeight;
 182   int bottom_margin =
 183       action_type == extensions::ActionInfo::TYPE_BROWSER ?
 184       kBottomMarginBrowserAction : kBottomMarginPageAction;
 185   int rect_y = bounds.bottom() - bottom_margin - kBadgeHeight;
 186   int rect_width = badge_width;
 187   int rect_x = (badge_width >= kCenterAlignThreshold) ?
 188       bounds.x() + (bounds.width() - badge_width) / 2 :
 189       bounds.right() - badge_width;
 190   gfx::Rect rect(rect_x, rect_y, rect_width, rect_height);
 191
 192   SkPaint rect_paint;
 193   rect_paint.setStyle(SkPaint::kFill_Style);
 194   rect_paint.setAntiAlias(true);
 195   rect_paint.setColor(background_color);
 196   canvas->DrawRoundRect(rect, 2, rect_paint);
 197
 198   // Overlay the gradient. It is stretchy, so we do this in three parts.
 199   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
 200   gfx::ImageSkia* gradient_left = rb.GetImageSkiaNamed(
 201       IDR_BROWSER_ACTION_BADGE_LEFT);
 202   gfx::ImageSkia* gradient_right = rb.GetImageSkiaNamed(
 203       IDR_BROWSER_ACTION_BADGE_RIGHT);
 204   gfx::ImageSkia* gradient_center = rb.GetImageSkiaNamed(
 205       IDR_BROWSER_ACTION_BADGE_CENTER);
 206
 207   canvas->DrawImageInt(*gradient_left, rect.x(), rect.y());
 208   canvas->TileImageInt(*gradient_center,
 209       rect.x() + gradient_left->width(),
 210       rect.y(),
 211       rect.width() - gradient_left->width() - gradient_right->width(),
 212       rect.height());
 213   canvas->DrawImageInt(*gradient_right,
 214       rect.right() - gradient_right->width(), rect.y());
 215
 216   // Finally, draw the text centered within the badge. We set a clip in case the
 217   // text was too large.
 218   rect.Inset(kPadding, 0);
 219   canvas->ClipRect(rect);
 220   canvas->sk_canvas()->drawText(
 221       text.c_str(), text.size(),
 222       SkFloatToScalar(rect.x() +
 223                       static_cast<float>(rect.width() - text_width) / 2),
 224       SkFloatToScalar(rect.y() + kTextSize + kTopTextPadding),
 225       *text_paint);
 226   canvas->Restore();
 227 }
 228
 229 }  // namespace badge_util