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      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 = 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 (SkScalarRound(text_width) > (icon.width() - kMinPadding * 2)) {
    113     // String is too large - use the alternate text.
    114     badge_text = 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 ((SkScalarRound(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, SkScalarFloor(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
    230