ui/base/cursor/cursor_util.cc

   1 // Copyright 2014 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/base/cursor/cursor_util.h"
   6
   7 #include "base/logging.h"
   8 #include "skia/ext/image_operations.h"
   9 #include "ui/base/resource/resource_bundle.h"
  10 #include "ui/gfx/geometry/point_conversions.h"
  11 #include "ui/gfx/geometry/size_conversions.h"
  12 #include "ui/gfx/image/image_skia.h"
  13 #include "ui/gfx/skbitmap_operations.h"
  14 #include "ui/gfx/skia_util.h"
  15
  16 namespace ui {
  17
  18 void ScaleAndRotateCursorBitmapAndHotpoint(float scale,
  19                                            gfx::Display::Rotation rotation,
  20                                            SkBitmap* bitmap,
  21                                            gfx::Point* hotpoint) {
  22   switch (rotation) {
  23     case gfx::Display::ROTATE_0:
  24       break;
  25     case gfx::Display::ROTATE_90:
  26       hotpoint->SetPoint(bitmap->height() - hotpoint->y(), hotpoint->x());
  27       *bitmap = SkBitmapOperations::Rotate(
  28           *bitmap, SkBitmapOperations::ROTATION_90_CW);
  29       break;
  30     case gfx::Display::ROTATE_180:
  31       hotpoint->SetPoint(
  32           bitmap->width() - hotpoint->x(), bitmap->height() - hotpoint->y());
  33       *bitmap = SkBitmapOperations::Rotate(
  34           *bitmap, SkBitmapOperations::ROTATION_180_CW);
  35       break;
  36     case gfx::Display::ROTATE_270:
  37       hotpoint->SetPoint(hotpoint->y(), bitmap->width() - hotpoint->x());
  38       *bitmap = SkBitmapOperations::Rotate(
  39           *bitmap, SkBitmapOperations::ROTATION_270_CW);
  40       break;
  41   }
  42
  43   if (scale < FLT_EPSILON) {
  44     NOTREACHED() << "Scale must be larger than 0.";
  45     scale = 1.0f;
  46   }
  47
  48   if (scale == 1.0f)
  49     return;
  50
  51   gfx::Size scaled_size = gfx::ToFlooredSize(
  52       gfx::ScaleSize(gfx::Size(bitmap->width(), bitmap->height()), scale));
  53
  54   *bitmap = skia::ImageOperations::Resize(
  55       *bitmap,
  56       skia::ImageOperations::RESIZE_BETTER,
  57       scaled_size.width(),
  58       scaled_size.height());
  59   *hotpoint = gfx::ToFlooredPoint(gfx::ScalePoint(*hotpoint, scale));
  60 }
  61
  62 void GetImageCursorBitmap(int resource_id,
  63                           float scale,
  64                           gfx::Display::Rotation rotation,
  65                           gfx::Point* hotspot,
  66                           SkBitmap* bitmap) {
  67   const gfx::ImageSkia* image =
  68       ResourceBundle::GetSharedInstance().GetImageSkiaNamed(resource_id);
  69   const gfx::ImageSkiaRep& image_rep = image->GetRepresentation(scale);
  70   // TODO(oshima): The cursor should use resource scale factor when
  71   // fractional scale factor is enabled. crbug.com/372212
  72   (*bitmap) = image_rep.sk_bitmap();
  73   ScaleAndRotateCursorBitmapAndHotpoint(
  74       scale / image_rep.scale(), rotation, bitmap, hotspot);
  75   // |image_rep| is owned by the resource bundle. So we do not need to free it.
  76 }
  77
  78 void GetAnimatedCursorBitmaps(int resource_id,
  79                               float scale,
  80                               gfx::Display::Rotation rotation,
  81                               gfx::Point* hotspot,
  82                               std::vector<SkBitmap>* bitmaps) {
  83   // TODO(oshima|tdanderson): Support rotation and fractional scale factor.
  84   const gfx::ImageSkia* image =
  85       ResourceBundle::GetSharedInstance().GetImageSkiaNamed(resource_id);
  86   const gfx::ImageSkiaRep& image_rep = image->GetRepresentation(scale);
  87   SkBitmap bitmap = image_rep.sk_bitmap();
  88   int frame_width = bitmap.height();
  89   int frame_height = frame_width;
  90   int total_width = bitmap.width();
  91   DCHECK_EQ(total_width % frame_width, 0);
  92   int frame_count = total_width / frame_width;
  93   DCHECK_GT(frame_count, 0);
  94
  95   bitmaps->resize(frame_count);
  96
  97   for (int frame = 0; frame < frame_count; ++frame) {
  98     int x_offset = frame_width * frame;
  99     DCHECK_LE(x_offset + frame_width, total_width);
 100
 101     SkBitmap cropped = SkBitmapOperations::CreateTiledBitmap(
 102         bitmap, x_offset, 0, frame_width, frame_height);
 103     DCHECK_EQ(frame_width, cropped.width());
 104     DCHECK_EQ(frame_height, cropped.height());
 105
 106     (*bitmaps)[frame] = cropped;
 107   }
 108 }
 109
 110 }  // namespace ui