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/gfx/nine_image_painter.h"
6
7 #include <limits>
8
9 #include "third_party/skia/include/core/SkPaint.h"
10 #include "third_party/skia/include/core/SkRect.h"
11 #include "third_party/skia/include/core/SkScalar.h"
12 #include "ui/gfx/canvas.h"
13 #include "ui/gfx/geometry/rect_conversions.h"
14 #include "ui/gfx/geometry/safe_integer_conversions.h"
15 #include "ui/gfx/image/image_skia_operations.h"
16 #include "ui/gfx/insets.h"
17 #include "ui/gfx/rect.h"
18 #include "ui/gfx/scoped_canvas.h"
19 #include "ui/gfx/skia_util.h"
20
21 namespace gfx {
22
23 namespace {
24
25 // The following functions width and height of the image in pixels for the
26 // scale factor in the Canvas.
ImageWidthInPixels(const ImageSkia & i,Canvas * c)27 int ImageWidthInPixels(const ImageSkia& i, Canvas* c) {
28 return i.GetRepresentation(c->image_scale()).pixel_width();
29 }
30
ImageHeightInPixels(const ImageSkia & i,Canvas * c)31 int ImageHeightInPixels(const ImageSkia& i, Canvas* c) {
32 return i.GetRepresentation(c->image_scale()).pixel_height();
33 }
34
35 // Stretches the given image over the specified canvas area.
Fill(Canvas * c,const ImageSkia & i,int x,int y,int w,int h,const SkPaint & paint)36 void Fill(Canvas* c,
37 const ImageSkia& i,
38 int x,
39 int y,
40 int w,
41 int h,
42 const SkPaint& paint) {
43 c->DrawImageIntInPixel(i, 0, 0, ImageWidthInPixels(i, c),
44 ImageHeightInPixels(i, c), x, y, w, h, false, paint);
45 }
46
47 } // namespace
48
NineImagePainter(const std::vector<ImageSkia> & images)49 NineImagePainter::NineImagePainter(const std::vector<ImageSkia>& images) {
50 DCHECK_EQ(arraysize(images_), images.size());
51 for (size_t i = 0; i < arraysize(images_); ++i)
52 images_[i] = images[i];
53 }
54
NineImagePainter(const ImageSkia & image,const Insets & insets)55 NineImagePainter::NineImagePainter(const ImageSkia& image,
56 const Insets& insets) {
57 DCHECK_GE(image.width(), insets.width());
58 DCHECK_GE(image.height(), insets.height());
59
60 // Extract subsets of the original image to match the |images_| format.
61 const int x[] =
62 { 0, insets.left(), image.width() - insets.right(), image.width() };
63 const int y[] =
64 { 0, insets.top(), image.height() - insets.bottom(), image.height() };
65
66 for (size_t j = 0; j < 3; ++j) {
67 for (size_t i = 0; i < 3; ++i) {
68 images_[i + j * 3] = ImageSkiaOperations::ExtractSubset(image,
69 Rect(x[i], y[j], x[i + 1] - x[i], y[j + 1] - y[j]));
70 }
71 }
72 }
73
~NineImagePainter()74 NineImagePainter::~NineImagePainter() {
75 }
76
IsEmpty() const77 bool NineImagePainter::IsEmpty() const {
78 return images_[0].isNull();
79 }
80
GetMinimumSize() const81 Size NineImagePainter::GetMinimumSize() const {
82 return IsEmpty() ? Size() : Size(
83 images_[0].width() + images_[1].width() + images_[2].width(),
84 images_[0].height() + images_[3].height() + images_[6].height());
85 }
86
Paint(Canvas * canvas,const Rect & bounds)87 void NineImagePainter::Paint(Canvas* canvas, const Rect& bounds) {
88 // When no alpha value is specified, use default value of 100% opacity.
89 Paint(canvas, bounds, std::numeric_limits<uint8>::max());
90 }
91
Paint(Canvas * canvas,const Rect & bounds,const uint8 alpha)92 void NineImagePainter::Paint(Canvas* canvas,
93 const Rect& bounds,
94 const uint8 alpha) {
95 if (IsEmpty())
96 return;
97
98 ScopedCanvas scoped_canvas(canvas);
99 canvas->Translate(bounds.OffsetFromOrigin());
100
101 SkPaint paint;
102 paint.setAlpha(alpha);
103
104 // Get the current transform from the canvas and apply it to the logical
105 // bounds passed in. This will give us the pixel bounds which can be used
106 // to draw the images at the correct locations.
107 // We should not scale the bounds by the canvas->image_scale() as that can be
108 // different from the real scale in the canvas transform.
109 SkMatrix matrix = canvas->sk_canvas()->getTotalMatrix();
110 SkRect scaled_rect;
111 matrix.mapRect(&scaled_rect, RectToSkRect(bounds));
112
113 int scaled_width = gfx::ToCeiledInt(SkScalarToFloat(scaled_rect.width()));
114 int scaled_height = gfx::ToCeiledInt(SkScalarToFloat(scaled_rect.height()));
115
116 // In case the corners and edges don't all have the same width/height, we draw
117 // the center first, and extend it out in all directions to the edges of the
118 // images with the smallest widths/heights. This way there will be no
119 // unpainted areas, though some corners or edges might overlap the center.
120 int i0w = ImageWidthInPixels(images_[0], canvas);
121 int i2w = ImageWidthInPixels(images_[2], canvas);
122 int i3w = ImageWidthInPixels(images_[3], canvas);
123 int i5w = ImageWidthInPixels(images_[5], canvas);
124 int i6w = ImageWidthInPixels(images_[6], canvas);
125 int i8w = ImageWidthInPixels(images_[8], canvas);
126
127 int i4x = std::min(std::min(i0w, i3w), i6w);
128 int i4w = scaled_width - i4x - std::min(std::min(i2w, i5w), i8w);
129
130 int i0h = ImageHeightInPixels(images_[0], canvas);
131 int i1h = ImageHeightInPixels(images_[1], canvas);
132 int i2h = ImageHeightInPixels(images_[2], canvas);
133 int i6h = ImageHeightInPixels(images_[6], canvas);
134 int i7h = ImageHeightInPixels(images_[7], canvas);
135 int i8h = ImageHeightInPixels(images_[8], canvas);
136
137 int i4y = std::min(std::min(i0h, i1h), i2h);
138 int i4h = scaled_height - i4y - std::min(std::min(i6h, i7h), i8h);
139 if (!images_[4].isNull())
140 Fill(canvas, images_[4], i4x, i4y, i4w, i4h, paint);
141 canvas->DrawImageIntInPixel(images_[0], 0, 0, i0w, i0h,
142 0, 0, i0w, i0h, false, paint);
143 Fill(canvas, images_[1], i0w, 0, scaled_width - i0w - i2w, i1h, paint);
144 canvas->DrawImageIntInPixel(images_[2], 0, 0, i2w, i2h, scaled_width - i2w,
145 0, i2w, i2h, false, paint);
146 Fill(canvas, images_[3], 0, i0h, i3w, scaled_height - i0h - i6h, paint);
147 Fill(canvas, images_[5], scaled_width - i5w, i2h, i5w,
148 scaled_height - i2h - i8h, paint);
149 canvas->DrawImageIntInPixel(images_[6], 0, 0, i6w, i6h, 0,
150 scaled_height - i6h, i6w, i6h, false, paint);
151 Fill(canvas, images_[7], i6w, scaled_height - i7h, scaled_width - i6w - i8w,
152 i7h, paint);
153 canvas->DrawImageIntInPixel(images_[8], 0, 0, i8w, i8h, scaled_width - i8w,
154 scaled_height - i8h, i8w, i8h, false, paint);
155 }
156
157 } // namespace gfx
158