Source/WebCore/rendering/style/NinePieceImage.cpp

   1 /*
   2  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
   3  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2000 Dirk Mueller (mueller@kde.org)
   5  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2013, 2015 Apple Inc. All rights reserved.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public License
  18  * along with this library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20  * Boston, MA 02110-1301, USA.
  21  *
  22  */
  23
  24 #include "config.h"
  25 #include "NinePieceImage.h"
  26
  27 #include "GraphicsContext.h"
  28 #include "LengthFunctions.h"
  29 #include "RenderStyle.h"
  30 #include <wtf/NeverDestroyed.h>
  31
  32 namespace WebCore {
  33
  34 static DataRef<NinePieceImageData>& defaultData()
  35 {
  36     static NeverDestroyed<DataRef<NinePieceImageData>> data(NinePieceImageData::create());
  37     return data.get();
  38 }
  39
  40 NinePieceImage::NinePieceImage()
  41     : m_data(defaultData())
  42 {
  43 }
  44
  45 NinePieceImage::NinePieceImage(PassRefPtr<StyleImage> image, LengthBox imageSlices, bool fill, LengthBox borderSlices, LengthBox outset, ENinePieceImageRule horizontalRule, ENinePieceImageRule verticalRule)
  46     : m_data(NinePieceImageData::create())
  47 {
  48     m_data.access()->image = image;
  49     m_data.access()->imageSlices = WTF::move(imageSlices);
  50     m_data.access()->borderSlices = WTF::move(borderSlices);
  51     m_data.access()->outset = WTF::move(outset);
  52     m_data.access()->fill = fill;
  53     m_data.access()->horizontalRule = horizontalRule;
  54     m_data.access()->verticalRule = verticalRule;
  55 }
  56
  57 LayoutUnit NinePieceImage::computeSlice(Length length, LayoutUnit width, LayoutUnit slice, LayoutUnit extent)
  58 {
  59     if (length.isRelative())
  60         return length.value() * width;
  61     if (length.isAuto())
  62         return slice;
  63     return valueForLength(length, extent);
  64 }
  65
  66 LayoutBoxExtent NinePieceImage::computeSlices(const LayoutSize& size, const LengthBox& lengths, int scaleFactor)
  67 {
  68     LayoutUnit top    = std::min<LayoutUnit>(size.height(), valueForLength(lengths.top(),    size.height())) * scaleFactor;
  69     LayoutUnit right  = std::min<LayoutUnit>(size.width(),  valueForLength(lengths.right(),  size.width()))  * scaleFactor;
  70     LayoutUnit bottom = std::min<LayoutUnit>(size.height(), valueForLength(lengths.bottom(), size.height())) * scaleFactor;
  71     LayoutUnit left   = std::min<LayoutUnit>(size.width(),  valueForLength(lengths.left(),   size.width()))  * scaleFactor;
  72     return LayoutBoxExtent(top, right, bottom, left);
  73 }
  74
  75 LayoutBoxExtent NinePieceImage::computeSlices(const LayoutSize& size, const LengthBox& lengths, const FloatBoxExtent& widths, const LayoutBoxExtent& slices)
  76 {
  77     LayoutUnit top    = computeSlice(lengths.top(),    widths.top(),    slices.top(),    size.height());
  78     LayoutUnit right  = computeSlice(lengths.right(),  widths.right(),  slices.right(),  size.width());
  79     LayoutUnit bottom = computeSlice(lengths.bottom(), widths.bottom(), slices.bottom(), size.height());
  80     LayoutUnit left   = computeSlice(lengths.left(),   widths.left(),   slices.left(),   size.width());
  81     return LayoutBoxExtent(top, right, bottom, left);
  82 }
  83
  84 void NinePieceImage::scaleSlicesIfNeeded(const LayoutSize& size, LayoutBoxExtent& slices, int scaleFactor)
  85 {
  86     LayoutUnit width  = std::max<LayoutUnit>(1 / scaleFactor, slices.left() + slices.right());
  87     LayoutUnit height = std::max<LayoutUnit>(1 / scaleFactor, slices.top() + slices.bottom());
  88
  89     float sliceScaleFactor = std::min((float)size.width() / width, (float)size.height() / height);
  90
  91     if (sliceScaleFactor >= 1)
  92         return;
  93
  94     // All slices are reduced by multiplying them by sliceScaleFactor.
  95     slices.top()    *= sliceScaleFactor;
  96     slices.right()  *= sliceScaleFactor;
  97     slices.bottom() *= sliceScaleFactor;
  98     slices.left()   *= sliceScaleFactor;
  99 }
 100
 101 bool NinePieceImage::isEmptyPieceRect(ImagePiece piece, const LayoutBoxExtent& slices)
 102 {
 103     if (piece == MiddlePiece)
 104         return false;
 105
 106     PhysicalBoxSide horizontalSide = imagePieceHorizontalSide(piece);
 107     PhysicalBoxSide verticalSide = imagePieceVerticalSide(piece);
 108     return !((horizontalSide == NilSide || slices.at(horizontalSide)) && (verticalSide == NilSide || slices.at(verticalSide)));
 109 }
 110
 111 bool NinePieceImage::isEmptyPieceRect(ImagePiece piece, const Vector<FloatRect>& destinationRects, const Vector<FloatRect>& sourceRects)
 112 {
 113     return destinationRects[piece].isEmpty() || sourceRects[piece].isEmpty();
 114 }
 115
 116 Vector<FloatRect> NinePieceImage::computeIntrinsicRects(const FloatRect& outer, const LayoutBoxExtent& slices, float deviceScaleFactor)
 117 {
 118     FloatRect inner = outer;
 119     inner.move(slices.left(), slices.top());
 120     inner.contract(slices.left() + slices.right(), slices.top() + slices.bottom());
 121     ASSERT(outer.contains(inner));
 122
 123     Vector<FloatRect> rects(MaxPiece);
 124
 125     rects[TopLeftPiece]     = snapRectToDevicePixels(outer.x(),    outer.y(),    slices.left(),  slices.top(),    deviceScaleFactor);
 126     rects[BottomLeftPiece]  = snapRectToDevicePixels(outer.x(),    inner.maxY(), slices.left(),  slices.bottom(), deviceScaleFactor);
 127     rects[LeftPiece]        = snapRectToDevicePixels(outer.x(),    inner.y(),    slices.left(),  inner.height(),  deviceScaleFactor);
 128
 129     rects[TopRightPiece]    = snapRectToDevicePixels(inner.maxX(), outer.y(),    slices.right(), slices.top(),    deviceScaleFactor);
 130     rects[BottomRightPiece] = snapRectToDevicePixels(inner.maxX(), inner.maxY(), slices.right(), slices.bottom(), deviceScaleFactor);
 131     rects[RightPiece]       = snapRectToDevicePixels(inner.maxX(), inner.y(),    slices.right(), inner.height(),  deviceScaleFactor);
 132
 133     rects[TopPiece]         = snapRectToDevicePixels(inner.x(),    outer.y(),    inner.width(),  slices.top(),    deviceScaleFactor);
 134     rects[BottomPiece]      = snapRectToDevicePixels(inner.x(),    inner.maxY(), inner.width(),  slices.bottom(), deviceScaleFactor);
 135
 136     rects[MiddlePiece]      = snapRectToDevicePixels(inner.x(),    inner.y(),    inner.width(),  inner.height(),  deviceScaleFactor);
 137     return rects;
 138 }
 139
 140 Vector<FloatRect> NinePieceImage::computeNonIntrinsicRects(const Vector<FloatRect>& intrinsicRects, const LayoutBoxExtent& slices)
 141 {
 142     Vector<FloatRect> rects(MaxPiece);
 143
 144     for (ImagePiece piece = MinPiece; piece < MaxPiece; ++piece) {
 145         if (isEmptyPieceRect(piece, slices))
 146             continue;
 147         rects[piece] = FloatRect(FloatPoint(), intrinsicRects[piece].size());
 148     }
 149
 150     return rects;
 151 }
 152
 153 FloatSize NinePieceImage::computeIntrinsicSideTileScale(ImagePiece piece, const Vector<FloatRect>& destinationRects, const Vector<FloatRect>& sourceRects)
 154 {
 155     ASSERT(!isCornerPiece(piece) && !isMiddlePiece(piece));
 156     if (isEmptyPieceRect(piece, destinationRects, sourceRects))
 157         return FloatSize(1, 1);
 158
 159     float scale;
 160     if (isVerticalPiece(piece))
 161         scale = destinationRects[piece].height() / sourceRects[piece].height();
 162     else
 163         scale = destinationRects[piece].width() / sourceRects[piece].width();
 164
 165     return FloatSize(scale, scale);
 166 }
 167
 168 FloatSize NinePieceImage::computeIntrinsicMiddleTileScale(const Vector<FloatSize>& scales, const Vector<FloatRect>& destinationRects, const Vector<FloatRect>& sourceRects, ENinePieceImageRule hRule, ENinePieceImageRule vRule)
 169 {
 170     FloatSize scale(1, 1);
 171     if (isEmptyPieceRect(MiddlePiece, destinationRects, sourceRects))
 172         return scale;
 173
 174     // Unlike the side pieces, the middle piece can have "stretch" specified in one axis but not the other.
 175     // In fact the side pieces don't even use the scale factor unless they have a rule other than "stretch".
 176     if (hRule == StretchImageRule)
 177         scale.setWidth(destinationRects[MiddlePiece].width() / sourceRects[MiddlePiece].width());
 178     else if (!isEmptyPieceRect(TopPiece, destinationRects, sourceRects))
 179         scale.setWidth(scales[TopPiece].width());
 180     else if (!isEmptyPieceRect(BottomPiece, destinationRects, sourceRects))
 181         scale.setWidth(scales[BottomPiece].width());
 182
 183     if (vRule == StretchImageRule)
 184         scale.setHeight(destinationRects[MiddlePiece].height() / sourceRects[MiddlePiece].height());
 185     else if (!isEmptyPieceRect(LeftPiece, destinationRects, sourceRects))
 186         scale.setHeight(scales[LeftPiece].height());
 187     else if (!isEmptyPieceRect(RightPiece, destinationRects, sourceRects))
 188         scale.setHeight(scales[RightPiece].height());
 189
 190     return scale;
 191 }
 192
 193 Vector<FloatSize> NinePieceImage::computeIntrinsicTileScales(const Vector<FloatRect>& destinationRects, const Vector<FloatRect>& sourceRects, ENinePieceImageRule hRule, ENinePieceImageRule vRule)
 194 {
 195     Vector<FloatSize> scales(MaxPiece, FloatSize(1, 1));
 196
 197     scales[TopPiece]    = computeIntrinsicSideTileScale(TopPiece,    destinationRects, sourceRects);
 198     scales[RightPiece]  = computeIntrinsicSideTileScale(RightPiece,  destinationRects, sourceRects);
 199     scales[BottomPiece] = computeIntrinsicSideTileScale(BottomPiece, destinationRects, sourceRects);
 200     scales[LeftPiece]   = computeIntrinsicSideTileScale(LeftPiece,   destinationRects, sourceRects);
 201
 202     scales[MiddlePiece] = computeIntrinsicMiddleTileScale(scales, destinationRects, sourceRects, hRule, vRule);
 203     return scales;
 204 }
 205
 206 Vector<FloatSize> NinePieceImage::computeNonIntrinsicTileScales()
 207 {
 208     return Vector<FloatSize>(MaxPiece, FloatSize(1, 1));
 209 }
 210
 211 void NinePieceImage::paint(GraphicsContext* graphicsContext, RenderElement* renderer, const RenderStyle& style, const LayoutRect& destination, const LayoutSize& source,  bool intrinsicSource, float deviceScaleFactor, CompositeOperator op) const
 212 {
 213     StyleImage* styleImage = image();
 214     ASSERT(styleImage && styleImage->isLoaded());
 215
 216     LayoutBoxExtent sourceSlices = computeSlices(source, imageSlices(), styleImage->imageScaleFactor());
 217     LayoutBoxExtent destinationSlices = computeSlices(destination.size(), borderSlices(), style.borderWidth(), sourceSlices);
 218
 219     scaleSlicesIfNeeded(destination.size(), destinationSlices, deviceScaleFactor);
 220
 221     Vector<FloatRect> destinationRects = computeIntrinsicRects(destination, destinationSlices, deviceScaleFactor);
 222     Vector<FloatRect> sourceRects;
 223     Vector<FloatSize> tileScales;
 224
 225     if (intrinsicSource) {
 226         sourceRects = computeIntrinsicRects(FloatRect(FloatPoint(), source), sourceSlices, deviceScaleFactor);
 227         tileScales = computeIntrinsicTileScales(destinationRects, sourceRects, horizontalRule(), verticalRule());
 228     } else {
 229         sourceRects = computeNonIntrinsicRects(destinationRects, sourceSlices);
 230         tileScales = computeNonIntrinsicTileScales();
 231     }
 232
 233     RefPtr<Image> image = styleImage->image(renderer, source);
 234     ColorSpace colorSpace = style.colorSpace();
 235
 236     for (ImagePiece piece = MinPiece; piece < MaxPiece; ++piece) {
 237         if ((piece == MiddlePiece && !fill()) || isEmptyPieceRect(piece, destinationRects, sourceRects))
 238             continue;
 239
 240         if (isCornerPiece(piece)) {
 241             graphicsContext->drawImage(image.get(), colorSpace, destinationRects[piece], sourceRects[piece], op);
 242             continue;
 243         }
 244
 245         Image::TileRule hRule = isHorizontalPiece(piece) ? static_cast<Image::TileRule>(horizontalRule()) : Image::StretchTile;
 246         Image::TileRule vRule = isVerticalPiece(piece) ? static_cast<Image::TileRule>(verticalRule()) : Image::StretchTile;
 247         graphicsContext->drawTiledImage(image.get(), colorSpace, destinationRects[piece], sourceRects[piece], tileScales[piece], hRule, vRule, op);
 248     }
 249 }
 250
 251 NinePieceImageData::NinePieceImageData()
 252     : fill(false)
 253     , horizontalRule(StretchImageRule)
 254     , verticalRule(StretchImageRule)
 255     , image(nullptr)
 256     , imageSlices(Length(100, Percent), Length(100, Percent), Length(100, Percent), Length(100, Percent))
 257     , borderSlices(Length(1, Relative), Length(1, Relative), Length(1, Relative), Length(1, Relative))
 258     , outset(0)
 259 {
 260 }
 261
 262 inline NinePieceImageData::NinePieceImageData(const NinePieceImageData& other)
 263     : RefCounted<NinePieceImageData>()
 264     , fill(other.fill)
 265     , horizontalRule(other.horizontalRule)
 266     , verticalRule(other.verticalRule)
 267     , image(other.image)
 268     , imageSlices(other.imageSlices)
 269     , borderSlices(other.borderSlices)
 270     , outset(other.outset)
 271 {
 272 }
 273
 274 Ref<NinePieceImageData> NinePieceImageData::copy() const
 275 {
 276     return adoptRef(*new NinePieceImageData(*this));
 277 }
 278
 279 bool NinePieceImageData::operator==(const NinePieceImageData& other) const
 280 {
 281     return StyleImage::imagesEquivalent(image.get(), other.image.get())
 282         && imageSlices == other.imageSlices
 283         && fill == other.fill
 284         && borderSlices == other.borderSlices
 285         && outset == other.outset
 286         && horizontalRule == other.horizontalRule
 287         && verticalRule == other.verticalRule;
 288 }
 289
 290 }