third_party/WebKit/Source/core/layout/svg/LayoutSVGInlineText.h

   1 /*
   2  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
   3  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
   4  * Copyright (C) 2008 Rob Buis <buis@kde.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  */
  21
  22 #ifndef LayoutSVGInlineText_h
  23 #define LayoutSVGInlineText_h
  24
  25 #include "core/layout/LayoutText.h"
  26 #include "core/layout/svg/SVGTextLayoutAttributes.h"
  27
  28 namespace blink {
  29
  30 class LayoutSVGInlineText final : public LayoutText {
  31 public:
  32     LayoutSVGInlineText(Node*, PassRefPtr<StringImpl>);
  33
  34     bool characterStartsNewTextChunk(int position) const;
  35     SVGTextLayoutAttributes* layoutAttributes() { return &m_layoutAttributes; }
  36     const SVGTextLayoutAttributes* layoutAttributes() const { return &m_layoutAttributes; }
  37
  38     float scalingFactor() const { return m_scalingFactor; }
  39     const Font& scaledFont() const { return m_scaledFont; }
  40     void updateScaledFont();
  41     static void computeNewScaledFontForStyle(LayoutObject*, const ComputedStyle*, float& scalingFactor, Font& scaledFont);
  42
  43     // Preserves floating point precision for the use in DRT. It knows how to round and does a better job than enclosingIntRect.
  44     FloatRect floatLinesBoundingBox() const;
  45
  46     PassRefPtr<StringImpl> originalText() const override;
  47
  48     const char* name() const override { return "LayoutSVGInlineText"; }
  49
  50 private:
  51     void setTextInternal(PassRefPtr<StringImpl>) override;
  52     void styleDidChange(StyleDifference, const ComputedStyle*) override;
  53
  54     FloatRect objectBoundingBox() const override { return floatLinesBoundingBox(); }
  55
  56     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectSVG || type == LayoutObjectSVGInlineText || LayoutText::isOfType(type); }
  57
  58     PositionWithAffinity positionForPoint(const LayoutPoint&) override;
  59     LayoutRect localCaretRect(InlineBox*, int caretOffset, LayoutUnit* extraWidthToEndOfLine = nullptr) override;
  60     IntRect linesBoundingBox() const override;
  61     InlineTextBox* createTextBox(int start, unsigned short length) override;
  62
  63     LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState*) const final;
  64
  65     float m_scalingFactor;
  66     Font m_scaledFont;
  67     SVGTextLayoutAttributes m_layoutAttributes;
  68 };
  69
  70 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutSVGInlineText, isSVGInlineText());
  71
  72 class SVGInlineTextMetricsIterator {
  73     DISALLOW_ALLOCATION();
  74 public:
  75     SVGInlineTextMetricsIterator() { reset(nullptr); }
  76
  77     void advanceToTextStart(const LayoutSVGInlineText* textLayoutObject, unsigned startCharacterOffset)
  78     {
  79         ASSERT(textLayoutObject);
  80         if (m_textLayoutObject != textLayoutObject) {
  81             reset(textLayoutObject);
  82             ASSERT(!metricsList().isEmpty());
  83         }
  84
  85         if (m_characterOffset == startCharacterOffset)
  86             return;
  87
  88         // TODO(fs): We could walk backwards through the metrics list in these cases.
  89         if (m_characterOffset > startCharacterOffset)
  90             reset(textLayoutObject);
  91
  92         while (m_characterOffset < startCharacterOffset)
  93             next();
  94     }
  95
  96     void next()
  97     {
  98         m_characterOffset += metrics().length();
  99         ++m_metricsListOffset;
 100     }
 101
 102     const SVGTextMetrics& metrics() const
 103     {
 104         ASSERT(m_textLayoutObject && m_metricsListOffset < metricsList().size());
 105         return metricsList()[m_metricsListOffset];
 106     }
 107     const Vector<SVGTextMetrics>& metricsList() const { return m_textLayoutObject->layoutAttributes()->textMetricsValues(); }
 108     unsigned metricsListOffset() const { return m_metricsListOffset; }
 109     unsigned characterOffset() const { return m_characterOffset; }
 110     bool isAtEnd() const { return m_metricsListOffset == metricsList().size(); }
 111
 112 private:
 113     void reset(const LayoutSVGInlineText* textLayoutObject)
 114     {
 115         m_textLayoutObject = textLayoutObject;
 116         m_characterOffset = 0;
 117         m_metricsListOffset = 0;
 118     }
 119
 120     const LayoutSVGInlineText* m_textLayoutObject;
 121     unsigned m_metricsListOffset;
 122     unsigned m_characterOffset;
 123 };
 124
 125 }
 126
 127 #endif // LayoutSVGInlineText_h