1 /* 2 * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 */ 19 20 #include "config.h" 21 22 #include "core/rendering/svg/SVGTextMetrics.h" 23 24 #include "core/rendering/svg/RenderSVGInlineText.h" 25 #include "core/rendering/svg/SVGTextRunRenderingContext.h" 26 27 namespace WebCore { 28 29 SVGTextMetrics::SVGTextMetrics() 30 : m_width(0) 31 , m_height(0) 32 , m_length(0) 33 , m_glyph(0) 34 { 35 } 36 37 SVGTextMetrics::SVGTextMetrics(SVGTextMetrics::MetricsType) 38 : m_width(0) 39 , m_height(0) 40 , m_length(1) 41 , m_glyph(0) 42 { 43 } 44 45 SVGTextMetrics::SVGTextMetrics(RenderSVGInlineText* textRenderer, const TextRun& run) 46 { 47 ASSERT(textRenderer); 48 49 float scalingFactor = textRenderer->scalingFactor(); 50 ASSERT(scalingFactor); 51 52 const Font& scaledFont = textRenderer->scaledFont(); 53 int length = 0; 54 55 // Calculate width/height using the scaled font, divide this result by the scalingFactor afterwards. 56 m_width = scaledFont.width(run, length, m_glyph) / scalingFactor; 57 m_height = scaledFont.fontMetrics().floatHeight() / scalingFactor; 58 59 ASSERT(length >= 0); 60 m_length = static_cast<unsigned>(length); 61 } 62 63 TextRun SVGTextMetrics::constructTextRun(RenderSVGInlineText* text, unsigned position, unsigned length) 64 { 65 ASSERT(text->style()); 66 return constructTextRun(text, position, length, text->style()->direction()); 67 } 68 69 TextRun SVGTextMetrics::constructTextRun(RenderSVGInlineText* text, unsigned position, unsigned length, TextDirection textDirection) 70 { 71 RenderStyle* style = text->style(); 72 ASSERT(style); 73 74 TextRun run(static_cast<const LChar*>(0) // characters, will be set below if non-zero. 75 , 0 // length, will be set below if non-zero. 76 , 0 // xPos, only relevant with allowTabs=true 77 , 0 // padding, only relevant for justified text, not relevant for SVG 78 , TextRun::AllowTrailingExpansion 79 , textDirection 80 , isOverride(style->unicodeBidi()) /* directionalOverride */); 81 82 if (length) { 83 if (text->is8Bit()) 84 run.setText(text->characters8() + position, length); 85 else 86 run.setText(text->characters16() + position, length); 87 } 88 89 if (textRunNeedsRenderingContext(style->font())) 90 run.setRenderingContext(SVGTextRunRenderingContext::create(text)); 91 92 run.disableRoundingHacks(); 93 94 // We handle letter & word spacing ourselves. 95 run.disableSpacing(); 96 97 // Propagate the maximum length of the characters buffer to the TextRun, even when we're only processing a substring. 98 run.setCharactersLength(text->textLength() - position); 99 ASSERT(run.charactersLength() >= run.length()); 100 return run; 101 } 102 103 SVGTextMetrics SVGTextMetrics::measureCharacterRange(RenderSVGInlineText* text, unsigned position, unsigned length, TextDirection textDirection) 104 { 105 ASSERT(text); 106 return SVGTextMetrics(text, constructTextRun(text, position, length, textDirection)); 107 } 108 109 SVGTextMetrics SVGTextMetrics::measureCharacterRange(RenderSVGInlineText* text, unsigned position, unsigned length) 110 { 111 ASSERT(text); 112 return SVGTextMetrics(text, constructTextRun(text, position, length)); 113 } 114 115 SVGTextMetrics::SVGTextMetrics(RenderSVGInlineText* text, unsigned position, unsigned length, float width, Glyph glyphNameGlyphId) 116 { 117 ASSERT(text); 118 119 bool needsContext = textRunNeedsRenderingContext(text->style()->font()); 120 float scalingFactor = text->scalingFactor(); 121 ASSERT(scalingFactor); 122 123 m_width = width / scalingFactor; 124 m_height = text->scaledFont().fontMetrics().floatHeight() / scalingFactor; 125 m_glyph = needsContext ? glyphNameGlyphId : 0; 126 127 m_length = length; 128 } 129 130 } 131