1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef WebFont_h 32 #define WebFont_h 33 34 #include "../platform/WebCanvas.h" 35 #include "../platform/WebColor.h" 36 #include "../platform/WebCommon.h" 37 38 namespace WebKit { 39 40 struct WebFontDescription; 41 struct WebFloatPoint; 42 struct WebFloatRect; 43 struct WebPoint; 44 struct WebRect; 45 struct WebTextRun; 46 47 class WebFont { 48 public: 49 virtual ~WebFont() { } 50 51 WEBKIT_EXPORT static WebFont* create(const WebFontDescription&); 52 53 virtual WebFontDescription fontDescription() const = 0; 54 55 virtual int ascent() const = 0; 56 virtual int descent() const = 0; 57 virtual int height() const = 0; 58 virtual int lineSpacing() const = 0; 59 virtual float xHeight() const = 0; 60 61 // Draws the text run to the given canvas. The text is positioned at the 62 // given left-hand point at the baseline. 63 // 64 // The text will be clipped to the given clip rect. |canvasIsOpaque| is 65 // used to control whether subpixel antialiasing is possible. If there is a 66 // possibility the area drawn could be semi-transparent, subpixel 67 // antialiasing will be disabled. 68 // 69 // |from| and |to| allow the caller to specify a subrange of the given text 70 // run to draw. If |to| is -1, the entire run will be drawn. 71 virtual void drawText(WebCanvas*, const WebTextRun&, const WebFloatPoint& leftBaseline, WebColor, 72 const WebRect& clip, bool canvasIsOpaque, 73 int from = 0, int to = -1) const = 0; 74 75 // Measures the width in pixels of the given text run. 76 virtual int calculateWidth(const WebTextRun&) const = 0; 77 78 // Returns the character offset corresponding to the given horizontal pixel 79 // position as measured from from the left of the run. 80 virtual int offsetForPosition(const WebTextRun&, float position) const = 0; 81 82 // Returns the rectangle representing the selection rect for the subrange 83 // |from| -> |to| of the given text run. You can use -1 for |to| to specify 84 // the entire run (this will do something similar to calling width()). 85 // 86 // The rect will be positioned as if the text was drawn at the given 87 // |leftBaseline| position. |height| indicates the height of the selection 88 // rect you want, typically this will just be the height() of this font. 89 // 90 // To get the pixel offset of some character (the opposite of 91 // offsetForPosition()), pass in a |leftBaseline| = (0, 0), |from| = 0, and 92 // |to| = the character you want. The right edge of the resulting selection 93 // rect will tell you the right side of the character. 94 virtual WebFloatRect selectionRectForText(const WebTextRun&, const WebFloatPoint& leftBaseline, 95 int height, int from = 0, int to = -1) const = 0; 96 }; 97 98 } // namespace WebKit 99 100 #endif 101