| /* |
| * Copyright (C) 2004 Red Hat, Inc. |
| * Copyright (C) 2010 Brent Fulgham <bfulgham@webkit.org> |
| * |
| * Based on Pango sources (see pangocairo-render.c) |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public |
| * License along with this library; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * |
| */ |
| |
| #ifndef DrawErrorUnderline_h |
| #define DrawErrorUnderline_h |
| |
| #if USE(CAIRO) |
| |
| #include <cairo.h> |
| |
| // |
| // Draws an error underline that looks like one of: |
| // |
| // H E H |
| // /\ /\ /\ /\ /\ - |
| // A/ \ / \ / \ A/ \ / \ | |
| // \ \ / \ / /D \ \ / \ | |
| // \ \/ C \/ / \ \/ C \ | height = heightSquares * square |
| // \ /\ F / \ F /\ \ | |
| // \ / \ / \ / \ \G | |
| // \ / \ / \ / \ / | |
| // \/ \/ \/ \/ - |
| // B B |
| // |---| |
| // unitWidth = (heightSquares - 1) * square |
| // |
| // The x, y, width, height passed in give the desired bounding box; |
| // x/width are adjusted to make the underline a integer number of units |
| // wide. |
| // |
| static inline void drawErrorUnderline(cairo_t* cr, double x, double y, double width, double height) |
| { |
| static const double heightSquares = 2.5; |
| |
| double square = height / heightSquares; |
| double halfSquare = 0.5 * square; |
| |
| double unitWidth = (heightSquares - 1.0) * square; |
| int widthUnits = static_cast<int>((width + 0.5 * unitWidth) / unitWidth); |
| |
| x += 0.5 * (width - widthUnits * unitWidth); |
| width = widthUnits * unitWidth; |
| |
| double bottom = y + height; |
| double top = y; |
| |
| // Bottom of squiggle |
| cairo_move_to(cr, x - halfSquare, top + halfSquare); // A |
| |
| int i = 0; |
| for (i = 0; i < widthUnits; i += 2) { |
| double middle = x + (i + 1) * unitWidth; |
| double right = x + (i + 2) * unitWidth; |
| |
| cairo_line_to(cr, middle, bottom); // B |
| |
| if (i + 2 == widthUnits) |
| cairo_line_to(cr, right + halfSquare, top + halfSquare); // D |
| else if (i + 1 != widthUnits) |
| cairo_line_to(cr, right, top + square); // C |
| } |
| |
| // Top of squiggle |
| for (i -= 2; i >= 0; i -= 2) { |
| double left = x + i * unitWidth; |
| double middle = x + (i + 1) * unitWidth; |
| double right = x + (i + 2) * unitWidth; |
| |
| if (i + 1 == widthUnits) |
| cairo_line_to(cr, middle + halfSquare, bottom - halfSquare); // G |
| else { |
| if (i + 2 == widthUnits) |
| cairo_line_to(cr, right, top); // E |
| |
| cairo_line_to(cr, middle, bottom - halfSquare); // F |
| } |
| |
| cairo_line_to(cr, left, top); // H |
| } |
| |
| cairo_fill(cr); |
| } |
| |
| #endif // USE(CAIRO) |
| |
| #endif // DrawErrorUnderline_h |
