font.cpp

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/*
 * Copyright 2008 François Revol <mmu_man@users.sourceforge.net>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/** \file
 * Font handling (BeOS implementation).
 * TODO: check for correctness, the code is taken from the GTK one.
 * maybe use the current view instead of constructing a new BFont each time ?
 */
 
 
#define __STDBOOL_H__   1
#include <stdbool.h>
#include <assert.h>
#include <stdio.h>
#include <Font.h>
#include <String.h>
#include <View.h>
 
extern "C" {
#include "utils/utils.h"
#include "utils/log.h"
#include "utils/nsoption.h"
#include "utils/nsurl.h"
#include "netsurf/layout.h"
}
 
#include "beos/gui.h"
#include "beos/font.h"
#include "beos/plotters.h"
 
 
/**
 * Convert a font style to a PangoFontDescription.
 *
 * \param font Beos font object.
 * \param fstyle style for this text
 */
void nsbeos_style_to_font(BFont &font, const struct plot_font_style *fstyle)
{
        float size;
        uint16 face = 0;
        const char *family;
 
        switch (fstyle->family) {
        case PLOT_FONT_FAMILY_SERIF:
                family = nsoption_charp(font_serif);
                break;
        case PLOT_FONT_FAMILY_MONOSPACE:
                family = nsoption_charp(font_mono);
                break;
        case PLOT_FONT_FAMILY_CURSIVE:
                family = nsoption_charp(font_cursive);
                break;
        case PLOT_FONT_FAMILY_FANTASY:
                family = nsoption_charp(font_fantasy);
                break;
        case PLOT_FONT_FAMILY_SANS_SERIF:
        default:
                family = nsoption_charp(font_sans);
                break;
        }
 
        if ((fstyle->flags & FONTF_ITALIC)) {
                face = B_ITALIC_FACE;
        } else if ((fstyle->flags & FONTF_OBLIQUE)) {
                face = B_ITALIC_FACE;
                // XXX: no OBLIQUE flag ??
                // maybe find "Oblique" style
                // or use SetShear() ?
        }
 
#ifndef __HAIKU__XXX
        if (fstyle->weight >= 600) {
                face |= B_BOLD_FACE;
        }
#else
        if (fstyle->weight >= 600) {
                if (fstyle->weight >= 800)
                        face |= B_HEAVY_FACE;
                else
                        face |= B_BOLD_FACE;
        } else if (fstyle->weight <= 300) {
                face |= B_LIGHT_FACE;
        }
#endif
/*
        case CSS_FONT_WEIGHT_100: weight = 100; break;
        case CSS_FONT_WEIGHT_200: weight = 200; break;
        case CSS_FONT_WEIGHT_300: weight = 300; break;
        case CSS_FONT_WEIGHT_400: weight = 400; break;
        case CSS_FONT_WEIGHT_500: weight = 500; break;
        case CSS_FONT_WEIGHT_600: weight = 600; break;
        case CSS_FONT_WEIGHT_700: weight = 700; break;
        case CSS_FONT_WEIGHT_800: weight = 800; break;
        case CSS_FONT_WEIGHT_900: weight = 900; break;
*/
 
        if (!face)
                face = B_REGULAR_FACE;
 
//fprintf(stderr, "nsbeos_style_to_font: %d, %d, %d -> '%s' %04x\n", style->font_family, style->font_style, style->font_weight, family, face);
 
        if (family) {
                font_family beos_family;
 
                strncpy(beos_family, family, B_FONT_FAMILY_LENGTH);
                // Ensure it's terminated
                beos_family[B_FONT_FAMILY_LENGTH] = '\0';
 
                font.SetFamilyAndFace(beos_family, face);
        } else {
                //XXX not used
                font = be_plain_font;
                font.SetFace(face);
        }
 
//fprintf(stderr, "nsbeos_style_to_font: value %f unit %d\n", style->font_size.value.length.value, style->font_size.value.length.unit);
        size = fstyle->size / PLOT_STYLE_SCALE;
 
//fprintf(stderr, "nsbeos_style_to_font: %f %d\n", size, style->font_size.value.length.unit);
 
        font.SetSize(size);
}
 
 
/**
 * Measure the width of a string.
 *
 * \param  fstyle  style for this text
 * \param  string  UTF-8 string to measure
 * \param  length  length of string
 * \param  width   updated to width of string[0..length)
 * \return  true on success, false on error and error reported
 */
static nserror beos_font_width(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int *width)
{
        //fprintf(stderr, "%s(, '%s', %d, )\n", __FUNCTION__, string, length);
        BFont font;
 
        if (length == 0) {
                *width = 0;
                return NSERROR_OK;
        }
 
        nsbeos_style_to_font(font, fstyle);
        *width = (int)font.StringWidth(string, length);
 
        return NSERROR_OK;
}
 
 
static int utf8_char_len(const char *c)
{
        uint8 *p = (uint8 *)c;
        uint8 m = 0xE0;
        uint8 v = 0xC0;
        int i;
 
        if (!*p)
                return 0;
        if ((*p & 0x80) == 0)
                return 1;
        if ((*p & 0xC0) == 0x80)
                return 1; // actually one of the remaining bytes...
        for (i = 2; i < 5; i++) {
                if ((*p & m) == v)
                        return i;
                v = (v >> 1) | 0x80;
                m = (m >> 1) | 0x80;
        }
        return i;
}
 
 
/**
 * Find the position in a string where an x coordinate falls.
 *
 * \param  fstyle       style for this text
 * \param  string       UTF-8 string to measure
 * \param  length       length of string
 * \param  x            x coordinate to search for
 * \param  char_offset  updated to offset in string of actual_x, [0..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 */
static nserror beos_font_position(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int x, size_t *char_offset, int *actual_x)
{
        NSLOG(netsurf, DEEPDEBUG, "(, '%s', %d, %d, , )", string, length, x);
 
        int index;
        BFont font;
 
        nsbeos_style_to_font(font, fstyle);
        BString str(string);
        int32 len = str.CountChars();
        float escapements[len];
        float esc = 0.0;
        float current = 0.0;
        int i;
 
        index = 0;
        font.GetEscapements(string, len, escapements);
        // slow but it should work
        for (i = 0; string[index] && i < len; i++) {
                esc += escapements[i];
                current = font.Size() * esc;
                index += utf8_char_len(&string[index]);
                // is current char already too far away?
                if (x < current)
                        break;
        }
        *actual_x = (int)current;
        *char_offset = i; //index;
 
        return NSERROR_OK;
}
 
 
/**
 * Find where to split a string to make it fit a width.
 *
 * \param  fstyle       style for this text
 * \param  string       UTF-8 string to measure
 * \param  length       length of string, in bytes
 * \param  x            width available
 * \param  char_offset  updated to offset in string of actual_x, [1..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 *
 * On exit, char_offset indicates first character after split point.
 *
 * Note: char_offset of 0 should never be returned.
 *
 *   Returns:
 *     char_offset giving split point closest to x, where actual_x <= x
 *   else
 *     char_offset giving split point closest to x, where actual_x > x
 *
 * Returning char_offset == length means no split possible
 */
static nserror beos_font_split(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int x, size_t *char_offset, int *actual_x)
{
        NSLOG(netsurf, DEEPDEBUG, "(, '%s', %d, %d, , )", string, length, x);
        int index = 0;
        BFont font;
 
        nsbeos_style_to_font(font, fstyle);
        BString str(string);
        int32 len = str.CountChars();
        float escapements[len];
        float esc = 0.0;
        float current = 0.0;
        float last_x = 0.0;
        int i;
        int last_space = 0;
 
        font.GetEscapements(string, len, escapements);
        // very slow but it should work
        for (i = 0; string[index] && i < len; i++) {
                if (string[index] == ' ') {
                        last_x = current;
                        last_space = index;
                }
                if (x < current && last_space != 0) {
                        *actual_x = (int)last_x;
                        *char_offset = last_space;
                        return NSERROR_OK;;
                }
                esc += escapements[i];
                current = font.Size() * esc;
                index += utf8_char_len(&string[index]);
        }
        *actual_x = MIN(*actual_x, (int)current);
        *char_offset = index;
 
        return NSERROR_OK;
}
 
 
/**
 * Render a string.
 *
 * \param  fstyle  style for this text
 * \param  string  UTF-8 string to measure
 * \param  length  length of string
 * \param  x       x coordinate
 * \param  y       y coordinate
 * \return  true on success, false on error and error reported
 */
 
bool nsfont_paint(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int x, int y)
{
        //fprintf(stderr, "%s(, '%s', %d, %d, %d, )\n", __FUNCTION__, string, length, x, y);
        //CALLED();
        BFont font;
        rgb_color oldbg;
        rgb_color background;
        rgb_color foreground;
        BView *view;
        float size;
 
        if (length == 0)
                return true;
 
        nsbeos_style_to_font(font, fstyle);
        background = nsbeos_rgb_colour(fstyle->background);
        foreground = nsbeos_rgb_colour(fstyle->foreground);
 
        view = nsbeos_current_gc/*_lock*/();
        if (view == NULL) {
                beos_warn_user("No GC", 0);
                return false;
        }
 
        oldbg = view->LowColor();
        drawing_mode oldmode = view->DrawingMode();
        view->SetLowColor(B_TRANSPARENT_32_BIT);
 
        //view->SetScale() XXX
 
//printf("nsfont_paint: Size: %f\n", font.Size());
        size = (float)font.Size();
#warning XXX use scale
 
        view->SetFont(&font);
        view->SetHighColor(foreground);
        view->SetDrawingMode(B_OP_OVER);
 
        BString line(string, length);
 
        BPoint where(x, y + 1);
        view->DrawString(line.String(), where);
        
        view->SetDrawingMode(oldmode);
        if (memcmp(&oldbg, &background, sizeof(rgb_color)))
                view->SetLowColor(oldbg);
 
        //nsbeos_current_gc_unlock();
 
        return true;
}
 
 
static struct gui_layout_table layout_table = {
  /*.width = */beos_font_width,
  /*.position = */beos_font_position,
  /*.split = */beos_font_split
};
 
struct gui_layout_table *beos_layout_table = &layout_table;