src/plugins/litehtml_viewer/lh_widget_text.cpp

   1 /*
   2  * Claws Mail -- A GTK+ based, lightweight, and fast e-mail client
   3  * Copyright(C) 2019 the Claws Mail Team
   4  *
   5  * litehtml callbacks related to text rendering
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  * This program 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
  14  * GNU General Public License for more details.
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write tothe Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  */
  19
  20 #include <glib.h>
  21
  22 #include "litehtml/litehtml.h"
  23
  24 #include "lh_widget.h"
  25
  26 litehtml::uint_ptr lh_widget::create_font( const litehtml::tchar_t* faceName, int size, int weight, litehtml::font_style italic, unsigned int decoration, litehtml::font_metrics* fm )
  27 {
  28         PangoFontDescription *desc =
  29                 pango_font_description_from_string(faceName);
  30
  31         pango_font_description_set_size(desc, size * PANGO_SCALE);
  32         pango_font_description_set_weight(desc, (PangoWeight)weight);
  33
  34         if (italic == litehtml::fontStyleItalic)
  35                 pango_font_description_set_style(desc, PANGO_STYLE_ITALIC);
  36         else
  37                 pango_font_description_set_style(desc, PANGO_STYLE_NORMAL);
  38
  39         if(fm != NULL) {
  40                 PangoContext *context = gtk_widget_get_pango_context(m_drawing_area);
  41                 PangoFontMetrics *metrics = pango_context_get_metrics(
  42                                 context, desc,
  43                                 pango_context_get_language(context));
  44                 PangoLayout *x_layout;
  45                 PangoRectangle rect;
  46
  47                 x_layout = pango_layout_new(context);
  48                 pango_layout_set_font_description(x_layout, desc);
  49                 pango_layout_set_text(x_layout, "x", -1);
  50                 pango_layout_get_pixel_extents(x_layout, NULL, &rect);
  51
  52                 fm->ascent              = pango_font_metrics_get_ascent(metrics) / PANGO_SCALE;
  53                 fm->descent             = pango_font_metrics_get_descent(metrics) / PANGO_SCALE;
  54                 fm->height              = fm->ascent + fm->descent;
  55                 fm->x_height    = rect.height;
  56
  57                 g_object_unref(x_layout);
  58                 pango_font_metrics_unref(metrics);
  59         }
  60
  61         pango_font *ret = new pango_font;
  62         ret->font = desc;
  63         ret->strikethrough = (decoration & litehtml::font_decoration_linethrough) ? true : false;
  64         ret->underline = (decoration & litehtml::font_decoration_underline) ? true : false;
  65
  66         return (litehtml::uint_ptr) ret;
  67 }
  68
  69 void lh_widget::delete_font( litehtml::uint_ptr hFont )
  70 {
  71         pango_font *fnt = (pango_font *)hFont;
  72
  73         if (fnt != NULL) {
  74                 pango_font_description_free(fnt->font);
  75                 delete fnt;
  76         }
  77 }
  78
  79 int lh_widget::text_width( const litehtml::tchar_t* text, litehtml::uint_ptr hFont )
  80 {
  81         pango_font *fnt = (pango_font *) hFont;
  82         PangoContext *context = gtk_widget_get_pango_context(m_drawing_area);
  83         PangoLayout *layout = pango_layout_new(context);
  84         PangoRectangle rect;
  85
  86         if (fnt)
  87                 pango_layout_set_font_description(layout, fnt->font);
  88
  89         pango_layout_set_text(layout, text, -1);
  90         pango_layout_get_pixel_extents(layout, NULL, &rect);
  91
  92         g_object_unref(layout);
  93
  94         return rect.width;
  95 }
  96
  97 void lh_widget::draw_text( litehtml::uint_ptr hdc, const litehtml::tchar_t* text, litehtml::uint_ptr hFont, litehtml::web_color color, const litehtml::position& pos )
  98 {
  99         pango_font *fnt = (pango_font *)hFont;
 100         cairo_t *cr = (cairo_t *)hdc;
 101         PangoLayout *layout = pango_cairo_create_layout(cr);
 102         PangoContext *context = pango_layout_get_context(layout);
 103
 104         if (fnt != NULL) {
 105                 /* Set font */
 106                 pango_layout_set_font_description(layout, fnt->font);
 107
 108                 /* Set additional font attributes */
 109                 if (fnt->underline || fnt->strikethrough) {
 110                         PangoAttrList *attr_list = pango_attr_list_new();
 111                         PangoUnderline ul;
 112
 113                         if (fnt->underline )
 114                                 ul = PANGO_UNDERLINE_SINGLE;
 115                         else
 116                                 ul = PANGO_UNDERLINE_NONE;
 117
 118                         pango_attr_list_insert(attr_list,
 119                                         pango_attr_underline_new(ul));
 120                         pango_attr_list_insert(attr_list,
 121                                         pango_attr_strikethrough_new(fnt->strikethrough));
 122
 123                         pango_layout_set_attributes(layout, attr_list);
 124                         pango_attr_list_unref(attr_list);
 125                 }
 126         }
 127
 128         /* Set actual text content */
 129         pango_layout_set_text(layout, text, -1);
 130
 131         cairo_save(cr);
 132
 133         /* Draw the text where it's supposed to be */
 134         apply_clip(cr);
 135         set_color(cr, color);
 136         cairo_move_to(cr, pos.left(), pos.top());
 137         pango_cairo_show_layout(cr, layout);
 138
 139         /* Cleanup */
 140         g_object_unref(layout);
 141         cairo_restore(cr);
 142 }