Pileus Git - ~andy/gtk/blob - gtk/gtkthemingbackground.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 2010 Carlos Garnacho <carlosg@gnome.org>
   3  * Copyright (C) 2011 Red Hat, Inc.
   4  *
   5  * Authors: Carlos Garnacho <carlosg@gnome.org>
   6  *          Cosimo Cecchi <cosimoc@gnome.org>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the
  20  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21  * Boston, MA 02111-1307, USA.
  22  */
  23
  24 #include "gtkcsstypesprivate.h"
  25 #include "gtkthemingbackgroundprivate.h"
  26 #include "gtkthemingengineprivate.h"
  27
  28 #include <gdk/gdk.h>
  29
  30 static void
  31 _gtk_theming_background_apply_window_background (GtkThemingBackground *bg,
  32                                                  cairo_t              *cr)
  33 {
  34   if (gtk_theming_engine_has_class (bg->engine, "background"))
  35     {
  36       cairo_set_source_rgba (cr, 1.0, 1.0, 1.0, 0.0); /* transparent */
  37       cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
  38       cairo_paint (cr);
  39     }
  40 }
  41
  42 static void
  43 _gtk_theming_background_apply_origin (GtkThemingBackground *bg)
  44 {
  45   GtkCssArea origin;
  46   cairo_rectangle_t image_rect;
  47
  48   gtk_theming_engine_get (bg->engine, bg->flags,
  49                           "background-origin", &origin,
  50                           NULL);
  51
  52   /* The default size of the background image depends on the
  53      background-origin value as this affects the top left
  54      and the bottom right corners. */
  55   switch (origin) {
  56   case GTK_CSS_AREA_BORDER_BOX:
  57     image_rect.x = 0;
  58     image_rect.y = 0;
  59     image_rect.width = bg->paint_area.width;
  60     image_rect.height = bg->paint_area.height;
  61     break;
  62   case GTK_CSS_AREA_CONTENT_BOX:
  63     image_rect.x = bg->border.left + bg->padding.left;
  64     image_rect.y = bg->border.top + bg->padding.top;
  65     image_rect.width = bg->paint_area.width - bg->border.left - bg->border.right - bg->padding.left - bg->padding.right;
  66     image_rect.height = bg->paint_area.height - bg->border.top - bg->border.bottom - bg->padding.top - bg->padding.bottom;
  67     break;
  68   case GTK_CSS_AREA_PADDING_BOX:
  69   default:
  70     image_rect.x = bg->border.left;
  71     image_rect.y = bg->border.top;
  72     image_rect.width = bg->paint_area.width - bg->border.left - bg->border.right;
  73     image_rect.height = bg->paint_area.height - bg->border.top - bg->border.bottom;
  74     break;
  75   }
  76
  77   bg->image_rect = image_rect;
  78 }
  79
  80 static void
  81 _gtk_theming_background_apply_clip (GtkThemingBackground *bg)
  82 {
  83   GtkCssArea clip;
  84
  85   gtk_theming_engine_get (bg->engine, bg->flags,
  86                           "background-clip", &clip,
  87                           NULL);
  88
  89   if (clip == GTK_CSS_AREA_PADDING_BOX)
  90     {
  91       _gtk_rounded_box_shrink (&bg->clip_box,
  92                                bg->border.top, bg->border.right,
  93                                bg->border.bottom, bg->border.left);
  94     }
  95   else if (clip == GTK_CSS_AREA_CONTENT_BOX)
  96     {
  97       _gtk_rounded_box_shrink (&bg->clip_box,
  98                                bg->border.top + bg->padding.top,
  99                                bg->border.right + bg->padding.right,
 100                                bg->border.bottom + bg->padding.bottom,
 101                                bg->border.left + bg->padding.left);
 102     }
 103 }
 104
 105 static void
 106 _gtk_theming_background_paint (GtkThemingBackground *bg,
 107                                cairo_t              *cr)
 108 {
 109   _gtk_rounded_box_path (&bg->clip_box, cr);
 110   gdk_cairo_set_source_rgba (cr, &bg->bg_color);
 111
 112   if (bg->pattern)
 113     {
 114       GtkCssBackgroundRepeat *repeat;
 115       cairo_surface_t *surface;
 116       int scale_width, scale_height;
 117
 118       gtk_theming_engine_get (bg->engine, bg->flags,
 119                               "background-repeat", &repeat,
 120                               NULL);
 121
 122       if (cairo_pattern_get_surface (bg->pattern, &surface) != CAIRO_STATUS_SUCCESS)
 123         surface = NULL;
 124
 125       if (surface && repeat)
 126         {
 127           scale_width = cairo_image_surface_get_width (surface);
 128           scale_height = cairo_image_surface_get_height (surface);
 129           if (repeat->repeat == GTK_CSS_BACKGROUND_REPEAT_STYLE_REPEAT)
 130             cairo_pattern_set_extend (bg->pattern, CAIRO_EXTEND_REPEAT);
 131           else if (repeat->repeat == GTK_CSS_BACKGROUND_REPEAT_STYLE_NO_REPEAT)
 132             cairo_pattern_set_extend (bg->pattern, CAIRO_EXTEND_NONE);
 133         }
 134       else
 135         {
 136           cairo_pattern_set_extend (bg->pattern, CAIRO_EXTEND_PAD);
 137           scale_width = bg->image_rect.width;
 138           scale_height = bg->image_rect.height;
 139         }
 140
 141       if (scale_width && scale_height)
 142         {
 143           /* Fill background color first */
 144           cairo_fill_preserve (cr);
 145
 146           cairo_translate (cr, bg->image_rect.x, bg->image_rect.y);
 147           cairo_scale (cr, scale_width, scale_height);
 148           cairo_set_source (cr, bg->pattern);
 149           cairo_scale (cr, 1.0 / scale_width, 1.0 / scale_height);
 150           cairo_translate (cr, -bg->image_rect.x, -bg->image_rect.y);
 151
 152           g_free (repeat);
 153
 154           cairo_pattern_destroy (bg->pattern);
 155           bg->pattern = NULL;
 156         }
 157     }
 158
 159   cairo_fill (cr);
 160 }
 161
 162 static void
 163 _gtk_theming_background_apply_shadow (GtkThemingBackground *bg,
 164                                       cairo_t              *cr)
 165 {
 166   GtkShadow *box_shadow;
 167
 168   gtk_theming_engine_get (bg->engine, bg->flags,
 169                           "box-shadow", &box_shadow,
 170                           NULL);
 171
 172   if (box_shadow != NULL)
 173     {
 174       _gtk_box_shadow_render (box_shadow, cr, &bg->padding_box);
 175       _gtk_shadow_unref (box_shadow);
 176     }
 177 }
 178
 179 static void
 180 _gtk_theming_background_init_engine (GtkThemingBackground *bg)
 181 {
 182   bg->flags = gtk_theming_engine_get_state (bg->engine);
 183
 184   gtk_theming_engine_get_border (bg->engine, bg->flags, &bg->border);
 185   gtk_theming_engine_get_padding (bg->engine, bg->flags, &bg->padding);
 186   gtk_theming_engine_get_background_color (bg->engine, bg->flags, &bg->bg_color);
 187
 188   /* In the CSS box model, by default the background positioning area is
 189    * the padding-box, i.e. all the border-box minus the borders themselves,
 190    * which determines also its default size, see
 191    * http://dev.w3.org/csswg/css3-background/#background-origin
 192    *
 193    * In the future we might want to support different origins or clips, but
 194    * right now we just shrink to the default.
 195    */
 196   _gtk_rounded_box_init_rect (&bg->padding_box, 0, 0, bg->paint_area.width, bg->paint_area.height);
 197   _gtk_rounded_box_apply_border_radius (&bg->padding_box, bg->engine, bg->flags, bg->junction);
 198
 199   bg->clip_box = bg->padding_box;
 200   _gtk_rounded_box_shrink (&bg->padding_box,
 201                            bg->border.top, bg->border.right,
 202                            bg->border.bottom, bg->border.left);
 203
 204   _gtk_theming_background_apply_clip (bg);
 205   _gtk_theming_background_apply_origin (bg);
 206
 207   gtk_theming_engine_get (bg->engine, bg->flags,
 208                           "background-image", &bg->pattern,
 209                           NULL);
 210 }
 211
 212 void
 213 _gtk_theming_background_init (GtkThemingBackground *bg,
 214                               GtkThemingEngine     *engine,
 215                               gdouble               x,
 216                               gdouble               y,
 217                               gdouble               width,
 218                               gdouble               height,
 219                               GtkJunctionSides      junction)
 220 {
 221   g_assert (bg != NULL);
 222
 223   bg->engine = engine;
 224
 225   bg->paint_area.x = x;
 226   bg->paint_area.y = y;
 227   bg->paint_area.width = width;
 228   bg->paint_area.height = height;
 229
 230   bg->pattern = NULL;
 231   bg->junction = junction;
 232
 233   _gtk_theming_background_init_engine (bg);
 234 }
 235
 236 void
 237 _gtk_theming_background_render (GtkThemingBackground *bg,
 238                                 cairo_t              *cr)
 239 {
 240   cairo_save (cr);
 241   cairo_translate (cr, bg->paint_area.x, bg->paint_area.y);
 242
 243   _gtk_theming_background_apply_window_background (bg, cr);
 244   _gtk_theming_background_paint (bg, cr);
 245   _gtk_theming_background_apply_shadow (bg, cr);
 246
 247   cairo_restore (cr);
 248 }
 249
 250 gboolean
 251 _gtk_theming_background_has_background_image (GtkThemingBackground *bg)
 252 {
 253   return (bg->pattern != NULL) ? TRUE : FALSE;
 254 }