Pileus Git - ~andy/gtk/blob - demos/gtk-demo/offscreen_window2.c

   1 /* Offscreen windows/Effects
   2  *
   3  * Offscreen windows can be used to render elements multiple times to achieve
   4  * various effects.
   5  */
   6 #include <gtk/gtk.h>
   7
   8 #define GTK_TYPE_MIRROR_BIN              (gtk_mirror_bin_get_type ())
   9 #define GTK_MIRROR_BIN(obj)              (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBin))
  10 #define GTK_MIRROR_BIN_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
  11 #define GTK_IS_MIRROR_BIN(obj)           (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_MIRROR_BIN))
  12 #define GTK_IS_MIRROR_BIN_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_MIRROR_BIN))
  13 #define GTK_MIRROR_BIN_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
  14
  15 typedef struct _GtkMirrorBin   GtkMirrorBin;
  16 typedef struct _GtkMirrorBinClass  GtkMirrorBinClass;
  17
  18 struct _GtkMirrorBin
  19 {
  20   GtkContainer container;
  21
  22   GtkWidget *child;
  23   GdkWindow *offscreen_window;
  24 };
  25
  26 struct _GtkMirrorBinClass
  27 {
  28   GtkContainerClass parent_class;
  29 };
  30
  31 GType      gtk_mirror_bin_get_type  (void) G_GNUC_CONST;
  32 GtkWidget* gtk_mirror_bin_new       (void);
  33
  34 /*** implementation ***/
  35
  36 static void     gtk_mirror_bin_realize       (GtkWidget       *widget);
  37 static void     gtk_mirror_bin_unrealize     (GtkWidget       *widget);
  38 static void     gtk_mirror_bin_size_request  (GtkWidget       *widget,
  39                                                GtkRequisition  *requisition);
  40 static void     gtk_mirror_bin_size_allocate (GtkWidget       *widget,
  41                                                GtkAllocation   *allocation);
  42 static gboolean gtk_mirror_bin_damage        (GtkWidget       *widget,
  43                                                GdkEventExpose  *event);
  44 static gboolean gtk_mirror_bin_expose        (GtkWidget       *widget,
  45                                                GdkEventExpose  *offscreen);
  46
  47 static void     gtk_mirror_bin_add           (GtkContainer    *container,
  48                                                GtkWidget       *child);
  49 static void     gtk_mirror_bin_remove        (GtkContainer    *container,
  50                                                GtkWidget       *widget);
  51 static void     gtk_mirror_bin_forall        (GtkContainer    *container,
  52                                                gboolean         include_internals,
  53                                                GtkCallback      callback,
  54                                                gpointer         callback_data);
  55 static GType    gtk_mirror_bin_child_type    (GtkContainer    *container);
  56
  57 G_DEFINE_TYPE (GtkMirrorBin, gtk_mirror_bin, GTK_TYPE_CONTAINER);
  58
  59 static void
  60 to_child (GtkMirrorBin *bin,
  61           double         widget_x,
  62           double         widget_y,
  63           double        *x_out,
  64           double        *y_out)
  65 {
  66   *x_out = widget_x;
  67   *y_out = widget_y;
  68 }
  69
  70 static void
  71 to_parent (GtkMirrorBin *bin,
  72            double         offscreen_x,
  73            double         offscreen_y,
  74            double        *x_out,
  75            double        *y_out)
  76 {
  77   *x_out = offscreen_x;
  78   *y_out = offscreen_y;
  79 }
  80
  81 static void
  82 gtk_mirror_bin_class_init (GtkMirrorBinClass *klass)
  83 {
  84   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
  85   GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
  86
  87   widget_class->realize = gtk_mirror_bin_realize;
  88   widget_class->unrealize = gtk_mirror_bin_unrealize;
  89   widget_class->size_request = gtk_mirror_bin_size_request;
  90   widget_class->size_allocate = gtk_mirror_bin_size_allocate;
  91   widget_class->expose_event = gtk_mirror_bin_expose;
  92
  93   g_signal_override_class_closure (g_signal_lookup ("damage-event", GTK_TYPE_WIDGET),
  94                                    GTK_TYPE_MIRROR_BIN,
  95                                    g_cclosure_new (G_CALLBACK (gtk_mirror_bin_damage),
  96                                                    NULL, NULL));
  97
  98   container_class->add = gtk_mirror_bin_add;
  99   container_class->remove = gtk_mirror_bin_remove;
 100   container_class->forall = gtk_mirror_bin_forall;
 101   container_class->child_type = gtk_mirror_bin_child_type;
 102 }
 103
 104 static void
 105 gtk_mirror_bin_init (GtkMirrorBin *bin)
 106 {
 107   GTK_WIDGET_UNSET_FLAGS (bin, GTK_NO_WINDOW);
 108 }
 109
 110 GtkWidget *
 111 gtk_mirror_bin_new (void)
 112 {
 113   return g_object_new (GTK_TYPE_MIRROR_BIN, NULL);
 114 }
 115
 116 static GdkWindow *
 117 pick_offscreen_child (GdkWindow     *offscreen_window,
 118                       double         widget_x,
 119                       double         widget_y,
 120                       GtkMirrorBin *bin)
 121 {
 122  GtkAllocation child_area;
 123  double x, y;
 124
 125  if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 126     {
 127       to_child (bin, widget_x, widget_y, &x, &y);
 128
 129       child_area = bin->child->allocation;
 130
 131       if (x >= 0 && x < child_area.width &&
 132           y >= 0 && y < child_area.height)
 133         return bin->offscreen_window;
 134     }
 135
 136   return NULL;
 137 }
 138
 139 static void
 140 offscreen_window_to_parent (GdkWindow     *offscreen_window,
 141                             double         offscreen_x,
 142                             double         offscreen_y,
 143                             double        *parent_x,
 144                             double        *parent_y,
 145                             GtkMirrorBin *bin)
 146 {
 147   to_parent (bin, offscreen_x, offscreen_y, parent_x, parent_y);
 148 }
 149
 150 static void
 151 offscreen_window_from_parent (GdkWindow     *window,
 152                               double         parent_x,
 153                               double         parent_y,
 154                               double        *offscreen_x,
 155                               double        *offscreen_y,
 156                               GtkMirrorBin *bin)
 157 {
 158   to_child (bin, parent_x, parent_y, offscreen_x, offscreen_y);
 159 }
 160
 161 static void
 162 gtk_mirror_bin_realize (GtkWidget *widget)
 163 {
 164   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 165   GdkWindowAttr attributes;
 166   gint attributes_mask;
 167   gint border_width;
 168   GtkRequisition child_requisition;
 169
 170   GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);
 171
 172   border_width = GTK_CONTAINER (widget)->border_width;
 173
 174   attributes.x = widget->allocation.x + border_width;
 175   attributes.y = widget->allocation.y + border_width;
 176   attributes.width = widget->allocation.width - 2 * border_width;
 177   attributes.height = widget->allocation.height - 2 * border_width;
 178   attributes.window_type = GDK_WINDOW_CHILD;
 179   attributes.event_mask = gtk_widget_get_events (widget)
 180                         | GDK_EXPOSURE_MASK
 181                         | GDK_POINTER_MOTION_MASK
 182                         | GDK_BUTTON_PRESS_MASK
 183                         | GDK_BUTTON_RELEASE_MASK
 184                         | GDK_SCROLL_MASK
 185                         | GDK_ENTER_NOTIFY_MASK
 186                         | GDK_LEAVE_NOTIFY_MASK;
 187
 188   attributes.visual = gtk_widget_get_visual (widget);
 189   attributes.colormap = gtk_widget_get_colormap (widget);
 190   attributes.wclass = GDK_INPUT_OUTPUT;
 191
 192   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
 193
 194   widget->window = gdk_window_new (gtk_widget_get_parent_window (widget),
 195                                    &attributes, attributes_mask);
 196   gdk_window_set_user_data (widget->window, widget);
 197   g_signal_connect (widget->window, "pick-embedded-child",
 198                     G_CALLBACK (pick_offscreen_child), bin);
 199
 200   attributes.window_type = GDK_WINDOW_OFFSCREEN;
 201
 202   child_requisition.width = child_requisition.height = 0;
 203   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 204     {
 205       attributes.width = bin->child->allocation.width;
 206       attributes.height = bin->child->allocation.height;
 207     }
 208   bin->offscreen_window = gdk_window_new (gtk_widget_get_root_window (widget),
 209                                           &attributes, attributes_mask);
 210   gdk_window_set_user_data (bin->offscreen_window, widget);
 211   if (bin->child)
 212     gtk_widget_set_parent_window (bin->child, bin->offscreen_window);
 213   gdk_offscreen_window_set_embedder (bin->offscreen_window, widget->window);
 214   g_signal_connect (bin->offscreen_window, "to-embedder",
 215                     G_CALLBACK (offscreen_window_to_parent), bin);
 216   g_signal_connect (bin->offscreen_window, "from-embedder",
 217                     G_CALLBACK (offscreen_window_from_parent), bin);
 218
 219   widget->style = gtk_style_attach (widget->style, widget->window);
 220
 221   gtk_style_set_background (widget->style, widget->window, GTK_STATE_NORMAL);
 222   gtk_style_set_background (widget->style, bin->offscreen_window, GTK_STATE_NORMAL);
 223   gdk_window_show (bin->offscreen_window);
 224 }
 225
 226 static void
 227 gtk_mirror_bin_unrealize (GtkWidget *widget)
 228 {
 229   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 230
 231   gdk_window_set_user_data (bin->offscreen_window, NULL);
 232   gdk_window_destroy (bin->offscreen_window);
 233   bin->offscreen_window = NULL;
 234
 235   GTK_WIDGET_CLASS (gtk_mirror_bin_parent_class)->unrealize (widget);
 236 }
 237
 238 static GType
 239 gtk_mirror_bin_child_type (GtkContainer *container)
 240 {
 241   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 242
 243   if (bin->child)
 244     return G_TYPE_NONE;
 245
 246   return GTK_TYPE_WIDGET;
 247 }
 248
 249 static void
 250 gtk_mirror_bin_add (GtkContainer *container,
 251                      GtkWidget    *widget)
 252 {
 253   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 254
 255   if (!bin->child)
 256     {
 257       gtk_widget_set_parent_window (widget, bin->offscreen_window);
 258       gtk_widget_set_parent (widget, GTK_WIDGET (bin));
 259       bin->child = widget;
 260     }
 261   else
 262     g_warning ("GtkMirrorBin cannot have more than one child\n");
 263 }
 264
 265 static void
 266 gtk_mirror_bin_remove (GtkContainer *container,
 267                         GtkWidget    *widget)
 268 {
 269   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 270   gboolean was_visible;
 271
 272   was_visible = GTK_WIDGET_VISIBLE (widget);
 273
 274   if (bin->child == widget)
 275     {
 276       gtk_widget_unparent (widget);
 277
 278       bin->child = NULL;
 279
 280       if (was_visible && GTK_WIDGET_VISIBLE (container))
 281         gtk_widget_queue_resize (GTK_WIDGET (container));
 282     }
 283 }
 284
 285 static void
 286 gtk_mirror_bin_forall (GtkContainer *container,
 287                         gboolean      include_internals,
 288                         GtkCallback   callback,
 289                         gpointer      callback_data)
 290 {
 291   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 292
 293   g_return_if_fail (callback != NULL);
 294
 295   if (bin->child)
 296     (*callback) (bin->child, callback_data);
 297 }
 298
 299 static void
 300 gtk_mirror_bin_size_request (GtkWidget      *widget,
 301                               GtkRequisition *requisition)
 302 {
 303   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 304   GtkRequisition child_requisition;
 305
 306   child_requisition.width = 0;
 307   child_requisition.height = 0;
 308
 309   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 310     gtk_widget_size_request (bin->child, &child_requisition);
 311
 312   requisition->width = GTK_CONTAINER (widget)->border_width * 2 + child_requisition.width + 10;
 313   requisition->height = GTK_CONTAINER (widget)->border_width * 2 + child_requisition.height * 2 + 10;
 314 }
 315
 316 static void
 317 gtk_mirror_bin_size_allocate (GtkWidget     *widget,
 318                                GtkAllocation *allocation)
 319 {
 320   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 321   gint border_width;
 322   gint w, h;
 323   widget->allocation = *allocation;
 324
 325   border_width = GTK_CONTAINER (widget)->border_width;
 326
 327   w = allocation->width - border_width * 2;
 328   h = allocation->height - border_width * 2;
 329
 330   if (GTK_WIDGET_REALIZED (widget))
 331     gdk_window_move_resize (widget->window,
 332                             allocation->x + border_width,
 333                             allocation->y + border_width,
 334                             w, h);
 335
 336   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 337     {
 338       GtkRequisition child_requisition;
 339       GtkAllocation child_allocation;
 340
 341       gtk_widget_get_child_requisition (bin->child, &child_requisition);
 342       child_allocation.x = 0;
 343       child_allocation.y = 0;
 344       child_allocation.height = child_requisition.height;
 345       child_allocation.width = child_requisition.width;
 346
 347       if (GTK_WIDGET_REALIZED (widget))
 348         gdk_window_move_resize (bin->offscreen_window,
 349                                 allocation->x + border_width,
 350                                 allocation->y + border_width,
 351                                 child_allocation.width, child_allocation.height);
 352       gtk_widget_size_allocate (bin->child, &child_allocation);
 353     }
 354 }
 355
 356 static gboolean
 357 gtk_mirror_bin_damage (GtkWidget      *widget,
 358                         GdkEventExpose *event)
 359 {
 360   gdk_window_invalidate_rect (widget->window, NULL, FALSE);
 361
 362   return TRUE;
 363 }
 364
 365 static gboolean
 366 gtk_mirror_bin_expose (GtkWidget      *widget,
 367                         GdkEventExpose *event)
 368 {
 369   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 370   gint width, height;
 371
 372   if (GTK_WIDGET_DRAWABLE (widget))
 373     {
 374       if (event->window == widget->window)
 375         {
 376           GdkPixmap *pixmap;
 377           cairo_t *cr;
 378           cairo_matrix_t matrix;
 379           cairo_pattern_t *mask;
 380
 381           if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 382             {
 383               pixmap = gdk_offscreen_window_get_pixmap (bin->offscreen_window);
 384               gdk_drawable_get_size (pixmap, &width, &height);
 385
 386               cr = gdk_cairo_create (widget->window);
 387
 388               cairo_save (cr);
 389
 390               cairo_rectangle (cr, 0, 0, width, height);
 391               cairo_clip (cr);
 392
 393               /* paint the offscreen child */
 394               gdk_cairo_set_source_pixmap (cr, pixmap, 0, 0);
 395               cairo_paint (cr);
 396
 397               cairo_restore (cr);
 398
 399               cairo_matrix_init (&matrix, 1.0, 0.0, 0.3, 1.0, 0.0, 0.0);
 400               cairo_matrix_scale (&matrix, 1.0, -1.0);
 401               cairo_matrix_translate (&matrix, -10, - 3 * height - 10);
 402               cairo_transform (cr, &matrix);
 403
 404               cairo_rectangle (cr, 0, height, width, height);
 405               cairo_clip (cr);
 406
 407               gdk_cairo_set_source_pixmap (cr, pixmap, 0, height);
 408
 409               /* create linear gradient as mask-pattern to fade out the source */
 410               mask = cairo_pattern_create_linear (0.0, height, 0.0, 2*height);
 411               cairo_pattern_add_color_stop_rgba (mask, 0.0,  0.0, 0.0, 0.0, 0.0);
 412               cairo_pattern_add_color_stop_rgba (mask, 0.25, 0.0, 0.0, 0.0, 0.01);
 413               cairo_pattern_add_color_stop_rgba (mask, 0.5,  0.0, 0.0, 0.0, 0.25);
 414               cairo_pattern_add_color_stop_rgba (mask, 0.75, 0.0, 0.0, 0.0, 0.5);
 415               cairo_pattern_add_color_stop_rgba (mask, 1.0,  0.0, 0.0, 0.0, 1.0);
 416
 417               /* paint the reflection */
 418               cairo_mask (cr, mask);
 419
 420               cairo_pattern_destroy (mask);
 421               cairo_destroy (cr);
 422             }
 423         }
 424       else if (event->window == bin->offscreen_window)
 425         {
 426           gtk_paint_flat_box (widget->style, event->window,
 427                               GTK_STATE_NORMAL, GTK_SHADOW_NONE,
 428                               &event->area, widget, "blah",
 429                               0, 0, -1, -1);
 430
 431           if (bin->child)
 432             gtk_container_propagate_expose (GTK_CONTAINER (widget),
 433                                             bin->child,
 434                                             event);
 435         }
 436     }
 437
 438   return FALSE;
 439 }
 440
 441 /*** ***/
 442
 443 static GtkWidget *window = NULL;
 444
 445 GtkWidget *
 446 do_offscreen_window2 (GtkWidget *do_widget)
 447 {
 448   if (!window)
 449     {
 450       GtkWidget *bin, *vbox;
 451       GtkWidget *hbox, *entry, *applybutton, *backbutton;
 452       GtkSizeGroup *group;
 453
 454       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 455       gtk_window_set_screen (GTK_WINDOW (window),
 456                              gtk_widget_get_screen (do_widget));
 457       gtk_window_set_title (GTK_WINDOW (window), "Effects");
 458
 459       g_signal_connect (window, "destroy",
 460                         G_CALLBACK (gtk_widget_destroyed), &window);
 461
 462       gtk_container_set_border_width (GTK_CONTAINER (window), 10);
 463
 464       vbox = gtk_vbox_new (0, FALSE);
 465
 466       bin = gtk_mirror_bin_new ();
 467
 468       group = gtk_size_group_new (GTK_SIZE_GROUP_VERTICAL);
 469
 470       hbox = gtk_hbox_new (FALSE, 6);
 471       backbutton = gtk_button_new ();
 472       gtk_container_add (GTK_CONTAINER (backbutton),
 473                          gtk_image_new_from_stock (GTK_STOCK_GO_BACK, 4));
 474       gtk_size_group_add_widget (group, backbutton);
 475       entry = gtk_entry_new ();
 476       gtk_size_group_add_widget (group, entry);
 477       applybutton = gtk_button_new ();
 478       gtk_size_group_add_widget (group, applybutton);
 479       gtk_container_add (GTK_CONTAINER (applybutton),
 480                          gtk_image_new_from_stock (GTK_STOCK_APPLY, 4));
 481
 482       gtk_container_add (GTK_CONTAINER (window), vbox);
 483       gtk_box_pack_start (GTK_BOX (vbox), bin, TRUE, TRUE, 0);
 484       gtk_container_add (GTK_CONTAINER (bin), hbox);
 485       gtk_box_pack_start (GTK_BOX (hbox), backbutton, FALSE, FALSE, 0);
 486       gtk_box_pack_start (GTK_BOX (hbox), entry, TRUE, TRUE, 0);
 487       gtk_box_pack_start (GTK_BOX (hbox), applybutton, FALSE, FALSE, 0);
 488     }
 489
 490   if (!GTK_WIDGET_VISIBLE (window))
 491     gtk_widget_show_all (window);
 492   else
 493     {
 494       gtk_widget_destroy (window);
 495       window = NULL;
 496     }
 497
 498   return window;
 499 }
 500