/* GTK - The GIMP Toolkit * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * 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. */#include <gtk/gtk.h>/* Backing pixmap for drawing area */static GdkPixmap *pixmap = NULL;/* Create a new backing pixmap of the appropriate size */static gbooleanconfigure_event (GtkWidget *widget, GdkEventConfigure *event){  if (pixmap)     g_object_unref (pixmap);  pixmap = gdk_pixmap_new (widget->window,                           widget->allocation.width,                           widget->allocation.height,                           -1);  gdk_draw_rectangle (pixmap,                      widget->style->white_gc,                      TRUE,                      0, 0,                      widget->allocation.width,                      widget->allocation.height);  return TRUE;}/* Redraw the screen from the backing pixmap */static gbooleanexpose_event (GtkWidget *widget, GdkEventExpose *event){  gdk_draw_drawable (widget->window,                     widget->style->fg_gc[GTK_WIDGET_STATE (widget)],                     pixmap,                     event->area.x, event->area.y,                     event->area.x, event->area.y,                     event->area.width, event->area.height);  return FALSE;}/* Draw a rectangle on the screen, size depending on pressure,   and color on the type of device */static voiddraw_brush (GtkWidget *widget, GdkInputSource source,            gdouble x, gdouble y, gdouble pressure){  GdkGC *gc;  GdkRectangle update_rect;  switch (source)    {    case GDK_SOURCE_MOUSE:      gc = widget->style->dark_gc[GTK_WIDGET_STATE (widget)];      break;    case GDK_SOURCE_PEN:      gc = widget->style->black_gc;      break;    case GDK_SOURCE_ERASER:      gc = widget->style->white_gc;      break;    default:      gc = widget->style->light_gc[GTK_WIDGET_STATE (widget)];    }  update_rect.x = x - 10 * pressure;  update_rect.y = y - 10 * pressure;  update_rect.width = 20 * pressure;  update_rect.height = 20 * pressure;  gdk_draw_rectangle (pixmap, gc, TRUE,                      update_rect.x, update_rect.y,                      update_rect.width, update_rect.height);  gtk_widget_queue_draw_area (widget,                       update_rect.x, update_rect.y,                      update_rect.width, update_rect.height);}static voidprint_button_press (GdkDevice *device){  g_print ("Button press on device '%s'\n", device->name);}static gbooleanbutton_press_event (GtkWidget *widget, GdkEventButton *event){  print_button_press (event->device);    if (event->button == 1 && pixmap != NULL) {    gdouble pressure;    gdk_event_get_axis ((GdkEvent *)event, GDK_AXIS_PRESSURE, &pressure);    draw_brush (widget, event->device->source, event->x, event->y, pressure);  }  return TRUE;}static gbooleanmotion_notify_event (GtkWidget *widget, GdkEventMotion *event){  gdouble x, y;  gdouble pressure;  GdkModifierType state;  if (event->is_hint)     {      gdk_device_get_state (event->device, event->window, NULL, &state);      gdk_event_get_axis ((GdkEvent *)event, GDK_AXIS_X, &x);      gdk_event_get_axis ((GdkEvent *)event, GDK_AXIS_Y, &y);      gdk_event_get_axis ((GdkEvent *)event, GDK_AXIS_PRESSURE, &pressure);    }  else    {      x = event->x;      y = event->y;      gdk_event_get_axis ((GdkEvent *)event, GDK_AXIS_PRESSURE, &pressure);      state = event->state;    }      if (state & GDK_BUTTON1_MASK && pixmap != NULL)    draw_brush (widget, event->device->source, x, y, pressure);    return TRUE;}voidinput_dialog_destroy (GtkWidget *w, gpointer data){  *((GtkWidget **)data) = NULL;}voidcreate_input_dialog (){  static GtkWidget *inputd = NULL;  if (!inputd)    {      inputd = gtk_input_dialog_new();      g_signal_connect (G_OBJECT (inputd), "destroy",                        G_CALLBACK (input_dialog_destroy), (gpointer) &inputd);      g_signal_connect_swapped (G_OBJECT (GTK_INPUT_DIALOG (inputd)->close_button),                                "clicked",                                G_CALLBACK (gtk_widget_hide),                                G_OBJECT (inputd));      gtk_widget_hide (GTK_INPUT_DIALOG (inputd)->save_button);      gtk_widget_show (inputd);    }  else    {      if (!GTK_WIDGET_MAPPED (inputd))        gtk_widget_show (inputd);      else        gdk_window_raise (inputd->window);    }}voidintmain (int argc, char *argv[]){  GtkWidget *window;  GtkWidget *drawing_area;  GtkWidget *vbox;  GtkWidget *button;  gtk_init (&argc, &argv);  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);  gtk_widget_set_name (window, "Test Input");  vbox = gtk_vbox_new (FALSE, 0);  gtk_container_add (GTK_CONTAINER (window), vbox);  gtk_widget_show (vbox);  g_signal_connect (G_OBJECT (window), "destroy",                    G_CALLBACK (gtk_main_quit), NULL);  /* Create the drawing area */  drawing_area = gtk_drawing_area_new ();  gtk_widget_set_size_request (GTK_WIDGET (drawing_area), 200, 200);  gtk_box_pack_start (GTK_BOX (vbox), drawing_area, TRUE, TRUE, 0);  gtk_widget_show (drawing_area);  /* Signals used to handle backing pixmap */  g_signal_connect (G_OBJECT (drawing_area), "expose_event",                    G_CALLBACK (expose_event), NULL);  g_signal_connect (G_OBJECT(drawing_area),"configure_event",                    G_CALLBACK (configure_event), NULL);  /* Event signals */  g_signal_connect (G_OBJECT (drawing_area), "motion_notify_event",                    G_CALLBACK (motion_notify_event), NULL);  g_signal_connect (G_OBJECT (drawing_area), "button_press_event",                    G_CALLBACK (button_press_event), NULL);  gtk_widget_set_events (drawing_area, GDK_EXPOSURE_MASK                         | GDK_LEAVE_NOTIFY_MASK                         | GDK_BUTTON_PRESS_MASK                         | GDK_POINTER_MOTION_MASK                         | GDK_POINTER_MOTION_HINT_MASK);  /* The following call enables tracking and processing of extension     events for the drawing area */  gtk_widget_set_extension_events (drawing_area, GDK_EXTENSION_EVENTS_CURSOR);  /* .. And some buttons */  button = gtk_button_new_with_label ("Input Dialog");  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);  g_signal_connect (G_OBJECT (button), "clicked",                    G_CALLBACK (create_input_dialog), NULL);  gtk_widget_show (button);  button = gtk_button_new_with_label ("Quit");  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);  g_signal_connect_swapped (G_OBJECT (button), "clicked",                            G_CALLBACK (gtk_widget_destroy),                            G_OBJECT (window));  gtk_widget_show (button);  gtk_widget_show (window);  gtk_main ();  return 0;}