src/cteddy.cxx

   1 // Copyright 2008 Philip Allison <sane@not.co.uk>
   2
   3 //    This file is part of cteddy.
   4 //
   5 //    cteddy is free software: you can redistribute it and/or modify
   6 //    it under the terms of the GNU General Public License as published by
   7 //    the Free Software Foundation, either version 3 of the License, or
   8 //    (at your option) any later version.
   9 //
  10 //    cteddy is distributed in the hope that it will be useful,
  11 //    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 //    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 //    GNU General Public License for more details.
  14 //
  15 //    You should have received a copy of the GNU General Public License
  16 //    along with cteddy.  If not, see <http://www.gnu.org/licenses/>.
  17
  18
  19 //
  20 // Includes
  21 //
  22
  23 // Language headers
  24 #include <string>
  25 #include <iostream>
  26 #include <cstring>
  27 #include <cerrno>
  28
  29 // Library headers
  30 #include <gtk/gtk.h>
  31 #include <gdk/gdkkeysyms.h>
  32
  33 // System headers
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <fcntl.h>
  37 #include <unistd.h>
  38
  39
  40 //
  41 // Globals
  42 //
  43
  44 // Main window
  45 GtkWidget* window;
  46
  47 // GTK/GDK returned pointer
  48 GError* gerr = NULL;
  49
  50 // Image to display and its dimensions
  51 GdkPixbuf* pixbuf;
  52 gint width, height;
  53
  54 // Whether or not the key & mouse binding for quit are disabled
  55 bool noquit = false;
  56
  57
  58 //
  59 // Implementation
  60 //
  61
  62 // Re-paint the window when necessary
  63 gboolean handle_expose(GtkWidget* widget, GdkEventExpose* event)
  64 {
  65         cairo_t* cairo = gdk_cairo_create(widget->window);
  66
  67         // Blank the surface
  68         cairo_set_source_rgba (cairo, 1.0f, 1.0f, 1.0f, 0.0f);
  69         cairo_set_operator (cairo, CAIRO_OPERATOR_SOURCE);
  70         cairo_paint (cairo);
  71
  72         // Set cairo's source pattern from the desired image
  73         gdk_cairo_set_source_pixbuf(cairo, pixbuf, 0.0f, 0.0f);
  74
  75         // Draw the image
  76         cairo_rectangle(cairo, 0.0f, 0.0f,
  77                 static_cast<double>(width), static_cast<double>(height));
  78         cairo_fill(cairo);
  79
  80         cairo_destroy(cairo);
  81
  82         return false;
  83 }
  84
  85 // Handle mouse click events
  86 gboolean window_clicked(GtkWidget* widget, GdkEventButton* event)
  87 {
  88         if (event->type == GDK_BUTTON_PRESS)
  89                 // Move the window with the mouse
  90                 gtk_window_begin_move_drag(GTK_WINDOW(window),
  91                         event->button, static_cast<gint>(event->x_root),
  92                         static_cast<gint>(event->y_root), event->time);
  93         return true;
  94 }
  95
  96 // Set up an RGBA colourmap for the window
  97 void handle_screen(GtkWidget* window, GdkScreen* old, gpointer data)
  98 {
  99         GdkScreen* s = gtk_widget_get_screen(window);
 100         GdkColormap* c = gdk_screen_get_rgba_colormap(s);
 101
 102         if (!c)
 103                 // Use standard RGB colourmap if we must. Window will have
 104                 // an ugly black border if this is the case.
 105                 c = gdk_screen_get_rgb_colormap(s);
 106
 107         gtk_widget_set_colormap(window, c);
 108 }
 109
 110 // Handle key press events
 111 void handle_key_press(GtkWidget *Window, GdkEventKey *theEvent)
 112 {
 113         switch( theEvent->keyval )
 114         {
 115                 case GDK_q:
 116                         // Quit on "q"
 117                         if (!noquit)
 118                                 gtk_main_quit();
 119                         break;
 120
 121                 default:
 122                         // Ignore all other keys
 123                         break;
 124         }
 125
 126 }
 127
 128 // Entry point
 129 int main (int argc, char* argv[])
 130 {
 131         gtk_init(&argc, &argv);
 132
 133         // Whether or not to set the window's keep-on-top hint
 134         bool ontop = false;
 135
 136         // Whether or not the window's sticky hint should be set
 137         bool sticky = false;
 138
 139         // Whether or not to fork into the background
 140         bool background = true;
 141
 142         // Mimic the image loading behaviour of xteddy, to an extent.
 143         {
 144                 // Start from the name of the executable itself
 145                 std::string image(argv[0]);
 146
 147                 // Take just the last component of the path
 148                 std::string::size_type s = image.find_last_of('/');
 149                 if (s != std::string::npos)
 150                         image = image.substr(s + 1);
 151
 152                 // Parse options
 153                 // XXX This code is really quick and nasty
 154                 for (int i = 1; i < argc; ++i)
 155                 {
 156                         // Allow image specification with -F<file>
 157                         if (strncmp(argv[i], "-F", 2) == 0)
 158                                 image = argv[i] + 2;
 159                         // Allow disablement of "q" keybinding
 160                         else if (strncmp(argv[i], "-noquit", 7) == 0)
 161                                 noquit = true;
 162                         // Allow keep-on-top
 163                         else if (strncmp(argv[i], "-float", 6) == 0)
 164                                 ontop = true;
 165                         // Allow sticking to all desktops
 166                         else if (strncmp(argv[i], "-stick", 6) == 0)
 167                                 sticky = true;
 168                         // Allow disablement of backgrounding
 169                         else if (strncmp(argv[i], "-nobg", 5) == 0)
 170                                 background = false;
 171                 }
 172
 173                 // If the given path contains slashes, assume it is absolute or
 174                 // relative to the current working directory and use it verbatim.
 175                 // Otherwise, search for it.
 176                 if (image.find_last_of('/') == std::string::npos)
 177                 {
 178                         // Append extensions one by one and search for the image
 179                         // XXX This code is really, REALLY quick and nasty
 180                         char* extensions[17];
 181                         bool found = false;
 182                         extensions[0] = '\0';
 183                         extensions[1] = ".png"; extensions[2] = ".gif"; extensions[3] = ".jpg";
 184                         extensions[4] = ".jpeg"; extensions[5] = ".pnm"; extensions[6] = ".xpm";
 185                         extensions[7] = ".tif"; extensions[8] = ".tiff";
 186                         extensions[9] = ".PNG"; extensions[10] = ".GIF"; extensions[11] = ".JPG";
 187                         extensions[12] = ".JPEG"; extensions[13] = ".PNM"; extensions[14] = ".XPM";
 188                         extensions[15] = ".TIF"; extensions[16] = ".TIFF";
 189                         for (size_t i = 0; i < 17; ++i)
 190                         {
 191                                 std::string searchimage(PKGDATADIR "/");
 192                                 searchimage.append(image);
 193                                 if (i > 0) searchimage.append(extensions[i]);
 194                                 struct stat s;
 195                                 if (stat(searchimage.c_str(), &s) == 0)
 196                                 {
 197                                         image = searchimage;
 198                                         found = true;
 199                                         break;
 200                                 }
 201                                 // Try converting a leading x to a c and vice versa
 202                                 if (image.at(0) == 'x')
 203                                 {
 204                                         std::string ximage(PKGDATADIR "/c");
 205                                         ximage.append(image.substr(1));
 206                                         if (i > 0) ximage.append(extensions[i]);
 207                                         if (stat(ximage.c_str(), &s) == 0)
 208                                         {
 209                                                 image = ximage;
 210                                                 found = true;
 211                                                 break;
 212                                         }
 213                                 }
 214                                 if (image.at(0) == 'c')
 215                                 {
 216                                         std::string ximage(PKGDATADIR "/x");
 217                                         ximage.append(image.substr(1));
 218                                         if (i > 0) ximage.append(extensions[i]);
 219                                         if (stat(ximage.c_str(), &s) == 0)
 220                                         {
 221                                                 image = ximage;
 222                                                 found = true;
 223                                                 break;
 224                                         }
 225                                 }
 226                                 // Try prepending c or x
 227                                 std::string ximage(PKGDATADIR "/c");
 228                                 ximage.append(image);
 229                                 if (i > 0) ximage.append(extensions[i]);
 230                                 if (stat(ximage.c_str(), &s) == 0)
 231                                 {
 232                                         image = ximage;
 233                                         found = true;
 234                                         break;
 235                                 }
 236                                 ximage = PKGDATADIR "/x";
 237                                 ximage.append(image);
 238                                 if (i > 0) ximage.append(extensions[i]);
 239                                 if (stat(ximage.c_str(), &s) == 0)
 240                                 {
 241                                         image = ximage;
 242                                         found = true;
 243                                         break;
 244                                 }
 245                         }
 246
 247                         if (!found)
 248                         {
 249                                 std::cerr << "Cannot find image!" << std::endl;
 250                                 return 1;
 251                         }
 252                 }
 253
 254                 // Load the image from the supplied file path
 255                 pixbuf = gdk_pixbuf_new_from_file(image.c_str(), &gerr);
 256                 if (gerr)
 257                 {
 258                         std::cerr << "Cannot load image \"" << image << "\": " << gerr->message << std::endl;
 259                         g_error_free(gerr);
 260                         return 1;
 261                 }
 262         }
 263
 264         // Create the window
 265         window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 266
 267         // Top-level windows don't normally respond to mouse button events directly.
 268         // We want this one to, though.
 269         gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);
 270
 271         // Set up event callbacks
 272         g_signal_connect(G_OBJECT(window), "expose-event", G_CALLBACK(handle_expose), NULL);
 273         g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);
 274         g_signal_connect(G_OBJECT(window), "button-press-event", G_CALLBACK(window_clicked), NULL);
 275         g_signal_connect(G_OBJECT(window), "screen-changed", G_CALLBACK(handle_screen), NULL);
 276         g_signal_connect(G_OBJECT(window), "key-press-event", G_CALLBACK(handle_key_press), NULL);
 277
 278         {
 279                 // Grap pixmap and alpha-thresholded bitmap from original pixmap
 280                 GdkPixmap* pixmap;
 281                 GdkBitmap* bitmap;
 282                 gdk_pixbuf_render_pixmap_and_mask(pixbuf, &pixmap, &bitmap, 128);
 283
 284                 // Set window size to image size
 285                 gdk_drawable_get_size(pixmap, &width, &height);
 286                 gtk_widget_set_size_request(window, width, height);
 287
 288                 // If we have an alpha channel on the image, set the window's input shape,
 289                 // clearing it completely first
 290                 if (bitmap)
 291                 {
 292                         gtk_widget_input_shape_combine_mask(window, NULL, 0, 0);
 293                         gtk_widget_input_shape_combine_mask(window, bitmap, 0, 0);
 294                 }
 295
 296                 g_object_unref(G_OBJECT(pixmap));
 297                 g_object_unref(G_OBJECT(bitmap));
 298         }
 299
 300         // Set up various other properties we're interested in
 301         gtk_window_set_title(GTK_WINDOW(window), "cteddy");
 302         gtk_window_set_resizable(GTK_WINDOW(window), false);
 303         gtk_window_set_decorated(GTK_WINDOW(window), false);
 304         gtk_widget_set_app_paintable(window, true);
 305
 306         // Trigger initial attempt to switch to an RGBA colourmap
 307         handle_screen(window, NULL, NULL);
 308
 309         // Have to do this before we can use window->window as a GdkWindow*
 310         gtk_widget_realize(window);
 311
 312         {
 313                 // Load in the heart-shaped cursor image and use it for our window's cursor
 314                 GdkPixbuf* heart =      gdk_pixbuf_new_from_file(PKGDATADIR "/heart.png", &gerr);
 315                 if (gerr)
 316                 {
 317                         std::cerr << "Cannot load image: " << gerr->message << std::endl;
 318                         g_error_free(gerr);
 319                         return 1;
 320                 }
 321                 GdkCursor* cursor = gdk_cursor_new_from_pixbuf(gdk_display_get_default(),
 322                         heart, 12, 12);
 323                 gdk_window_set_cursor(window->window, cursor);
 324         }
 325
 326         // Clear the window's default background
 327         gdk_window_set_back_pixmap(window->window, NULL, false);
 328
 329         // Don't steal input focus when we start
 330         g_object_set(G_OBJECT(window), "focus-on-map", false, NULL);
 331
 332         // Honour float & sticky options
 333         if (ontop)
 334                 gtk_window_set_keep_above(GTK_WINDOW(window), true);
 335         if (sticky)
 336                 gtk_window_stick(GTK_WINDOW(window));
 337
 338         gtk_widget_show_all(window);
 339
 340         // Fork into background if desired
 341         if (background)
 342         {
 343                 pid_t p = fork();
 344                 if (p < 0)
 345                 {
 346                         std::cerr << "Could not fork: " << strerror(errno) << std::endl;
 347                         return 1;
 348                 }
 349                 else if (p == 0)
 350                 {
 351                         // Close stdin
 352                         while (close(0) != 0)
 353                         {
 354                                 if (errno == EINTR)
 355                                         continue;
 356                                 std::cerr << "Could not close stdin: " << strerror(errno) << std::endl;
 357                                 return 1;
 358                         }
 359                         // Redirect stdout & stderr to /dev/null
 360                         int nullfd;
 361                         while ((nullfd = open("/dev/null", O_WRONLY)) < 0)
 362                         {
 363                                 if (errno == EINTR)
 364                                         continue;
 365                                 std::cerr << "Cannot open /dev/null: " << strerror(errno) << std::endl;
 366                                 return 1;
 367                         }
 368                         while (dup2(nullfd, 1) < 0)
 369                         {
 370                                 if (errno == EINTR)
 371                                         continue;
 372                                 std::cerr << "Cannot redirect stdout to /dev/null: " << strerror(errno) << std::endl;
 373                                 return 1;
 374                         }
 375                         while (dup2(nullfd, 2) < 0)
 376                         {
 377                                 if (errno == EINTR)
 378                                         continue;
 379                                 std::cerr << "Cannot redirect stderr to /dev/null: " << strerror(errno) << std::endl;
 380                                 return 1;
 381                         }
 382                         // Create new process session
 383                         if (setsid() < 0)
 384                         {
 385                                 std::cerr << "Cannot create new session: " << strerror(errno) << std::endl;
 386                                 return 1;
 387                         }
 388                 }
 389                 else
 390                         return 0;
 391         }
 392
 393         gtk_main();
 394
 395         return 0;
 396 }