i3
src/sighandler.c
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00001 /*
00002  * vim:ts=8:expandtab
00003  *
00004  * i3 - an improved dynamic tiling window manager
00005  *
00006  * © 2009-2010 Michael Stapelberg and contributors
00007  * © 2009-2010 Jan-Erik Rediger
00008  *
00009  * See file LICENSE for license information.
00010  *
00011  * sighandler.c: contains all functions for signal handling
00012  *
00013  */
00014 #include <ev.h>
00015 #include <stdio.h>
00016 #include <stdlib.h>
00017 #include <string.h>
00018 #include <unistd.h>
00019 #include <iconv.h>
00020 #include <signal.h>
00021 
00022 #include <xcb/xcb.h>
00023 #include <xcb/xcb_aux.h>
00024 #include <xcb/xcb_event.h>
00025 #include <xcb/xcb_keysyms.h>
00026 
00027 #include <X11/keysym.h>
00028 
00029 #include "i3.h"
00030 #include "util.h"
00031 #include "xcb.h"
00032 #include "log.h"
00033 #include "config.h"
00034 #include "randr.h"
00035 
00036 static xcb_gcontext_t pixmap_gc;
00037 static xcb_pixmap_t pixmap;
00038 static int raised_signal;
00039 
00040 static char *crash_text[] = {
00041         "i3 just crashed.",
00042         "To debug this problem, either attach gdb now",
00043         "or press 'e' to exit and get a core-dump.",
00044         "If you want to keep your session,",
00045         "press 'r' to restart i3 in-place."
00046 };
00047 static int crash_text_longest = 1;
00048 
00049 /*
00050  * Draw the window containing the info text
00051  *
00052  */
00053 static int sig_draw_window(xcb_connection_t *conn, xcb_window_t win, int width, int height, int font_height) {
00054         /* re-draw the background */
00055         xcb_rectangle_t border = { 0, 0, width, height},
00056                         inner = { 2, 2, width - 4, height - 4};
00057         xcb_change_gc_single(conn, pixmap_gc, XCB_GC_FOREGROUND, get_colorpixel(conn, "#FF0000"));
00058         xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &border);
00059         xcb_change_gc_single(conn, pixmap_gc, XCB_GC_FOREGROUND, get_colorpixel(conn, "#000000"));
00060         xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &inner);
00061 
00062         /* restore font color */
00063         xcb_change_gc_single(conn, pixmap_gc, XCB_GC_FOREGROUND, get_colorpixel(conn, "#FFFFFF"));
00064 
00065         for (int i = 0; i < sizeof(crash_text) / sizeof(char*); i++) {
00066                 int text_len = strlen(crash_text[i]);
00067                 char *full_text = convert_utf8_to_ucs2(crash_text[i], &text_len);
00068                 xcb_image_text_16(conn, text_len, pixmap, pixmap_gc, 8 /* X */,
00069                                 3 + (i + 1) * font_height /* Y = baseline of font */,
00070                                 (xcb_char2b_t*)full_text);
00071                 free(full_text);
00072         }
00073 
00074         /* Copy the contents of the pixmap to the real window */
00075         xcb_copy_area(conn, pixmap, win, pixmap_gc, 0, 0, 0, 0, width, height);
00076         xcb_flush(conn);
00077 
00078         return 1;
00079 }
00080 
00081 /*
00082  * Handles keypresses of 'e' or 'r' to exit or restart i3
00083  *
00084  */
00085 static int sig_handle_key_press(void *ignored, xcb_connection_t *conn, xcb_key_press_event_t *event) {
00086         uint16_t state = event->state;
00087 
00088         /* Apparantly, after activating numlock once, the numlock modifier
00089          * stays turned on (use xev(1) to verify). So, to resolve useful
00090          * keysyms, we remove the numlock flag from the event state */
00091         state &= ~xcb_numlock_mask;
00092 
00093         xcb_keysym_t sym = xcb_key_press_lookup_keysym(keysyms, event, state);
00094 
00095         if (sym == 'e') {
00096                 DLOG("User issued exit-command, raising error again.\n");
00097                 raise(raised_signal);
00098                 exit(1);
00099         }
00100 
00101         if (sym == 'r')
00102                 i3_restart();
00103 
00104         return 1;
00105 }
00106 
00107 /*
00108  * Opens the window we use for input/output and maps it
00109  *
00110  */
00111 static xcb_window_t open_input_window(xcb_connection_t *conn, Rect screen_rect, uint32_t width, uint32_t height) {
00112         xcb_window_t win = xcb_generate_id(conn);
00113 
00114         uint32_t mask = 0;
00115         uint32_t values[2];
00116 
00117         mask |= XCB_CW_BACK_PIXEL;
00118         values[0] = 0;
00119 
00120         mask |= XCB_CW_OVERRIDE_REDIRECT;
00121         values[1] = 1;
00122 
00123         /* center each popup on the specified screen */
00124         uint32_t x = screen_rect.x + ((screen_rect.width / 2) - (width / 2)),
00125                  y = screen_rect.y + ((screen_rect.height / 2) - (height / 2));
00126 
00127         xcb_create_window(conn,
00128                         XCB_COPY_FROM_PARENT,
00129                         win, /* the window id */
00130                         root, /* parent == root */
00131                         x, y, width, height, /* dimensions */
00132                         0, /* border = 0, we draw our own */
00133                         XCB_WINDOW_CLASS_INPUT_OUTPUT,
00134                         XCB_WINDOW_CLASS_COPY_FROM_PARENT, /* copy visual from parent */
00135                         mask,
00136                         values);
00137 
00138         /* Map the window (= make it visible) */
00139         xcb_map_window(conn, win);
00140 
00141         return win;
00142 }
00143 
00144 /*
00145  * Handle signals
00146  * It creates a window asking the user to restart in-place
00147  * or exit to generate a core dump
00148  *
00149  */
00150 void handle_signal(int sig, siginfo_t *info, void *data) {
00151         DLOG("i3 crashed. SIG: %d\n", sig);
00152 
00153         struct sigaction action;
00154         action.sa_handler = SIG_DFL;
00155         sigaction(sig, &action, NULL);
00156         raised_signal = sig;
00157 
00158         xcb_connection_t *conn = global_conn;
00159 
00160         /* setup event handler for key presses */
00161         xcb_event_handlers_t sig_evenths;
00162         memset(&sig_evenths, 0, sizeof(xcb_event_handlers_t));
00163         xcb_event_handlers_init(conn, &sig_evenths);
00164         xcb_event_set_key_press_handler(&sig_evenths, sig_handle_key_press, NULL);
00165 
00166         i3Font *font = load_font(conn, config.font);
00167 
00168         /* width and height of the popup window, so that the text fits in */
00169         int crash_text_num = sizeof(crash_text) / sizeof(char*);
00170         int height = 13 + (crash_text_num * font->height);
00171 
00172         /* calculate width for longest text */
00173         int text_len = strlen(crash_text[crash_text_longest]);
00174         char *longest_text = convert_utf8_to_ucs2(crash_text[crash_text_longest], &text_len);
00175         int font_width = predict_text_width(conn, config.font, longest_text, text_len);
00176         int width = font_width + 20;
00177 
00178         /* Open a popup window on each virtual screen */
00179         Output *screen;
00180         xcb_window_t win;
00181         TAILQ_FOREACH(screen, &outputs, outputs) {
00182                 if (!screen->active)
00183                         continue;
00184                 win = open_input_window(conn, screen->rect, width, height);
00185 
00186                 /* Create pixmap */
00187                 pixmap = xcb_generate_id(conn);
00188                 pixmap_gc = xcb_generate_id(conn);
00189                 xcb_create_pixmap(conn, root_depth, pixmap, win, width, height);
00190                 xcb_create_gc(conn, pixmap_gc, pixmap, 0, 0);
00191 
00192                 /* Create graphics context */
00193                 xcb_change_gc_single(conn, pixmap_gc, XCB_GC_FONT, font->id);
00194 
00195                 /* Grab the keyboard to get all input */
00196                 xcb_grab_keyboard(conn, false, win, XCB_CURRENT_TIME, XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC);
00197 
00198                 /* Grab the cursor inside the popup */
00199                 xcb_grab_pointer(conn, false, win, XCB_NONE, XCB_GRAB_MODE_ASYNC,
00200                                  XCB_GRAB_MODE_ASYNC, win, XCB_NONE, XCB_CURRENT_TIME);
00201 
00202                 sig_draw_window(conn, win, width, height, font->height);
00203                 xcb_flush(conn);
00204         }
00205 
00206         xcb_event_wait_for_event_loop(&sig_evenths);
00207 }
00208 
00209 /*
00210  * Setup signal handlers to safely handle SIGSEGV and SIGFPE
00211  *
00212  */
00213 void setup_signal_handler() {
00214         struct sigaction action;
00215 
00216         action.sa_sigaction = handle_signal;
00217         action.sa_flags = SA_NODEFER | SA_RESETHAND | SA_SIGINFO;
00218         sigemptyset(&action.sa_mask);
00219 
00220         if (sigaction(SIGSEGV, &action, NULL) == -1 ||
00221             sigaction(SIGFPE, &action, NULL) == -1)
00222                 ELOG("Could not setup signal handler");
00223 }