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Date:: Sun May 20 08:03:31 2018 UTC
Message:: memory leak fixed
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1 /* mymenu -- simple dmenu alternative */
2 
3 /* Copyright (C) 2018  Omar Polo <omar.polo@europecom.net>
4  *
5  * This program 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  * This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
17  */
18 
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>    // strdup, strnlen, ...
22 #include <ctype.h>     // isalnum
23 #include <locale.h>    // setlocale
24 #include <unistd.h>
25 #include <sysexits.h>
26 #include <stdbool.h>
27 #include <limits.h>
28 #include <errno.h>
29 
30 #include <X11/Xlib.h>
31 #include <X11/Xutil.h> // XLookupString
32 #include <X11/Xresource.h>
33 #include <X11/Xcms.h>  // colors
34 #include <X11/keysym.h>
35 
36 #ifdef USE_XINERAMA
37 # include <X11/extensions/Xinerama.h>
38 #endif
39 
40 #define nil NULL
41 #define resname "MyMenu"
42 #define resclass "mymenu"
43 
44 #define MIN(X, Y) (((X) < (Y)) ? (X) : (Y))
45 #define MAX(a, b) ((a) > (b) ? (a) : (b))
46 #define OVERLAP(a,b,c,d) (((a)==(c) && (b)==(d)) || MIN((a)+(b), (c)+(d)) - MAX((a), (c)) > 0)
47 #define INTERSECT(x,y,w,h,x1,y1,w1,h1) (OVERLAP((x),(w),(x1),(w1)) && OVERLAP((y),(h),(y1),(h1)))
48 
49 #define update_completions(cs, text, lines) {   \
50     compl_delete(cs);                           \
51     cs = filter(text, lines);                   \
52   }
53 
54 // TODO: dynamic?
55 #define INITIAL_ITEMS 64
56 
57 #define TODO(s) {                               \
58     fprintf(stderr, "TODO! " s "\n");           \
59   }
60 
61 #define cannot_allocate_memory {                        \
62     fprintf(stderr, "Could not allocate memory\n");     \
63     exit(EX_UNAVAILABLE);                               \
64   }
65 
66 #define check_allocation(a) {     \
67     if (a == nil)                 \
68       cannot_allocate_memory;     \
69   }
70 
71 enum state {LOOPING, OK, ERR};
72 
73 struct rendering {
74   Display *d;
75   Window w;
76   GC prompt;
77   GC prompt_bg;
78   GC completion;
79   GC completion_bg;
80   GC completion_highlighted;
81   GC completion_highlighted_bg;
82   int width;
83   int height;
84   XFontSet *font;
85   bool horizontal_layout;
86 };
87 
88 struct completions {
89   char *completion;
90   bool selected;
91   struct completions *next;
92 };
93 
94 struct completions *compl_new() {
95   struct completions *c = malloc(sizeof(struct completions));
96 
97   if (c == nil)
98     return c;
99 
100   c->completion = nil;
101   c->selected = false;
102   c->next = nil;
103   return c;
104 }
105 
106 void compl_delete(struct completions *c) {
107   free(c);
108 }
109 
110 struct completions *compl_select_next(struct completions *c, bool n) {
111   if (c == nil)
112     return nil;
113   if (n) {
114     c->selected = true;
115     return c;
116   }
117 
118   struct completions *orig = c;
119   while (c != nil) {
120     if (c->selected) {
121       c->selected = false;
122       if (c->next != nil) {
123         // the current one is selected and the next one exists
124         c->next->selected = true;
125         return c->next;
126       } else {
127         // the current one is selected and the next one is nill,
128         // select the first one
129         orig->selected = true;
130         return orig;
131       }
132     }
133     c = c->next;
134   }
135   return nil;
136 }
137 
138 struct completions *compl_select_prev(struct completions *c, bool n) {
139   if (c == nil)
140     return nil;
141 
142   struct completions *cc = c;
143 
144   if (n) // select the last one
145     while (cc != nil) {
146       if (cc->next == nil) {
147         cc->selected = true;
148         return cc;
149       }
150       cc = cc->next;
151     }
152   else // select the previous one
153     while (cc != nil) {
154       if (cc->next != nil && cc->next->selected) {
155         cc->next->selected = false;
156         cc->selected = true;
157         return cc;
158       }
159       cc = cc->next;
160     }
161   
162   return nil;
163 }
164 
165 struct completions *filter(char *text, char **lines) {
166   int i = 0;
167   struct completions *root = compl_new();
168   struct completions *c = root;
169 
170   for (;;) {
171     char *l = lines[i];
172     if (l == nil)
173       break;
174 
175     if (strstr(l, text) != nil) {
176       c->next = compl_new();
177       c = c->next;
178       c->completion = l;
179     }
180 
181     ++i;
182   }
183 
184   struct completions *r = root->next;
185   compl_delete(root);
186   return r;
187 }
188 
189 // push the character c at the end of the string pointed by p
190 int pushc(char **p, int maxlen, char c) {
191   int len = strnlen(*p, maxlen);
192 
193   if (!(len < maxlen -2)) {
194     maxlen += maxlen >> 1;
195     char *newptr = realloc(*p, maxlen);
196     if (newptr == nil) { // bad!
197       return -1;
198     }
199     *p = newptr;
200   }
201 
202   (*p)[len] = c;
203   (*p)[len+1] = '\0';
204   return maxlen;
205 }
206 
207 int utf8strnlen(char *s, int maxlen) {
208   int len = 0;
209   while (*s && maxlen > 0) {
210     len += (*s++ & 0xc0) != 0x80;
211     maxlen--;
212   }
213   return len;
214 }
215 
216 // remove the last *glyph* from the *utf8* string!
217 // this is different from just setting the last byte to 0 (in some
218 // cases ofc). The actual implementation is quite inefficient because
219 // it remove the last char until the number of glyphs doesn't change
220 void popc(char *p, int maxlen) {
221   int len = strnlen(p, maxlen);
222 
223   if (len == 0)
224     return;
225 
226   int ulen = utf8strnlen(p, maxlen);
227   while (len > 0 && utf8strnlen(p, maxlen) == ulen) {
228     len--;
229     p[len] = 0;
230   }
231 }
232 
233 // read an arbitrary long line from stdin and return a pointer to it
234 // TODO: resize the allocated memory to exactly fit the string once
235 // read?
236 char *readline(bool *eof) {
237   int maxlen = 8;
238   char *str = calloc(maxlen, sizeof(char));
239   if (str == nil) {
240     fprintf(stderr, "Cannot allocate memory!\n");
241     exit(EX_UNAVAILABLE);
242   }
243 
244   int c;
245   while((c = getchar()) != EOF) {
246     if (c == '\n')
247       return str;
248     else
249       maxlen = pushc(&str, maxlen, c);
250 
251     if (maxlen == -1) {
252       fprintf(stderr, "Cannot allocate memory!\n");
253       exit(EX_UNAVAILABLE);
254     }
255   }
256   *eof = true;
257   return str;
258 }
259 
260 int readlines (char ***lns, int items) {
261   bool finished = false;
262   int n = 0;
263   char **lines = *lns;
264   while (true) {
265     lines[n] = readline(&finished);
266 
267     if (strlen(lines[n]) == 0 || lines[n][0] == '\n') {
268       free(lines[n]);
269       --n; // forget about this line
270     }
271 
272     if (finished)
273       break;
274 
275     ++n;
276 
277     if (n == items - 1) {
278       items += items >>1;
279       char **l = realloc(lines, sizeof(char*) * items);
280       check_allocation(l);
281       *lns = l;
282       lines = l;
283     }
284   }
285 
286   n++;
287   lines[n] = nil;
288   return items;
289 }
290 
291 // |------------------|----------------------------------------------|
292 // | 20 char text     | completion | completion | completion | compl |
293 // |------------------|----------------------------------------------|
294 void draw_horizontally(struct rendering *r, char *text, struct completions *cs) {
295   // TODO: make these dynamic?
296   int prompt_width = 20; // char
297   int padding = 10;
298   /* int start_at = XTextWidth(r->font, " ", 1) * prompt_width + padding; */
299 
300   XRectangle rect;
301   int start_at = XmbTextExtents(*r->font, " ", 1, nil, &rect);
302   start_at = start_at * prompt_width + padding;
303 
304   int texty = (rect.height + r->height) >>1;
305 
306   XFillRectangle(r->d, r->w, r->prompt_bg, 0, 0, start_at, r->height);
307 
308   int text_len = strlen(text);
309   if (text_len > prompt_width)
310     text = text + (text_len - prompt_width);
311   /* XDrawString(r->d, r->w, r->prompt, padding, texty, text, MIN(text_len, prompt_width)); */
312   Xutf8DrawString(r->d, r->w, *r->font, r->prompt, padding, texty, text, MIN(text_len, prompt_width));
313 
314   XFillRectangle(r->d, r->w, r->completion_bg, start_at, 0, r->width, r->height);
315 
316   while (cs != nil) {
317     GC g = cs->selected ? r->completion_highlighted    : r->completion;
318     GC h = cs->selected ? r->completion_highlighted_bg : r->completion_bg;
319 
320     int len = strlen(cs->completion);
321     /* int text_width = XTextWidth(r->font, cs->completion, len); */
322     int text_width = XmbTextExtents(*r->font, cs->completion, len, nil, nil);
323 
324     XFillRectangle(r->d, r->w, h, start_at, 0, text_width + padding*2, r->height);
325 
326     /*  XDrawString(r->d, r->w,           g, start_at + padding, texty, cs->completion, len); */
327     Xutf8DrawString(r->d, r->w, *r->font, g, start_at + padding, texty, cs->completion, len);
328 
329     start_at += text_width + padding * 2;
330 
331     if (start_at > r->width)
332       break; // don't draw completion if the space isn't enough
333 
334     cs = cs->next;
335   }
336 
337   XFlush(r->d);
338 }
339 
340 // |-----------------------------------------------------------------|
341 // |  prompt                                                         |
342 // |-----------------------------------------------------------------|
343 // |  completion                                                     |
344 // |-----------------------------------------------------------------|
345 // |  completion                                                     |
346 // |-----------------------------------------------------------------|
347 // TODO: dunno why but in the call to Xutf8DrawString, by logic,
348 // should be padding and not padding*2, but the text doesn't seem to
349 // be vertically centered otherwise....
350 void draw_vertically(struct rendering *r, char *text, struct completions *cs) {
351   int padding = 10; // TODO make this dynamic
352 
353   XRectangle rect;
354   XmbTextExtents(*r->font, "fjpgl", 5, &rect, nil);
355   int start_at = rect.height + padding*2;
356 
357   XFillRectangle(r->d, r->w, r->completion_bg, 0, 0, r->width, r->height);
358   XFillRectangle(r->d, r->w, r->prompt_bg, 0, 0, r->width, start_at);
359   Xutf8DrawString(r->d, r->w, *r->font, r->prompt, padding, padding*2, text, strlen(text));
360 
361   while (cs != nil) {
362     GC g = cs->selected ? r->completion_highlighted    : r->completion;
363     GC h = cs->selected ? r->completion_highlighted_bg : r->completion_bg;
364 
365     int len = strlen(cs->completion);
366     XmbTextExtents(*r->font, cs->completion, len, &rect, nil);
367     XFillRectangle(r->d, r->w, h, 0, start_at, r->width, rect.height + padding*2);
368     Xutf8DrawString(r->d, r->w, *r->font, g, padding, start_at + padding*2, cs->completion, len);
369 
370     start_at += rect.height + padding *2;
371 
372     if (start_at > r->height)
373       break; // don't draw completion if the space isn't enough
374 
375     cs = cs->next;
376   }
377 
378   XFlush(r->d);
379 }
380 
381 void draw(struct rendering *r, char *text, struct completions *cs) {
382   if (r->horizontal_layout)
383     draw_horizontally(r, text, cs);
384   else
385     draw_vertically(r, text, cs);
386 }
387 
388 /* Set some WM stuff */
389 void set_win_atoms_hints(Display *d, Window w, int width, int height) {
390   Atom type;
391   type = XInternAtom(d, "_NET_WM_WINDOW_TYPE_DOCK", false);
392   XChangeProperty(
393                   d,
394                   w,
395                   XInternAtom(d, "_NET_WM_WINDOW_TYPE", false),
396                   XInternAtom(d, "ATOM", false),
397                   32,
398                   PropModeReplace,
399                   (unsigned char *)&type,
400                   1
401                   );
402 
403   /* some window managers honor this properties */
404   type = XInternAtom(d, "_NET_WM_STATE_ABOVE", false);
405   XChangeProperty(d,
406                   w,
407                   XInternAtom(d, "_NET_WM_STATE", false),
408                   XInternAtom(d, "ATOM", false),
409                   32,
410                   PropModeReplace,
411                   (unsigned char *)&type,
412                   1
413                   );
414 
415   type = XInternAtom(d, "_NET_WM_STATE_FOCUSED", false);
416   XChangeProperty(d,
417                   w,
418                   XInternAtom(d, "_NET_WM_STATE", false),
419                   XInternAtom(d, "ATOM", false),
420                   32,
421                   PropModeAppend,
422                   (unsigned char *)&type,
423                   1
424                   );
425 
426   // setting window hints
427   XClassHint *class_hint = XAllocClassHint();
428   if (class_hint == nil) {
429     fprintf(stderr, "Could not allocate memory for class hint\n");
430     exit(EX_UNAVAILABLE);
431   }
432   class_hint->res_name = "mymenu";
433   class_hint->res_class = "mymenu";
434   XSetClassHint(d, w, class_hint);
435   XFree(class_hint);
436 
437   XSizeHints *size_hint = XAllocSizeHints();
438   if (size_hint == nil) {
439     fprintf(stderr, "Could not allocate memory for size hint\n");
440     exit(EX_UNAVAILABLE);
441   }
442   size_hint->min_width = width;
443   size_hint->base_width = width;
444   size_hint->min_height = height;
445   size_hint->base_height = height;
446 
447   XFlush(d);
448 }
449 
450 void get_wh(Display *d, Window *w, int *width, int *height) {
451   XWindowAttributes win_attr;
452   XGetWindowAttributes(d, *w, &win_attr);
453   *height = win_attr.height;
454   *width = win_attr.width;
455 }
456 
457 // I know this may seem a little hackish BUT is the only way I managed
458 // to actually grab that goddam keyboard. Only one call to
459 // XGrabKeyboard does not always end up with the keyboard grabbed!
460 int take_keyboard(Display *d, Window w) {
461   int i;
462   for (i = 0; i < 100; i++) {
463     if (XGrabKeyboard(d, w, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess)
464       return 1;
465     usleep(1000);
466   }
467   return 0;
468 }
469 
470 void release_keyboard(Display *d) {
471   XUngrabKeyboard(d, CurrentTime);
472 }
473 
474 int parse_integer(const char *str, int default_value, int max) {
475   int len = strlen(str);
476   if (len > 0 && str[len-1] == '%') {
477     char *cpy = strdup(str);
478     check_allocation(cpy);
479     cpy[len-1] = '\0';
480     int val = parse_integer(cpy, default_value, max);
481     free(cpy);
482     return val * max / 100;
483   }
484 
485   errno = 0;
486   char *ep;
487   long lval = strtol(str, &ep, 10);
488   if (str[0] == '\0' || *ep != '\0') { // NaN
489     fprintf(stderr, "'%s' is not a valid number! Using %d as default.\n", str, default_value);
490     return default_value;
491   }
492   if ((errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN)) ||
493       (lval > INT_MAX || lval < INT_MIN)) {
494     fprintf(stderr, "%s out of range! Using %d as default.\n", str, default_value);
495     return default_value;
496   }
497   return lval;
498 }
499 
500 int parse_int_with_middle(const char *str, int default_value, int max, int self) {
501   if (!strcmp(str, "middle")) {
502     return (max - self)/2;
503   }
504   return parse_integer(str, default_value, max);
505 }
506 
507 int main() {
508   /* char *lines[INITIAL_ITEMS] = {0}; */
509   char **lines = calloc(INITIAL_ITEMS, sizeof(char*));
510   int nlines = readlines(&lines, INITIAL_ITEMS);
511 
512   setlocale(LC_ALL, getenv("LANG"));
513 
514   enum state status = LOOPING;
515 
516   // where the monitor start (used only with xinerama)
517   int offset_x = 0;
518   int offset_y = 0;
519 
520   // width and height of the window
521   int width = 400;
522   int height = 20;
523 
524   // position on the screen
525   int x = 0;
526   int y = 0;
527 
528   char *fontname = strdup("fixed");
529   check_allocation(fontname);
530 
531   int textlen = 10;
532   char *text = malloc(textlen * sizeof(char));
533   check_allocation(text);
534 
535   struct completions *cs = filter(text, lines);
536   bool nothing_selected = true;
537 
538   // start talking to xorg
539   Display *d = XOpenDisplay(nil);
540   if (d == nil) {
541     fprintf(stderr, "Could not open display!\n");
542     return EX_UNAVAILABLE;
543   }
544 
545   // get display size
546   // XXX: is getting the default root window dimension correct?
547   XWindowAttributes xwa;
548   XGetWindowAttributes(d, DefaultRootWindow(d), &xwa);
549   int d_width = xwa.width;
550   int d_height = xwa.height;
551 
552 #ifdef USE_XINERAMA
553   // TODO: this bit still needs to be improved
554   if (XineramaIsActive(d)) {
555     int monitors;
556     XineramaScreenInfo *info = XineramaQueryScreens(d, &monitors);
557     if (info)
558       for (int i = 0; i < monitors; ++i) {
559         if (INTERSECT(x, y, 1, 1, info[i].x_org, info[i].y_org, info[i].width, info[i].height)) {
560           offset_x = info[x].x_org;
561           offset_y = info[y].y_org;
562           d_width = info[i].width;
563           d_height = info[i].height;
564         }
565       }
566     XFree(info);
567   }
568 #endif
569 
570   /* fprintf(stderr, "offset_x:\t%d\n" */
571   /*                 "offset_y:\t%d\n" */
572   /*                 "d_width:\t%d\n" */
573   /*                 "d_height:\t%d\n" */
574   /*         , offset_x, offset_y, d_width, d_height); */
575 
576   Colormap cmap = DefaultColormap(d, DefaultScreen(d));
577   XColor p_fg, p_bg,
578     compl_fg, compl_bg,
579     compl_highlighted_fg, compl_highlighted_bg;
580 
581   bool horizontal_layout = true;
582 
583   // read resource
584   XrmInitialize();
585   char *xrm = XResourceManagerString(d);
586   XrmDatabase xdb = nil;
587   if (xrm != nil) {
588     xdb = XrmGetStringDatabase(xrm);
589     XrmValue value;
590     char *datatype[20];
591 
592     if (XrmGetResource(xdb, "MyMenu.font", "*", datatype, &value) == true) {
593       fontname = strdup(value.addr);
594       check_allocation(fontname);
595     }
596     else
597       fprintf(stderr, "no font defined, using %s\n", fontname);
598 
599     if (XrmGetResource(xdb, "MyMenu.layout", "*", datatype, &value) == true) {
600       char *v = strdup(value.addr);
601       check_allocation(v);
602       horizontal_layout = !strcmp(v, "horizontal");
603       free(v);
604     }
605     else
606       fprintf(stderr, "no layout defined, using horizontal\n");
607 
608     if (XrmGetResource(xdb, "MyMenu.width", "*", datatype, &value) == true)
609       width = parse_integer(value.addr, width, d_width);
610     else
611       fprintf(stderr, "no width defined, using %d\n", width);
612 
613     if (XrmGetResource(xdb, "MyMenu.height", "*", datatype, &value) == true)
614       height = parse_integer(value.addr, height, d_height);
615     else
616       fprintf(stderr, "no height defined, using %d\n", height);
617 
618     if (XrmGetResource(xdb, "MyMenu.x", "*", datatype, &value) == true)
619       x = parse_int_with_middle(value.addr, x, d_width, width);
620     else
621       fprintf(stderr, "no x defined, using %d\n", width);
622 
623     if (XrmGetResource(xdb, "MyMenu.y", "*", datatype, &value) == true)
624       y = parse_int_with_middle(value.addr, y, d_height, height);
625     else
626       fprintf(stderr, "no y defined, using %d\n", height);
627 
628     XColor tmp;
629     // TODO: tmp needs to be free'd after every allocation?
630 
631     // prompt
632     if (XrmGetResource(xdb, "MyMenu.prompt.foreground", "*", datatype, &value) == true)
633       XAllocNamedColor(d, cmap, value.addr, &p_fg, &tmp);
634     else
635       XAllocNamedColor(d, cmap, "white", &p_fg, &tmp);
636 
637     if (XrmGetResource(xdb, "MyMenu.prompt.background", "*", datatype, &value) == true)
638       XAllocNamedColor(d, cmap, value.addr, &p_bg, &tmp);
639     else
640       XAllocNamedColor(d, cmap, "black", &p_bg, &tmp);
641 
642     // completion
643     if (XrmGetResource(xdb, "MyMenu.completion.foreground", "*", datatype, &value) == true)
644       XAllocNamedColor(d, cmap, value.addr, &compl_fg, &tmp);
645     else
646       XAllocNamedColor(d, cmap, "white", &compl_fg, &tmp);
647 
648     if (XrmGetResource(xdb, "MyMenu.completion.background", "*", datatype, &value) == true)
649       XAllocNamedColor(d, cmap, value.addr, &compl_bg, &tmp);
650     else
651       XAllocNamedColor(d, cmap, "black", &compl_bg, &tmp);
652 
653     // completion highlighted
654     if (XrmGetResource(xdb, "MyMenu.completion_highlighted.foreground", "*", datatype, &value) == true)
655       XAllocNamedColor(d, cmap, value.addr, &compl_highlighted_fg, &tmp);
656     else
657       XAllocNamedColor(d, cmap, "black", &compl_highlighted_fg, &tmp);
658 
659     if (XrmGetResource(xdb, "MyMenu.completion_highlighted.background", "*", datatype, &value) == true)
660       XAllocNamedColor(d, cmap, value.addr, &compl_highlighted_bg, &tmp);
661     else
662       XAllocNamedColor(d, cmap, "white", &compl_highlighted_bg, &tmp);
663   } else {
664     XColor tmp;
665     XAllocNamedColor(d, cmap, "white", &p_fg, &tmp);
666     XAllocNamedColor(d, cmap, "black", &p_bg, &tmp);
667     XAllocNamedColor(d, cmap, "white", &compl_fg, &tmp);
668     XAllocNamedColor(d, cmap, "black", &compl_bg, &tmp);
669     XAllocNamedColor(d, cmap, "black", &compl_highlighted_fg, &tmp);
670     XAllocNamedColor(d, cmap, "white", &compl_highlighted_bg, &tmp);
671   }
672 
673   // load the font
674   /* XFontStruct *font = XLoadQueryFont(d, fontname); */
675   /* if (font == nil) { */
676   /*   fprintf(stderr, "Unable to load %s font\n", fontname); */
677   /*   font = XLoadQueryFont(d, "fixed"); */
678   /* } */
679   // load the font
680   char **missing_charset_list;
681   int missing_charset_count;
682   XFontSet font = XCreateFontSet(d, fontname, &missing_charset_list, &missing_charset_count, nil);
683   if (font == nil) {
684     fprintf(stderr, "Unable to load the font(s) %s\n", fontname);
685     return EX_UNAVAILABLE;
686   }
687 
688   // create the window
689   XSetWindowAttributes attr;
690 
691   Window w = XCreateWindow(d,                                   // display
692                            DefaultRootWindow(d),                // parent
693                            x + offset_x, y + offset_y,          // x y
694                            width, height,                       // w h
695                            0,                                   // border width
696                            DefaultDepth(d, DefaultScreen(d)),   // depth
697                            InputOutput,                         // class
698                            DefaultVisual(d, DefaultScreen(d)),  // visual
699                            0,                                   // value mask
700                            &attr);
701 
702   set_win_atoms_hints(d, w, width, height);
703 
704   // we want some events
705   XSelectInput(d, w, StructureNotifyMask | KeyPressMask | KeyReleaseMask | KeymapStateMask);
706 
707   // make the window appear on the screen
708   XMapWindow(d, w);
709 
710   // wait for the MapNotify event (i.e. the event "window rendered")
711   for (;;) {
712     XEvent e;
713     XNextEvent(d, &e);
714     if (e.type == MapNotify)
715       break;
716   }
717 
718   // get the *real* width & height after the window was rendered
719   get_wh(d, &w, &width, &height);
720 
721   // grab keyboard
722   take_keyboard(d, w);
723 
724   // Create some graphics contexts
725   XGCValues values;
726   /* values.font = font->fid; */
727 
728   struct rendering r = {
729     .d                          = d,
730     .w                          = w,
731     .prompt                     = XCreateGC(d, w, 0, &values),
732     .prompt_bg                  = XCreateGC(d, w, 0, &values),
733     .completion                 = XCreateGC(d, w, 0, &values),
734     .completion_bg              = XCreateGC(d, w, 0, &values),
735     .completion_highlighted     = XCreateGC(d, w, 0, &values),
736     .completion_highlighted_bg  = XCreateGC(d, w, 0, &values),
737     /* .prompt                     = XCreateGC(d, w, GCFont, &values), */
738     /* .prompt_bg                  = XCreateGC(d, w, GCFont, &values), */
739     /* .completion                 = XCreateGC(d, w, GCFont, &values), */
740     /* .completion_bg              = XCreateGC(d, w, GCFont, &values), */
741     /* .completion_highlighted     = XCreateGC(d, w, GCFont, &values), */
742     /* .completion_highlighted_bg  = XCreateGC(d, w, GCFont, &values), */
743     .width                      = width,
744     .height                     = height,
745     .font                       = &font,
746     .horizontal_layout          = horizontal_layout
747   };
748 
749   // load the colors in our GCs
750   XSetForeground(d, r.prompt, p_fg.pixel);
751   XSetForeground(d, r.prompt_bg, p_bg.pixel);
752   XSetForeground(d, r.completion, compl_fg.pixel);
753   XSetForeground(d, r.completion_bg, compl_bg.pixel);
754   XSetForeground(d, r.completion_highlighted, compl_highlighted_fg.pixel);
755   XSetForeground(d, r.completion_highlighted_bg, compl_highlighted_bg.pixel);
756 
757   // open the X input method
758   XIM xim = XOpenIM(d, xdb, resname, resclass);
759   check_allocation(xim);
760 
761   XIMStyles *xis = nil;
762   if (XGetIMValues(xim, XNQueryInputStyle, &xis, NULL) || !xis) {
763     fprintf(stderr, "Input Styles could not be retrieved\n");
764     return EX_UNAVAILABLE;
765   }
766 
767   XIMStyle bestMatchStyle = 0;
768   for (int i = 0; i < xis->count_styles; ++i) {
769     XIMStyle ts = xis->supported_styles[i];
770     if (ts == (XIMPreeditNothing | XIMStatusNothing)) {
771       bestMatchStyle = ts;
772       break;
773     }
774   }
775   XFree(xis);
776 
777   if (!bestMatchStyle) {
778     fprintf(stderr, "No matching input style could be determined\n");
779   }
780 
781   XIC xic = XCreateIC(xim, XNInputStyle, bestMatchStyle, XNClientWindow, w, XNFocusWindow, w, NULL);
782   check_allocation(xic);
783 
784   // draw the window for the first time
785   draw(&r, text, cs);
786 
787   // main loop
788   while (status == LOOPING) {
789     XEvent e;
790     XNextEvent(d, &e);
791 
792     if (XFilterEvent(&e, w))
793       continue;
794 
795     switch (e.type) {
796     case KeymapNotify:
797       XRefreshKeyboardMapping(&e.xmapping);
798       break;
799 
800     case KeyRelease: break; // ignore this
801 
802     case KeyPress: {
803       XKeyPressedEvent *ev = (XKeyPressedEvent*)&e;
804 
805       if (ev->keycode == XKeysymToKeycode(d, XK_Tab)) {
806         bool shift = (ev->state & ShiftMask);
807         struct completions *n = shift ? compl_select_prev(cs, nothing_selected)
808                                       : compl_select_next(cs, nothing_selected);
809         if (n != nil) {
810           nothing_selected = false;
811           free(text);
812           text = strdup(n->completion);
813           if (text == nil) {
814             fprintf(stderr, "Memory allocation error!\n");
815             status = ERR;
816             break;
817           }
818           textlen = strlen(text);
819         }
820         draw(&r, text, cs);
821         break;
822       }
823 
824       if (ev->keycode == XKeysymToKeycode(d, XK_BackSpace)) {
825         nothing_selected = true;
826         popc(text, textlen);
827         update_completions(cs, text, lines);
828         draw(&r, text, cs);
829         break;
830       }
831 
832       if (ev->keycode == XKeysymToKeycode(d, XK_Return)) {
833         status = OK;
834         break;
835       }
836 
837       if (ev->keycode == XKeysymToKeycode(d, XK_Escape)) {
838         status = ERR;
839         break;
840       }
841 
842       // try to read what the user pressed
843       int symbol = 0;
844       Status s = 0;
845       Xutf8LookupString(xic, ev, (char*)&symbol, 4, 0, &s);
846 
847       if (s == XBufferOverflow) {
848         // should not happen since there are no utf-8 characters
849         // larger than 24bits, but is something to be aware of when
850         // used to directly write to a string buffer
851         fprintf(stderr, "Buffer overflow when trying to create keyboard symbol map.\n");
852         break;
853       }
854       char *str = (char*)&symbol;
855 
856       if (ev->state & ControlMask) {
857         // check for some key bindings
858         if (!strcmp(str, "")) { // C-u
859           nothing_selected = true;
860           for (int i = 0; i < textlen; ++i)
861             text[i] = 0;
862           update_completions(cs, text, lines);
863         }
864         if (!strcmp(str, "")) { // C-h
865           nothing_selected = true;
866           popc(text, textlen);
867           update_completions(cs, text, lines);
868         }
869         if (!strcmp(str, "")) { // C-w
870           nothing_selected = true;
871 
872           // `textlen` is the length of the allocated string, not the
873           // length of the ACTUAL string
874           int p = strlen(text) - 1;
875           if (p >= 0) { // delete the current char
876             text[p] = 0;
877             p--;
878           }
879           while (p >= 0 && isalnum(text[p])) {
880             text[p] = 0;
881             p--;
882           }
883           // erase also trailing white space
884           while (p >= 0 && isspace(text[p])) {
885             text[p] = 0;
886             p--;
887           }
888           update_completions(cs, text, lines);
889         }
890         if (!strcmp(str, "\r")) { // C-m
891           status = OK;
892         }
893         draw(&r, text, cs);
894         break;
895       }
896 
897       int str_len = strlen(str);
898       for (int i = 0; i < str_len; ++i) {
899         textlen = pushc(&text, textlen, str[i]);
900         if (textlen == -1) {
901           fprintf(stderr, "Memory allocation error\n");
902           status = ERR;
903           break;
904         }
905         nothing_selected = true;
906         update_completions(cs, text, lines);
907       }
908 
909     }
910       draw(&r, text, cs);
911       break;
912 
913     default:
914       fprintf(stderr, "Unknown event %d\n", e.type);
915     }
916   }
917 
918   release_keyboard(d);
919 
920   if (status == OK)
921     printf("%s\n", text);
922 
923   for (int i = 0; i < nlines; ++i) {
924     free(lines[i]);
925   }
926 
927   free(fontname);
928   free(text);
929   free(lines);
930   compl_delete(cs);
931 
932   /* XDestroyWindow(d, w); */
933   XCloseDisplay(d);
934 
935   return status == OK ? 0 : 1;
936 }