pctb/pages.c

   1 /*
   2   */
   3
   4 #include "ocr.h"
   5
   6 #include <X11/Xlib.h>
   7 #include <X11/extensions/XTest.h>
   8 #include <X11/keysym.h>
   9
  10 CanonImage *page_images[MAX_PAGES];
  11 int npages;
  12
  13 static Window id;
  14 static Display *disp;
  15 static struct timeval tv_startup;
  16
  17 static KeyCode keycode(KeySym sym) {
  18   return XKeysymToKeycode(disp,sym);
  19 }
  20
  21 static void check_pclose(FILE *f, char *cmd) {
  22   int r;
  23   eassert(!ferror(f));
  24   r= fgetc(f);  eassert(r==EOF);  eassert(feof(f));
  25   r= pclose(f);  eassert(r>=0);  eassert(WIFEXITED(r) && !WEXITSTATUS(r));
  26   free(cmd);
  27 }
  28
  29 #if 0
  30 static CanonImage *screenshot_now(void) {
  31   char *cmd;
  32   CanonImage *ci;
  33   int r;
  34
  35   r= asprintf(&cmd, "xwd -silent -id 0x%lx | xwdtopnm", (unsigned long)id);
  36   eassert(r>=0);
  37   FILE *f= popen(cmd,"r");  eassert(f);
  38   ci= file_read_image(f);
  39   check_pclose(f, cmd);
  40   return ci;
  41 }
  42 #endif
  43
  44 static void screenshot_startup(void) {
  45   int r;
  46   disp= XOpenDisplay(0);  eassert(disp);
  47   r= gettimeofday(&tv_startup,0);  eassert(!r);
  48 }
  49
  50 #if 0
  51 static CanonImage *single_page(void) {
  52   int r;
  53   r= XRaiseWindow(disp, id);  eassert(r);
  54   r= XSync(disp, False);  eassert(r);
  55   return screenshot_now();
  56 }
  57 #endif
  58
  59 static void raise_and_set_focus(void) {
  60   int r;
  61   XWindowAttributes attr;
  62   int xpos,ypos, evbase,errbase,majver,minver;
  63   unsigned width,height,bd,depth;
  64   Window dummy;
  65
  66   fprintf(stderr,"PAGING raise_and_set_focus\n");
  67
  68   r= XTestQueryExtension(disp, &evbase,&errbase,&majver,&minver);
  69   eassert(r==True);
  70
  71   r= XRaiseWindow(disp, id);  eassert(r);
  72
  73   r= XGetWindowAttributes(disp, id, &attr);  eassert(r);
  74   r= XGetGeometry(disp,id, &attr.root,&xpos,&ypos,&width,&height, &bd,&depth);
  75   eassert(r);
  76
  77   r= XTranslateCoordinates(disp, id,attr.root, 160,160, &xpos,&ypos,
  78                            &dummy);
  79   eassert(r);
  80
  81   int screen= XScreenNumberOfScreen(attr.screen);
  82   XTestFakeMotionEvent(disp,screen, xpos, ypos, 0);
  83
  84   XTestFakeButtonEvent(disp,1,1, 50);
  85   XTestFakeButtonEvent(disp,1,0, 50);
  86   r= XSync(disp, False);  eassert(r);
  87
  88   fprintf(stderr,"PAGING raise_and_set_focus done.\n");
  89 }
  90
  91 /*---------- pager ----------*/
  92
  93 typedef struct {
  94   size_t len;
  95   unsigned char d[];
  96 } Snapshot;
  97
  98 static void send_key(KeySym sym) {
  99   int r;
 100   XTestFakeKeyEvent(disp, keycode(sym),1, 10);
 101   XTestFakeKeyEvent(disp, keycode(sym),0, 10);
 102   r= XSync(disp, False);  eassert(r);
 103 }
 104
 105 static void send_pgup_many(void) {
 106   int i;
 107   fprintf(stderr,"PAGING   PageUp\n");
 108   for (i=0; i<25; i++)
 109     send_key(XK_Prior);
 110 }
 111 static void send_pgdown(void) {
 112   fprintf(stderr,"PAGING   PageDown\n");
 113   send_key(XK_Next);
 114 }
 115
 116 static double timestamp(void) {
 117   struct timeval tv;
 118   int r;
 119
 120   r= gettimeofday(&tv,0);  eassert(!r);
 121   double t= (tv.tv_sec - tv_startup.tv_sec) +
 122             (tv.tv_usec - tv_startup.tv_usec) * 1e-6;
 123   fprintf(stderr,"%f\n",t);
 124   return t;
 125 }
 126
 127 static double worst_snapshot= 0.050;
 128 static double worst_stabilise= 0.100;
 129 static size_t snapshot_alloc= 1024;
 130
 131 static void snapshot(Snapshot **output) {
 132   char *cmd;
 133   int r;
 134
 135   free(*output);  *output=0;
 136   double a= timestamp();
 137
 138   fprintf(stderr,"PAGING   snapshot\n");
 139
 140   r= asprintf(&cmd, "xwd -silent -id 0x%lx", (unsigned long)id); eassert(r>=0);
 141   FILE *f= popen(cmd,"r"); eassert(f);
 142
 143   int need_alloc=1;
 144   size_t used=0;
 145   for (;;) {
 146     size_t allow= snapshot_alloc - used;
 147     if (!allow) {
 148       snapshot_alloc <<= 1;
 149       need_alloc= 1;
 150       fprintf(stderr,"PAGING   snapshot   grow %ld\n", (long)snapshot_alloc);
 151       continue;
 152     }
 153     if (need_alloc) {
 154       *output= realloc(*output, sizeof(**output) + snapshot_alloc);
 155       eassert(*output);
 156       need_alloc= 0;
 157     }
 158     size_t got= fread((*output)->d, 1, allow, f);
 159     if (got==0) break;
 160     used += got;
 161   }
 162   check_pclose(f,cmd);
 163
 164   (*output)->len= used;
 165   snapshot_alloc= used+1;
 166   *output= realloc(*output, sizeof(**output) + snapshot_alloc);
 167   eassert(*output);
 168
 169   double b= timestamp();
 170   double it_took= b-a;
 171   if (it_took > worst_snapshot)
 172     worst_snapshot= it_took;
 173
 174   fprintf(stderr,"PAGING   snapshot took=%f len=%ld\n",
 175           it_took, (long)used);
 176 }
 177
 178 static void snapshot_idle(void) {
 179   int r;
 180   r= usleep(worst_snapshot * 1e6 * 0.5);
 181   /* spend no more than 2/3 of our time constantly snapshotting */
 182   eassert(!r);
 183 }
 184
 185 static int identical(const Snapshot *a, const Snapshot *b) {
 186   return !(memcmp(a,    b,    sizeof(*a)) ||
 187            memcmp(a->d, b->d, a->len));
 188 }
 189
 190 static void wait_for_stability(Snapshot **output,
 191                                const Snapshot *previously,
 192                                void (*with_keypress)(void)) {
 193   Snapshot *last=0;
 194   /* waits longer if we're going to return an image identical to previously
 195    * if previously==0, all images are considered identical to it */
 196
 197   double when_started= timestamp();
 198   double last_change= when_started;
 199   double it_took= -1;
 200
 201   fprintf(stderr,"PAGING  wait_for_stability"
 202           "  worst_snapshot=%f worst_stabilise=%f  previously=%p\n",
 203           worst_snapshot, worst_stabilise, previously);
 204
 205   for (;;) {
 206     double at_snapshot= timestamp();
 207     snapshot(output);
 208     double right_now= timestamp();
 209
 210     if (!last) {
 211       fprintf(stderr,"PAGING  wait_for_stability first...\n");
 212       last_change= when_started= right_now;
 213       last=*output; *output=0;
 214     } else if (!identical(*output,last)) {
 215       fprintf(stderr,"PAGING  wait_for_stability changed...\n");
 216       last_change= right_now;
 217       free(last); last=*output; *output=0;
 218       it_took= -1;
 219     } else {
 220       if (it_took<0)
 221         it_took= at_snapshot - when_started;
 222
 223       double threshold= worst_stabilise + worst_snapshot;
 224       if (!previously || identical(*output,previously))
 225         threshold *= 2;  threshold += 1.5;
 226
 227       double stable_for= right_now - last_change;
 228       fprintf(stderr,"PAGING  wait_for_stability"
 229               "  worst_snapshot=%f worst_stabilise=%f"
 230               "  it_took=%f stable_for=%f threshold=%f...\n",
 231               worst_snapshot, worst_stabilise,
 232               it_took, stable_for, threshold);
 233
 234       if (stable_for > threshold)
 235         break;
 236     }
 237     if (with_keypress)
 238       with_keypress();
 239     snapshot_idle();
 240   }
 241
 242   if (!with_keypress && it_took > worst_stabilise)
 243     worst_stabilise= it_took;
 244
 245   free(last);
 246   fprintf(stderr,"PAGING  wait_for_stability done.\n");
 247 }
 248
 249 static void read_pages(void) {
 250   Snapshot *current=0, *last=0;
 251
 252   raise_and_set_focus();
 253
 254   /* page to the top - keep pressing page up until the image stops changing */
 255   wait_for_stability(&last,0, send_pgup_many);
 256
 257   /* now to actually page down */
 258   for (;;) {
 259     fprintf(stderr,"PAGING page %d\n",npages);
 260     //eassert(npages < MAX_PAGES);
 261     //page_images[npages++]=
 262     npages++;
 263
 264     wait_for_stability(&current,last, 0);
 265     if (npages &&  /* first pagedown doesn't do much */
 266         identical(current,last)) {
 267       free(current);
 268       break;
 269     }
 270
 271     free(last); last=current; current=0;
 272
 273     send_pgdown();
 274   }
 275   fprintf(stderr,"PAGING all done.\n");
 276 }
 277
 278 int main(int argc, char **argv) {
 279   screenshot_startup();
 280
 281   id= strtoul(*++argv,0,0);
 282
 283   read_pages();
 284   return 0;
 285 }
 286