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 CanonImage *screenshot_now(void) {
  22   char *cmd;
  23   CanonImage *ci;
  24   int r;
  25
  26   r= asprintf(&cmd, "xwd -silent -id 0x%lx | xwdtopnm", (unsigned long)id);
  27   eassert(r>=0);
  28   FILE *f= popen(cmd,"r");  eassert(f);
  29   ci= file_read_image(f);
  30   r= fgetc(f);  eassert(r==EOF);  eassert(feof(f));
  31   r= pclose(f);  eassert(r>=0);  eassert(WIFEXITED(r) && !WEXITSTATUS(r));
  32   free(cmd);
  33   return ci;
  34 }
  35
  36 static void screenshot_startup(void) {
  37   int r;
  38   disp= XOpenDisplay(0);  eassert(disp);
  39   r= gettimeofday(&tv_startup,0);  eassert(!r);
  40 }
  41
  42 #if 0
  43 static CanonImage *single_page(void) {
  44   int r;
  45   r= XRaiseWindow(disp, id);  eassert(r);
  46   r= XSync(disp, False);  eassert(r);
  47   return screenshot_now();
  48 }
  49 #endif
  50
  51 static void raise_and_set_focus(void) {
  52   int r;
  53   XWindowAttributes attr;
  54   int xpos,ypos, evbase,errbase,majver,minver;
  55   unsigned width,height,bd,depth;
  56   Window dummy;
  57
  58   fprintf(stderr,"PAGING raise_and_set_focus\n");
  59
  60   r= XTestQueryExtension(disp, &evbase,&errbase,&majver,&minver);
  61   eassert(r==True);
  62
  63   r= XRaiseWindow(disp, id);  eassert(r);
  64
  65   r= XGetWindowAttributes(disp, id, &attr);  eassert(r);
  66   r= XGetGeometry(disp,id, &attr.root,&xpos,&ypos,&width,&height, &bd,&depth);
  67   eassert(r);
  68
  69   r= XTranslateCoordinates(disp, id,attr.root, 160,160, &xpos,&ypos,
  70                            &dummy);
  71   eassert(r);
  72
  73   int screen= XScreenNumberOfScreen(attr.screen);
  74   XTestFakeMotionEvent(disp,screen, xpos, ypos, 0);
  75
  76   XTestFakeButtonEvent(disp,1,1, 50);
  77   XTestFakeButtonEvent(disp,1,0, 50);
  78   r= XSync(disp, False);  eassert(r);
  79
  80   fprintf(stderr,"PAGING raise_and_set_focus done.\n");
  81 }
  82
  83 static void send_key(KeySym sym) {
  84   int r;
  85   XTestFakeKeyEvent(disp, keycode(sym),1, 10);
  86   XTestFakeKeyEvent(disp, keycode(sym),0, 10);
  87   r= XSync(disp, False);  eassert(r);
  88 }
  89
  90 static void send_pgup(void) {
  91   fprintf(stderr,"PAGING   PageUp\n");
  92   send_key(XK_Prior);
  93 }
  94 static void send_pgdown(void) {
  95   fprintf(stderr,"PAGING   PageDown\n");
  96   send_key(XK_Next);
  97 }
  98
  99 static double timestamp(void) {
 100   struct timeval tv;
 101   int r;
 102
 103   r= gettimeofday(&tv,0);  eassert(!r);
 104   return (tv.tv_sec - tv_startup.tv_sec) +
 105          (tv.tv_usec - tv_startup.tv_usec) * 1e-6;
 106 }
 107
 108 static double worst_snapshot= 0.050, worst_stabilise= 0.100;
 109
 110 static void snapshot(CanonImage **output) {
 111   free(*output);
 112   double a= timestamp();
 113   *output= screenshot_now();
 114   fprintf(stderr,"PAGING   snapshot\n");
 115   double b= timestamp();
 116   double it_took= b-a;
 117   fprintf(stderr,"PAGING   snapshot took=%f\n",it_took);
 118   if (it_took > worst_snapshot)
 119     worst_snapshot= it_took;
 120 }
 121
 122 static void snapshot_idle(void) {
 123   int r;
 124   r= usleep(worst_snapshot * 1e6 * 2);
 125   /* spend no more than 1/3 of our time constantly snapshotting */
 126   eassert(!r);
 127 }
 128
 129 static int identical(const CanonImage *a, const CanonImage *b) {
 130   return !(memcmp(a,    b,    sizeof(*a)) ||
 131            memcmp(a->d, b->d, a->w * a->h));
 132 }
 133
 134 static void wait_for_stability(CanonImage **output,
 135                                const CanonImage *previously,
 136                                void (*with_keypress)(void)) {
 137   CanonImage *last=0;
 138   /* waits longer if we're going to return an image identical to previously
 139    * if previously==0, all images are considered identical to it */
 140
 141   double when_started= timestamp();
 142   double last_change= when_started;
 143   double it_took= -1;
 144
 145   fprintf(stderr,"PAGING  wait_for_stability"
 146           "  worst_snapshot=%f worst_stabilise=%f\n",
 147           worst_snapshot, worst_stabilise);
 148
 149   for (;;) {
 150     snapshot(output);
 151     double right_now= timestamp();
 152
 153     if (!last || !identical(*output,last)) {
 154       fprintf(stderr,"PAGING  wait_for_stability changed...\n");
 155       last_change= right_now;
 156       free(last); last=*output; *output=0;
 157       it_took= -1;
 158     } else {
 159       if (it_took<0)
 160         it_took= right_now - when_started;
 161
 162       double threshold= (worst_stabilise + worst_snapshot) * 3;
 163       if (!previously || identical(*output,previously))
 164         threshold *= 2;  threshold += 1.5;
 165
 166       double stable_for= right_now - last_change;
 167       fprintf(stderr,"PAGING  wait_for_stability"
 168               "  worst_snapshot=%f worst_stabilise=%f"
 169               "  stable for %f thresh %f...\n",
 170               worst_snapshot, worst_stabilise,
 171               stable_for, threshold);
 172
 173       if (stable_for > threshold)
 174         break;
 175     }
 176     if (with_keypress)
 177       with_keypress();
 178     snapshot_idle();
 179   }
 180
 181   if (it_took > worst_stabilise)
 182     worst_stabilise= it_took;
 183
 184   free(last);
 185   fprintf(stderr,"PAGING  wait_for_stability done.\n");
 186 }
 187
 188 static void read_pages(void) {
 189   CanonImage *current=0, *last;
 190
 191   raise_and_set_focus();
 192
 193   /* page to the top - keep pressing page up until the image stops changing */
 194   wait_for_stability(&current,0, send_pgup);
 195
 196   /* now to actually page down */
 197   for (;;) {
 198     fprintf(stderr,"PAGING page %d\n",npages);
 199     eassert(npages < MAX_PAGES);
 200     page_images[npages++]= last= current;
 201     send_pgdown();
 202     wait_for_stability(&current,last, 0);
 203     if (npages &&  /* first pagedown doesn't do much */
 204         identical(current,last)) {
 205       free(current);
 206       break;
 207     }
 208   }
 209   fprintf(stderr,"PAGING all done.\n");
 210 }
 211
 212 int main(int argc, char **argv) {
 213   screenshot_startup();
 214
 215   id= strtoul(*++argv,0,0);
 216
 217   read_pages();
 218   return 0;
 219 }
 220