Date: 2013-07-02T14:38:30+00:00

Actual source code: zoom.c
petsc-3.4.2 2013-07-02

      2: #include <petscdraw.h>     /*I "petscdraw.h"  I*/

      4: #if defined(PETSC_HAVE_SETJMP_H) && defined(PETSC_HAVE_X)
      5: #include <X11/Xlib.h>
      6: #include <X11/Xutil.h>
      7: #include <setjmp.h>
      8: static jmp_buf PetscXIOErrorJumpBuf;
      9: static void PetscXIOHandler(Display *dpy)
     10: {
     11:   longjmp(PetscXIOErrorJumpBuf, 1);
     12: }
     13: #endif

     17: /*@C
     18:     PetscDrawZoom - Allows one to create a graphic that users may zoom into.

     20:     Collective on PetscDraw

     22:     Input Parameters:
     23: +   draw - the window where the graph will be made.
     24: .   func - users function that draws the graphic
     25: -   ctx - pointer to any user required data

     27:   Level: advanced

     29:   Concepts: graphics^zooming
     30:   Concepts: drawing^zooming
     31:   Concepts: zooming^in graphics

     33: .seealso:
     34: @*/
     35: PetscErrorCode  PetscDrawZoom(PetscDraw draw,PetscErrorCode (*func)(PetscDraw,void*),void *ctx)
     36: {
     37:   PetscErrorCode  ierr;
     38:   PetscDrawButton button;
     39:   PetscReal       dpause,xc,yc,scale = 1.0,w,h,xr,xl,yr,yl,xmin,xmax,ymin,ymax;
     40:   PetscBool       isnull;

     43:   PetscDrawIsNull(draw,&isnull);
     44:   if (isnull) return(0);

     46: #if defined(PETSC_HAVE_SETJMP_H) && defined(PETSC_HAVE_X)
     47:   if (!setjmp(PetscXIOErrorJumpBuf)) XSetIOErrorHandler((XIOErrorHandler)PetscXIOHandler);
     48:   else {
     49:     XSetIOErrorHandler(NULL);
     50:     PetscDrawSetType(draw,PETSC_DRAW_NULL);
     51:     return(0);
     52:   }
     53: #endif

     55:   PetscDrawCheckResizedWindow(draw);
     56:   PetscDrawSynchronizedClear(draw);
     57:   (*func)(draw,ctx);
     58:   PetscDrawSynchronizedFlush(draw);

     60:   PetscDrawGetPause(draw,&dpause);
     61:   if (dpause >= 0) {
     62:     PetscSleep(dpause);
     63:     goto theend;
     64:   }
     65:   if (dpause != -1) goto theend;

     67:   PetscDrawCheckResizedWindow(draw);
     68:   PetscDrawSynchronizedGetMouseButton(draw,&button,&xc,&yc,0,0);
     69:   PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);
     70:   w    = xr - xl; xmin = xl; ymin = yl; xmax = xr; ymax = yr;
     71:   h    = yr - yl;

     73:   if (button != PETSC_BUTTON_NONE) {
     74:     while (button != PETSC_BUTTON_RIGHT) {

     76:       PetscDrawSynchronizedClear(draw);
     77:       if (button == PETSC_BUTTON_LEFT)        scale = .5;
     78:       else if (button == PETSC_BUTTON_CENTER) scale = 2.;
     79:       xl   = scale*(xl + w - xc) + xc - w*scale;
     80:       xr   = scale*(xr - w - xc) + xc + w*scale;
     81:       yl   = scale*(yl + h - yc) + yc - h*scale;
     82:       yr   = scale*(yr - h - yc) + yc + h*scale;
     83:       w   *= scale; h *= scale;
     84:       PetscDrawSetCoordinates(draw,xl,yl,xr,yr);

     86:       (*func)(draw,ctx);
     87:       PetscDrawSynchronizedFlush(draw);
     88:       PetscDrawCheckResizedWindow(draw);
     89:       PetscDrawSynchronizedGetMouseButton(draw,&button,&xc,&yc,0,0);
     90:     }
     91:   }
     92:   PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);
     93: theend:
     94: #if defined(PETSC_HAVE_SETJMP_H) && defined(PETSC_HAVE_X)
     95:   XSetIOErrorHandler(NULL);
     96: #endif
     97:   return(0);
     98: }