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1991
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04
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v_open.c
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C/C++ Source or Header
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1991-05-03
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2KB
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63 lines
/* v_open.c- Display Viewport */
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <tools/viewport.h>
int v_open( viewport *v )
{
/* Open (save underlying text and clear underlying region) the viewport.
* If clearok is enabled, area under viewport is filled with blanks
* the first time the viewport is opened, the behavior of subsequent
* calls depends on whether the viewport was closed or deactivated.
* If closed and clearok is enabled, the area is filled with blanks.
* If deactivated, the area is filled with the previous contents
* (at deactivate time). Underlying is saved if saveok is enabled
* and (1) this is a new or closed viewport or (2) this is a deactivated,
* hidden viewport. The text isn't saved for deactivated, but visible
* viewports. All the viewport-manipulation functions will open
* the window implicitly if an explicit open hasn't been performed.
*/
if( v->magic != VMAGIC )
return 0;
/* If the window is closed, then it doesn't exist on the screen. Save
* the underlying text and initialize if required. If it's inactive
* but not closed, then it still exists on the screen and a refresh
* is required.
*/
if( v->closed || v->inactive )
{
if( v->saveok && !v->savebuf )
{
if( !(v->savebuf = VMALLOC(v->nrows * v->ncols * sizeof(int))))
return 0;
_v_save_scr( v->savebuf, v->row, v->col, v->nrows, v->ncols );
}
/* Initialize the viewport, either to the original image (before
* it was deactivated) or to blanks (if clearok is true). If neither
* condition is true, don't initialize. (I'm assuming that the
* application will then fill up the window.)
*/
if( v->inactive && v->old_image )
{
_v_restore_scr( v->old_image, v->row, v->col, v->nrows, v->ncols );
VFREE( v->old_image );
v->old_image = NULL;
}
else if( v->clearok )
v_clear( v );
}
v->closed = 0;
v->inactive = 0;
v_gotorc( v, v->cur_row, v->cur_col );
return 1;
}