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SCROLL.C
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─────Run-Time Library───────────────────────────────────────────────────────
/* SCROLL.C illustrates:
* _gettextwindow _settextwindow _scrolltextwindow
*
* See MODES.C for another use of _settextwindow.
*/
#include <stdio.h>
#include <conio.h>
#include <graph.h>
void deleteline( void );
void insertline( void );
void status( char *msg );
void main()
{
short row;
char buf[40];
/* Set up screen for scrolling; put text window around scroll area. */
_settextrows( 25 );
_clearscreen( _GCLEARSCREEN );
for( row = 1; row <= 25; row++ )
{
_settextposition( row, 1 );
sprintf( buf, "Line %c %2d", row + 'A' - 1, row );
_outtext( buf );
}
_getch();
_settextwindow( 1, 1, 25, 10 );
/* Delete some lines. */
_settextposition( 11, 1 );
for( row = 12; row < 20; row++ )
deleteline();
status( "Deleted 8 lines" );
/* Insert some lines. */
_settextposition( 5, 1 );
for( row = 1; row < 6; row++ )
insertline();
status( "Inserted 5 lines" );
/* Scroll up and down. */
_scrolltextwindow( -7 );
status( "Scrolled down 7 lines" );
_scrolltextwindow( 5 );
status( "Scrolled up 5 lines" );
_setvideomode( _DEFAULTMODE );
}
/* Delete lines by scrolling them off the top of the current text window.
* Save and restore original window.
*/
void deleteline()
{
short left, top, right, bottom;
struct _rccoord rc;
_gettextwindow( &top, &left, &bottom, &right );
rc = _gettextposition();
_settextwindow( rc.row, left, bottom, right );
_scrolltextwindow( _GSCROLLUP );
_settextwindow( top, left, bottom, right );
_settextposition( rc.row, rc.col );
}
/* Insert some lines by scrolling in blank lines from the top of the
* current text window. Save and restore original window.
*/
void insertline()
{
short left, top, right, bottom;
struct _rccoord rc;
_gettextwindow( &top, &left, &bottom, &right );
rc = _gettextposition();
_settextwindow( rc.row, left, bottom, right );
_scrolltextwindow( _GSCROLLDOWN );
_settextwindow( top, left, bottom, right );
_settextposition( rc.row, rc.col );
}
/* Display and clear status in its own window. */
void status( char *msg )
{
short left, top, right, bottom;
_gettextwindow( &top, &left, &bottom, &right );
_settextwindow( 1, 50, 2, 80 );
_outtext( msg );
_getch();
_clearscreen( _GWINDOW );
_settextwindow( top, left, bottom, right );
}
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