_scrolltextwindow

Description

Scrolls a text window.

#include <graph.h>

void __far _scrolltextwindow( short lines );

Remarks

The _scrolltextwindow function scrolls a text window (previously defined by the _settextwindow function). The lines argument specifies the number of lines to scroll. A positive value of lines scrolls the window up (the usual direction); a negative value scrolls the window down. Specifying a number larger than the height of the current text window is equivalent to calling _clearscreen( _GWINDOW ). A value of 0 for lines has no effect on the text.

Return Value

None.

Compatibility

Standards:None

16-Bit:DOS

32-Bit:None

See Also

_gettextposition, _outmem, _outtext, _settextposition, _settextwindow

Example

/* SCRTXWIN.C: This program displays text in text windows and then

* scrolls, inserts, and deletes lines.

*/

#include <stdio.h>

#include <conio.h>

#include <graph.h>

void deleteline( void );

void insertline( void );

void status( char *msg );

void main( void )

{

short row;

char buf[40];

/* Set up screen for scrolling, and 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;

struct _rccoord rc;

_gettextwindow( &top, &left, &bottom, &right );

_settextwindow( 1, 50, 2, 80 );

_outtext( msg );

_getch();

_clearscreen( _GWINDOW );

_settextwindow( top, left, bottom, right );

}