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#ifndef _IPXE_JUMPSCROLL_H
#define _IPXE_JUMPSCROLL_H
/** @file
*
* Jump scrolling
*
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
/** A jump scroller */
struct jump_scroller {
/** Maximum number of visible rows */
unsigned int rows;
/** Total number of items */
unsigned int count;
/** Currently selected item */
unsigned int current;
/** First visible item */
unsigned int first;
};
/**
* Construct scroll movement
*
* @v delta Change in scroller position
* @ret move Scroll movement
*/
#define SCROLL( delta ) ( ( unsigned int ) ( uint16_t ) ( int16_t ) (delta) )
/**
* Extract change in scroller position
*
* @v move Scroll movement
* @ret delta Change in scroller position
*/
#define SCROLL_DELTA( scroll ) ( ( int16_t ) ( (scroll) & 0x0000ffffUL ) )
/** Scroll movement flags */
#define SCROLL_FLAGS 0xffff0000UL
#define SCROLL_WRAP 0x80000000UL /**< Wrap around scrolling */
/** Do not scroll */
#define SCROLL_NONE SCROLL ( 0 )
/** Scroll up by one line */
#define SCROLL_UP SCROLL ( -1 )
/** Scroll down by one line */
#define SCROLL_DOWN SCROLL ( +1 )
/**
* Check if jump scroller is currently on first page
*
* @v scroll Jump scroller
* @ret is_first Scroller is currently on first page
*/
static inline int jump_scroll_is_first ( struct jump_scroller *scroll ) {
return ( scroll->first == 0 );
}
/**
* Check if jump scroller is currently on last page
*
* @v scroll Jump scroller
* @ret is_last Scroller is currently on last page
*/
static inline int jump_scroll_is_last ( struct jump_scroller *scroll ) {
return ( ( scroll->first + scroll->rows ) >= scroll->count );
}
extern unsigned int jump_scroll_key ( struct jump_scroller *scroll, int key );
extern unsigned int jump_scroll_move ( struct jump_scroller *scroll,
unsigned int move );
extern int jump_scroll ( struct jump_scroller *scroll );
#endif /* _IPXE_JUMPSCROLL_H */
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