shithub: libscroll

ref: 52965c9a8366b1b30742215543032ef863f0b217
dir: /scroll.c/

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <mouse.h>
#include <frame.h>
#include "scroll.h"

enum {
	Scrollwid = 12,	/* width of scroll bar */
	Scrollgap = 4,	/* gap right of scroll bar */
};

Rectangle
scrollinit(Scroll *s, Rectangle r, Image *b, Image **cols)
{
	if(cols != nil)
		memmove(s->cols, cols, sizeof(s->cols));
	s->r = r;
	s->r.max.x = r.min.x + Scrollwid;
	s->image = b;
	r.min.x += Scrollwid + Scrollgap;
	return r;
}

void
scrollpos(Scroll *s, uint p₀, uint p₁, uint tot)
{
	Rectangle q;
	int h;

	q = s->r;
	h = Dy(q);
	if(tot > 1024*1024){
		tot>>=10;
		p₀>>=10;
		p₁>>=10;
	}
	if(tot > 0){
		q.min.y += h*p₀/tot;
		q.max.y = q.min.y+h*(p₁-p₀)/tot;
	}
	draw(s->image, s->r, s->cols[BORD], nil, ZP);
	draw(s->image, insetrect(q, 1), s->cols[BACK], nil, ZP);
}

int
scrollscr(Scroll *s, Mouse *m, uint *p₀)
{
	return -1;
}