#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include <panel.h>
#include "pldefs.h"
typedef struct Scrollbar Scrollbar;
struct Scrollbar{
	int dir;		/* HORIZ or VERT */
	int lo, hi;		/* setting, in screen coordinates */
	int buttons;		/* saved mouse buttons for transmittal to scrollee */
	Rectangle interior;
	Point minsize;
};
#define	SBWID	15	/* should come from draw.c? */
void pl_drawscrollbar(Panel *p){
	Scrollbar *sp;
	sp=p->data;
	sp->interior=pl_outline(p->b, p->r, p->state);
	pl_sliderupd(p->b, sp->interior, sp->dir, sp->lo, sp->hi);
}
int pl_hitscrollbar(Panel *g, Mouse *m){
	int oldstate, pos, len, dy;
	Point ul, size;
	Scrollbar *sp;
	sp=g->data;
	ul=g->r.min;
	size=subpt(g->r.max, g->r.min);
	pl_interior(g->state, &ul, &size);
	oldstate=g->state;
	if(m->buttons&OUT && m->buttons&7){
		if(m->xy.y<g->r.min.y) m->xy.y=g->r.min.y;
		if(m->xy.y>=g->r.max.y) m->xy.y=g->r.max.y-1;
		if(ptinrect(m->xy, g->r))
			m->buttons&=~OUT;
	}
	if(sp->dir==HORIZ){
		pos=m->xy.x-ul.x;
		len=size.x;
	}
	else{
		pos=m->xy.y-ul.y;
		len=size.y;
	}
	if(pos<0) pos=0;
	else if(pos>len) pos=len;
	if(m->buttons&7){
		g->state=DOWN;
		if(g->r.min.x<=m->xy.x && m->xy.x<g->r.max.x){
			sp->buttons=m->buttons;
			switch(m->buttons){
			case 1:
				dy=pos*(sp->hi-sp->lo)/len;
				pl_sliderupd(g->b, sp->interior, sp->dir, sp->lo-dy,
					sp->hi-dy);
				break;
			case 2:
				if(g->scrollee && g->scrollee->scroll)
					g->scrollee->scroll(g->scrollee, sp->dir,
						m->buttons, pos, len);
				break;
			case 4:
				dy=pos*(sp->hi-sp->lo)/len;
				pl_sliderupd(g->b, sp->interior, sp->dir, sp->lo+dy,
					sp->hi+dy);
				break;
			}
		}
	}
	else{
		if(!(sp->buttons&2) && g->state==DOWN && g->scrollee && g->scrollee->scroll)
			g->scrollee->scroll(g->scrollee, sp->dir, sp->buttons,
				pos, len);
		g->state=UP;
	}
	if(oldstate!=g->state) pldraw(g, g->b);
	return g->state==DOWN;
}
void pl_typescrollbar(Panel *p, Rune c){
	USED(p, c);
}
Point pl_getsizescrollbar(Panel *p, Point children){
	USED(children);
	return pl_boxsize(((Scrollbar *)p->data)->minsize, p->state);
}
void pl_childspacescrollbar(Panel *p, Point *ul, Point *size){
	USED(p, ul, size);
}
/*
 * Arguments lo, hi and len are in the scrollee's natural coordinates
 */
void pl_setscrollbarscrollbar(Panel *p, int lo, int hi, int len){
	Point ul, size;
	int mylen;
	Scrollbar *sp;
	sp=p->data;
	ul=p->r.min;
	size=subpt(p->r.max, p->r.min);
	pl_interior(p->state, &ul, &size);
	mylen=sp->dir==HORIZ?size.x:size.y;
	if(len==0) len=1;
	sp->lo=lo*mylen/len;
	sp->hi=hi*mylen/len;
	if(sp->lo<0) sp->lo=0;
	if(sp->lo>=mylen) sp->hi=mylen-1;
	if(sp->hi<=sp->lo) sp->hi=sp->lo+1;
	if(sp->hi>mylen) sp->hi=mylen;
	pldraw(p, p->b);
}
int pl_priscrollbar(Panel *, Point){
	return PRI_SCROLLBAR;
}
void plinitscrollbar(Panel *v, int flags){
	Scrollbar *sp;
	sp=v->data;
	v->flags=flags|LEAF;
	v->pri=pl_priscrollbar;
	v->state=UP;
	v->draw=pl_drawscrollbar;
	v->hit=pl_hitscrollbar;
	v->type=pl_typescrollbar;
	v->getsize=pl_getsizescrollbar;
	v->childspace=pl_childspacescrollbar;
	v->setscrollbar=pl_setscrollbarscrollbar;
	switch(flags&PACK){
	case PACKN:
	case PACKS:
		sp->dir=HORIZ;
		sp->minsize=Pt(0, SBWID);
		v->flags|=FILLX;
		break;
	case PACKE:
	case PACKW:
		sp->dir=VERT;
		sp->minsize=Pt(SBWID, 0);
		v->flags|=FILLY;
		break;
	}
	sp->lo=0;
	sp->hi=0;
	v->kind="scrollbar";
}
Panel *plscrollbar(Panel *parent, int flags){
	Panel *v;
	v=pl_newpanel(parent, sizeof(Scrollbar));
	plinitscrollbar(v, flags);
	return v;
}