/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <draw.h>#include <thread.h>#include <cursor.h>#include <mouse.h>#include <keyboard.h>#include <frame.h>#include <fcall.h>#include <plumb.h>#include "dat.h"#include "fns.h" static Image *scrtmp; staticRectanglescrpos(Rectangle r, uint p0, uint p1, uint tot){	Rectangle q;	int h; 	q = r;	h = q.max.y-q.min.y;	if(tot == 0)		return q;	if(tot > 1024*1024){		tot>>=10;		p0>>=10;		p1>>=10;	}	if(p0 > 0)		q.min.y += h*p0/tot;	if(p1 < tot)		q.max.y -= h*(tot-p1)/tot;	if(q.max.y < q.min.y+2){		if(q.min.y+2 <= r.max.y)			q.max.y = q.min.y+2;		else			q.min.y = q.max.y-2;	}	return q;} voidscrlresize(void){	freeimage(scrtmp);	scrtmp = allocimage(display, Rect(0, 0, 32, screen->r.max.y), screen->chan, 0, DNofill);	if(scrtmp == nil)		error("scroll alloc");} voidtextscrdraw(Text *t){	Rectangle r, r1, r2;	Image *b; 	if(t->w==nil || t!=&t->w->body)		return;	if(scrtmp == nil)		scrlresize();	r = t->scrollr;	b = scrtmp;	r1 = r;	r1.min.x = 0;	r1.max.x = Dx(r);	r2 = scrpos(r1, t->org, t->org+t->nchars, t->file->nc);	if(!eqrect(r2, t->lastsr)){		t->lastsr = r2;		draw(b, r1, t->cols[BORD], nil, ZP);		draw(b, r2, t->cols[BACK], nil, ZP);		r2.min.x = r2.max.x-1;		draw(b, r2, t->cols[BORD], nil, ZP);		draw(t->b, r, b, nil, Pt(0, r1.min.y));/*flushimage(display, 1);/*BUG?*/	}} voidscrsleep(uint dt){	Timer	*timer;	static Alt alts[3]; 	timer = timerstart(dt);	alts[0].c = timer->c;	alts[0].v = nil;	alts[0].op = CHANRCV;	alts[1].c = mousectl->c;	alts[1].v = &mousectl->Mouse;	alts[1].op = CHANRCV;	alts[2].op = CHANEND;	for(;;)		switch(alt(alts)){		case 0:			timerstop(timer);			return;		case 1:			timercancel(timer);			return;		}} voidtextscroll(Text *t, int but){	uint p0, oldp0;	Rectangle s;	int x, y, my, h, first; 	s = insetrect(t->scrollr, 1);	h = s.max.y-s.min.y;	x = (s.min.x+s.max.x)/2;	oldp0 = ~0;	first = TRUE;	do{		flushimage(display, 1);		my = mouse->xy.y;		if(my < s.min.y)			my = s.min.y;		if(my >= s.max.y)			my = s.max.y;		if(!eqpt(mouse->xy, Pt(x, my))){			moveto(mousectl, Pt(x, my));			readmouse(mousectl);		/* absorb event generated by moveto() */		}		if(but == 2){			y = my;			p0 = (vlong)t->file->nc*(y-s.min.y)/h;			if(p0 >= t->q1)				p0 = textbacknl(t, p0, 2);			if(oldp0 != p0)				textsetorigin(t, p0, FALSE);			oldp0 = p0;			readmouse(mousectl);			continue;		}		if(but == 1)			p0 = textbacknl(t, t->org, (my-s.min.y)/t->font->height);		else			p0 = t->org+frcharofpt(t, Pt(s.max.x, my));		if(oldp0 != p0)			textsetorigin(t, p0, TRUE);		oldp0 = p0;		/* debounce */		if(first){			flushimage(display, 1);			sleep(200);			nbrecv(mousectl->c, &mousectl->Mouse);			first = FALSE;		}		scrsleep(80);	}while(mouse->buttons & (1<<(but-1)));	while(mouse->buttons)		readmouse(mousectl);}