#include "parse.h"

void
frame_disp_all(Frame *f)
{	
	frame_disp_area(f, 0, 0, f->r_w, f->r_h);
}

void
frame_scroll(Frame *f, int dx, int dy)
{
	int scr_y, scr_x;
	scr_x = f->scr_x + dx;
	scr_y = f->scr_y + dy;
	if (scr_x > f->formatted_width - f->width)
		scr_x = f->formatted_width - f->width;
	if (scr_x < 0)
		scr_x = 0;
	if (scr_y > f->formatted_height - f->height)
		scr_y = f->formatted_height - f->height;
	if (scr_y < 0)
		scr_y = 0;
	if (scr_x != f->scr_x || scr_y != f->scr_y) {
		frame_set_pos(f, scr_x, scr_y);
		frame_expose(f, 0, 0, f->r_w, f->r_h);
	}
}

void
frame_set_pos(Frame *f, int scr_x, int scr_y)
{
	int dx = f->scr_x - scr_x;
	int dy = f->scr_y - scr_y;

	f->scr_x = scr_x;
	f->scr_y = scr_y;

	if (abs(dx) >= f->r_w || abs(dy) >= f->r_h) {
		frame_disp_area(f,0,0,f->r_w,f->r_h);
	} else if (dy > 0) {
		if (dx > 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  0, 0, f->r_w - dx, f->r_h - dy, dx, dy);
			frame_disp_area(f,0,0,f->r_w,dy);
			frame_disp_area(f,0,dy,dx,f->r_h-dy);
		} else if (dx < 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  -dx, 0, f->r_w + dx, f->r_h - dy, 0, dy);
			frame_disp_area(f,0,0,f->r_w,dy);
			frame_disp_area(f,f->r_w+dx,dy,-dx,f->r_h-dy);
		} else {	/* dx == 0 */
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  0, 0, f->r_w, f->r_h - dy, 0, dy);
			frame_disp_area(f,0,0,f->r_w,dy);
		}
	} else if (dy < 0) {
		if (dx > 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  0, -dy, f->r_w - dx, f->r_h + dy, dx, 0);
			frame_disp_area(f,0,f->r_h+dy,f->r_w,-dy);
			frame_disp_area(f,0,0,dx,f->r_h+dy);
		} else if (dx < 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  -dx, -dy, f->r_w + dx, f->r_h + dy, 0, 0);
			frame_disp_area(f,0,f->r_h+dy,f->r_w,-dy);
			frame_disp_area(f,f->r_w+dx,0,-dx,f->r_h+dy);
		} else {	/* dx == 0 */
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  0, -dy, f->r_w, f->r_h + dy, 0, 0);
			frame_disp_area(f,0,f->r_h+dy,f->r_w,-dy);
		}
	} else {		/* dy == 0 */
		if (dx > 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  0, 0, f->r_w - dx, f->r_h, dx, 0);
			frame_disp_area(f,0,0,dx,f->r_h);
		} else if (dx < 0) {
			XCopyArea(f->dpy, f->backup, f->backup, f->gc,
					  -dx, 0, f->r_w + dx, f->r_h, 0, 0);
			frame_disp_area(f,f->r_w+dx,0,-dx,f->r_h);
		}
	}
	frame_check_area(f);
}

#ifndef MIN
#define MIN(a,b) (((a)<(b))?(a):(b))
#endif

void
frame_check_area(Frame *f)
{
	int x1, y1;
	HTMLObj *p;

	if (!f->body)
		return;

	p = f->body->next;
	f->disp_start = NULL;
	f->disp_end   = NULL;
	
	while (p != f->body) {
		y1 = p->y - p->ascent - f->scr_y + f->off_y;
		x1 = p->x + p->lbearing - f->scr_x + f->off_x;
		if (y1 < 0) {
			if (0 > y1 + p->ascent + p->descent)
				goto next;
		} else {
			if (y1 > f->r_h)
				goto next;
		}
		if (x1 < 0) {
			if (0 > (p->x + p->rbearing - f->scr_x + f->off_x))
				goto next;
		} else {
			if (x1 > f->r_w)
				goto next;
		}		
		if (!f->disp_start)
			f->disp_start = p;
		f->disp_end = p;
#if 0
		goto cont;
#endif
	next:
#if 0
		if (f->disp_end)
			if (f->disp_end->y != p->y)
				break;
	cont:
#endif
		p = p->next;
	}
	
	if (f->disp_end)
		f->disp_end = f->disp_end->next;

	return;
}

void
frame_disp_area(Frame *f, int x, int y, int w, int h)
{
	HTMLObj *p;
	int x1, y1, w2, h2;

	if (!f->body)
		return;

	p = f->body->next;
	if (f->bg_image && f->bg_image->pixmap != None) {
		XSetTile(f->dpy, f->gc, f->bg_image->pixmap);
		XSetTSOrigin(f->dpy, f->gc, f->off_x - f->scr_x, f->off_y -f->scr_y);
		XSetFillStyle(f->dpy, f->gc, FillTiled);
		XFillRectangle(f->dpy, f->backup, f->gc, x, y, w, h);
		XSetFillStyle(f->dpy, f->gc, FillSolid);
	} else {
		XSetForeground(f->dpy, f->gc, f->background);
		XFillRectangle(f->dpy, f->backup, f->gc, x, y, w, h);
	}

	while (p != f->body) {
#if 1
		y1 = p->y - p->ascent - f->scr_y + f->off_y;
		x1 = p->x + p->lbearing - f->scr_x + f->off_x;
		if (y1 < y) {
			if (y > y1 + p->ascent + p->descent)
				goto next;
			y1 = y - y1;
			h2  = p->height - y1;
		} else {
			if (y1 > y + h)
				goto next;
			h2  = MIN(h - (y1 - y), p->height);
			y1 = 0;
		}
		if (x1 < x) {
			if (x > (p->x + p->rbearing - f->scr_x + f->off_x))
				goto next;
			x1 = x - x1;
			w2  = p->width - x1;
		} else {
			if (x1 > x + w)
				goto next;
			w2  = MIN(w-(x1 - x), p->width);
			x1 = 0;
		}	
#endif
		htmlobj_draw(f->dpy, f->backup, f->gc, 
					 f->off_x - f->scr_x, f->off_y - f->scr_y , p,
					 x1, y1, w2, h2);
	next:
		p = p->next;
	}
	return;
}

void
frame_disp_obj(Frame *f, HTMLObj *p)
{
	int x1, y1, w2, h2, x2, y2;

	if (p->type == HTMLOBJ_NONE)
		return;
	
	y1 = p->y - p->ascent - f->scr_y + f->off_y;
	x1 = p->x + p->lbearing - f->scr_x + f->off_x;
	if (y1 < 0) {
		if (0 > y1 + p->ascent + p->descent)
			goto next;
		y1 = - y1;
		h2  = p->height - y1;
	} else {
		if (y1 > f->r_h)
			goto next;
		h2  = MIN(f->r_h - y1, p->height);
		y1 = 0;
	}
	if (x1 < 0) {
		if (0 > (p->x + p->rbearing - f->scr_x + f->off_x))
			goto next;
		x1 = - x1;
		w2  = p->width - x1;
	} else {
		if (x1 > f->r_w)
			goto next;
		w2  = MIN(f->r_w - x1, p->width);
		x1 = 0;
	}	

	x2 = p->x + p->lbearing - f->scr_x + f->off_x + x1;
	y2 = p->y - p->ascent   - f->scr_y + f->off_y + y1;

	if (f->bg_image && f->bg_image->pixmap != None) {
		XSetTile(f->dpy, f->gc, f->bg_image->pixmap);
		XSetTSOrigin(f->dpy, f->gc, f->off_x - f->scr_x, f->off_y -f->scr_y);
		XSetFillStyle(f->dpy, f->gc, FillTiled);
		XFillRectangle(f->dpy, f->backup, f->gc, x2, y2, w2, h2);
		XSetFillStyle(f->dpy, f->gc, FillSolid);
	} else {
		XSetForeground(f->dpy, f->gc, f->background);
		XFillRectangle(f->dpy, f->backup, f->gc, x2, y2, w2, h2);
	}
	
	htmlobj_draw(f->dpy, f->backup, f->gc, 
				 f->off_x - f->scr_x, f->off_y - f->scr_y , p,
				 x1, y1, w2, h2);

	frame_expose(f, x2, y2, w2, h2);

 next:
	return;
}

static HTMLHrefInfo *
find_url(HTMLObj *o, int x, int y)
{
	HTMLHrefInfo *ret;
	int x1, y1, x2, y2;

	if (o->type == HTMLOBJ_BLOCK) {
		HTMLBlockObj *bo = o->data;
		HTMLObj *p = bo->obj->next;
		while (p != bo->obj) {
			if ((ret = find_url(p, x, y)))
				return ret;
			p = p->next;
		}
		return NULL;
	} else {
		x1 = o->x + o->lbearing;
		x2 = o->x + o->rbearing;
		y1 = o->y - o->ascent;
		y2 = o->y + o->descent;
		if (x >= x1 && x <= x2 && y >= y1 && y <= y2)
			return o->link;
		else
			return NULL;
	}
}


HTMLHrefInfo *
frame_get_url(Frame *f, int x, int y)
{
	HTMLHrefInfo *ret;
	HTMLObj *p = f->disp_start;
	y -= (-f->scr_y + f->off_y);
	x -= (-f->scr_x + f->off_x);
	while (p != f->disp_end) {
		if ((ret = find_url(p, x, y)))
			return ret;
		p = p->next;
	}
	return NULL;
}