/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* e-canvas-utils.c
* Copyright (C) 2000 Helix Code, Inc.
* Author: Chris Lahey <clahey@helixcode.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "e-canvas-utils.h"
void
e_canvas_item_move_absolute (GnomeCanvasItem *item, double dx, double dy)
{
double translate[6];
g_return_if_fail (item != NULL);
g_return_if_fail (GNOME_IS_CANVAS_ITEM (item));
art_affine_translate (translate, dx, dy);
gnome_canvas_item_affine_absolute (item, translate);
}
static double
compute_offset(double top, double bottom, double page_top, double page_bottom, double min, double max)
{
double size = bottom - top;
double offset = 0;
if (top <= page_top && bottom >= page_bottom)
return CLAMP(0, min - top, max - top);
if (bottom > page_bottom)
offset = (bottom - page_bottom);
if (top < page_top + offset)
offset = (top - page_top);
if (top <= page_top + offset && bottom >= page_bottom + offset)
return CLAMP(offset, min - top, max - top);
if (top < page_top + offset + size * 1.5)
offset = top - (page_top + size * 1.5);
if (bottom > page_bottom + offset - size * 1.5)
offset = bottom - (page_bottom - size * 1.5);
if (top < page_top + offset + size * 1.5)
offset = top - ((page_top + page_bottom - (bottom - top)) / 2);
return CLAMP(offset, min - top, max - top);
}
void
e_canvas_item_show_area (GnomeCanvasItem *item, double x1, double y1, double x2, double y2)
{
GtkAdjustment *h, *v;
double dx = 0, dy = 0;
g_return_if_fail (item != NULL);
g_return_if_fail (GNOME_IS_CANVAS_ITEM (item));
gnome_canvas_item_i2w(item, &x1, &y1);
gnome_canvas_item_i2w(item, &x2, &y2);
h = gtk_layout_get_hadjustment(GTK_LAYOUT(item->canvas));
dx = compute_offset(x1, x2, h->value, h->value + h->page_size, 0, h->upper - h->page_size);
if (dx)
gtk_adjustment_set_value(h, h->value + dx);
v = gtk_layout_get_vadjustment(GTK_LAYOUT(item->canvas));
dy = compute_offset(y1, y2, v->value, v->value + v->page_size, 0, v->upper - v->page_size);
if (dy)
gtk_adjustment_set_value(v, v->value + dy);
}