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/* The GIMP -- an image manipulation program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include "appenv.h"
#include "scale.h"
#include "scroll.h"
#include "cursorutil.h"
#include "tools.h"
/* This is the delay before dithering begins
* for example, after an operation such as scrolling
*/
#define DITHER_DELAY 250 /* milliseconds */
/* Locally defined functions */
static int scroll_display (GDisplay *, int, int);
/* STATIC variables */
/* These are the values of the initial pointer grab */
static int startx, starty;
gint
scrollbar_vert_update (GtkAdjustment *adjustment,
gpointer data)
{
GDisplay *gdisp;
gdisp = (GDisplay *) data;
scroll_display (gdisp, 0, (adjustment->value - gdisp->offset_y));
return FALSE;
}
gint
scrollbar_horz_update (GtkAdjustment *adjustment,
gpointer data)
{
GDisplay *gdisp;
gdisp = (GDisplay *) data;
scroll_display (gdisp, (adjustment->value - gdisp->offset_x), 0);
return FALSE;
}
void
start_grab_and_scroll (GDisplay *gdisp,
GdkEventButton *bevent)
{
GdkCursor *cursor;
startx = bevent->x + gdisp->offset_x;
starty = bevent->y + gdisp->offset_y;
cursor = gdk_cursor_new (GDK_FLEUR);
gdk_window_set_cursor (gdisp->canvas->window, cursor);
gdk_cursor_destroy (cursor);
}
void
end_grab_and_scroll (GDisplay *gdisp,
GdkEventButton *bevent)
{
GdkCursor *cursor;
cursor = gdk_cursor_new (gdisp->current_cursor);
gdk_window_set_cursor (gdisp->canvas->window, cursor);
gdk_cursor_destroy (cursor);
}
void
grab_and_scroll (GDisplay *gdisp,
GdkEventMotion *mevent)
{
scroll_display (gdisp, (startx - mevent->x - gdisp->offset_x),
(starty - mevent->y - gdisp->offset_y));
}
void
scroll_to_pointer_position (GDisplay *gdisp,
GdkEventMotion *mevent)
{
int child_x, child_y;
int off_x, off_y;
off_x = off_y = 0;
/* The cases for scrolling */
if (mevent->x < 0)
off_x = mevent->x;
else if (mevent->x > gdisp->disp_width)
off_x = mevent->x - gdisp->disp_width;
if (mevent->y < 0)
off_y = mevent->y;
else if (mevent->y > gdisp->disp_height)
off_y = mevent->y - gdisp->disp_height;
if (scroll_display (gdisp, off_x, off_y))
{
gdk_window_get_pointer (gdisp->canvas->window, &child_x, &child_y, NULL);
if (child_x == mevent->x && child_y == mevent->y)
/* Put this event back on the queue -- so it keeps scrolling */
gdk_event_put ((GdkEvent *) mevent);
}
}
static int
scroll_display (GDisplay *gdisp,
int x_offset,
int y_offset)
{
int old_x, old_y;
int src_x, src_y;
int dest_x, dest_y;
GdkEvent *event;
old_x = gdisp->offset_x;
old_y = gdisp->offset_y;
gdisp->offset_x += x_offset;
gdisp->offset_y += y_offset;
bounds_checking (gdisp);
/* the actual changes in offset */
x_offset = (gdisp->offset_x - old_x);
y_offset = (gdisp->offset_y - old_y);
if (x_offset || y_offset)
{
setup_scale (gdisp);
src_x = (x_offset < 0) ? 0 : x_offset;
src_y = (y_offset < 0) ? 0 : y_offset;
dest_x = (x_offset < 0) ? -x_offset : 0;
dest_y = (y_offset < 0) ? -y_offset : 0;
/* reset the old values so that the tool can accurately redraw */
gdisp->offset_x = old_x;
gdisp->offset_y = old_y;
/* stop the currently active tool */
active_tool_control (PAUSE, (void *) gdisp);
/* set the offsets back to the new values */
gdisp->offset_x += x_offset;
gdisp->offset_y += y_offset;
gdk_draw_pixmap (gdisp->canvas->window,
gdisp->scroll_gc,
gdisp->canvas->window,
src_x, src_y,
dest_x, dest_y,
(gdisp->disp_width - abs (x_offset)),
(gdisp->disp_height - abs (y_offset)));
/* resume the currently active tool */
active_tool_control (RESUME, (void *) gdisp);
/* scale the image into the exposed regions */
if (x_offset)
{
src_x = (x_offset < 0) ? 0 : gdisp->disp_width - x_offset;
src_y = 0;
gdisplay_expose_area (gdisp,
src_x, src_y,
abs (x_offset), gdisp->disp_height);
}
if (y_offset)
{
src_x = 0;
src_y = (y_offset < 0) ? 0 : gdisp->disp_height - y_offset;
gdisplay_expose_area (gdisp,
src_x, src_y,
gdisp->disp_width, abs (y_offset));
}
if (x_offset || y_offset)
gdisplays_flush ();
/* Make sure graphics expose events are processed before scrolling
* again */
while ((event = gdk_event_get_graphics_expose (gdisp->canvas->window))
!= NULL)
{
gtk_widget_event (gdisp->canvas, event);
if (event->expose.count == 0)
{
gdk_event_free (event);
break;
}
gdk_event_free (event);
}
return 1;
}
return 0;
}
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