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/* Dia -- an diagram creation/manipulation program
* Copyright (C) 1998 Alexander Larsson
*
* 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 <config.h>
#include "scroll_tool.h"
#include "handle_ops.h"
#include "object_ops.h"
#include "connectionpoint_ops.h"
#include "message.h"
#include "cursor.h"
static void scroll_button_press(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp);
static void scroll_button_release(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp);
static void scroll_motion(ScrollTool *tool, GdkEventMotion *event,
DDisplay *ddisp);
static void scroll_double_click(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp);
Tool *
create_scroll_tool(void)
{
ScrollTool *tool;
tool = g_new0(ScrollTool, 1);
tool->tool.type = SCROLL_TOOL;
tool->tool.button_press_func = (ButtonPressFunc) &scroll_button_press;
tool->tool.button_release_func = (ButtonReleaseFunc) &scroll_button_release;
tool->tool.motion_func = (MotionFunc) &scroll_motion;
tool->tool.double_click_func = (DoubleClickFunc) &scroll_double_click;
tool->scrolling = FALSE;
tool->use_hand = TRUE;
ddisplay_set_all_cursor_name (NULL, "grab");
return (Tool *)tool;
}
void
free_scroll_tool (Tool *tool)
{
g_clear_pointer (&tool, g_free);
ddisplay_set_all_cursor (default_cursor);
}
static void
scroll_double_click(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp)
{
/* Do nothing */
}
static void
scroll_button_press(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp)
{
Point clickedpoint;
tool->use_hand = (event->state & GDK_SHIFT_MASK) == 0;
if (tool->use_hand)
ddisplay_set_all_cursor_name (NULL, "grabbing");
else
ddisplay_set_all_cursor_name (NULL, "move");
ddisplay_untransform_coords(ddisp,
(int)event->x, (int)event->y,
&clickedpoint.x, &clickedpoint.y);
tool->scrolling = TRUE;
tool->last_pos = clickedpoint;
}
static void
scroll_motion(ScrollTool *tool, GdkEventMotion *event,
DDisplay *ddisp)
{
Point to;
Point delta;
/* set the cursor appropriately, and change use_hand if needed */
if (!tool->scrolling) {
/* try to minimise the number of cursor type changes */
if ((event->state & GDK_SHIFT_MASK) == 0) {
if (!tool->use_hand) {
tool->use_hand = TRUE;
ddisplay_set_all_cursor_name (NULL, "grab");
}
} else
if (tool->use_hand) {
tool->use_hand = FALSE;
ddisplay_set_all_cursor_name (NULL, "move");
}
return;
}
ddisplay_untransform_coords(ddisp, event->x, event->y, &to.x, &to.y);
if (tool->use_hand) {
delta = tool->last_pos;
point_sub(&delta, &to);
tool->last_pos = to;
point_add(&tool->last_pos, &delta);
/* we use this so you can scroll past the edge of the image */
point_add(&delta, &ddisp->origo);
ddisplay_set_origo(ddisp, delta.x, delta.y);
ddisplay_update_scrollbars(ddisp);
ddisplay_add_update_all(ddisp);
} else {
delta = to;
point_sub(&delta, &tool->last_pos);
point_scale(&delta, 0.5);
ddisplay_scroll(ddisp, &delta);
tool->last_pos = to;
}
ddisplay_flush(ddisp);
}
static void
scroll_button_release(ScrollTool *tool, GdkEventButton *event,
DDisplay *ddisp)
{
tool->use_hand = (event->state & GDK_SHIFT_MASK) == 0;
if (tool->use_hand) {
ddisplay_set_all_cursor_name (NULL, "grab");
} else {
ddisplay_set_all_cursor_name (NULL, "move");
}
tool->scrolling = FALSE;
}
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