/** Ensure the object is visible but minimize scrolling
*/
gboolean
ddisplay_present_object(DDisplay *ddisp, DiaObject *obj)
{
const Rectangle *r = dia_object_get_enclosing_box(obj);
const Rectangle *v = &ddisp->visible;
display_set_active(ddisp);
if (!rectangle_in_rectangle(v, r)) {
Point delta = { 0, 0 };
if ((r->right - r->left) > (v->right - v->left)) /* object bigger than visible area */
delta.x = (r->left - v->left + r->right - v->right) / 2;
else if (r->left < v->left)
delta.x = r->left - v->left;
else if (r->right > v->right)
delta.x = r->right - v->right;
if ((r->bottom - r->top) > (v->bottom - v->top)) /* object bigger than visible area */
delta.y = (r->top - v->top + r->bottom - v->bottom) / 2;
else if (r->top < v->top)
delta.y = r->top - v->top;
else if (r->bottom > v->bottom)
delta.y = r->bottom - v->bottom;
ddisplay_scroll(ddisp, &delta);
return TRUE;
}
return FALSE;
}
void ddisplay_scroll_right(DDisplay *ddisp)
{
Point delta;
delta.x = (ddisp->visible.right - ddisp->visible.left)/4.0;
delta.y = 0;
ddisplay_scroll(ddisp, &delta);
}
void ddisplay_scroll_down(DDisplay *ddisp)
{
Point delta;
delta.x = 0;
delta.y = (ddisp->visible.bottom - ddisp->visible.top)/4.0;
ddisplay_scroll(ddisp, &delta);
}
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;
if (!open_hand_cursor)
open_hand_cursor = create_cursor(ddisp->canvas->window,
hand_open_data_bits,
hand_open_data_width,
hand_open_data_height,
hand_open_mask_bits,
hand_open_data_width/2,
hand_open_data_height/2);
ddisplay_set_all_cursor(open_hand_cursor);
}
} else
if (tool->use_hand) {
tool->use_hand = FALSE;
ddisplay_set_all_cursor(scroll_cursor);
}
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 PyObject *
PyDiaDisplay_Scroll(PyDiaDisplay *self, PyObject *args)
{
Point delta;
if (!PyArg_ParseTuple(args, "dd:Display.scroll", &delta.x, &delta.y))
return NULL;
ddisplay_scroll(self->disp, &delta);
Py_INCREF(Py_None);
return Py_None;
}
/** Scroll display to have the diagram point p at the center.
* Returns TRUE if anything changed. */
gboolean
ddisplay_scroll_center_point(DDisplay *ddisp, Point *p)
{
Point center;
g_return_val_if_fail (ddisp != NULL, FALSE);
/* Find current center */
center.x = (ddisp->visible.right+ddisp->visible.left)/2;
center.y = (ddisp->visible.top+ddisp->visible.bottom)/2;
point_sub(p, ¢er);
return ddisplay_scroll(ddisp, p);
}
/** Scroll display to where point x,y (window coords) is visible */
gboolean
ddisplay_autoscroll(DDisplay *ddisp, int x, int y)
{
guint16 width, height;
Point scroll;
if (! ddisp->autoscroll)
return FALSE;
scroll.x = scroll.y = 0;
width = GTK_WIDGET(ddisp->canvas)->allocation.width;
height = GTK_WIDGET(ddisp->canvas)->allocation.height;
if (x < 0)
{
scroll.x = x;
}
else if ( x > width)
{
scroll.x = x - width;
}
if (y < 0)
{
scroll.y = y;
}
else if (y > height)
{
scroll.y = y - height;
}
if ((scroll.x != 0) || (scroll.y != 0))
{
gboolean scrolled;
scroll.x = ddisplay_untransform_length(ddisp, scroll.x);
scroll.y = ddisplay_untransform_length(ddisp, scroll.y);
scrolled = ddisplay_scroll(ddisp, &scroll);
if (scrolled) {
ddisplay_flush(ddisp);
return TRUE;
}
}
return FALSE;
}
