/*
When using the mouse wheel button to zoom in and out, it is more
intuitive to maintain the drawing zoom center-point based on the
cursor position. This can help orientation and prevent the drawing
from "jumping" around while zooming in and out.
*/
void
ddisplay_zoom_centered(DDisplay *ddisp, Point *point, real magnify)
{
Rectangle *visible;
real width, height;
/* cursor position ratios */
real rx,ry;
if ((ddisp->zoom_factor <= DDISPLAY_MIN_ZOOM) && (magnify<=1.0))
return;
if ((ddisp->zoom_factor >= DDISPLAY_MAX_ZOOM) && (magnify>=1.0))
return;
visible = &ddisp->visible;
/* calculate cursor position ratios */
rx = (point->x-visible->left)/(visible->right - visible->left);
ry = (point->y-visible->top)/(visible->bottom - visible->top);
width = (visible->right - visible->left)/magnify;
height = (visible->bottom - visible->top)/magnify;
ddisp->zoom_factor *= magnify;
/* set new origin based on the calculated ratios before zooming */
ddisplay_set_origo(ddisp, point->x-(width*rx),point->y-(height*ry));
ddisplay_update_scrollbars(ddisp);
ddisplay_add_update_all(ddisp);
ddisplay_flush(ddisp);
update_zoom_status (ddisp);
}
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_SetOrigion(PyDiaDisplay *self, PyObject *args)
{
double x, y;
if (!PyArg_ParseTuple(args, "dd:Display.set_origion", &x, &y))
return NULL;
ddisplay_set_origo(self->disp, x, y);
Py_INCREF(Py_None);
return Py_None;
}
void
ddisplay_resize_canvas(DDisplay *ddisp,
int width, int height)
{
if (ddisp->renderer==NULL) {
if (ddisp->aa_renderer)
ddisp->renderer = new_aa_renderer (ddisp);
else
ddisp->renderer = new_gdk_renderer(ddisp);
}
dia_renderer_set_size(ddisp->renderer, gtk_widget_get_window(ddisp->canvas), width, height);
ddisplay_set_origo(ddisp, ddisp->origo.x, ddisp->origo.y);
ddisplay_add_update_all(ddisp);
ddisplay_flush(ddisp);
}
/** Scroll the display by delta (diagram coords) */
gboolean
ddisplay_scroll(DDisplay *ddisp, Point *delta)
{
Rectangle *visible = &ddisp->visible;
real width = visible->right - visible->left;
real height = visible->bottom - visible->top;
Rectangle extents = ddisp->diagram->data->extents;
real ex_width = extents.right - extents.left;
real ex_height = extents.bottom - extents.top;
Point new_origo = ddisp->origo;
point_add(&new_origo, delta);
rectangle_union(&extents, visible);
if (new_origo.x < extents.left - ex_width)
new_origo.x = extents.left - ex_width;
if (new_origo.x+width > extents.right + ex_width)
new_origo.x = extents.right - width + ex_width;
if (new_origo.y < extents.top - ex_height)
new_origo.y = extents.top - ex_height;
if (new_origo.y+height > extents.bottom + ex_height)
new_origo.y = extents.bottom - height + ex_height;
if ( (new_origo.x != ddisp->origo.x) ||
(new_origo.y != ddisp->origo.y) ) {
ddisplay_set_origo(ddisp, new_origo.x, new_origo.y);
ddisplay_update_scrollbars(ddisp);
ddisplay_add_update_all(ddisp);
return TRUE;
}
return FALSE;
}
void
ddisplay_zoom(DDisplay *ddisp, Point *point, real magnify)
{
Rectangle *visible;
real width, height, old_zoom;
visible = &ddisp->visible;
if ((ddisp->zoom_factor <= DDISPLAY_MIN_ZOOM) && (magnify<=1.0))
return;
if ((ddisp->zoom_factor >= DDISPLAY_MAX_ZOOM) && (magnify>=1.0))
return;
old_zoom = ddisp->zoom_factor;
ddisp->zoom_factor = old_zoom * magnify;
/* clip once more */
if (ddisp->zoom_factor < DDISPLAY_MIN_ZOOM)
ddisp->zoom_factor = DDISPLAY_MIN_ZOOM;
else if (ddisp->zoom_factor > DDISPLAY_MAX_ZOOM)
ddisp->zoom_factor = DDISPLAY_MAX_ZOOM;
/* the real one used - after clipping */
magnify = ddisp->zoom_factor / old_zoom;
width = (visible->right - visible->left)/magnify;
height = (visible->bottom - visible->top)/magnify;
ddisplay_set_origo(ddisp, point->x - width/2.0, point->y - height/2.0);
ddisplay_update_scrollbars(ddisp);
ddisplay_add_update_all(ddisp);
ddisplay_flush(ddisp);
update_zoom_status (ddisp);
}
