NAME
Gtk2::Ex::Geo::Overlay - A Gtk2 widget for a visual overlay of geospatial data
SYNOPSIS
my $overlay = Gtk2::Ex::Geo::Overlay->new;
$overlay->my_inits;
DESCRIPTION
Gtk2::Ex::Geo::Overlay is a subclass of Gtk2::ScrolledWindow
ATTRIBUTES
public:
bg_color = ($red, $green, $blue) # a color for the background for the overlay
rubberbanding = FALSE, /line/, /rect/, /ellipse/
private:
image event_box zoom_factor step
METHODS
my_inits
some initializations which cannot be done automagically (for some reason unknown to me...)
add_layer($layer, $do_not_zoom_to);
adds a spatial data layer to the top of the overlay, the default behavior is to zoom to the new layer
layer_count
get_layer_by_index($index)
get_layer_by_name($name)
returns a layer by its index (top = 0) or name
zoom_to($layer) or zoom_to($minx, $miny, $maxx, $maxy)
sets the given bounding box as the world
zoom_to_all
sets the bounding box which bounds all layers as the world
set_event_handler($event_handler, $user_param)
sets a subroutine which gets called when something happens in the widget, the sub is called like this: $event_handler->($user_param, $event, @xy);
set_draw_on($draw_on, $user_param)
sets a subroutine which gets called whenever a new pixmap is drawn for the widget, the sub is called like this: $draw_on->($user_param, $pixmap);
get_focus
Returns the visible area or the selection, if one exists, as ($minx, $miny, $maxx, $maxy).
render(key=>value,..)
Does the actual rendering by calling (creating) a new Gtk2::Ex::Geo::Renderer object. Creates the pixmap for the image. Deletes the backup pixmap if one exists. Currently used parameters:
filename=>filename, type=>type
if filename is set, calls pixbuf->save with given optionscreate_backup_pixmap
Creates a backup pixmap unless one already exists.
restore_pixmap
Restores the pixmap to the state it was right after last call to create_backup_pixmap that actually had an effect.
update_image
Updates the image on the screen to show the changes in pixmap.
zoom($w_offset, $h_offset, $pixel_size)
select a part of the world into the visible area
zoom_in($event, $center_x, $center_y)
zooms in a zoom_factor amount
zoom_out($event, $center_x, $center_y)
zooms out a zoom_factor amount
note: may enlarge the world
pan($w_move, $h_move, $event)
pans the viewport
internal handling of key and button events
+ => zoom_in - => zoom_out arrow keys => pan
the attribute rubberbanding defines what is done with button press, move and release
coordinate transforms
event_pixel2point => returns event coordinates as world coordinates
point2pixmap_pixel => returns world coordinates as pixmap pixel coordinates
SEE ALSO
Gtk2::Ex::Geo
AUTHOR
Ari Jolma, <ajolma at tkk.fi>
COPYRIGHT AND LICENSE
Copyright (C) 2006 by Ari Jolma
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.5 or, at your option, any later version of Perl 5 you may have available.