gala/lib/Plugin.vala
2019-09-05 22:18:43 +02:00

211 lines
7.0 KiB
Vala

//
// Copyright (C) 2014 Tom Beckmann
//
// 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 3 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, see <http://www.gnu.org/licenses/>.
//
namespace Gala {
public enum PluginFunction {
ADDITION,
WINDOW_SWITCHER,
DESKTOP,
WORKSPACE_VIEW,
WINDOW_OVERVIEW
}
public enum LoadPriority {
/**
* Have your plugin loaded immediately once gala has started
*/
IMMEDIATE,
/**
* Allow gala to defer loading your plugin once it got the
* major part of the initialization done
*/
DEFERRED
}
public struct PluginInfo {
string name;
string author;
/**
* Type of your plugin class, has to be derived from the Plugin class.
*/
Type plugin_type;
/**
* This property allows you to override default functionality of gala
* so systems won't be instantiated next to each other. Use
* PluginFunction.ADDITION if no special component is overridden.
*/
PluginFunction provides;
/**
* Give gala a hint for when to load your plugin. Especially use DEFERRED
* if you're adding a completely new ui component that's not directly
* related to the wm.
*/
LoadPriority load_priority;
/**
* You don't have to fill this field, it will be filled by gala with
* the filename in which your module was found.
*/
string module_name;
}
/**
* This class has to be implemented by every plugin.
* Additionally, the plugin module is required to have a register_plugin
* function which returns a PluginInfo struct.
* The plugin_type field has to be the type of your plugin class derived
* from this class.
*/
public abstract class Plugin : Object {
/**
* Emitted when update_region is called. Mainly for internal purposes.
*/
public signal void region_changed ();
/**
* The region indicates an area where mouse events should be sent to
* the stage, which means your actors, instead of the windows.
*
* It is calculated by the system whenever update_region is called.
* You can influce it with the custom_region and the track_actor function.
*/
public Meta.Rectangle[] region { get; private set; }
/**
* This list will be merged with the region property. See region for
* more details. Changing this property will cause update_region to be
* called. Default to null.
*/
protected Meta.Rectangle[]? custom_region {
get {
return _custom_region;
}
protected set {
_custom_region = value;
update_region ();
}
}
/**
* Set this property to true while animating an actor if you have tracked
* actors to prevent constant recalculations of the regions during an
* animation.
*/
protected bool freeze_track {
get {
return _freeze_track;
}
set {
_freeze_track = value;
if (!_freeze_track)
update_region ();
}
}
private bool _freeze_track = false;
private Meta.Rectangle[]? _custom_region = null;
private List<Clutter.Actor> tracked_actors = new List<Clutter.Actor> ();
/**
* Once this method is called you can start adding actors to the stage
* via the windowmanager instance that is given to you.
*
* @param wm The window manager.
*/
public abstract void initialize (WindowManager wm);
/**
* This method is currently not called in the code, however you should
* still implement it to be compatible whenever we decide to use it.
* It should make sure that everything your plugin added to the stage
* is cleaned up.
*/
public abstract void destroy ();
/**
* Listen to changes to the allocation of actor and update the region
* accordingly. You may add multiple actors, their shapes will be
* combined when one of them changes.
*
* @param actor The actor to be tracked
*/
public void track_actor (Clutter.Actor actor) {
tracked_actors.prepend (actor);
actor.allocation_changed.connect (actor_allocation_changed);
update_region ();
}
/**
* Stop listening to allocation changes and remove the actor's
* allocation from the region array.
*
* @param actor The actor to stop listening the changes on
*/
public void untrack_actor (Clutter.Actor actor) {
tracked_actors.remove (actor);
actor.allocation_changed.disconnect (actor_allocation_changed);
}
/**
* You can call this method to force the system to update the region that
* is used by the window manager. It will automatically upon changes to
* the custom_region property and when a tracked actor's allocation changes
* unless freeze_track is set to true. You may need to call this function
* after setting freeze_track back to false after an animation to make the
* wm aware of the new position of the actor in question.
*/
public void update_region () {
var has_custom = custom_region != null;
var len = tracked_actors.length () + (has_custom ? custom_region.length : 0);
Meta.Rectangle[] regions = new Meta.Rectangle[len];
var i = 0;
if (has_custom) {
for (var j = 0; j < custom_region.length; j++) {
regions[i++] = custom_region[j];
}
}
foreach (var actor in tracked_actors) {
float x, y, w, h;
actor.get_transformed_position (out x, out y);
actor.get_transformed_size (out w, out h);
if (w == 0 || h == 0)
continue;
regions[i++] = { (int) x, (int) y, (int) w, (int) h };
}
region = regions;
region_changed ();
}
private void actor_allocation_changed (Clutter.ActorBox box, Clutter.AllocationFlags f) {
if (!freeze_track)
update_region ();
}
}
}