Current File : //usr/share/doc/gjs/examples/glistmodel.js
// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
// SPDX-FileCopyrightText: 2020 Andy Holmes <andrew.g.r.holmes@gmail.com>
import GObject from 'gi://GObject';
import Gio from 'gi://Gio';
/**
* An example of implementing the GListModel interface in GJS. The only real
* requirement here is that the class be derived from some GObject.
*/
export let GjsListStore = GObject.registerClass({
GTypeName: 'GjsListStore',
Implements: [Gio.ListModel],
}, class MyList extends GObject.Object {
constructor() {
super();
/* We'll use a native Array as internal storage for the list model */
this._items = [];
}
/* Implementing this function amounts to returning a GType. This could be a
* more specific GType, but must be a subclass of GObject. */
vfunc_get_item_type() {
return GObject.Object.$gtype;
}
/* Implementing this function just requires returning the GObject at
* @position or %null if out-of-range. This must explicitly return %null,
* not `undefined`. */
vfunc_get_item(position) {
return this._items[position] || null;
}
/* Implementing this function is as simple as return the length of the
* storage object, in this case an Array. */
vfunc_get_n_items() {
return this._items.length;
}
/**
* Insert an item in the list. If @position is greater than the number of
* items in the list or less than `0` it will be appended to the end of the
* list.
*
* @param {GObject.Object} item - the item to add
* @param {number} position - the position to add the item
*/
insertItem(item, position) {
if (!(item instanceof GObject.Object))
throw new TypeError('not a GObject');
if (position < 0 || position > this._items.length)
position = this._items.length;
this._items.splice(position, 0, item);
this.items_changed(position, 0, 1);
}
/**
* Append an item to the list.
*
* @param {GObject.Object} item - the item to add
*/
appendItem(item) {
if (!(item instanceof GObject.Object))
throw new TypeError('not a GObject');
let position = this._items.length;
this._items.push(item);
this.items_changed(position, 0, 1);
}
/**
* Prepend an item to the list.
*
* @param {GObject.Object} item - the item to add
*/
prependItem(item) {
if (!(item instanceof GObject.Object))
throw new TypeError('not a GObject');
this._items.unshift(item);
this.items_changed(0, 0, 1);
}
/**
* Remove @item from the list. If @item is not in the list, this function
* does nothing.
*
* @param {GObject.Object} item - the item to remove
*/
removeItem(item) {
if (!(item instanceof GObject.Object))
throw new TypeError('not a GObject');
let position = this._items.indexOf(item);
if (position === -1)
return;
this._items.splice(position, 1);
this.items_changed(position, 1, 0);
}
/**
* Remove the item at @position. If @position is outside the length of the
* list, this function does nothing.
*
* @param {number} position - the position of the item to remove
*/
removePosition(position) {
if (position < 0 || position >= this._items.length)
return;
this._items.splice(position, 1);
this.items_changed(position, 1, 0);
}
/**
* Clear the list of all items.
*/
clear() {
let length = this._items.length;
if (length === 0)
return;
this._items = [];
this.items_changed(0, length, 0);
}
});
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