73 lines
2.4 KiB
Dart
73 lines
2.4 KiB
Dart
/*
|
|
* Copyright (c) 2024-2026 Fabian Freund.
|
|
*
|
|
* This file is part of WebLibre
|
|
* (see https://weblibre.eu).
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero 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 Affero General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Affero General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
import 'dart:ui';
|
|
|
|
/// A wrapper around [Image] that compares by a precomputed byte-hash.
|
|
///
|
|
/// Instances are byte-hash deduped via the decoder's LRU, so the same
|
|
/// `EquatableImage` may be shared across many holders (multiple tabs of
|
|
/// the same site, the icon cache, widget closures). To make that safe,
|
|
/// the underlying `ui.Image` is disposed via a [Finalizer] when this
|
|
/// wrapper becomes unreachable — never on cache eviction or state
|
|
/// transitions, where another holder might still be using it.
|
|
class EquatableImage {
|
|
static final Finalizer<Image> _finalizer = Finalizer<Image>(
|
|
(image) => image.dispose(),
|
|
);
|
|
|
|
Image? _value;
|
|
final int _imageHash;
|
|
bool _isDisposed = false;
|
|
|
|
EquatableImage(Image value, {required int hash})
|
|
: _value = value,
|
|
_imageHash = hash {
|
|
_finalizer.attach(this, value, detach: this);
|
|
}
|
|
|
|
/// The underlying ui.Image. Returns null if explicitly disposed.
|
|
Image? get value => _isDisposed ? null : _value;
|
|
|
|
/// Whether this image has been explicitly disposed.
|
|
bool get isDisposed => _isDisposed;
|
|
|
|
/// Explicitly release the underlying GPU resource now.
|
|
///
|
|
/// Optional — if not called, the resource is freed when this wrapper is
|
|
/// garbage collected. Only call this when you are certain no other holder
|
|
/// still references the image; otherwise prefer to drop your reference
|
|
/// and let GC handle it.
|
|
void dispose() {
|
|
if (_isDisposed) return;
|
|
_isDisposed = true;
|
|
_finalizer.detach(this);
|
|
_value?.dispose();
|
|
_value = null;
|
|
}
|
|
|
|
@override
|
|
int get hashCode => _imageHash.hashCode;
|
|
|
|
@override
|
|
bool operator ==(Object other) {
|
|
return other is EquatableImage && other._imageHash == _imageHash;
|
|
}
|
|
}
|