Page exit prevention refactor (#637)

* Add page exit prevention functionality to SettingsController

* Update dictionary controller to use new page exit prevention system

* Remove page-exit-prevention.js

1 files changed, 0 insertions, 59 deletions

diff --git a/ext/bg/js/page-exit-prevention.js b/ext/bg/js/page-exit-prevention.js
deleted file mode 100644
index f55cf024..00000000
--- a/ext/bg/js/page-exit-prevention.js
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright (C) 2019-2020  Yomichan Authors
- *
- * 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 <https://www.gnu.org/licenses/>.
- */
-
-
-class PageExitPrevention {
-    constructor() {
-    }
-
-    start() {
-        PageExitPrevention._addInstance(this);
-    }
-
-    end() {
-        PageExitPrevention._removeInstance(this);
-    }
-
-    static _addInstance(instance) {
-        const size = PageExitPrevention._instances.size;
-        PageExitPrevention._instances.set(instance, true);
-        if (size === 0) {
-            window.addEventListener('beforeunload', PageExitPrevention._onBeforeUnload);
-        }
-    }
-
-    static _removeInstance(instance) {
-        if (
-            PageExitPrevention._instances.delete(instance) &&
-            PageExitPrevention._instances.size === 0
-        ) {
-            window.removeEventListener('beforeunload', PageExitPrevention._onBeforeUnload);
-        }
-    }
-
-    static _onBeforeUnload(e) {
-        if (PageExitPrevention._instances.size === 0) {
-            return;
-        }
-
-        e.preventDefault();
-        e.returnValue = '';
-        return '';
-    }
-}
-
-PageExitPrevention._instances = new Map();