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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
/**
* Redux store object wrapper to temporarily disable the store update notifications
* while the panel is hidden. The Redux actions are still dispatched and the reducers
* will be updating, but the changes are not communicated to connected components.
* i.e. redux's `connect` method won't be calling `mapStateToProps` function of all connected components.
*/
function visibilityHandlerStore(store) {
return {
/**
* Override to pause calling `listener` function while the panel is hidden.
* The function will be called once when the panel is shown.
*
* @param {Function} listener
* @param {Object} options
* @param {Boolean} options.ignoreVisibility
* If true, bypass this helper to listen to all store updates,
* regarless of panel visibility. This is useful for tests.
*/
subscribe(listener, { ignoreVisibility = false } = {}) {
// Test may pass a custom flag to ignore the visibility handler and listener
// to all state changes regarless of panel's visibility.
if (ignoreVisibility) {
return store.subscribe(listener);
}
function onVisibilityChange() {
if (document.visibilityState == "visible") {
// Force an update to resume updates when the panel becomes visible again
listener();
}
}
document.addEventListener("visibilitychange", onVisibilityChange);
const unsubscribe = store.subscribe(function () {
// This is the key operation of this class, to prevent notification
// when the panel is hidden.
if (document.visibilityState == "visible") {
listener();
}
});
// Calling `subscribe` should return an unsubscribe function
return function () {
unsubscribe();
document.removeEventListener("visibilitychange", onVisibilityChange);
};
},
// Provide expected default store functions
getState() {
return store.getState();
},
dispatch(action) {
return store.dispatch(action);
},
};
}
exports.visibilityHandlerStore = visibilityHandlerStore;