status-desktop/ui/imports/utils/Backpressure/Backpressure.qml

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pragma Singleton
import QtQuick 2.0
Item {
id: backpressure
property var _timers: ({})
property int _nextId: 0
function setTimeout(owner, timeout, callback) {
var tid = ++_nextId;
var cleanup = function() {
if (tid !== null) {
clearTimeout(tid);
}
}
if (!owner) {
owner = backpressure;
}
owner.Component.destruction.connect(cleanup);
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var obj = Qt.createQmlObject('import QtQuick 2.0; Timer {running: false; repeat: false; interval: ' + timeout + '}', backpressure, "setTimeout");
obj.triggered.connect(function() {
callback();
obj.destroy();
owner.Component.destruction.disconnect(cleanup);
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delete _timers[tid];
});
obj.running = true;
_timers[tid] = obj;
return tid;
}
function clearTimeout(timerId) {
if (!_timers.hasOwnProperty(timerId)) {
return;
}
var timer = _timers[timerId];
timer.stop();
timer.destroy();
delete _timers[timerId];
}
function oneInTime(owner, duration, callback) {
var pending = false;
var timerId = null;
return function() {
if (pending) {
return;
}
pending = true;
var args = arguments;
callback.apply(null, args);
timerId = setTimeout(owner, duration , function() {
pending = false;
}, duration);
}
}
function promisedOneInTime(owner, callback) {
var q = priv.loadPromiseLib();
var promise = null;
return function() {
var args = arguments;
if (promise !== null) {
return q.rejected();
}
promise = q.promise(function(fulfill, reject) {
fulfill(callback.apply(null, args));
});
promise.then(function() {
promise = null;
}, function() {
promise = null;
});
return promise;
};
}
function debounce(owner, duration, callback) {
var timerId = null;
return function() {
var args = arguments;
if (timerId !== null) {
clearTimeout(timerId);
}
timerId = setTimeout(owner, duration, function() {
timerId = null;
callback.apply(null, args);
});
}
}
QtObject {
id: priv
property var q: null
function loadPromiseLib() {
if (q !== null) {
return q.q;
}
q = Qt.createQmlObject('import QtQuick 2.0; import QuickPromise 1.0; Item { property var q: Q;}', backpressure);
if (q.hasOwnProperty("qmlErrors")) {
console.error("Backpressure: Failed to load QuickPromise. Please check your installation.");
}
return q.q;
}
}
}