Update upstream source from tag 'upstream/3.9.1'

[minitube] / lib / promises / promise.h

diff --git a/lib/promises/promise.h b/lib/promises/promise.h
new file mode 100644 (file)
index 0000000..5bf1c87
--- /dev/null
+++ b/lib/promises/promise.h
@@ -0,0 +1,46 @@
+#ifndef PROMISE_H
+#define PROMISE_H
+
+#include <QtCore>
+
+/// private, don't use directly
+class BasePromise : public QObject {
+    Q_OBJECT
+
+public:
+    explicit BasePromise(QObject *parent = nullptr) : QObject(parent) {
+        connect(this, &BasePromise::resolve, this, &QObject::deleteLater);
+        connect(this, &BasePromise::reject, this, &QObject::deleteLater);
+    };
+
+    template <typename Function> BasePromise &then(Function func) {
+        connect(this, &BasePromise::resolve, this, func);
+        return *this;
+    }
+    template <typename Function> BasePromise &onFailed(Function func) {
+        connect(this, &BasePromise::reject, this, func);
+        return *this;
+    }
+    template <typename Function> BasePromise &finally(Function func) {
+        connect(this, &BasePromise::destroyed, this, func);
+        return *this;
+    }
+
+signals:
+    void resolve();
+    void reject(const QString &message);
+};
+
+template <class T> class Promise : public BasePromise {
+public:
+    void resolve(T value) {
+        data = value;
+        resolve();
+    }
+    T result() const { return data; }
+
+private:
+    T data;
+};
+
+#endif // PROMISE_H