Support choose history command by Key_Up and Key_Down

common/myeventfilter.cpp

@@ -0,0 +1,13 @@
+#include "myeventfilter.h"
+
+MyEventFilter::MyEventFilter(QEvent::Type filter)
+{
+    targetEventType = filter;
+}
+
+bool MyEventFilter::eventFilter(QObject *obj, QEvent *event)
+{
+    if(event->type() == targetEventType)
+        emit eventHappened(obj, *event);
+    return QObject::eventFilter(obj, event);
+}

common/myeventfilter.h

@@ -0,0 +1,22 @@
+#ifndef MYEVENTFILTER_H
+#define MYEVENTFILTER_H
+
+#include <QObject>
+#include <QKeyEvent>
+
+class MyEventFilter : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit MyEventFilter(QEvent::Type filter);
+protected:
+    bool eventFilter(QObject *obj, QEvent *event) override;
+
+signals:
+    void eventHappened(QObject* obj_addr, QEvent& event);
+private:
+    QEvent::Type targetEventType;
+};
+
+#endif // MYEVENTFILTER_H