first push

filter.cpp

@@ -0,0 +1,30 @@
+#include "filter.h"
+#include <QKeyEvent>
+
+filter::filter(QObject *parent) :
+    QObject(parent)
+{
+    m_ctrlPressed = true;
+}
+
+bool filter::eventFilter(QObject *obj, QEvent *ev) {
+    switch(ev->type()) {
+    case QEvent::KeyPress: {
+        QKeyEvent *ke = static_cast<QKeyEvent*>(ev);
+        if(ke->key() == Qt::Key_Control) {
+            emit ctrlPressed();
+            m_ctrlPressed = true;
+        }
+    } break;
+    case QEvent::KeyRelease: {
+        QKeyEvent *ke = static_cast<QKeyEvent*>(ev);
+        if(ke->key() == Qt::Key_Control) {
+            emit ctrlReleased();
+            m_ctrlPressed = false;
+        }
+    } break;
+    default: break;
+    }
+
+    return QObject::eventFilter(obj, ev);
+}