Port away from deprecated Qt::MidButton

src/widgets/TerminalDisplay.cpp

@@ -2373,7 +2373,7 @@ void TerminalDisplay::mousePressEvent(QMouseEvent* ev)
                     emit mouseSignal(0, charColumn + 1, charLine + 1 + _scrollBar->value() - _scrollBar->maximum() , 0);
             }
         }
-    } else if (ev->button() == Qt::MidButton) {
+    } else if (ev->button() == Qt::MiddleButton) {
         processMidButtonClick(ev);
     } else if (ev->button() == Qt::RightButton) {
         if (!_usesMouseTracking || ((ev->modifiers() & Qt::ShiftModifier) != 0u)) {
@@ -2475,7 +2475,7 @@ void TerminalDisplay::mouseMoveEvent(QMouseEvent* ev)
         if ((ev->buttons() & Qt::LeftButton) != 0u) {
             button = 0;
         }
-        if ((ev->buttons() & Qt::MidButton) != 0u) {
+        if ((ev->buttons() & Qt::MiddleButton) != 0u) {
             button = 1;
         }
         if ((ev->buttons() & Qt::RightButton) != 0u) {
@@ -2514,7 +2514,7 @@ void TerminalDisplay::mouseMoveEvent(QMouseEvent* ev)
     }
 
 // don't extend selection while pasting
-    if ((ev->buttons() & Qt::MidButton) != 0u) {
+    if ((ev->buttons() & Qt::MiddleButton) != 0u) {
         return;
     }
 
@@ -2724,9 +2724,9 @@ void TerminalDisplay::mouseReleaseEvent(QMouseEvent* ev)
     }
 
     if (_usesMouseTracking &&
-            (ev->button() == Qt::RightButton || ev->button() == Qt::MidButton) &&
+            (ev->button() == Qt::RightButton || ev->button() == Qt::MiddleButton) &&
             !(ev->modifiers() & Qt::ShiftModifier)) {
-        emit mouseSignal(ev->button() == Qt::MidButton ? 1 : 2,
+        emit mouseSignal(ev->button() == Qt::MiddleButton ? 1 : 2,
                          charColumn + 1,
                          charLine + 1 + _scrollBar->value() - _scrollBar->maximum() ,
                          2);
@@ -2788,7 +2788,7 @@ void TerminalDisplay::processMidButtonClick(QMouseEvent* ev)
 void TerminalDisplay::mouseDoubleClickEvent(QMouseEvent* ev)
 {
     // Yes, successive middle click can trigger this event
-    if (ev->button() == Qt::MidButton) {
+    if (ev->button() == Qt::MiddleButton) {
         processMidButtonClick(ev);
         return;
     }