bugfixes (#188)

Bugfixes for several issues: closes #163, closes #151, closes #176, closes #138, closes #104

Co-authored-by: Dominik Demuth <dominik.demuth@physik.tu-darmstadt.de>
Reviewed-on: #188

src/gui_qt/graphs/graphwindow.py

@@ -27,6 +27,7 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
     mouseDoubleClicked = QtCore.pyqtSignal()
     positionClicked = QtCore.pyqtSignal(tuple, bool)
     aboutToClose = QtCore.pyqtSignal(list)
+    newData = QtCore.pyqtSignal(list, str)
 
     counter = itertools.count()
 
@@ -87,6 +88,9 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
 
         self.bwbutton.toggled.connect(self.change_background)
 
+        self.setAcceptDrops(True)
+        self.graphic.installEventFilter(self)
+
     def _init_gui(self):
         self.setWindowTitle('Graph ' + str(next(QGraphWindow.counter)))
 
@@ -119,6 +123,34 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
         for lineedit in [self.xmin_lineedit, self.xmax_lineedit, self.ymin_lineedit, self.ymax_lineedit]:
             lineedit.setValidator(QtGui.QDoubleValidator())
 
+    def eventFilter(self, obj: QtCore.QObject, evt: QtCore.QEvent):
+        """
+        Catch drag and Drop to prevent anything inside self.graphic to accept the events.
+        Without event filter, we cannot process it here and start file reading
+        """
+        if evt.type() == QtCore.QEvent.Type.DragEnter:
+            evt.accept()
+            return True
+
+        elif evt.type() == QtCore.QEvent.Type.Drop:
+            return self._handle_drop(evt)
+
+        else:
+            return False
+
+    def dropEvent(self, evt: QtGui.QDropEvent):
+        return self._handle_drop(evt)
+
+    def _handle_drop(self, evt: QtGui.QDropEvent):
+        if evt.mimeData().hasUrls():
+            files = [str(url.toLocalFile()) for url in evt.mimeData().urls()]
+            self.newData.emit(files, self.id)
+
+            evt.accept()
+            return True
+
+        return False
+
     def __contains__(self, item: str):
         return item in self.sets
 
@@ -304,6 +336,8 @@ class QGraphWindow(QtWidgets.QGraphicsView, Ui_GraphWindow):
                 if item in self.graphic.items():
                     self.graphic.removeItem(item)
 
+        self.show_legend()
+
     @QtCore.pyqtSlot(bool, name='on_imag_button_toggled')
     @QtCore.pyqtSlot(bool, name='on_real_button_toggled')
     def set_imag_visible(self, visible: bool):