Added concrete class for main UI window, added stubs for slots + implementation of file selection.

sohstationviewer/view/mainwindow.py

+import sys
+from PySide2 import QtCore, QtGui, QtWidgets
+from main_ui import Ui_MainWindow
+
+class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
+    """
+    Implements the core logic for the Ui_MainWindow class
+    produced by Qt Designer. Any custom slots / signals
+    should be implemented in this class. Any modifications to
+    Ui_MainWindow *will* be lost if the UI is ever updated in
+    Qt Designer.
+    """
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setupUi(self)
+
+    @QtCore.Slot()
+    def readSelectedFile(self):
+        print('Reading currently selected file.')
+
+    @QtCore.Slot()
+    def stopFileRead(self):
+        print('Abandoning file read.')
+
+    @QtCore.Slot()
+    def writePSFile(self):
+        print('Writing PS file.')
+
+    @QtCore.Slot()
+    def reloadFile(self):
+        print('Reloading last file.')
+
+    @QtCore.Slot(str)
+    def changeCurrentDirectory(self, path=''):
+        fd = QtWidgets.QFileDialog(self)
+        fd.setFileMode(QtWidgets.QFileDialog.Directory)
+        fd.exec_()
+        new_path = fd.selectedFiles()[0]
+        self.currentDirectoryChanged.emit(new_path)
+
+    currentDirectoryChanged = QtCore.Signal(str)
+
+
+if __name__ == '__main__':
+    app = QtWidgets.QApplication(sys.argv)
+    wnd = MainWindow()
+    wnd.show()
+    sys.exit(app.exec_())
+