PrintIn the next step, we add the code for creating the QApplication and the QMainWindow and QDialog objects for the main window and the dialog for creating a new shapefile with their respective GUIs. For this, please paste the following code into your script directly under the comment “# create app and main window + dialog GUI”:
app = QApplication(sys.argv)
# set up main window
mainWindow = QMainWindow()
ui = gui_main.Ui_MainWindow()
ui.setupUi(mainWindow)
ui.actionExit.setIcon(app.style().standardIcon(QStyle.SP_DialogCancelButton))
ui.layerRefreshTB.setIcon(app.style().standardIcon(QStyle.SP_BrowserReload))
ui.directInputLatLE.setValidator(QDoubleValidator())
ui.directInputLonLE.setValidator(QDoubleValidator())
ui.nominatimLimitLE.setValidator(QIntValidator())
ui.geonamesLimitLE.setValidator(QIntValidator())
mapWV = WebMapWidget()
mapWV.page().profile().setHttpAcceptLanguage("en-US")
mapWV.setHtml(core_functions.webMapFromDictionaryList([]))
ui.resultsListAndMapHBL.addWidget(mapWV)
mapWV.setFixedSize(300,200)
mapWV.setSizePolicy(QSizePolicy(QSizePolicy.Fixed,QSizePolicy.Fixed))
# set up new shapefile dialog
createShapefileDialog = QDialog(mainWindow)
createShapefileDialog_ui = gui_newshapefile.Ui_Dialog()
createShapefileDialog_ui.setupUi(createShapefileDialog)
In lines 4 to 6, we are creating the mainWindow object and then its GUI by calling the ui.SetupUi(…) method of an object we created from the Ui_MainWindow class defined in gui_main.py. The same happens in lines 23 to 25 for the dialog box for creating a new shapefile. The rest of the code is for creating some additional elements or setting some properties of GUI elements that we couldn’t take care of in QT Designer:
- Lines 8 and 9: Here we set the icons for the exit and refresh tool buttons in the GUI taking icons from the QT standard icon set.
- Lines 11 to 14: What happens here is something that we did not discuss before. QT provides some way to set up so-called Validator objects for determining what the user is allowed to enter into a line edit widget. We use QDoubleValidator and QIntValidator objects to restrict the input for Latitude and Longitude widgets of the “Direct Input” tab to floating point numbers and for the Limit widgets of the Nominatim and GeoNames query tabs to integer numbers, respectively.
- Line 16 to 20 are for creating the web view widget next to the list view widget in the third row of our main window layout. Remember how we explained in the previous section that we are defining the name WebMapWidget as an alias for the web widget that is available in the version of PyQt5 that is being used. In QT Designer, we created a QHBoxLayout for this row which is now accessible in ui.resultsListAndMapHBL, so we add the new widget to that layout and make some changes to its layout related attributes to give the widget a constant size that matches the size of the web map produced by the function webMapFromDictionaryList(…) from the core_functions.py module.
- At this point, you can actually run the code and it should already produce the desired GUI for the main window. You just won’t be able to do much with it, since we have not defined any event handlers yet.