 The fourth row of our layout is again very similar to the second one. We have a tab widget with a button below it and then we have to set up the widgets for the different tabs. So first thing is to take a tab widget under containers and drag it over, drop it onto the group box for it features, and then I'm going to change the layout of the group box to use a vertical layout. And I'm going to add a third page to that tab by doing the right click on top of it and using InselPage. And now I'm going to give the tabs the right names in the property editor. Again we have to scroll down to the green area and there on the current tab text we change the titles, the first one should be called shape file, the second one to be called layer, and the third one should be called CSV. And you have to make sure that you rename the entire tab widget as shown in the graphic. It's in the figure in the lesson materials and also the individual tabs. So these entries here in the hierarchy need to be renamed. And then we can add the horizontal layout for the single button here. So that's something you have seen before now. I'm going to drag the horizontal layout, drop it below the tab widget, and then we're going to add a push button to that horizontal layout and a horizontal spacer so that the button is pushed all the way to the left. And the title of the button, double clicking it again and changing it to add. Okay, at this point we just have to create the content for the different tabs starting with the shape file. Like the tabs above for the services, all these are using grid layouts to arrange the items. Starting with a button that is for creating a new shape file. I'm dropping a push button into the shape file tab widget and then I'm going to do a right click and change the layout to grid. And the title of the button should be changed to create new shape file and three dots. Because this one is going to open a dialogue which is indicated by three dots. Then we have two labels below it. I'm going to add the first label and changing it to say add to shape file. And then the second label below it. This one says field to store name. And then for the second row we need a line edit widget for entering the name of a shape file. I'm dropping it here with the vertical blue bar on the right. For the third row we need a combo box widget. So one which allows the user to pick between a small number of choices. Going to place there will be a horizontal layout. And then we're going to add the combo box to that horizontal layout. And we add a horizontal spacer so that the effect of that is that just the combo box again is not expanded all the way but just as much as needed to display the items in it. And then the last thing missing is this tool button we have here that is going to open the file dialogue for picking a shape file. So we take a tool button under buttons and dropping it in the second row to the right of the line edit widget like this. And then we have set up everything for this shape file tab. And we can move on to the layer tab. It looks somewhat similar. We can start by adding the two labels. One will be called pick layer. And the second one will be called field to store name. We're setting the layout of this tab to use it with. And then we actually have two combo boxes here for both rows. So I'm dragging a combo box and place it to the right of the pick layer label. And another combo box to the right of the field to store name label. And then we have another tool button for refreshing the list of layers. So that tool button I will drag over and drop to the right of the first combo box. And finally, so that all of this does not take more space than needed, we're going to place a horizontal spacer as a kind of the fourth column. And then everything will be pushed over to the left as much as possible. So that's it for the layer tab. And we can move on to the CSV tab. And that one is really simple now. It just has a grid with a single row. So we could also use a horizontal layout for that. So I'm going to start with the label for that label add to file. Now I'm going to do right click layout, layout horizontally. And then I'm going to drop the line edit for entering the name of the CSV file to the right of the label. And finally, another tool button for opening a file dialog to the right of the line edit. So now I'm saving everything. So basically we have the key for our main window done. There's just a little thing to do for this exit tool button we have at the top. And this one, for this one, we have to set up an action so that we can directly say inside QT designer that this tool button here at the top should basically close the application. The action editor can be found here at the bottom right. And I just click this button, the first button at the top, which is for creating a new action. And then I'm filling out the dialog, the text for that action should be exit, the object name, action exit that can remain like it is. And we can enter a tool to exit program for it. And that's basically all we're going to do here. We're going to pick an icon for this later on from our code using the standard set of icons coming with QT. So I'm pressing OK. And now we have this action in our list of actions here. And I can actually take the action and drag it and drop it on top of our toolbar that we have on top of the main window. And we now see that we have the action shown up there as exit and we will replace the text data with the icon as I said. So far we have not said what the action should do. So I'm going to change to the signal and slot editor now by clicking on the tab below the action editor below. And I'm now going to add an entry there by clicking on the plus symbol. And for sender, I'm picking the action exit that we just created. Then I'm picking the signal triggered. So meaning whenever action exit is triggered, for instance, by clicking on the exit button in the toolbar, the signal should be sent to, and now I'm picking our application. So I'm clicking the main window, I mean, and picking the close slot. So meaning when the signal is sent to the main window, its close method will be executed and the application will be closed. Now saving the program. And let's look at the preview for a moment. So we see the elements are all there. The different tabs are showing up correctly. But obviously we don't have much functionalities and not a lot is going to happen, except that we can use already the tool bar to close the application.