To start the tour of the watch example, look at the Graph Browser in the MetaEdit+ main launcher. All models related to the watch example are shown on the Graphs list (make sure ‘Digital Watch’ is selected in the Projects list). Choose the ‘WatchModels’ WatchFamily diagram from the list and open it in the Diagram Editor by double-clicking it, or by selecting Open from the pop-up menu (as shown in Figure 2-1).

The ‘WatchModels’ WatchFamily diagram (Figure 2-2) presents a family of related wristwatch models. In the diagram, each individual watch model like Ace is shown as a green filled relationship that combines a Display on the left with a Logical watch application on the right.

To further explore the watch example, let us take a look at how the logical watch applications have been constructed. Hold down the Ctrl-key and double-click the one called ‘TASTW’ to open the ‘TASTW’ WatchApplication diagram as shown in Figure 2-3 (you could also have opened this diagram from the Graph Browser). Note that on a Mac, wherever this manual says to use Ctrl, you should use the Command key.

This diagram shows the configuration of the logical watch application. It only contains the top-level logical configuration of sub-applications, basically showing which sub-applications have been included into this specific logical watch and in which order they are invoked. When the logical watch application is started (i.e. the watch is powered up), the basic Time sub-application will be invoked. If this sub-application is exited, a Stopwatch sub-application will be started. The cycle is completed when Time will be re-activated when exiting from the WorldTime sub-application. The name ‘TASTW’ comes from these sub-applications’ initials in order. To see how the sub-applications have been defined, choose one and open its decomposition graph by double-clicking the sub-application element while holding down the Ctrl-key.

Now we are ready to generate the code of the test environment for our watch models. Close all WatchApplication diagrams and go back to the WatchFamily diagram. Before we run the generation, we have to choose the target platform for which the code will be generated. Select Graph | Properties... in the WatchFamily Diagram Editor and choose the language and platform you are on from the Generation target platform list. ‘C#: Windows’ should work by default out-of-the-box in most Windows installations. Java works on a wider choice of platforms – ‘Java: Windows’, ‘Java: Linux’ or ‘Java: Mac OS X’ – but requires you to install the Java SE Development Kit and set its path, as explained in the Preface.

To invoke the code generation, select Graph | Generate... (or press the Generate button in the Diagram Editor toolbar) and choose ‘Autobuild’ from the list that opens. Since this generator is used frequently, it has also been given its own Build button on the toolbar. However you invoke it, this will generate the code for all watch models in the family, and compile and start a Watch Launcher for those models. The Watch Launcher for ‘C#: Windows’ is shown in Figure 2-4.

To test a watch model, click its button in the Watch Launcher to open its test environment, as shown for Ace in Figure 2-5. In the watch test environment you can test the watch as it would appear in real life by pressing the buttons and observing the behavior of the times and icons on the display. The current application is shown above the screen display, and the current state is shown below the screen display for debugging purposes.

It is also possible to generate a test environment for just some selected watch models. To do this, open the graph properties dialog for the ‘WatchModels’ WatchFamily diagram and add the desired watch models into the Models selected for generation list by selecting Add Existing... from the list pop-up menu and double-clicking the appropriate watch models from the dialog that opens. When the models have been added to the list, run the ‘Autobuild’ generator as explained previously.

Along with the code for the Watch test environment it is also possible to generate the model documentation directly from the Watch models. To try this feature out, run the generator called ‘Watch family documentation’. The output will be shown in your web browser with clickable pictures and links.