We'll write the remainder of this page as if it were describing stories for the music library/player. We'll use italics when we want to point out features of the framework. You might as well run the example now before you continue reading.SampleApplications. See the MusicExampleObjectModel to understand all of the objects in play here.
The music browser starts up looking at the whole library of songs. We specify the library (an advanced feature) so that we know what we are talking about in this document.
This is a the file that library reads. It is tab separated text. Try downloading it and looking at it with a spreadsheet. http:Release/Source/eg/music/Music.txt
We can pick songs and see details of our selection as we go.
ActionFixture interprets the words in the first column. The actions operate on fields and buttons on the Browser screen we started in the first table. The Browser (or what ever other Fixtures we start) interprets the names in the second column. Each name maps to a method of the Browser. The third column provides data that are pass as arguments to Browser methods or compared with Browser method results. See MusicExampleWithErrors to see how errors are reported.
Once we've picked a song, we can play it. We can continue operating the Brower while music is playing. Since this sequence is long, we'll explain what we are doing in an unused column.
This table is interpreted by Realtime, a Fixture that adds actions having to do with realtime operation of the music player. This fixture calls on a simulator to keep track of system events. We do so here only because the application we are testing isn't a real music player. Our toy application cooperates with the simulator to keep track of time. A real player would do things that take real time and it would use the computer's realtime clock to keep track of time. We could still use a fixture with actions like pause and await but there wouldn't need to be a simulator too.
Searching for Music
There are buttons on the browser to find more songs like the one we have picked.
Our searches take a few seconds to complete. Eventually we will want to try mashing buttons faster than the computer can respond. For now we will be polite and await completion of our searches.
The selected songs are displayed in a table.
Here we use Display (a RowFixture) to directly examine the Music object found by our search. Things like artist and track() are fields and methods of the domain objects.
We can find songs related in different ways. Each new way produces a (possibly) different list of songs. Show all restores the display to the initial conditions.
Yielding the display:
Domain objects typically have lots more fields and methods than we can conveniently look at in a single table. We compose a table specific to our needs by choosing column headings of interest. Here is another look at the results of the previous search.
Notice that the songs in the two tables are not in the same order. That is because we didn't type the tables in the same order, and the order we type is preserved. RowFixture(s) use the left hand columns to line up the search results with the table values. Check out MusicExampleWithErrors to see how this works when the rows don't match up.
The kaffe jvm/library has trouble with date formatting so you may see errors when running this from wiki.
This completes the MusicExample.
We've run quite a few test. We'll call up one more Fixture that will add a summary to the end of our document.
|Last edited October 11, 2002
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