Aplets

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Aplets are the heart and soul of the calculator. Essentially, creating your own involves making a copy of one of the standard ones and then grafting new abilities onto it.

The key to the entire process of creating completely new aplets is the VIEWS menu and its controlling command function SETVIEWS. This function allows you to override the normal behaviour of an aplet and superimpose new properties by linking in a set of programs written by you. It is mildly deceptive to call these aplets "new", as they derive from one of the standard ones, but the modification of the VIEWS menu means that their final appearance and behaviour can be very different to the aplet they derive from. Essentially the process involves the following stages...

bulletChoose the parent aplet;
bulletAnalyse the expected behaviour of your new aplet and design the VIEWS menu;
bulletWrite the 'helper' programs and attach them to the aplet using the SETVIEWS function;
bulletAdd supporting documentation.

Choosing the parent aplet

The first stage in the creation process is to decide which of the standard aplets you wish to make the "parent" of your new child aplet. For some aplets this may not matter, but for others this can be a very important choice. All the abilities of the parent are inherited by the child so the parent choice is crucial if your aplet requires particular abilities. The most commonly used parent aplets are the Function and Statistics aplets, whereas the Quadratic and Trig Explorers would probably not make good parent aplets, since they are specialized teaching aplets without the flexibility of the others.
If your new aplet is going to be concerned with analysing data then your best choice for a parent would probably be the Statistics aplet. On the other hand if you were planning to write an aplet to teach the behaviour of graphs then the Function or Parametric aplets would obviously be best. All the tools of the parent are available to the child, so consider carefully what tools you require.

If your new aplet is going to be concerned with analysing data then your best choice for a parent would probably be the Statistics aplet. On the other hand if you were planning to write an aplet to teach the behaviour of graphs then the Function or Parametric aplets would obviously be best. All the tools of the parent are available to the child, so consider carefully what tools you require.

A detailed explanation of the whole process, including a number of detailed examples, can be found here. I strongly suggest that you read this as it contains a lot of information that took me a long time to learn!

Finally, let me make an appeal to new programmers. Don't neglect the documentation! Many programmers think that the process begins and ends with the aplet, forgetting that that other people need to have instructions on how to use it! Download one of my aplets and have a look at the standard I use.

 
Last modified: 19 Dec 2007                                             Sitemap        Home        Contact Me