Category Archives: Techniques

Java and External Data Structures on IBM i

One of my favorite techniques for passing structured bulk data around is using datas queue’s with the format of the data defined in an external data structure.

In RPG this is very easy … you defined a data structure using the EXTNAME keyword.

dcl-ds stuct1 extname('EXTDS1') end-ds;  Code language: JavaScript (javascript)

Then you just use the data structure name when calling the QRCVDTAQ or QSNDDTAQ api’s and the data will be nicely mapped into the appropriate structure field.

But what if you wanted to allow a Java application to consume or populate the data queue?

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Confirming cancel in a ProgressMonitorDialog

I’m working on a routine that downloads content from a host to the users desktop.

As the content is being downloaded, a progress dialog is displayed (implemented as ProgressMonitorDialog).

In the progress monitor, the cancel button is enabled.

In the default implementation, if the cancel button is pressed on the ProgressMonitorDialog, the cancel button is disabled.

I wanted to be able to ask the user if they really want to cancel the operation. If they don’t, then continue on with the operation. If they do, then perform the cancellation as usual.

I couldn’t find a straight forward way to implement this with the default operation, so I came up with my own solution…

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Dynamically populating a Combo based on shift key

In a recent project I had a combo box that I wanted to add additional entries to if they clicked on it with the shift key pressed.

This is to allow to select entries that would not normally be displayed (for example, out dated values that could actually be selected).

To do this, I added key-up & key-down listeners on the Display object and populated the Combo based on the shift key state.
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Adding Help to Dialogs

I’m in the process of updating the help text for my RCP and have found that some of the dialogs that I’m invoking don’t have the ability to directly add help context id’s.

After a bit of digging, I found it’s not that difficult to add help to an object that extends Dialog.

For this example, I’m going to add a help id to the InputDialog class.

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