Hi,

With the successful preliminary implementation of java events calling pascal code, my next step is to try to integrate android's visual controls. Can anyone give a very basic example using pascal/JNI only (even pseudo code) on how to create and display an android control from scratch? In other words, what are the steps needed?

To make an analogy, creating a Lazarus button requires these basic steps to make a button visible:
- Create the button object (TButton.Create)
- Set its owner (button.Owner := form)
- Set its parent (button.Parent := form)

Stephano

The Owner is only needed for streaming.

- Set its parent (button.Parent := form)

Mattias

The thought never occurred to me as setting the owner is as almost like breathing. You just don't think about it :)

Stephano

There is a JNI example app here:
http://sourceforge.net/p/lazarus-ccr/svn/HEAD/tree/bindings/android-ndk/examples/jnitest/

It doesn't create a button, instead it creates a TextView, and it doesn't create it in Pascal, but in Java. Anyway, it is a starting point to do whatever you want, including creating buttons in Pascal.

Thanks.

I had already progressed but I am using
LazAndroidModuleWizard to kickstart, it seems I can't use that method, especially that the code that creates the button is called from the main data module. I am trying to find how to "inject" the button into the datamodule.

If the concept works, then the workflow of creating an android app with Lazarus would be:

- Use a project wizard to setup the project. It will place a fixed java snippet in the src project folder and set up manifest files and ancillary files.

- Run a tool which reads android "headers" and produces a pascal unit(s) according to certain rules.

- Code in pascal :)

The tool will produce for each java class a corresponding pascal class. For example, the pascal android media player class will be analogous to the java one, but acts as a gateway to the actual java class. It uses normal pascal events instead of listeners.

example code for the media player:
   gMediaPlayer := TJMediaPlayer.Create;
   ....
   gMediaPlayer.SetOnCompletionListener(DataModuleOnCompletion);
   gMediaPlayer.SetOnPreparedListener(DataModuleOnPrepared);
gMediaPlayer.SetDataSource('http://www.soundjay.com/button/button-1.mp3');
   gMediaPlayer.Prepare;
   gMediaPlayer.Start;
   ...
   gMediaPlayer.Free;

DataModuleOnCompletion and DataModuleOnPrepared are normal pascal methods (TNotifyEvent in this case).

Stephano