Question

Is it possible to add gui components to blackberry screen beginning from the bottom instead of the top ?

Thanks

Answer 1

A quick response would be no but let me explain why and suggest afew work arounds;

Screens don’t actually handle the laying out of fields onto themselves, to do this they delcare a delegate manager which can be any type of manager, vertical, horizontal etc. The problem is all managers begin painting themselves from the top left. For a manager to paint fields starting from the bottom it would have to know exaclty where the bottom is located and add components up rather than down which goes against all the low level code inside the manager class. You can read more on managers in the BlackBerry API documentation.

You could still achieve an effect similar to this though by tweaking how you add fields and playing with field styles. For example consider this code:

  add(new LabelField("field 1"));
  add(new LabelField("field 2"));

This would give us the results;

 field 1
 field 2

because field 1 is drawn then field 2 below it. However if we were always to insert fields at the begining of our manager e.g. position 0 like so:

   insert(new LabelField("field 1", FIELD_BOTTOM), 0);
   insert(new LabelField("field 2", FIELD_BOTTOM), 0);

We would get the results;

field 2
field 1

Which is the results you’d expect from a screen described in your question.

I’m not really sure how you’d get the fields to paint to the bottom of a screen though, you could try researching the “position relative bottom” styles but I’m honestly unsure.