What are the best Layout Managers to use in these cases?

Question

(1) I have a form with labels at text fields. Right now, there are three lables and three text fields. There is a good chance (90%) that I will need to add additional fields and labels, so it needs to be expandable. Now, all of these features reside on a JPanel which resides as a tab in a JTabbedPane which resides in a JFrame. Regardless of the size of the JFrame, the contents of the JPanel should be their default sizes. Also - if anyone says SpringLayout, no - I use the code for the SpringForm from the Java tutorial, and I always get exceptions related to arrays (out of bounds, IIRC - I don't have the code on this PC).
(2) I have another form (of sorts) that, right now, includes only one row of three components (a label, a text field, and a button). However, There's a 99% chance I'll be adding other things to this menu. What's a good layout manager that will help me keep everything their default sizes as well as add more "rows" of components that might have different numbers of components in them?

Answer 1

If you really want advice then you need to learn how to specify requirements.
1) "I have a form with labels at text fields. Right now, there are three lables and three text fields."
and how do you want the component layed out????
a) do you want all the fields on a single line, in which case you would use a FlowLayout or a horizontal BoxLayout.
b) do you want all the fields on separate lines, in which case you could use a vertical BoxLayout
c) do you want pairs of label and text fields on a single line? If so, then do you want each lable and text field in a column? If so then do you want the labels left or right justified, or centered? You have many options depending on your requirements:
- use a GridBagLayout.
- use a GridLayout. Each cell will be the same size but you can add your components to a JPanel first and then add the panel to the GridLayout. In this case the panel will be resized, but the component will retain its original size.
- use a BorderLayout.. The West will contain a panel of your labels in a GridLayout. The East will be the text fields in a GridLayout.
- figure out how to use the SpringLayout correctly. The demo doesn't cause errors, so its obviously your code that is causing the problem. Do some debugging to fix your problem.
- write your own LayoutManager. I wrote one which I called ColumnLayout, which I posted in the forum somewhere. It is like the GridLayout excepct each column is the widht of the widest component in the column and each row is the height of the talles component in the row.
2) Learn to mix and match LayoutManagers.
includes only one row of three componentsSounds like a FlowLayout
as well as add more "rows" of components that might have different numbers of components in them? Sounds like another FlowLayout.
Each row would then be added to a main panel using a vertical BoxLayout.
The point is you are not restricted to a single LayoutManager for a form. Mix and match to get the effect you desire.