Add vertical spacing between fields on VerticalFieldManager - blackberry

Question

I am adding fields to a VerticalFieldManager. Is there a method of adding vertical spacing between fields?

Answer 1

There's several solutions to this, one being that you can create a custom field to be used as a spacer between your other fields.
private static class SpacerField extends Field
{
private int spacerWidth;
private int spacerHeight;
private SpacerField(int width, int height) {
spacerWidth = width;
spacerHeight = height;
}
protected void layout(int width, int height) {
setExtent(getPreferredWidth(), getPreferredHeight());
}
protected void paint(Graphics g) {
// nothing to paint; this is a blank field
}
public int getPreferredHeight() {
return spacerHeight;
}
public int getPreferredWidth() {
return spacerWidth;
}
}
//...
// Usage
add(new LabelField("Before Spacer"));
add(new SpacerField(0, 100));
add(new LabelField("After Spacer"));
Setting the padding or margins of your contained fields is another solution. It's up to you on what you think is the best way of managing things.

Answer 2

There are more elogant ways of doing this using the setPositionChild() methods but a simple work around is to give your fields padding using the setPadding(int top, int right, int bottom, int left) method.
myField.setPadding(5, 0, 5, 0);

Answer 3

I actually find that most times, what you want to do is call setMargin() on the vertical field manager's child fields, not sePadding(). I certainly think creating a SpacerField is now unnecessarily complex.
myField.setMargin(5, 0, 5, 0);
It depends on which kind of child field we're talking about, and how its size is specified, but in general, setPadding() will actually make the field bigger, which could have a visual impact, depending on how the field's background and border are drawn. setMargin() does not make the field any bigger, which I think is more consistent with what the question is asking.
See Mr Vincenzo's answer here, with pictures!
Note: setMargin() and setPadding() were officially added to the Field API relatively late in the BlackBerry Java evolution, but were available as undocumented methods before that.
Another Note: I have seen strange problems when using setMargin(), like the one described in this question. In that case, I did have to resort to one of the other two solutions here.