maximumLayoutSize()
This method is called by a container when its getMaximumSize() method is called. The layout manager is
responsible for calculating the amount of space that the container needs to display all of its components using
their maximum sizes.
In the case of DividerLayout, it identifies the largest height value from the three components and
determines which of the two outer components has a larger width value. That width value is multiplied by 2
since there are two "outer" components that will be assigned identical widths and the result is added to the
width of the center component, as shown below:
public Dimension maximumLayoutSize(Container target) {
Dimension size;
int width = 0;
int height = 0;
if ((westComponent != null) && (westComponent.isVisible())) {
size = westComponent.getMaximumSize();
width = Math.max(width, size.width);
height = Math.max(height, size.height);
}
if ((eastComponent != null) && (eastComponent.isVisible())) {
size = eastComponent.getMaximumSize();
width = Math.max(width, size.width);
height = Math.max(height, size.height);
}
width *= 2;
if ((centerComponent != null) && (centerComponent.isVisible())) {
size = centerComponent.getPreferredSize();
width += size.width;
height = Math.max(height, size.height);
}
return new Dimension(width, height);
}
getLayoutAlignmentX() and getLayoutAlignmentY()
These methods are provided for layout managers such as BoxLayout that use an alignment value to position
the components within the container. Like most layout managers, however, DividerLayout does not use
alignment values, so the value returned isn't important, and "dummy" implementations are shown below:
public float getLayoutAlignmentX(Container target) {
return 0.0f;
}
public float getLayoutAlignmentY(Container target) {
return 0.0f;
}
invalidateLayout()
This method is called to indicate to the layout manager that it should clear any cached information related to the
size and position of the container's components. This is only related to information that has been derived by the
layout manager itself, and a call to this method does not indicate that constraint information that was explicitly
passed to the layout manager should be discarded. For example, if your layout manager performs computations
that are slow and complex, it may be worthwhile to cache the results of those computations. Like most layout
managers, no action needs to be taken in DividerLayout's implementation of this method:
public void invalidateLayout(Container target) {
}
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