Composite

How to hide a Composite

To hide a composite managed with GridLayout, set visible to false, set the composite’s GridData.exclude to true, and force parent layout: 

public void headerVisible(boolean visible){
    header.setVisible(visible);                // header is the composite that may need to be hidden
    GridData gridData = (GridData) header.getLayoutData();
    gridData.exclude = !visible;               // If visible, exclude is false; if hidden, exclude is true.
    parent.layout(true); //force parent layout
}

Updating a composite after widgets have been added or removed

Under GridLayout: 

• a call to pack() will show the new widget, but will shrink the size of the composite and its contents.
• a call to layout() or layout(true) will do absolutly nothing–contrary to what the JavaDocs might say.
• only layout(true,true) will refresh the content of the composite without shrinking the size of the composite itself.

Note in the following snippet that adding a widget requires setting the layout data for the new widget. 

private void addToComposite(Address address) {
 AddressDisplayComposite adc = new AddressDisplayComposite(addressComposite, SWT.NONE);
 adc.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false, 1, 1));
 adc.setAddress(address);  // initializes the composite using the address object
 
 this.addressComposite.layout(true, true);
}