Bug 31395 Child window of Preferences dialog centers between screens
On the Preferences->Java->Code Generation->Names tab, the Edit button opens a dialog that is split between multiple monitors, instead of centering on the main Preference window like the rest of its child windows do.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/OptionsConfigurationBlock.java
Label labelControl= new Label(parent, SWT.LEFT | SWT.WRAP);
		labelControl.setText(label);
		labelControl.setLayoutData(gd);
		
		Combo comboBox= new Combo(parent, SWT.READ_ONLY);
		comboBox.setItems(valueLabels);
		comboBox.setData(data);
		comboBox.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL));
		comboBox.addSelectionListener(getSelectionListener());
		
		String currValue= (String)fWorkingValues.get(key);	
		comboBox.select(data.getSelection(currValue));
		
		fComboBoxes.add(comboBox);
	}
	
	protected Text addTextField(Composite parent, String label, String key, int indent, int widthHint) {	
		Label labelControl= new Label(parent, SWT.NONE);
		labelControl.setText(label);
		labelControl.setLayoutData(new GridData());
				
		Text textBox= new Text(parent, SWT.BORDER | SWT.SINGLE);
		textBox.setData(key);
		textBox.setLayoutData(new GridData());
		
		String currValue= (String) fWorkingValues.get(key);	
		textBox.setText(currValue);
		textBox.addModifyListener(getTextModifyListener());
		GridData data= new GridData(GridData.HORIZONTAL_ALIGN_FILL);