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/CodeFormatterConfigurationBlock.java
addCheckBox(newlineComposite, label, PREF_NEWLINE_OPENING_BRACES, insertNotInsert, 0);	
		
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.newline_control_statement.label"); 
		addCheckBox(newlineComposite, label, PREF_NEWLINE_CONTROL_STATEMENT, insertNotInsert, 0);	
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.newline_clear_lines"); 
		addCheckBox(newlineComposite, label, PREF_NEWLINE_CLEAR_ALL, new String[] { CLEAR_ALL, PRESERVE_ONE }, 0);	
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.newline_else_if.label"); 
		addCheckBox(newlineComposite, label, PREF_NEWLINE_ELSE_IF, insertNotInsert, 0);	
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.newline_empty_block.label"); 
		addCheckBox(newlineComposite, label, PREF_NEWLINE_EMPTY_BLOCK, insertNotInsert, 0);	
		
		layout= new GridLayout();
		layout.numColumns= 2;	
		
		Composite lineSplittingComposite= new Composite(folder, SWT.NULL);
		lineSplittingComposite.setLayout(layout);
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.split_line.label"); 
		addTextField(lineSplittingComposite, label, PREF_LINE_SPLIT, 0, textWidth);
		layout= new GridLayout();
		layout.numColumns= 2;	
		
		Composite styleComposite= new Composite(folder, SWT.NULL);
		styleComposite.setLayout(layout);
		
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.style_compact_assignement.label"); 
		addCheckBox(styleComposite, label, PREF_STYLE_COMPACT_ASSIGNEMENT, new String[] { COMPACT, NORMAL }, 0);		
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.style_space_castexpression.label"); 
		addCheckBox(styleComposite, label, PREF_SPACE_CASTEXPRESSION, insertNotInsert, 0);		
		label= PreferencesMessages.getString("CodeFormatterPreferencePage.tab_char.label"); 
		addCheckBox(styleComposite, label, PREF_TAB_CHAR, new String[] { TAB, SPACE }, 0);