Java tip: Problems and special features of the CDE/Motif look and feel, part 2

This part 2 of 4 articles continues a component by component review of problems, workarounds, and special features for the classic Java Swing CDE/Motif look and feel. Example images are included along with UIDefaults values, color swatches, and icon images.

Part 1 of this series reviewed how to select the look and feel and access its UIDefaults, then started an alphabetical run through its components from JButton through JEditorPane. Part 2 here covers JFileChooser through JOptionPane. Part 3 covers JPanel through JSplitPane. And Part 4 covers JTabbedPane through JViewport.

Working with the CDE/Motif look and feel

Below continues an alphabetical run through the look and feel's UIDefaults and Swing components. Non-string keys and UI class values are implementation artifacts and are not included here.

JFileChooser

Problems

• The default size of a JFileChooser is wide enough for the entire absolute file path to the starting directory. The longer the path, the bigger the dialog box! You can prevent this unfortunate behavior by setting the size of the chooser explicitly with setSize( Dimension d ) (other look and feels don't have this behavior).
• The default accept-all file filter's description in the filter menu is "*" instead of the typical "All Files". You can override this by disabling the default accept-all filter with setAcceptAllFileFilterUsed( false ), and then create and add your own accept-all filter with addChoosableFileFilter( FileFilter f ) using any menu text you like.
• The default approve button text for an open dialog is "OK" instead of the usual "Open". You can correct this by calling setApproveButtonText( String s ).
• The "OK" button is enabled even when no files or folders are selected, but pressing it does nothing until a file is chosen (other look and feels disable the button until a file is selected).
• The "Help" button is always present, but always disabled. It's hard-coded that way. There is no way to install an action listener to respond to the button without burrowing through the component's children to find an unnamed button with a "Help" label.
• There is no "New Folder" button (most look and feels include such a button).
• None of the dialog's buttons are initially marked as the dialog's default button (some look and feels set a default, and some do not). Pressing tab cycles the keyboard focus through the chooser's components and will make any button with the focus the default button.
• The buttons along the bottom don't have uniform size and they stretch as the chooser is resized. This looks sloppy and it cannot be corrected without digging through the component's children and overriding the layout.
• The bottom buttons are crowded against the bottom of the chooser. When one of the buttons is marked as the default, its groove around the button and pink keyboard focus outline go right to the edge of the chooser. You can't add border space when using the showOpenDialog( Component c ) or showSaveDialog( Component c ) methods. Instead, you can create your own JDialog, add an EmptyBorder to the dialog's content pane, then add the JFileChooser. This also lets you set the size of the dialog box so that it isn't as wide as the directory path.
• The chooser includes a transparent gap between the opaque upper and lower panels. If you're using a parent container with a different background color, it'll show through here. But you can't make the parent's color show through for the rest of the panel without digging through the chooser's child components, which will give you implementation dependent results. There are no standard methods on JFileChooser to get the child panels.
• The file chooser is not the native Mac, Windows, or Linux file chooser users are likely to be familiar with. Its non-standard appearance and layout may confuse users.
• The placement of buttons along the bottom of the dialogs is not consistent with native platform conventions. For the Mac, Windows, and Linux, dialog button conventions right-align all buttons instead of spreading them out. On the Mac, the approve button should be right-most, while for Windows it should be left-most.

JFormattedTextField

Special features

• The UIDefaults "FormattedTextField.border" contains a border object that draws the recessed beveled border around the text field.

  FormattedTextField.border

Problems

• An editable JFormattedTextField only indicates the keyboard focus with a black caret. The component doesn't draw the pink outline used by most components to indicate the focus.
• The field's text is crowded against the edges of the component border. You can increase the margins with setMargin( Insets m ).

JInternalFrame

Special features

• The UIDefaults "InternalFrame.border" gives a border object that draws a frame's thick beveled border, but not the title bar. You can use the border to give a frame-like look to any component, such as a JPanel, though it will only show resize corners on a JInternalFrame subclass.

  InternalFrame.border

Problems

• Except for "InternalFrame.icon", all of the UIDefaults icons are empty. "InternalFrame.icon" contains a small unused Java cup icon. There are no UIDefaults icons for the actual title bar icons (some look and feels provide them, and some do not).

  InternalFrame.icon 16 x 16

• Any frame icon set with setFrameIcon( Icon i ) is ignored (most look and feels show the frame icon on the title bar).
• There is no way to set the desktop icon for an iconified JInternalFrame. The JDesktopPane default icon is always used (most look and feels instead use the frame icon as the desktop icon).
• There is no visual difference between an enabled and disabled JInternalFrame (some look and feels dim the frame's title bar colors when the frame is disabled).
• The frame's decorations depend upon its configured abilities (most look and feels do something similar). The title bar's big square button on the right is present if the frame is maximizable. The small square button beside it is present if the frame is iconifiable. The corner marks on all four frame corners are present if the frame is resizable. The dash button on the title bar is always present and shows a pull-down menu of frame operations.
• There is no way to control the title bar menu's colors or content. It always contains menu items for "Restore", "Move", "Size", "Minimize", "Maximize", and "Close". These names may not match the native platform conventions. For instance, on the Mac the "Maximize" item should be "Zoom" and "Restore" should be "Open."
• The "Move" and "Size" menu items on the title bar menu are always disabled. They're hard-coded that way.
• The look and feel of the JInternalFrame title bar buttons has nothing to do with the conventions of the native platform, so they may leave users confused about which button does what.

JLabel

Problems

• Disabled text is not drawn with the UIDefaults "Label.disabledForeground" or "Label.disabledShadow" colors. Instead it's always drawn using a pair of light and dark colors calculated from the current background color using the Color class's brighter( ) and darker( ) methods. While the disabled text color cannot be set directly, the component's background color used to calculate the disabled colors can be set using setBackground( Color c ).

JList

Note: JList is shown above within a JScrollPane, as it is typically used. The first row is selected.

Special features

• The UIDefaults "List.focusCellHighlightBorder" contains a border object that draws the pink keyboard focus outline around the focused list row.

  List.focusCellHighlightBorder

Problems

• When the list is disabled, the selected row still has a highlighted black background, but the foreground text reverts to the unselected black color. This creates black text on a black background, which makes the selected item unreadable (other look and feels don't have this problem). These colors can be overridden with setForeground( Color c ), setBackground( Color c ), setSelectionForeground( Color c ), and setSelectionBackground( Color c ).
• When the list has the keyboard focus, it draws a pink outline around the selected item. There is no UIDefaults entry for this pink focus color, but the same color is available for other components, such as"CheckBox.focus" and "RadioButton.focus".
• The list's margins crowd text along the left side of the list box. Space can be added by overriding the list's default cell renderer with setCellRenderer( ListCellRenderer r ).

JMenu

Note: JMenu is shown above within a JPopupMenu.

Special features

• The normal menu arrow icon is available in the UIDefaults "Menu.arrowIcon".

  Menu.arrowIcon 10 x 10

• The UIDefaults "Menu.border" contains a border object that draws the recessed border around an armed menu.

  Menu.border

Problems

• There is no UIDefaults entry for the armed version of the menu arrow icon.
• If any menu item on a menu has an icon, all of the menu items leave room for the icon (most look and feels do this). This can look odd if a menu item has an icon but no label. To avoid this look, always give menu items labels.

JMenuBar

Special features

• The UIDefaults "MenuBar.border" contains a border object that draws the normal beveled border around the menu bar.

  MenuBar.border

Problems

• Menu icons are cropped vertically to 22 pixels.

JMenuItem

Special features

• The UIDefaults "MenuItem.border" contains a border object that draws the recessed border around an armed or selected menu item.

  MenuItem.border

Problems

• The UIDefaults "MenuItem.arrowIcon" is empty, but it isn't needed anyway (the icon is an implementation artifact).
• If any menu item on a menu has an icon, all of the menu items leave room for the icon (most look and feels do this). This can look odd if a menu item has an icon but no label. To avoid this look, always give menu items labels.

JOptionPane

Special features

• The UIDefaults "OptionPane.errorIcon", et al contain the default icons for the corresponding option pane types. Unfortunately, they're ugly.

  OptionPane.errorIcon 18 x 18

  OptionPane.informationIcon 12 x 24

  OptionPane.questionIcon 24 x 24

  OptionPane.warningIcon 12 x 24

Problems

• The option pane icons aren't all the same size. This will cause slightly different layouts for different option pane types.
• The placement of buttons along the bottom of the panes is not consistent with native platform conventions. For the Mac, Windows, and Linux, dialog button conventions right-align all buttons instead of spreading them out. On the Mac, the "OK" button should be right-most, while for Windows the "OK" button should be left-most.

Downloads

The CDE/Motif UIDefaults colors are available for download in the X11 rgb.txt file format:

• CDE-Motif-UIDefaults-Colors-RGB.txt

Further reading

Related articles at NadeauSoftware.com

• Java tip: Problems and special features of the CDE/Motif look and feel, part 1 of this series covers JButton through JEditorPane.
• Java tip: Problems and special features of the CDE/Motif look and feel, part 3 of this series covers JPanel through JSplitPane.
• Java tip: Problems and special features of the CDE/Motif look and feel, part 4 of this series covers JTabbedPane through JViewport.
• Java tip: How to use SystemColors to access OS user interface theme colors begins a series of articles on SystemColor values for standard OS themes.
• Java tip: Use gradient backgrounds to add interest and polish to a user interface shows how to add gradients to panel backgrounds and get around some look and feel quirks, like the opaque backgrounds of some CDE/Motif components.
• All UI defaults names for common Java look and feels on Windows, Mac OS X, and Linux runs through all of the major look and feels and notes which ones support which UI defaults keys.

Web articles

• How to Set the Look and Feel is a somewhat dated Oracle tutorial on how to select the look and feel and list those that are available.