How do you change the size and font of a joptionpane?

Question

Can you change the font and size of the text of a JOptionPane? I tried it and it works only if I "run file" on that specific java class. If you start the whole project it does not change the font. I only want to change only a specific JOptionPane not all of them.

Here is the code:

 UIManager.put("OptionPane.messageFont", new FontUIResource(new Font(  
          "Arial", Font.BOLD, 18)));       
 JOptionPane.showMessageDialog(null,"MESSAGE","ERROR",JOptionPane.WARNING_MESSAGE);         

Answer 1

This is the way we shall use:

UIManager.getLookAndFeelDefaults().put("OptionPane.messageFont", new Font("Arial", Font.BOLD, 14)); UIManager.getLookAndFeelDefaults().put("OptionPane.buttonFont", new Font("Arial", Font.PLAIN, 12));

UIManager.put("OptionPane.messageFont", new Font("Arial", Font.BOLD, 14));
UIManager.put("OptionPane.buttonFont", new Font("Arial", Font.PLAIN, 12));

Just remember to set it before any JOptionPane dialog appears. I just put it in the first line of the main method.

To see why I do this, the DOC of UIManager is always useful.

Defaults

UIManager manages three sets of UIDefaults. In order, they are:

Developer defaults. With few exceptions Swing does not alter the developer defaults; these are intended to be modified and used by the developer.

Look and feel defaults. The look and feel defaults are supplied by the look and feel at the time it is installed as the current look and feel (setLookAndFeel() is invoked). The look and feel defaults can be obtained using the getLookAndFeelDefaults() method.

System defaults. The system defaults are provided by Swing. Invoking any of the various get methods results in checking each of the defaults, in order, returning the first non-null value. For example, invoking UIManager.getString("Table.foreground") results in first checking developer defaults. If the developer defaults contain a value for "Table.foreground" it is returned, otherwise the look and feel defaults are checked, followed by the system defaults. It's important to note that getDefaults returns a custom instance of UIDefaults with this resolution logic built into it. For example, UIManager.getDefaults().getString("Table.foreground") is equivalent to UIManager.getString("Table.foreground"). Both resolve using the algorithm just described. In many places the documentation uses the word defaults to refer to the custom instance of UIDefaults with the resolution logic as previously described.

So, we should change first the developer defaults. And the method UIManager.put(Object key, Object value) is the method to use.

public static Object put(Object key, Object value)

Stores an object in the developer defaults. This is a cover method for getDefaults().put(key, value). This only affects the developer defaults, not the system or look and feel defaults.

Parameters:

key - an Object specifying the retrieval key

value - the Object to store; refer to UIDefaults for details on how null is handled

Returns: the Object returned by UIDefaults.put(java.lang.Object, java.lang.Object)

Throws:

NullPointerException - if key is null

This is exactly what I am looking for: no extra panels, no more trouble of overriding the default UI of JOptionPane.

A complete list of names of attributes in JOptionPane is here:

http://www.java2s.com/Tutorial/Java/0240__Swing/CustomizingaJOptionPaneLookandFeel.htm

Property String                                 Object Type

OptionPane.actionMap                            ActionMap
OptionPane.background                           Color
OptionPane.border                               Border
OptionPane.buttonAreaBorder                     Border
OptionPane.buttonClickThreshhold                Integer
OptionPane.buttonFont                           Font
OptionPane.buttonOrientation                    Integer
OptionPane.buttonPadding                        Integer
OptionPane.cancelButtonMnemonic                 String
OptionPane.cancelButtonText                     String
OptionPane.cancelIcon                           Icon
OptionPane.errorDialog.border.background        Color
OptionPane.errorDialog.titlePane.background     Color
OptionPane.errorDialog.titlePane.foreground     Color
OptionPane.errorDialog.titlePane.shadow         Color
OptionPane.errorIcon                            Icon
OptionPane.errorSound                           String
OptionPane.font                                 Font
OptionPane.foreground                           Color
OptionPane.informationIcon                      Icon
OptionPane.informationSound                     String
OptionPane.inputDialogTitle                     String
OptionPane.isYesLast                            Boolean
OptionPane.messageAnchor                        Integer
OptionPane.messageAreaBorder                    Border
OptionPane.messageFont                          Font
OptionPane.messageForeground                    Color
OptionPane.messageDialogTitle                   String
OptionPane.minimumSize                          Dimension
OptionPane.noButtonMnemonic                     String
OptionPane.noButtonText                         String
OptionPane.noIcon                               Icon
OptionPane.okButtonMnemonic                     String
OptionPane.okButtonText                         String
OptionPane.okIcon                               Icon
OptionPane.questionDialog.border.background     Color
OptionPane.questionDialog.titlePane.background  Color
OptionPane.questionDialog.titlePane.foreground  Color
OptionPane.questionDialog.titlePane.shadow      Color
OptionPane.questionIcon                         Icon
OptionPane.questionSound                        String
OptionPane.sameSizeButtons                      Boolean
OptionPane.separatorPadding                     Integer
OptionPane.setButtonMargin                      Boolean
OptionPane.titleText                            String
OptionPane.warningDialog.border.background      Color
OptionPane.warningDialog.titlePane.background   Color
OptionPane.warningDialog.titlePane.foreground   Color
OptionPane.warningDialog.titlePane.shadow       Color
OptionPane.warningIcon                          Icon
OptionPane.warningSound                         String
OptionPane.windowBindings                       Object[ ]
OptionPane.yesButtonMnemonic                    String
OptionPane.yesButtonText                        String
OptionPane.yesIcon                              Icon
OptionPaneUI                                    String

Answer 2

It's really easy. JOption pane accepts not only strings but also components. So you can create a label set its font and use it as message.

JLabel label = new JLabel("MESSAGE");
label.setFont(new Font("Arial", Font.BOLD, 18));
JOptionPane.showMessageDialog(null,label,"ERROR",JOptionPane.WARNING_MESSAGE);

I don't understand why nobody answered this question before

Answer 3

There is an easy way to change the default font in JOptionPane. Pass a string modified in html format, which means you can either use <font> tag or even CSS.

Using <font> tag.

JOptionPane.showMessageDialog(this, 
        "<html><font face='Calibri' size='15' color='red'>Hello");

Using CSS.

JOptionPane.showMessageDialog(this, 
        "<html><h1 style='font-family: Calibri; font-size: 36pt;'>Hello");

Answer 4

I have detected that in NIMBUS L&F initially no 'messageFont' is set (UIManager.get("OptionPane.messageFont") == null).

So if you want to derive the new font (/font-size) from the default one you can use the key "OptionPane.font" instead (--> UIManager.get("OptionPane.font")), which apparently never returns null. And then set the derived font using key "OptionPane.messageFont".