< prev index next >

src/java.desktop/share/classes/javax/swing/plaf/UIResource.java

Print this page

        

*** 26,37 **** package javax.swing.plaf; /** * This interface is used to mark objects created by ComponentUI delegates. ! * The <code>ComponentUI.installUI()</code> and ! * <code>ComponentUI.uninstallUI()</code> methods can use this interface * to decide if a properties value has been overridden. For example, the * JList cellRenderer property is initialized by BasicListUI.installUI(), * only if it's initial value is null: * <pre> * if (list.getCellRenderer() == null) { --- 26,37 ---- package javax.swing.plaf; /** * This interface is used to mark objects created by ComponentUI delegates. ! * The {@code ComponentUI.installUI()} and ! * {@code ComponentUI.uninstallUI()} methods can use this interface * to decide if a properties value has been overridden. For example, the * JList cellRenderer property is initialized by BasicListUI.installUI(), * only if it's initial value is null: * <pre> * if (list.getCellRenderer() == null) {
*** 47,57 **** *</pre> * This pattern applies to all properties except the java.awt.Component * properties font, foreground, and background. If one of these * properties isn't initialized, or is explicitly set to null, * its container provides the value. For this reason the ! * <code>"== null"</code> is unreliable when installUI() is called * to dynamically change a components look and feel. So at installUI() * time we check to see if the current value is a UIResource: *<pre> * if (!(list.getFont() instanceof UIResource)) { * list.setFont(UIManager.getFont("List.font")); --- 47,57 ---- *</pre> * This pattern applies to all properties except the java.awt.Component * properties font, foreground, and background. If one of these * properties isn't initialized, or is explicitly set to null, * its container provides the value. For this reason the ! * {@code "== null"} is unreliable when installUI() is called * to dynamically change a components look and feel. So at installUI() * time we check to see if the current value is a UIResource: *<pre> * if (!(list.getFont() instanceof UIResource)) { * list.setFont(UIManager.getFont("List.font"));
< prev index next >