The InputVerifier Class
InputVerifier
is an abstract class introduced in SDK 1.3. Subclasses of
InputVerifier
can be attached to
JComponent
s to control whether they
are willing to give up focus. Typically, this is done to force the user
to put a component in a “valid” state before allowing the user to
transfer focus to another component.
A brief example of using an InputVerifier
with a JFormattedTextField
appeared earlier in this
chapter. (See the focusLostBehavior
property of the JFormattedTextField
class.)
Public Methods
- public abstract boolean verify(JComponent input)
Return
true
if the component should give up focus, orfalse
to keep focus. You should implement this method to examine the component and make the determination, but you should not produce any side effects on the component.- public boolean shouldYieldFocus(JComponent input)
This method is called when the user attempts to transfer focus from the given component elsewhere. Return
true
if the component should give up focus, orfalse
to keep focus. This method is permitted to produce side effects.InputVerifier
’s implementation simply defers to theverify( )
method, but implementing classes may override either. Typically, subclasses provide only averify( )
method unless they intend to produce side effects.
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