public abstract class InputVerifier extends Object
InputVerifier
and, using JComponent
's
setInputVerifier
method, attach an instance of their subclass to
the JComponent
which is the source of the focus transfer operation.
The InputVerifier
also provides the possibility to validate against
the target of the focus transfer which may reject the focus.
Before focus is transferred from the source Swing component to the target
Swing component, the input verifier's
shouldYieldFocus(source, target)
method is called. Focus is
transferred only if that method returns
true
.
The following example has two text fields, with the first one expecting the string "pass" to be entered by the user. If either that string is entered in the first text field or the second text field contains "accept" string, then the user can advance focus to the second text field by clicking in it or by pressing TAB. However, if another string is entered in the first text field and the second text field does not contain "accept", then the user will be unable to transfer focus to the second text field.
import java.awt.*; import javax.swing.*; // This program demonstrates the use of the Swing InputVerifier class. // It creates two text fields; the first of the text fields expects the // string "pass" as input, and will allow focus to advance to the second text // field if either that string is typed in by the user or the second // field contains "accept" string. public class VerifierTest extends JFrame { public VerifierTest() { JTextField field1 = new JTextField("Type \"pass\" here"); JTextField field2 = new JTextField("or \"accept\" here"); getContentPane().add(field1, BorderLayout.NORTH); getContentPane().add(field2, BorderLayout.SOUTH); field.setInputVerifier(new InputVerifier() { public boolean verify(JComponent input) { return "pass".equals(((JTextField) input).getText()); } public boolean verifyTarget(JComponent input) { return "accept".equals(((JTextField) input).getText()); } public boolean shouldYieldFocus(JComponent source, JComponent target) { return verify(source) || verifyTarget(target); } }); pack(); setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(VerifierTest::new); } }
Constructor | Description |
---|---|
InputVerifier() |
Modifier and Type | Method | Description |
---|---|---|
boolean |
shouldYieldFocus(JComponent input) |
Deprecated.
use
shouldYieldFocus(JComponent, JComponent)
instead. |
boolean |
shouldYieldFocus(JComponent source,
JComponent target) |
Is called by Swing if this
InputVerifier is assigned to the
source Swing component to check whether the requested focus
transfer from the source to target is allowed. |
abstract boolean |
verify(JComponent input) |
Checks whether the JComponent's input is valid.
|
boolean |
verifyTarget(JComponent target) |
Checks whether the target JComponent that will be receiving the focus
is ready to accept it.
|
public abstract boolean verify(JComponent input)
input
- the JComponent to verifytrue
when valid, false
when invalidJComponent.setInputVerifier(javax.swing.InputVerifier)
,
JComponent.getInputVerifier()
@Deprecated(since="9") public boolean shouldYieldFocus(JComponent input)
shouldYieldFocus(JComponent, JComponent)
instead.verify(input)
to ensure that the input is valid.
This method can have side effects. In particular, this method
is called when the user attempts to advance focus out of the
argument component into another Swing component in this window.
If this method returns true
, then the focus is transferred
normally; if it returns false
, then the focus remains in
the argument component.input
- the JComponent to verifytrue
when valid, false
when invalidJComponent.setInputVerifier(javax.swing.InputVerifier)
,
JComponent.getInputVerifier()
public boolean verifyTarget(JComponent target)
true
.target
- the target JComponent to verifytrue
when valid, false
when invalidJComponent.setInputVerifier(javax.swing.InputVerifier)
,
JComponent.getInputVerifier()
public boolean shouldYieldFocus(JComponent source, JComponent target)
InputVerifier
is assigned to the
source
Swing component to check whether the requested focus
transfer from the source
to target
is allowed.
This method can have side effects.
If this method returns true
, then the focus is transferred
normally; if it returns false
, then the focus remains in
the first argument component.verify(input)
and
verifyTarget(input)
to ensure that both the source and the target
components are in valid state.source
- the source JComponent of the focus transfertarget
- the target JComponent of the focus transfertrue
when valid, false
when invalidJComponent.setInputVerifier(javax.swing.InputVerifier)
,
JComponent.getInputVerifier()
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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DRAFT 9-internal+0-adhoc.mlchung.jdk9-jdeps