java isfocusowner_Java JTextArea.isFocusOwner方法代码示例

import javax.swing.JTextArea; //导入方法依赖的package包/类

public void start ()

{

setSize (200,200);

setVisible(true);

validate();

JFrame frame = new JFrame("The Frame");

Set ftk = new HashSet();

ftk.add(AWTKeyStroke.getAWTKeyStroke(KeyEvent.VK_DOWN, 0));

frame.getContentPane().

setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,

ftk);

JCheckBox checkbox = new JCheckBox("test");

frame.getContentPane().add(checkbox, BorderLayout.NORTH);

JTextArea textarea = new JTextArea(40, 10);

frame.getContentPane().add(textarea);

frame.pack();

frame.setVisible(true);

Util.waitForIdle(robot);

if (!frame.isActive()) {

throw new RuntimeException("Test Fialed: frame isn't active");

}

// verify if checkbox has focus

if (!checkbox.isFocusOwner()) {

checkbox.requestFocusInWindow();

Util.waitForIdle(robot);

if (!checkbox.isFocusOwner()) {

throw new RuntimeException("Test Failed: checkbox doesn't have focus");

}

}

// press VK_DOWN

robot.keyPress(KeyEvent.VK_DOWN);

robot.delay(50);

robot.keyRelease(KeyEvent.VK_DOWN);

robot.delay(50);

Util.waitForIdle(robot);

// verify if text area has focus

if (!textarea.isFocusOwner()) {

throw new RuntimeException("Test Failed: focus wasn't transfered to text area");

}

// press '1'

robot.keyPress(KeyEvent.VK_1);

robot.delay(50);

robot.keyRelease(KeyEvent.VK_1);

robot.delay(50);

Util.waitForIdle(robot);

// verify if KEY_TYPED arrived

if (!"1".equals(textarea.getText())) {

throw new RuntimeException("Test Failed: text area text is \"" + textarea.getText() + "\", not \"1\"");

}

System.out.println("Test Passed");

}