Java Reference
In-Depth Information
1
// Fig. 12.47: TextAreaFrame.java
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// Copying selected text from one JText area to another.
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import
java.awt.event.ActionListener;
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import
java.awt.event.ActionEvent;
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import
javax.swing.Box;
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import
javax.swing.JFrame;
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import
javax.swing.JTextArea;
import
javax.swing.JButton;
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10
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import
javax.swing.JScrollPane;
public
class
TextAreaFrame
extends
JFrame
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{
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private final
JTextArea textArea1;
// displays demo string
private final
JTextArea textArea2;
// highlighted text is copied here
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private final
JButton copyJButton;
// initiates copying of text
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// no-argument constructor
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public
TextAreaFrame()
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{
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super
(
"TextArea Demo"
);
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Box box = Box.createHorizontalBox();
// create box
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String demo =
"This is a demo string to\n"
+
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"illustrate copying text\nfrom one textarea to \n"
+
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"another textarea using an\nexternal event\n"
;
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textArea1 =
new
JTextArea(demo,
10
,
15
);
box.add(
new
JScrollPane(textArea1));
// add scrollpane
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28
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copyJButton =
new
JButton(
"Copy >>>"
);
// create copy button
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box.add(copyJButton);
// add copy button to box
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copyJButton.addActionListener(
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new
ActionListener()
// anonymous inner class
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{
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// set text in textArea2 to selected text from textArea1
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@Override
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public
void
actionPerformed(ActionEvent event)
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{
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textArea2.setText(textArea1.getSelectedText());
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}
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}
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);
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textArea2 =
new
JTextArea(
10
,
15
);
textArea2.setEditable(
false
);
box.add(
new
JScrollPane(textArea2));
// add scrollpane
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add(box);
// add box to frame
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}
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}
// end class TextAreaFrame
Fig. 12.47
|
Copying selected text from one
JTextArea
to another.
In the constructor (lines 18-48), line 21 creates a
Box
container (package
javax.swing
) to organize the GUI components.
Box
is a subclass of
Container
that uses
