Here, numLines specifies the height, in lines, of the text area, and numChars specifies its width,
in characters. Initial text can be specified by str. In the fifth form, you can specify the scroll
bars that you want the control to have. sBars must be one of these values:
SCROLLBARS_BOTH
SCROLLBARS_NONE
SCROLLBARS_HORIZONTAL_ONLY
SCROLLBARS_VERTICAL_ONLY
TextArea is a subclass of TextComponent. Therefore, it supports the getText( ), setText( ),
getSelectedText( ), select( ), isEditable( ), and setEditable( ) methods described in the
preceding section.
TextArea adds the following methods:
void append(String str)
void insert(String str, int index)
void replaceRange(String str, int startIndex, int endIndex)
The append( ) method appends the string specified by str to the end of the current text. insert( )
inserts the string passed in str at the specified index. To replace text, call replaceRange( ). It
replaces the characters from startIndex to endIndex1, with the replacement text passed in str.
Text areas are almost self-contained controls. Your program incurs virtually no
management overhead. Text areas only generate got-focus and lost-focus events.
Normally, your program simply obtains the current text when it is needed.
The following program creates a TextArea control:
// Demonstrate TextArea.
import java.awt.*;
import java.applet.*;
/*
<applet code="TextAreaDemo" width=300 height=250>
</applet>
*/
public class TextAreaDemo extends Applet {
public void init() {
String val =
"Java SE 6 is the latest version of the most\n" +
"widely-used computer language for Internet programming.\n" +
"Building on a rich heritage, Java has advanced both\n" +
"the art and science of computer language design.\n\n" +
"One of the reasons for Java's ongoing success is its\n" +
"constant, steady rate of evolution. Java has never stood\n" +
"still. Instead, Java has consistently adapted to the\n" +
"rapidly changing landscape of the networked world.\n" +
"Moreover, Java has often led the way, charting the\n" +
"course for others to follow.";
TextArea text = new TextArea(val, 10, 30);
add(text);
}
}
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