TextField and TextAreahttp://improvejava.blogspot.in/                                  1
ObjectiveOn completion of this period, you would beable to know• TextField• TextArea              http://improvejava.blogs...
RecapIn the previous class, you have leant• Lists• Scroll bars                http://improvejava.blogspot.in/             ...
TextField• The TextField class implements a single-line  text-entry area• It is usually called an edit control• Text field...
TextField                        contd..• TextField defines the following constructors:   –   TextField( )   –   TextField...
TextField                 contd..• To obtain the string  currently contained in the  text field, call getText( )• To set t...
TextField                                 contd..• The other methods of interest are  –   String getSelectedText( )  –   v...
Handling a TextField• Let us see an example that creates the  classic user name and password screen// Demonstrate text fie...
Handling a TextField                            contd..public class TextFieldDemo extends Applet implements ActionListener...
Handling a TextField                            contd..    // User pressed Enter.    public void actionPerformed(ActionEve...
Handling a TextField                         contd..• Here is the sample output              Fig. 73.1 Output of TextField...
TextArea• Sometimes a single line of text input is not enough  for a given task• To handle these situations, the AWT inclu...
TextArea                         contd..• Here,  – numLines specifies the height, in lines, of the    text area  – numChar...
TextArea                   contd..• TextArea adds the following methods  – void append(String str)  – void insert(String s...
Example Program// Demonstrate TextArea.import java.awt.*;import java.applet.*;/*<applet code="TextAreaDemo" width=300 heig...
Example Program                             contd..        "Theres an old story about the person who wishedn" +        "hi...
Example Program                           contd..• The output of TextAreaDemo is shown here                  Fig. 73.2 Out...
Summary• We have discussed  – TextField  – TextArea components  – The related program• These components are useful for use...
Quiz1. Which method TextField is used to show the    effect of password  a)   setPwdChar()  b)   setEchoChar()  c)   setPa...
Quiz                 contd..2. Which component is useful for entering the    address details(as a single unit) of a person...
Frequently Asked Questions1. List and explain the methods of TextField2. List the different constructors of TextArea3. Wri...
Upcoming SlideShare
Loading in …5
×

Text field and textarea

5,189 views

Published on

  • thanks dude...
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Text field and textarea

  1. 1. TextField and TextAreahttp://improvejava.blogspot.in/ 1
  2. 2. ObjectiveOn completion of this period, you would beable to know• TextField• TextArea http://improvejava.blogspot.in/ 2
  3. 3. RecapIn the previous class, you have leant• Lists• Scroll bars http://improvejava.blogspot.in/ 3
  4. 4. TextField• The TextField class implements a single-line text-entry area• It is usually called an edit control• Text fields allow the user – to enter strings – to edit the text using the arrow keys, cut and paste keys, and mouse selections• TextField is a subclass of TextComponent http://improvejava.blogspot.in/ 4
  5. 5. TextField contd..• TextField defines the following constructors: – TextField( ) – TextField(int numChars) – TextField(String str) – TextField(String str, int numChars) – The first version creates a default text field – The second form creates a text field that is numChars characters wide – The third form initializes the text field with the string contained in str – The fourth form initializes a text field and sets its width http://improvejava.blogspot.in/ 5
  6. 6. TextField contd..• To obtain the string currently contained in the text field, call getText( )• To set the text, call setText( )• These methods are as follows – String getText( ) – void setText(String str) – Here, str is the new string http://improvejava.blogspot.in/ 6
  7. 7. TextField contd..• The other methods of interest are – String getSelectedText( ) – void select(int startIndex, int endIndex) – boolean isEditable( ) – void setEditable(boolean canEdit) – void setEchoChar(char ch) – boolean echoCharIsSet( ) – char getEchoChar( ) http://improvejava.blogspot.in/ 7
  8. 8. Handling a TextField• Let us see an example that creates the classic user name and password screen// Demonstrate text field.import java.awt.*;import java.awt.event.*;import java.applet.*;/*<applet code="TextFieldDemo" width=380 height=150></applet>*/ http://improvejava.blogspot.in/ 8
  9. 9. Handling a TextField contd..public class TextFieldDemo extends Applet implements ActionListener { TextField name, pass; public void init() { Label namep = new Label("Name: ", Label.RIGHT); Label passp = new Label("Password: ", Label.RIGHT); name = new TextField(12); pass = new TextField(8); pass.setEchoChar(?); add(namep); add(name); add(passp); add(pass); // register to receive action events name.addActionListener(this); pass.addActionListener(this); } http://improvejava.blogspot.in/ 9
  10. 10. Handling a TextField contd.. // User pressed Enter. public void actionPerformed(ActionEvent ae) { repaint(); } public void paint(Graphics g) { g.drawString("Name: " + name.getText(), 6, 60); g.drawString("Selected text in name: " + name.getSelectedText(), 6, 80); g.drawString("Password: " + pass.getText(), 6, 100); }} http://improvejava.blogspot.in/ 10
  11. 11. Handling a TextField contd..• Here is the sample output Fig. 73.1 Output of TextFieldDemo http://improvejava.blogspot.in/ 11
  12. 12. TextArea• Sometimes a single line of text input is not enough for a given task• To handle these situations, the AWT includes a simple multiline editor called TextArea• Following are the constructors for TextArea – TextArea( ) – TextArea(int numLines, int numChars) – TextArea(String str) – TextArea(String str, int numLines, int numChars) – TextArea(String str, int numLines, int numChars, int Bars) http://improvejava.blogspot.in/ 12
  13. 13. TextArea contd..• Here, – numLines specifies the height, in lines, of the text area – 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 http://improvejava.blogspot.in/ 13
  14. 14. TextArea contd..• TextArea adds the following methods – void append(String str) – void insert(String str, int index) – void replaceRange(String str, int startIndex, int endIndex) http://improvejava.blogspot.in/ 14
  15. 15. Example Program// 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 = "There are two ways of constructing " + "a software design.n" + "One way is to make it so simplen" + "that there are obviously no deficiencies.n" + "And the other way is to make it so complicatedn" + "that there are no obvious deficiencies.nn" + " -C.A.R. Hoarenn" + http://improvejava.blogspot.in/ 15
  16. 16. Example Program contd.. "Theres an old story about the person who wishedn" + "his computer were as easy to use as his telephone.n" + "That wish has come true,n" + "since I no longer know how to use my telephone.nn" + " -Bjarne Stroustrup, AT&T, (inventor of C++)"; TextArea text = new TextArea(val, 10, 30); add(text); }} http://improvejava.blogspot.in/ 16
  17. 17. Example Program contd..• The output of TextAreaDemo is shown here Fig. 73.2 Output of TextAreaDemo http://improvejava.blogspot.in/ 17
  18. 18. Summary• We have discussed – TextField – TextArea components – The related program• These components are useful for user text data entry http://improvejava.blogspot.in/ 18
  19. 19. Quiz1. Which method TextField is used to show the effect of password a) setPwdChar() b) setEchoChar() c) setPassword() d) None http://improvejava.blogspot.in/ 19
  20. 20. Quiz contd..2. Which component is useful for entering the address details(as a single unit) of a person ? a) TextField b) TextArea c) Label d) List http://improvejava.blogspot.in/ 20
  21. 21. Frequently Asked Questions1. List and explain the methods of TextField2. List the different constructors of TextArea3. Write a Java program to accept the details of student like, PIN, Name, branch etc., in TextFields and show the same in labels http://improvejava.blogspot.in/ 21

×