LAB SESSION 9

1
LAB SESSION 9

• COMPONENTS IN JAPPLET
• SETBOUNDS METHOD
• DIRECTION OF INPUT TO STDIN

2

• JAPPLET IS A SUB CLASS OF APPLET
• Components in JAPPLET AND APPLET
• JApplet Applet
• JButton Button
• JTextField TextField
• JCheckbox Checkbox
• JRadioButton RadioButton
• JComboBox Choice control
• ListBox
• ScrollBars
• TextArea

3
JLABEL

• JLabel(String str,int align)
• Str is a message displayed on label
• Align indicates the message should be aligned in
  center,left or right
• There are two methods to set the text and get the
  text on the Jlabel
• String getText()
• Void setText()

4

• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JLabel llnew JButton(String str)
• ll.setBounds(10,10,50,50)
• Cpane.add(ll)

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JTextField

• JTextField(String str,int cols)
• JTextField(int cols)
• Here str is string that is intially to be
  displayed in the textBox when applet is loaded
• cols-no of cols in textBox(width of the
  textBox)

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• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JTextField ttnew JButton(String str)
• tt.setBounds(10,10,50,50)
• Cpane.add(tt)

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JButton

• JButton(String str)
• Str is a message displayed on button
• There are two methods to set the text and get the
  text on the Jlabel
• String getText()
• Void setText()

8

• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JButton jbnew JButton(String str)
• Cpane.add(jb)
• Jb.setForeground(Color.BLUE)

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JCheckBox

• JCheckBox(String s,boolean state)
• Str is a message displayed on checkbox.
• state is set to True or False indicates
  whether the textbox should be selected or not
• The state of the textbox can be changed via
• this method
• Void setSelected(boolean state)
• void getSelected() //get selected items

10

• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JCheckBox cbnew JButton(String str)
• Cb.setBounds(10,10,45,70)
• Cpane.add(cb)

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JRadioButton

• JRadioButton(String s,boolean state)
• Str is a message displayed on Radiobutton
• State indicates whether it is selected or not
• The state of the textbox can be changed via
• this method
• Void setSelected(boolean state)
• void getSelected() //get selected items

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• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• RadioButtonGroup jpgnew RadioButtonGroup()
• JRadioButton bbnew JButton(String str)
• JRadioButton bb1new JButton(String str)
• bb.setBounds(10,10,50,50)
• bb1.setBounds(10,10,50,50)
• Jbg.add(bb)
• Jbg.add(bb1)
• Cpane.add(bb)

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COMBOBOX(Dropdown list)

• JComboBox()
• JComboBox(vector v)
• Its a dropdown list containing items that can be
  selected
• We can add items by using this method
• Void additem(Object ob)

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• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JComboBox jcbnew JButton(String str)
• Cpane.add(jcb)
• Jcb.add(france)
• Jcb.add(England)

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LISTS

• LIST(int cols,int multipleselect)
• it list a list of items that can be selected
• cols indicates the length the list
• how many can be listed
• multiselect indicates 0/1
• 0-only one can be selected at a time
• 1 user can select 2 or more items
• Methods used to add items are
• Void add(String name)
• Void add(String str,int index)

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• There are two more methods to get selcted item
  name or index
• String getSelectedItem()
• int getSelectedIndex()
• IF MULTISELECT IS 1 THEN
• String getSelectedItems()
• int getSelectedIndexes()
• Void select(int index)
• Int itemCount()

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• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• ListBox lbnew ListBox(5,0)
• Cpane.add(lb)
• Jcb.additem(france,4)
• Jcb.additem(England)

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SETBOUNDS METHOD

• This method is used to set the Size and shape of
  all awt components
• This method works when we set the layout to null
  and we want to add the components manually
• Void setBounds(int x1,int y1,int width,int
  Height)
• X1,y1coordinates where the component has to be
  placed
• Width and height are that of the components

19

• Public applet1 extends JApplet
• Public void init()
• Container cpanegetContentPane()
• Cpane.setLayout(null)
• JButton b1new JButton(String str)
• Jb.setBounds(10,10,50,50)
• Cpane.add(b1)

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Setting color for components

• Void setBackground(Color.c)
• Void setForeground(Color.c)
• Public applet1 extends JApplet
• Public void init()
• JButton jbnew JButton(String str)
• Jb.setBackground(Color.GREEN)
• Jb.setForeground(Color.BLUE)