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AWT Scrollbar Class
Introduction
Scrollbar control represents a scroll bar component in order to enable user to select from range of values.
Class declaration
Following is the declaration for java.awt.Scrollbar class:
public class Scrollbar extends Component implements Adjustable, Accessible
Field
Following are the fields for java.awt.Image class:
static int HORIZONTAL --A constant that indicates a horizontal scroll bar.
static int VERTICAL --A constant that indicates a vertical scroll bar.
Class constructors
S.N. | Constructor & Description |
---|---|
1 | Scrollbar() Constructs a new vertical scroll bar. |
2 | Scrollbar(int orientation) Constructs a new scroll bar with the specified orientation. |
3 | Scrollbar(int orientation, int value, int visible, int minimum, int maximum) Constructs a new scroll bar with the specified orientation, initial value, visible amount, and minimum and maximum values. |
Class methods
S.N. | Method & Description |
---|---|
1 | void addAdjustmentListener(AdjustmentListener l) Adds the specified adjustment listener to receive instances of AdjustmentEvent from this scroll bar. |
2 | void addNotify() Creates the Scrollbar's peer. |
3 | int getBlockIncrement() Gets the block increment of this scroll bar. |
4 | int getLineIncrement() Deprecated. As of JDK version 1.1, replaced by getUnitIncrement(). |
5 | int getMaximum() Gets the maximum value of this scroll bar. |
6 | int getMinimum() Gets the minimum value of this scroll bar. |
7 | int getOrientation() Returns the orientation of this scroll bar. |
8 | int getPageIncrement() Deprecated. As of JDK version 1.1, replaced by getBlockIncrement(). |
9 | int getUnitIncrement() Gets the unit increment for this scrollbar. |
10 | int getValue() Gets the current value of this scroll bar. |
11 | boolean getValueIsAdjusting() Returns true if the value is in the process of changing as a result of actions being taken by the user. |
12 | int getVisible() Deprecated. As of JDK version 1.1, replaced by getVisibleAmount(). |
13 | int getVisibleAmount() Gets the visible amount of this scroll bar. |
14 | protected String paramString() Returns a string representing the state of this Scrollbar. |
15 | protected void processAdjustmentEvent(AdjustmentEvent e) Processes adjustment events occurring on this scrollbar by dispatching them to any registered AdjustmentListener objects. |
16 | protected void processEvent(AWTEvent e) Processes events on this scroll bar. |
17 | void removeAdjustmentListener(AdjustmentListener l) Removes the specified adjustment listener so that it no longer receives instances of AdjustmentEvent from this scroll bar. |
18 | void setBlockIncrement(int v) Sets the block increment for this scroll bar. |
19 | void setLineIncrement(int v) Deprecated. As of JDK version 1.1, replaced by setUnitIncrement(int). |
20 | void setMaximum(int newMaximum) Sets the maximum value of this scroll bar. |
21 | void setMinimum(int newMinimum) Sets the minimum value of this scroll bar. |
22 | void setOrientation(int orientation) Sets the orientation for this scroll bar. |
23 | void setPageIncrement(int v) Deprecated. As of JDK version 1.1, replaced by setBlockIncrement(). |
24 | void setUnitIncrement(int v) Sets the unit increment for this scroll bar. |
25 | void setValue(int newValue) Sets the value of this scroll bar to the specified value. |
26 | void setValueIsAdjusting(boolean b) Sets the valueIsAdjusting property. |
27 | void setValues(int value, int visible, int minimum, int maximum) Sets the values of four properties for this scroll bar: value, visibleAmount, minimum, and maximum. |
28 | void setVisibleAmount(int newAmount) Sets the visible amount of this scroll bar. |
29 | AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this Scrollbar. |
30 | AdjustmentListener[] getAdjustmentListeners() Returns an array of all the adjustment listeners registered on this scrollbar. |
31 | <T extends EventListener>T[] getListeners(Class<T> listenerType) Returns an array of all the objects currently registered as FooListeners upon this Scrollbar. |
Methods inherited
This class inherits methods from the following classes:
java.awt.Component
java.lang.Object
Choice Example
Create the following java program using any editor of your choice in say D:/ > AWT > com > tutorialspoint > gui >
AwtControlDemopackage com.tutorialspoint.gui; import java.awt.*; import java.awt.event.*; public class AwtControlDemo { private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; public AwtControlDemo(){ prepareGUI(); } public static void main(String[] args){ AwtControlDemo awtControlDemo = new AwtControlDemo(); awtControlDemo.showScrollbarDemo(); } private void prepareGUI(){ mainFrame = new Frame("Java AWT Examples"); mainFrame.setSize(400,400); mainFrame.setLayout(new GridLayout(3, 1)); mainFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent windowEvent){ System.exit(0); } }); headerLabel = new Label(); headerLabel.setAlignment(Label.CENTER); statusLabel = new Label(); statusLabel.setAlignment(Label.CENTER); statusLabel.setSize(350,100); controlPanel = new Panel(); controlPanel.setLayout(new FlowLayout()); mainFrame.add(headerLabel); mainFrame.add(controlPanel); mainFrame.add(statusLabel); mainFrame.setVisible(true); } private void showScrollbarDemo(){ headerLabel.setText("Control in action: Scrollbar"); final Scrollbar horizontalScroller = new Scrollbar(Scrollbar.HORIZONTAL); final Scrollbar verticalScroller = new Scrollbar(); verticalScroller.setOrientation(Scrollbar.VERTICAL); horizontalScroller.setMaximum (100); horizontalScroller.setMinimum (1); verticalScroller.setMaximum (100); verticalScroller.setMinimum (1); horizontalScroller.addAdjustmentListener(new AdjustmentListener() { @Override public void adjustmentValueChanged(AdjustmentEvent e) { statusLabel.setText("Horozontal: " +horizontalScroller.getValue() +" ,Vertical: " + verticalScroller.getValue()); } }); verticalScroller.addAdjustmentListener(new AdjustmentListener() { @Override public void adjustmentValueChanged(AdjustmentEvent e) { statusLabel.setText("Horozontal: " +horizontalScroller.getValue() +" ,Vertical: "+ verticalScroller.getValue()); } }); controlPanel.add(horizontalScroller); controlPanel.add(verticalScroller); mainFrame.setVisible(true); } }
Compile the program using command prompt. Go to D:/ > AWT and type the following command.
D:\AWT>javac com\tutorialspoint\gui\AwtControlDemo.java
If no error comes that means compilation is successful. Run the program using following command.
D:\AWT>java com.tutorialspoint.gui.AwtControlDemo
Verify the following output