Package Summary Overview Summary

### class:JScrollBar [NONE]
- All Implemented Interfaces: Adjustable, ImageObserver, MenuContainer, Serializable, Accessible Direct Known Subclasses: JScrollPane.ScrollBar
      public class JScrollBar
      extends JComponent
      implements Adjustable, Accessible
An implementation of a scrollbar. The user positions the knob in the scrollbar to determine the contents of the viewing area. The program typically adjusts the display so that the end of the scrollbar represents the end of the displayable contents, or 100% of the contents. The start of the scrollbar is the beginning of the displayable contents, or 0%. The position of the knob within those bounds then translates to the corresponding percentage of the displayable contents. Typically, as the position of the knob in the scrollbar changes a corresponding change is made to the position of the JViewport on the underlying view, changing the contents of the JViewport. Warning: Swing is not thread safe. For more information see Swing's Threading Policy . Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans™ has been added to the `java.beans` package. Please see `XMLEncoder`. Since: 1.2 See Also: `JScrollPane`

### field:model [NONE]
- #### model
      protected BoundedRangeModel model
The model that represents the scrollbar's minimum, maximum, extent (aka "visibleAmount") and current value. See Also: `setModel(javax.swing.BoundedRangeModel)`

### field:orientation [NONE]
- #### orientation
      protected int orientation
See Also: `setOrientation(int)`

### field:unitIncrement [NONE]
- #### unitIncrement
      protected int unitIncrement
See Also: `setUnitIncrement(int)`

### field:blockIncrement [NONE]
- #### blockIncrement
      protected int blockIncrement
See Also: `setBlockIncrement(int)`

### constructor:JScrollBar(int, int, int, int, int) [NONE]
- #### JScrollBar
      public JScrollBar(int orientation,
                        int value,
                        int extent,
                        int min,
                        int max)
Creates a scrollbar with the specified orientation, value, extent, minimum, and maximum. The "extent" is the size of the viewable area. It is also known as the "visible amount". Note: Use `setBlockIncrement` to set the block increment to a size slightly smaller than the view's extent. That way, when the user jumps the knob to an adjacent position, one or two lines of the original contents remain in view. Parameters: `orientation` - an orientation of the `JScrollBar` `value` - an int giving the current value `extent` - an int giving the amount by which the value can "jump" `min` - an int giving the minimum value `max` - an int giving the maximum value Throws: `IllegalArgumentException` - if orientation is not one of VERTICAL, HORIZONTAL See Also: `setOrientation(int)`, `setValue(int)`, `setVisibleAmount(int)`, `setMinimum(int)`, `setMaximum(int)`

### constructor:JScrollBar(int) [NONE]
- #### JScrollBar
      public JScrollBar(int orientation)
  Creates a scrollbar with the specified orientation and the following initial values:
       minimum = 0
       maximum = 100
       value = 0
       extent = 10
Parameters: `orientation` - an orientation of the `JScrollBar`

### constructor:JScrollBar() [NONE]
- #### JScrollBar
      public JScrollBar()
  Creates a vertical scrollbar with the following initial values:
       minimum = 0
       maximum = 100
       value = 0
       extent = 10

### method:setUI(javax.swing.plaf.ScrollBarUI) [NONE]
- #### setUI
      public void setUI(ScrollBarUI ui)
Sets the L&F object that renders this component. Parameters: `ui` - the `ScrollBarUI` L&F object Since: 1.4 See Also: `UIDefaults.getUI(javax.swing.JComponent)`

### method:getUI() [NONE]
- #### getUI
      public ScrollBarUI getUI()
Returns the delegate that implements the look and feel for this component. Returns: the scroll bar's current UI. See Also: `JComponent.setUI(javax.swing.plaf.ComponentUI)`

### method:updateUI() [NONE]
- #### updateUI
      public void updateUI()
Overrides `JComponent.updateUI`. Overrides: `updateUI` in class `JComponent` See Also: `JComponent.updateUI()`

### method:getUIClassID() [NONE]
- #### getUIClassID
      public String getUIClassID()
Returns the name of the LookAndFeel class for this component. Overrides: `getUIClassID` in class `JComponent` Returns: "ScrollBarUI" See Also: `JComponent.getUIClassID()`, `UIDefaults.getUI(javax.swing.JComponent)`

### method:getOrientation() [NONE]
- #### getOrientation
      public int getOrientation()
Returns the component's orientation (horizontal or vertical). Specified by: `getOrientation` in interface `Adjustable` Returns: VERTICAL or HORIZONTAL See Also: `setOrientation(int)`, `Adjustable.getOrientation()`

### method:setOrientation(int) [NONE]
- #### setOrientation
      public void setOrientation(int orientation)
Set the scrollbar's orientation to either VERTICAL or HORIZONTAL. Parameters: `orientation` - an orientation of the `JScrollBar` Throws: `IllegalArgumentException` - if orientation is not one of VERTICAL, HORIZONTAL See Also: `getOrientation()`

### method:getModel() [NONE]
- #### getModel
      public BoundedRangeModel getModel()
Returns data model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent. Returns: the data model See Also: `setModel(javax.swing.BoundedRangeModel)`

### method:setModel(javax.swing.BoundedRangeModel) [NONE]
- #### setModel
      public void setModel(BoundedRangeModel newModel)
Sets the model that handles the scrollbar's four fundamental properties: minimum, maximum, value, extent. Parameters: `newModel` - a new model See Also: `getModel()`

### method:getUnitIncrement(int) [NONE]
- #### getUnitIncrement
      public int getUnitIncrement(int direction)
Returns the amount to change the scrollbar's value by, given a unit up/down request. A ScrollBarUI implementation typically calls this method when the user clicks on a scrollbar up/down arrow and uses the result to update the scrollbar's value. Subclasses my override this method to compute a value, e.g. the change required to scroll up or down one (variable height) line text or one row in a table. The JScrollPane component creates scrollbars (by default) that override this method and delegate to the viewports Scrollable view, if it has one. The Scrollable interface provides a more specialized version of this method. Some look and feels implement custom scrolling behavior and ignore this property. Parameters: `direction` - is -1 or 1 for up/down respectively Returns: the value of the unitIncrement property See Also: `setUnitIncrement(int)`, `setValue(int)`, `Scrollable.getScrollableUnitIncrement(java.awt.Rectangle, int, int)`

### method:setUnitIncrement(int) [NONE]
- #### setUnitIncrement
      public void setUnitIncrement(int unitIncrement)
Sets the unitIncrement property. Note, that if the argument is equal to the value of Integer.MIN_VALUE, the most look and feels will not provide the scrolling to the right/down. Some look and feels implement custom scrolling behavior and ignore this property. Specified by: `setUnitIncrement` in interface `Adjustable` Parameters: `unitIncrement` - the unit increment See Also: `getUnitIncrement(int)`

### method:getBlockIncrement(int) [NONE]
- #### getBlockIncrement
      public int getBlockIncrement(int direction)
Returns the amount to change the scrollbar's value by, given a block (usually "page") up/down request. A ScrollBarUI implementation typically calls this method when the user clicks above or below the scrollbar "knob" to change the value up or down by large amount. Subclasses my override this method to compute a value, e.g. the change required to scroll up or down one paragraph in a text document. The JScrollPane component creates scrollbars (by default) that override this method and delegate to the viewports Scrollable view, if it has one. The Scrollable interface provides a more specialized version of this method. Some look and feels implement custom scrolling behavior and ignore this property. Parameters: `direction` - is -1 or 1 for up/down respectively Returns: the value of the blockIncrement property See Also: `setBlockIncrement(int)`, `setValue(int)`, `Scrollable.getScrollableBlockIncrement(java.awt.Rectangle, int, int)`

### method:setBlockIncrement(int) [NONE]
- #### setBlockIncrement
      public void setBlockIncrement(int blockIncrement)
Sets the blockIncrement property. Note, that if the argument is equal to the value of Integer.MIN_VALUE, the most look and feels will not provide the scrolling to the right/down. Some look and feels implement custom scrolling behavior and ignore this property. Specified by: `setBlockIncrement` in interface `Adjustable` Parameters: `blockIncrement` - the block increment See Also: `getBlockIncrement()`

### method:getUnitIncrement() [NONE]
- #### getUnitIncrement
      public int getUnitIncrement()
For backwards compatibility with java.awt.Scrollbar. Specified by: `getUnitIncrement` in interface `Adjustable` Returns: the unit value increment for the adjustable object See Also: `Adjustable.getUnitIncrement()`, `getUnitIncrement(int)`

### method:getBlockIncrement() [NONE]
- #### getBlockIncrement
      public int getBlockIncrement()
For backwards compatibility with java.awt.Scrollbar. Specified by: `getBlockIncrement` in interface `Adjustable` Returns: the block value increment for the adjustable object See Also: `Adjustable.getBlockIncrement()`, `getBlockIncrement(int)`

### method:getValue() [NONE]
- #### getValue
      public int getValue()
Returns the scrollbar's value. Specified by: `getValue` in interface `Adjustable` Returns: the model's value property See Also: `setValue(int)`

### method:setValue(int) [NONE]
- #### setValue
      public void setValue(int value)
Sets the scrollbar's value. This method just forwards the value to the model. Specified by: `setValue` in interface `Adjustable` Parameters: `value` - the current value, between `minimum` and `maximum` - `visibleAmount` See Also: `getValue()`, `BoundedRangeModel.setValue(int)`

### method:getVisibleAmount() [NONE]
- #### getVisibleAmount
      public int getVisibleAmount()
Returns the scrollbar's extent, aka its "visibleAmount". In many scrollbar look and feel implementations the size of the scrollbar "knob" or "thumb" is proportional to the extent. Specified by: `getVisibleAmount` in interface `Adjustable` Returns: the value of the model's extent property See Also: `setVisibleAmount(int)`

### method:setVisibleAmount(int) [NONE]
- #### setVisibleAmount
      public void setVisibleAmount(int extent)
Set the model's extent property. Specified by: `setVisibleAmount` in interface `Adjustable` Parameters: `extent` - the length of the indicator See Also: `getVisibleAmount()`, `BoundedRangeModel.setExtent(int)`

### method:getMinimum() [NONE]
- #### getMinimum
      public int getMinimum()
Returns the minimum value supported by the scrollbar (usually zero). Specified by: `getMinimum` in interface `Adjustable` Returns: the value of the model's minimum property See Also: `setMinimum(int)`

### method:setMinimum(int) [NONE]
- #### setMinimum
      public void setMinimum(int minimum)
Sets the model's minimum property. Specified by: `setMinimum` in interface `Adjustable` Parameters: `minimum` - the minimum value See Also: `getMinimum()`, `BoundedRangeModel.setMinimum(int)`

### method:getMaximum() [NONE]
- #### getMaximum
      public int getMaximum()
The maximum value of the scrollbar is maximum - extent. Specified by: `getMaximum` in interface `Adjustable` Returns: the value of the model's maximum property See Also: `setMaximum(int)`

### method:setMaximum(int) [NONE]
- #### setMaximum
      public void setMaximum(int maximum)
Sets the model's maximum property. Note that the scrollbar's value can only be set to maximum - extent. Specified by: `setMaximum` in interface `Adjustable` Parameters: `maximum` - the maximum value See Also: `getMaximum()`, `BoundedRangeModel.setMaximum(int)`

### method:getValueIsAdjusting() [NONE]
- #### getValueIsAdjusting
      public boolean getValueIsAdjusting()
True if the scrollbar knob is being dragged. Returns: the value of the model's valueIsAdjusting property See Also: `setValueIsAdjusting(boolean)`

### method:setValueIsAdjusting(boolean) [NONE]
- #### setValueIsAdjusting
      public void setValueIsAdjusting(boolean b)
Sets the model's valueIsAdjusting property. Scrollbar look and feel implementations should set this property to true when a knob drag begins, and to false when the drag ends. The scrollbar model will not generate ChangeEvents while valueIsAdjusting is true. Parameters: `b` - `true` if the upcoming changes to the value property are part of a series See Also: `getValueIsAdjusting()`, `BoundedRangeModel.setValueIsAdjusting(boolean)`

### method:setValues(int, int, int, int) [NONE]
- #### setValues
      public void setValues(int newValue,
                            int newExtent,
                            int newMin,
                            int newMax)
  Sets the four BoundedRangeModel properties after forcing the arguments to obey the usual constraints:
       minimum ≤ value ≤ value+extent ≤ maximum
Parameters: `newValue` - an int giving the current value `newExtent` - an int giving the amount by which the value can "jump" `newMin` - an int giving the minimum value `newMax` - an int giving the maximum value See Also: `BoundedRangeModel.setRangeProperties(int, int, int, int, boolean)` , `setValue(int)`, `setVisibleAmount(int)`, `setMinimum(int)`, `setMaximum(int)`

### method:addAdjustmentListener(java.awt.event.AdjustmentListener) [NONE]
- #### addAdjustmentListener
      public void addAdjustmentListener(AdjustmentListener l)
Adds an AdjustmentListener. Adjustment listeners are notified each time the scrollbar's model changes. Adjustment events are provided for backwards compatibility with java.awt.Scrollbar. Note that the AdjustmentEvents type property will always have a placeholder value of AdjustmentEvent.TRACK because all changes to a BoundedRangeModels value are considered equivalent. To change the value of a BoundedRangeModel one just sets its value property, i.e. model.setValue(123). No information about the origin of the change, e.g. it's a block decrement, is provided. We don't try fabricate the origin of the change here. Specified by: `addAdjustmentListener` in interface `Adjustable` Parameters: `l` - the AdjustmentLister to add See Also: `removeAdjustmentListener(java.awt.event.AdjustmentListener)`, `BoundedRangeModel.addChangeListener(javax.swing.event.ChangeListener)`

### method:removeAdjustmentListener(java.awt.event.AdjustmentListener) [NONE]
- #### removeAdjustmentListener
      public void removeAdjustmentListener(AdjustmentListener l)
Removes an AdjustmentEvent listener. Specified by: `removeAdjustmentListener` in interface `Adjustable` Parameters: `l` - the AdjustmentLister to remove See Also: `addAdjustmentListener(java.awt.event.AdjustmentListener)`

### method:getAdjustmentListeners() [NONE]
- #### getAdjustmentListeners
      public AdjustmentListener[] getAdjustmentListeners()
Returns an array of all the `AdjustmentListener`s added to this JScrollBar with addAdjustmentListener(). Returns: all of the `AdjustmentListener`s added or an empty array if no listeners have been added Since: 1.4

### method:fireAdjustmentValueChanged(int, int, int) [NONE]
- #### fireAdjustmentValueChanged
      protected void fireAdjustmentValueChanged(int id,
                                                int type,
                                                int value)
Notify listeners that the scrollbar's model has changed. Parameters: `id` - an integer indicating the type of event. `type` - an integer indicating the adjustment type. `value` - the current value of the adjustment See Also: `addAdjustmentListener(java.awt.event.AdjustmentListener)`, `EventListenerList`

### method:getMinimumSize() [NONE]
- #### getMinimumSize
      public Dimension getMinimumSize()
The scrollbar is flexible along it's scrolling axis and rigid along the other axis. Overrides: `getMinimumSize` in class `JComponent` Returns: the value of the `minimumSize` property See Also: `JComponent.setMinimumSize(java.awt.Dimension)`, `ComponentUI`

### method:getMaximumSize() [NONE]
- #### getMaximumSize
      public Dimension getMaximumSize()
The scrollbar is flexible along it's scrolling axis and rigid along the other axis. Overrides: `getMaximumSize` in class `JComponent` Returns: the value of the `maximumSize` property See Also: `JComponent.setMaximumSize(java.awt.Dimension)`, `ComponentUI`

### method:setEnabled(boolean) [NONE]
- #### setEnabled
      public void setEnabled(boolean x)
Enables the component so that the knob position can be changed. When the disabled, the knob position cannot be changed. Overrides: `setEnabled` in class `JComponent` Parameters: `x` - a boolean value, where true enables the component and false disables it See Also: `Component.isEnabled()`, `Component.isLightweight()`

### method:paramString() [NONE]
- #### paramString
      protected String paramString()
Returns a string representation of this JScrollBar. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be `null`. Overrides: `paramString` in class `JComponent` Returns: a string representation of this JScrollBar.

### method:getAccessibleContext() [NONE]
- #### getAccessibleContext
      public AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this JScrollBar. For JScrollBar, the AccessibleContext takes the form of an AccessibleJScrollBar. A new AccessibleJScrollBar instance is created if necessary. Specified by: `getAccessibleContext` in interface `Accessible` Overrides: `getAccessibleContext` in class `Component` Returns: an AccessibleJScrollBar that serves as the AccessibleContext of this JScrollBar