public class

JSplitPane

extends JComponent
implements Accessible
java.lang.Object
   ↳ java.awt.Component
     ↳ java.awt.Container
       ↳ javax.swing.JComponent
         ↳ javax.swing.JSplitPane

Class Overview

JSplitPane is used to divide two (and only two) Components. The two Components are graphically divided based on the look and feel implementation, and the two Components can then be interactively resized by the user. Information on using JSplitPane is in How to Use Split Panes in The Java Tutorial.

The two Components in a split pane can be aligned left to right using JSplitPane.HORIZONTAL_SPLIT, or top to bottom using JSplitPane.VERTICAL_SPLIT. The preferred way to change the size of the Components is to invoke setDividerLocation where location is either the new x or y position, depending on the orientation of the JSplitPane.

To resize the Components to their preferred sizes invoke resetToPreferredSizes.

When the user is resizing the Components the minimum size of the Components is used to determine the maximum/minimum position the Components can be set to. If the minimum size of the two components is greater than the size of the split pane the divider will not allow you to resize it. To alter the minimum size of a JComponent, see setMinimumSize(Dimension).

When the user resizes the split pane the new space is distributed between the two components based on the resizeWeight property. A value of 0, the default, indicates the right/bottom component gets all the space, where as a value of 1 indicates the left/top component gets all the space.

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 JavaBeansTM has been added to the java.beans package. Please see XMLEncoder.

Summary

Nested Classes
class JSplitPane.AccessibleJSplitPane This class implements accessibility support for the JSplitPane class. 
Constants
String BOTTOM Used to add a Component below the other Component.
String CONTINUOUS_LAYOUT_PROPERTY Bound property name for continuousLayout.
String DIVIDER Used to add a Component that will represent the divider.
String DIVIDER_LOCATION_PROPERTY Bound property for the dividerLocation.
String DIVIDER_SIZE_PROPERTY Bound property name for border.
int HORIZONTAL_SPLIT Horizontal split indicates the Components are split along the x axis.
String LAST_DIVIDER_LOCATION_PROPERTY Bound property for lastLocation.
String LEFT Used to add a Component to the left of the other Component.
String ONE_TOUCH_EXPANDABLE_PROPERTY Bound property for oneTouchExpandable.
String ORIENTATION_PROPERTY Bound property name for orientation (horizontal or vertical).
String RESIZE_WEIGHT_PROPERTY Bound property for weight.
String RIGHT Used to add a Component to the right of the other Component.
String TOP Used to add a Component above the other Component.
int VERTICAL_SPLIT Vertical split indicates the Components are split along the y axis.
[Expand]
Inherited Constants
From class javax.swing.JComponent
From class java.awt.Component
From interface java.awt.image.ImageObserver
Fields
protected boolean continuousLayout Whether or not the views are continuously redisplayed while resizing.
protected int dividerSize Size of the divider.
protected int lastDividerLocation Previous location of the split pane.
protected Component leftComponent The left or top component.
protected boolean oneTouchExpandable Is a little widget provided to quickly expand/collapse the split pane?
protected int orientation How the views are split.
protected Component rightComponent The right or bottom component.
[Expand]
Inherited Fields
From class javax.swing.JComponent
Public Constructors
JSplitPane()
Creates a new JSplitPane configured to arrange the child components side-by-side horizontally with no continuous layout, using two buttons for the components.
JSplitPane(int newOrientation)
Creates a new JSplitPane configured with the specified orientation and no continuous layout.
JSplitPane(int newOrientation, boolean newContinuousLayout)
Creates a new JSplitPane with the specified orientation and redrawing style.
JSplitPane(int newOrientation, Component newLeftComponent, Component newRightComponent)
Creates a new JSplitPane with the specified orientation and with the specified components that do not do continuous redrawing.
JSplitPane(int newOrientation, boolean newContinuousLayout, Component newLeftComponent, Component newRightComponent)
Creates a new JSplitPane with the specified orientation and redrawing style, and with the specified components.
Public Methods
AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this JSplitPane.
Component getBottomComponent()
Returns the component below, or to the right of the divider.
int getDividerLocation()
Returns the last value passed to setDividerLocation.
int getDividerSize()
Returns the size of the divider.
int getLastDividerLocation()
Returns the last location the divider was at.
Component getLeftComponent()
Returns the component to the left (or above) the divider.
int getMaximumDividerLocation()
Returns the maximum location of the divider from the look and feel implementation.
int getMinimumDividerLocation()
Returns the minimum location of the divider from the look and feel implementation.
int getOrientation()
Returns the orientation.
double getResizeWeight()
Returns the number that determines how extra space is distributed.
Component getRightComponent()
Returns the component to the right (or below) the divider.
Component getTopComponent()
Returns the component above, or to the left of the divider.
SplitPaneUI getUI()
Returns the SplitPaneUI that is providing the current look and feel.
String getUIClassID()
Returns the name of the L&F class that renders this component.
boolean isContinuousLayout()
Gets the continuousLayout property.
boolean isOneTouchExpandable()
Gets the oneTouchExpandable property.
boolean isValidateRoot()
Returns true, so that calls to revalidate on any descendant of this JSplitPane will cause a request to be queued that will validate the JSplitPane and all its descendants.
void remove(Component component)
Removes the child component, component from the pane.
void remove(int index)
Removes the Component at the specified index.
void removeAll()
Removes all the child components from the split pane.
void resetToPreferredSizes()
Lays out the JSplitPane layout based on the preferred size of the children components.
void setBottomComponent(Component comp)
Sets the component below, or to the right of the divider.
void setContinuousLayout(boolean newContinuousLayout)
Sets the value of the continuousLayout property, which must be true for the child components to be continuously redisplayed and laid out during user intervention.
void setDividerLocation(int location)
Sets the location of the divider.
void setDividerLocation(double proportionalLocation)
Sets the divider location as a percentage of the JSplitPane's size.
void setDividerSize(int newSize)
Sets the size of the divider.
void setLastDividerLocation(int newLastLocation)
Sets the last location the divider was at to newLastLocation.
void setLeftComponent(Component comp)
Sets the component to the left (or above) the divider.
void setOneTouchExpandable(boolean newValue)
Sets the value of the oneTouchExpandable property, which must be true for the JSplitPane to provide a UI widget on the divider to quickly expand/collapse the divider.
void setOrientation(int orientation)
Sets the orientation, or how the splitter is divided.
void setResizeWeight(double value)
Specifies how to distribute extra space when the size of the split pane changes.
void setRightComponent(Component comp)
Sets the component to the right (or below) the divider.
void setTopComponent(Component comp)
Sets the component above, or to the left of the divider.
void setUI(SplitPaneUI ui)
Sets the L&F object that renders this component.
void updateUI()
Notification from the UIManager that the L&F has changed.
Protected Methods
void addImpl(Component comp, Object constraints, int index)
Adds the specified component to this split pane.
void paintChildren(Graphics g)
Subclassed to message the UI with finishedPaintingChildren after super has been messaged, as well as painting the border.
String paramString()
Returns a string representation of this JSplitPane.
[Expand]
Inherited Methods
From class javax.swing.JComponent
From class java.awt.Container
From class java.awt.Component
From class java.lang.Object
From interface java.awt.MenuContainer
From interface java.awt.image.ImageObserver
From interface javax.accessibility.Accessible

Constants

public static final String BOTTOM

Used to add a Component below the other Component.

Constant Value: "bottom"

public static final String CONTINUOUS_LAYOUT_PROPERTY

Bound property name for continuousLayout.

Constant Value: "continuousLayout"

public static final String DIVIDER

Used to add a Component that will represent the divider.

Constant Value: "divider"

public static final String DIVIDER_LOCATION_PROPERTY

Bound property for the dividerLocation.

Constant Value: "dividerLocation"

public static final String DIVIDER_SIZE_PROPERTY

Bound property name for border.

Constant Value: "dividerSize"

public static final int HORIZONTAL_SPLIT

Horizontal split indicates the Components are split along the x axis. For example the two Components will be split one to the left of the other.

Constant Value: 1 (0x00000001)

public static final String LAST_DIVIDER_LOCATION_PROPERTY

Bound property for lastLocation.

Constant Value: "lastDividerLocation"

public static final String LEFT

Used to add a Component to the left of the other Component.

Constant Value: "left"

public static final String ONE_TOUCH_EXPANDABLE_PROPERTY

Bound property for oneTouchExpandable.

Constant Value: "oneTouchExpandable"

public static final String ORIENTATION_PROPERTY

Bound property name for orientation (horizontal or vertical).

Constant Value: "orientation"

public static final String RESIZE_WEIGHT_PROPERTY

Bound property for weight.

Constant Value: "resizeWeight"

public static final String RIGHT

Used to add a Component to the right of the other Component.

Constant Value: "right"

public static final String TOP

Used to add a Component above the other Component.

Constant Value: "top"

public static final int VERTICAL_SPLIT

Vertical split indicates the Components are split along the y axis. For example the two Components will be split one on top of the other.

Constant Value: 0 (0x00000000)

Fields

protected boolean continuousLayout

Whether or not the views are continuously redisplayed while resizing.

protected int dividerSize

Size of the divider.

protected int lastDividerLocation

Previous location of the split pane.

protected Component leftComponent

The left or top component.

protected boolean oneTouchExpandable

Is a little widget provided to quickly expand/collapse the split pane?

protected int orientation

How the views are split.

protected Component rightComponent

The right or bottom component.

Public Constructors

public JSplitPane ()

Creates a new JSplitPane configured to arrange the child components side-by-side horizontally with no continuous layout, using two buttons for the components.

public JSplitPane (int newOrientation)

Creates a new JSplitPane configured with the specified orientation and no continuous layout.

Parameters
newOrientation JSplitPane.HORIZONTAL_SPLIT or JSplitPane.VERTICAL_SPLIT
Throws
IllegalArgumentException if orientation is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT.

public JSplitPane (int newOrientation, boolean newContinuousLayout)

Creates a new JSplitPane with the specified orientation and redrawing style.

Parameters
newOrientation JSplitPane.HORIZONTAL_SPLIT or JSplitPane.VERTICAL_SPLIT
newContinuousLayout a boolean, true for the components to redraw continuously as the divider changes position, false to wait until the divider position stops changing to redraw
Throws
IllegalArgumentException if orientation is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT

public JSplitPane (int newOrientation, Component newLeftComponent, Component newRightComponent)

Creates a new JSplitPane with the specified orientation and with the specified components that do not do continuous redrawing.

Parameters
newOrientation JSplitPane.HORIZONTAL_SPLIT or JSplitPane.VERTICAL_SPLIT
newLeftComponent the Component that will appear on the left of a horizontally-split pane, or at the top of a vertically-split pane
newRightComponent the Component that will appear on the right of a horizontally-split pane, or at the bottom of a vertically-split pane
Throws
IllegalArgumentException if orientation is not one of: HORIZONTAL_SPLIT or VERTICAL_SPLIT

public JSplitPane (int newOrientation, boolean newContinuousLayout, Component newLeftComponent, Component newRightComponent)

Creates a new JSplitPane with the specified orientation and redrawing style, and with the specified components.

Parameters
newOrientation JSplitPane.HORIZONTAL_SPLIT or JSplitPane.VERTICAL_SPLIT
newContinuousLayout a boolean, true for the components to redraw continuously as the divider changes position, false to wait until the divider position stops changing to redraw
newLeftComponent the Component that will appear on the left of a horizontally-split pane, or at the top of a vertically-split pane
newRightComponent the Component that will appear on the right of a horizontally-split pane, or at the bottom of a vertically-split pane
Throws
IllegalArgumentException if orientation is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT

Public Methods

public AccessibleContext getAccessibleContext ()

Gets the AccessibleContext associated with this JSplitPane. For split panes, the AccessibleContext takes the form of an AccessibleJSplitPane. A new AccessibleJSplitPane instance is created if necessary.

Returns
  • an AccessibleJSplitPane that serves as the AccessibleContext of this JSplitPane

public Component getBottomComponent ()

Returns the component below, or to the right of the divider.

Returns
  • the Component displayed in that position

public int getDividerLocation ()

Returns the last value passed to setDividerLocation. The value returned from this method may differ from the actual divider location (if setDividerLocation was passed a value bigger than the curent size).

Returns
  • an integer specifying the location of the divider

public int getDividerSize ()

Returns the size of the divider.

Returns
  • an integer giving the size of the divider in pixels

public int getLastDividerLocation ()

Returns the last location the divider was at.

Returns
  • an integer specifying the last divider location as a count of pixels from the left (or upper) edge of the pane to the left (or upper) edge of the divider

public Component getLeftComponent ()

Returns the component to the left (or above) the divider.

Returns
  • the Component displayed in that position

public int getMaximumDividerLocation ()

Returns the maximum location of the divider from the look and feel implementation.

Returns
  • an integer specifying a UI-specific value for the maximum location (typically a pixel count); or -1 if the UI is null

public int getMinimumDividerLocation ()

Returns the minimum location of the divider from the look and feel implementation.

Returns
  • an integer specifying a UI-specific value for the minimum location (typically a pixel count); or -1 if the UI is null

public int getOrientation ()

Returns the orientation.

Returns
  • an integer giving the orientation

public double getResizeWeight ()

Returns the number that determines how extra space is distributed.

Returns
  • how extra space is to be distributed on a resize of the split pane

public Component getRightComponent ()

Returns the component to the right (or below) the divider.

Returns
  • the Component displayed in that position

public Component getTopComponent ()

Returns the component above, or to the left of the divider.

Returns
  • the Component displayed in that position

public SplitPaneUI getUI ()

Returns the SplitPaneUI that is providing the current look and feel.

Returns
  • the SplitPaneUI object that renders this component

public String getUIClassID ()

Returns the name of the L&F class that renders this component.

Returns
  • the string "SplitPaneUI"

public boolean isContinuousLayout ()

Gets the continuousLayout property.

Returns
  • the value of the continuousLayout property

public boolean isOneTouchExpandable ()

Gets the oneTouchExpandable property.

Returns
  • the value of the oneTouchExpandable property

public boolean isValidateRoot ()

Returns true, so that calls to revalidate on any descendant of this JSplitPane will cause a request to be queued that will validate the JSplitPane and all its descendants.

Returns
  • true
See Also

public void remove (Component component)

Removes the child component, component from the pane. Resets the leftComponent or rightComponent instance variable, as necessary.

Parameters
component the Component to remove

public void remove (int index)

Removes the Component at the specified index. Updates the leftComponent and rightComponent instance variables as necessary, and then messages super.

Parameters
index an integer specifying the component to remove, where 1 specifies the left/top component and 2 specifies the bottom/right component

public void removeAll ()

Removes all the child components from the split pane. Resets the leftComonent and rightComponent instance variables.

public void resetToPreferredSizes ()

Lays out the JSplitPane layout based on the preferred size of the children components. This will likely result in changing the divider location.

public void setBottomComponent (Component comp)

Sets the component below, or to the right of the divider.

Parameters
comp the Component to display in that position

public void setContinuousLayout (boolean newContinuousLayout)

Sets the value of the continuousLayout property, which must be true for the child components to be continuously redisplayed and laid out during user intervention. The default value of this property is false. Some look and feels might not support continuous layout; they will ignore this property.

Parameters
newContinuousLayout true if the components should continuously be redrawn as the divider changes position

public void setDividerLocation (int location)

Sets the location of the divider. This is passed off to the look and feel implementation, and then listeners are notified. A value less than 0 implies the divider should be reset to a value that attempts to honor the preferred size of the left/top component. After notifying the listeners, the last divider location is updated, via setLastDividerLocation.

Parameters
location an int specifying a UI-specific value (typically a pixel count)

public void setDividerLocation (double proportionalLocation)

Sets the divider location as a percentage of the JSplitPane's size.

This method is implemented in terms of setDividerLocation(int). This method immediately changes the size of the split pane based on its current size. If the split pane is not correctly realized and on screen, this method will have no effect (new divider location will become (current size * proportionalLocation) which is 0).

Parameters
proportionalLocation a double-precision floating point value that specifies a percentage, from zero (top/left) to 1.0 (bottom/right)
Throws
IllegalArgumentException if the specified location is < 0 or > 1.0

public void setDividerSize (int newSize)

Sets the size of the divider.

Parameters
newSize an integer giving the size of the divider in pixels

public void setLastDividerLocation (int newLastLocation)

Sets the last location the divider was at to newLastLocation.

Parameters
newLastLocation an integer specifying the last divider location in pixels, from the left (or upper) edge of the pane to the left (or upper) edge of the divider

public void setLeftComponent (Component comp)

Sets the component to the left (or above) the divider.

Parameters
comp the Component to display in that position

public void setOneTouchExpandable (boolean newValue)

Sets the value of the oneTouchExpandable property, which must be true for the JSplitPane to provide a UI widget on the divider to quickly expand/collapse the divider. The default value of this property is false. Some look and feels might not support one-touch expanding; they will ignore this property.

Parameters
newValue true to specify that the split pane should provide a collapse/expand widget

public void setOrientation (int orientation)

Sets the orientation, or how the splitter is divided. The options are:

  • JSplitPane.VERTICAL_SPLIT (above/below orientation of components)
  • JSplitPane.HORIZONTAL_SPLIT (left/right orientation of components)

Parameters
orientation an integer specifying the orientation
Throws
IllegalArgumentException if orientation is not one of: HORIZONTAL_SPLIT or VERTICAL_SPLIT.

public void setResizeWeight (double value)

Specifies how to distribute extra space when the size of the split pane changes. A value of 0, the default, indicates the right/bottom component gets all the extra space (the left/top component acts fixed), where as a value of 1 specifies the left/top component gets all the extra space (the right/bottom component acts fixed). Specifically, the left/top component gets (weight * diff) extra space and the right/bottom component gets (1 - weight) * diff extra space.

Parameters
value as described above
Throws
IllegalArgumentException if value is < 0 or > 1

public void setRightComponent (Component comp)

Sets the component to the right (or below) the divider.

Parameters
comp the Component to display in that position

public void setTopComponent (Component comp)

Sets the component above, or to the left of the divider.

Parameters
comp the Component to display in that position

public void setUI (SplitPaneUI ui)

Sets the L&F object that renders this component.

Parameters
ui the SplitPaneUI L&F object

public void updateUI ()

Notification from the UIManager that the L&F has changed. Replaces the current UI object with the latest version from the UIManager.

See Also

Protected Methods

protected void addImpl (Component comp, Object constraints, int index)

Adds the specified component to this split pane. If constraints identifies the left/top or right/bottom child component, and a component with that identifier was previously added, it will be removed and then comp will be added in its place. If constraints is not one of the known identifiers the layout manager may throw an IllegalArgumentException.

The possible constraints objects (Strings) are:

  • JSplitPane.TOP
  • JSplitPane.LEFT
  • JSplitPane.BOTTOM
  • JSplitPane.RIGHT
If the constraints object is null, the component is added in the first available position (left/top if open, else right/bottom).

Parameters
comp the component to add
constraints an Object specifying the layout constraints (position) for this component
index an integer specifying the index in the container's list.
Throws
IllegalArgumentException if the constraints object does not match an existing component

protected void paintChildren (Graphics g)

Subclassed to message the UI with finishedPaintingChildren after super has been messaged, as well as painting the border.

Parameters
g the Graphics context within which to paint

protected String paramString ()

Returns a string representation of this JSplitPane. 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.

Returns
  • a string representation of this JSplitPane.