Class ScrollPane

java.lang.Object

java.awt.Component

java.awt.Container

java.awt.ScrollPane

All Implemented Interfaces:: ImageObserver, MenuContainer, Serializable, Accessible

public class ScrollPane extends Container implements Accessible

A container class which implements automatic horizontal and/or vertical scrolling for a single child component. The display policy for the scrollbars can be set to:

as needed: scrollbars created and shown only when needed by scrollpane
always: scrollbars created and always shown by the scrollpane
never: scrollbars never created or shown by the scrollpane

The state of the horizontal and vertical scrollbars is represented by two ScrollPaneAdjustable objects (one for each dimension) which implement the Adjustable interface. The API provides methods to access those objects such that the attributes on the Adjustable object (such as unitIncrement, value, etc.) can be manipulated.

Certain adjustable properties (minimum, maximum, blockIncrement, and visibleAmount) are set internally by the scrollpane in accordance with the geometry of the scrollpane and its child and these should not be set by programs using the scrollpane.

If the scrollbar display policy is defined as "never", then the scrollpane can still be programmatically scrolled using the setScrollPosition() method and the scrollpane will move and clip the child's contents appropriately. This policy is useful if the program needs to create and manage its own adjustable controls.

The placement of the scrollbars is controlled by platform-specific properties set by the user outside of the program.

The initial size of this container is set to 100x100, but can be reset using setSize().

Scrolling with the wheel on a wheel-equipped mouse is enabled by default. This can be disabled using setWheelScrollingEnabled. Wheel scrolling can be customized by setting the block and unit increment of the horizontal and vertical Adjustables. For information on how mouse wheel events are dispatched, see the class description for MouseWheelEvent.

Insets are used to define any space used by scrollbars and any borders created by the scroll pane. getInsets() can be used to get the current value for the insets. If the value of scrollbarsAlwaysVisible is false, then the value of the insets will change dynamically depending on whether the scrollbars are currently visible or not.

See Also:

Nested Class Summary

Modifier and Type	Class	Description
`protected class`	`ScrollPane.AccessibleAWTScrollPane`	This class implements accessibility support for the `ScrollPane` class.

Nested classes/interfaces declared in class Container

Container.AccessibleAWTContainer

Modifier and Type	Class	Description
`protected class`	`Container.AccessibleAWTContainer`	Inner class of Container used to provide default support for accessibility.

Nested classes/interfaces declared in class Component

Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Modifier and Type	Class	Description
`protected class`	`Component.AccessibleAWTComponent`	Inner class of Component used to provide default support for accessibility.
`static enum`	`Component.BaselineResizeBehavior`	Enumeration of the common ways the baseline of a component can change as the size changes.
`protected class`	`Component.BltBufferStrategy`	Inner class for blitting offscreen surfaces to a component.
`protected class`	`Component.FlipBufferStrategy`	Inner class for flipping buffers on a component.

Field Summary

Modifier and Type	Field	Description
`static final int`	`SCROLLBARS_ALWAYS`	Specifies that horizontal/vertical scrollbars should always be shown regardless of the respective sizes of the scrollpane and child.
`static final int`	`SCROLLBARS_AS_NEEDED`	Specifies that horizontal/vertical scrollbar should be shown only when the size of the child exceeds the size of the scrollpane in the horizontal/vertical dimension.
`static final int`	`SCROLLBARS_NEVER`	Specifies that horizontal/vertical scrollbars should never be shown regardless of the respective sizes of the scrollpane and child.

Fields declared in class Component

accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Modifier and Type	Field	Description
`protected AccessibleContext`	`accessibleContext`	The `AccessibleContext` associated with this `Component`.
`static final float`	`BOTTOM_ALIGNMENT`	Ease-of-use constant for `getAlignmentY`.
`static final float`	`CENTER_ALIGNMENT`	Ease-of-use constant for `getAlignmentY` and `getAlignmentX`.
`static final float`	`LEFT_ALIGNMENT`	Ease-of-use constant for `getAlignmentX`.
`static final float`	`RIGHT_ALIGNMENT`	Ease-of-use constant for `getAlignmentX`.
`static final float`	`TOP_ALIGNMENT`	Ease-of-use constant for `getAlignmentY()`.

Fields declared in interface ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Modifier and Type	Field	Description
`static final int`	`ABORT`	This flag in the infoflags argument to imageUpdate indicates that an image which was being tracked asynchronously was aborted before production was complete.
`static final int`	`ALLBITS`	This flag in the infoflags argument to imageUpdate indicates that a static image which was previously drawn is now complete and can be drawn again in its final form.
`static final int`	`ERROR`	This flag in the infoflags argument to imageUpdate indicates that an image which was being tracked asynchronously has encountered an error.
`static final int`	`FRAMEBITS`	This flag in the infoflags argument to imageUpdate indicates that another complete frame of a multi-frame image which was previously drawn is now available to be drawn again.
`static final int`	`HEIGHT`	This flag in the infoflags argument to imageUpdate indicates that the height of the base image is now available and can be taken from the height argument to the imageUpdate callback method.
`static final int`	`PROPERTIES`	This flag in the infoflags argument to imageUpdate indicates that the properties of the image are now available.
`static final int`	`SOMEBITS`	This flag in the infoflags argument to imageUpdate indicates that more pixels needed for drawing a scaled variation of the image are available.
`static final int`	`WIDTH`	This flag in the infoflags argument to imageUpdate indicates that the width of the base image is now available and can be taken from the width argument to the imageUpdate callback method.

Constructor Summary

Constructor	Description
`ScrollPane()`	Create a new scrollpane container with a scrollbar display policy of "as needed".
`ScrollPane(int scrollbarDisplayPolicy)`	Create a new scrollpane container.

Method Summary

Modifier and Type	Method	Description
`protected final void`	`addImpl(Component comp, Object constraints, int index)`	Adds the specified component to this scroll pane container.
`void`	`addNotify()`	Creates the scroll pane's peer.
`void`	`doLayout()`	Lays out this container by resizing its child to its preferred size.
`protected boolean`	`eventTypeEnabled(int type)`	If wheel scrolling is enabled, we return true for MouseWheelEvents
`AccessibleContext`	`getAccessibleContext()`	Gets the AccessibleContext associated with this ScrollPane.
`Adjustable`	`getHAdjustable()`	Returns the `ScrollPaneAdjustable` object which represents the state of the horizontal scrollbar.
`int`	`getHScrollbarHeight()`	Returns the height that would be occupied by a horizontal scrollbar, which is independent of whether it is currently displayed by the scroll pane or not.
`int`	`getScrollbarDisplayPolicy()`	Returns the display policy for the scrollbars.
`Point`	`getScrollPosition()`	Returns the current x,y position within the child which is displayed at the 0,0 location of the scrolled panel's view port.
`Adjustable`	`getVAdjustable()`	Returns the `ScrollPaneAdjustable` object which represents the state of the vertical scrollbar.
`Dimension`	`getViewportSize()`	Returns the current size of the scroll pane's view port.
`int`	`getVScrollbarWidth()`	Returns the width that would be occupied by a vertical scrollbar, which is independent of whether it is currently displayed by the scroll pane or not.
`boolean`	`isWheelScrollingEnabled()`	Indicates whether or not scrolling will take place in response to the mouse wheel.
`void`	`layout()`	Deprecated. As of JDK version 1.1, replaced by `doLayout()`.
`String`	`paramString()`	Returns a string representing the state of this `ScrollPane`.
`void`	`printComponents(Graphics g)`	Prints the component in this scroll pane.
`protected void`	`processMouseWheelEvent(MouseWheelEvent e)`	Process mouse wheel events that are delivered to this `ScrollPane` by scrolling an appropriate amount.
`final void`	`setLayout(LayoutManager mgr)`	Sets the layout manager for this container.
`void`	`setScrollPosition(int x, int y)`	Scrolls to the specified position within the child component.
`void`	`setScrollPosition(Point p)`	Scrolls to the specified position within the child component.
`void`	`setWheelScrollingEnabled(boolean handleWheel)`	Enables/disables scrolling in response to movement of the mouse wheel.

Methods declared in class Container

add, add, add, add, add, addContainerListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getInsets, getLayout, getListeners, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, isValidateRoot, list, list, locate, minimumSize, paint, paintComponents, preferredSize, print, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, transferFocusDownCycle, update, validate, validateTree

Modifier and Type	Method	Description
`Component`	`add(Component comp)`	Appends the specified component to the end of this container.
`Component`	`add(Component comp, int index)`	Adds the specified component to this container at the given position.
`void`	`add(Component comp, Object constraints)`	Adds the specified component to the end of this container.
`void`	`add(Component comp, Object constraints, int index)`	Adds the specified component to this container with the specified constraints at the specified index.
`Component`	`add(String name, Component comp)`	Adds the specified component to this container.
`void`	`addContainerListener(ContainerListener l)`	Adds the specified container listener to receive container events from this container.
`void`	`addPropertyChangeListener(PropertyChangeListener listener)`	Adds a PropertyChangeListener to the listener list.
`void`	`addPropertyChangeListener(String propertyName, PropertyChangeListener listener)`	Adds a PropertyChangeListener to the listener list for a specific property.
`void`	`applyComponentOrientation(ComponentOrientation o)`	Sets the `ComponentOrientation` property of this container and all components contained within it.
`boolean`	`areFocusTraversalKeysSet(int id)`	Returns whether the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Container.
`int`	`countComponents()`	Deprecated. As of JDK version 1.1, replaced by getComponentCount().
`void`	`deliverEvent(Event e)`	Deprecated. As of JDK version 1.1, replaced by `dispatchEvent(AWTEvent e)`
`Component`	`findComponentAt(int x, int y)`	Locates the visible child component that contains the specified position.
`Component`	`findComponentAt(Point p)`	Locates the visible child component that contains the specified point.
`float`	`getAlignmentX()`	Returns the alignment along the x axis.
`float`	`getAlignmentY()`	Returns the alignment along the y axis.
`Component`	`getComponent(int n)`	Gets the nth component in this container.
`Component`	`getComponentAt(int x, int y)`	Locates the component that contains the x,y position.
`Component`	`getComponentAt(Point p)`	Gets the component that contains the specified point.
`int`	`getComponentCount()`	Gets the number of components in this panel.
`Component[]`	`getComponents()`	Gets all the components in this container.
`int`	`getComponentZOrder(Component comp)`	Returns the z-order index of the component inside the container.
`ContainerListener[]`	`getContainerListeners()`	Returns an array of all the container listeners registered on this container.
`Set<AWTKeyStroke>`	`getFocusTraversalKeys(int id)`	Returns the Set of focus traversal keys for a given traversal operation for this Container.
`FocusTraversalPolicy`	`getFocusTraversalPolicy()`	Returns the focus traversal policy that will manage keyboard traversal of this Container's children, or null if this Container is not a focus cycle root.
`Insets`	`getInsets()`	Determines the insets of this container, which indicate the size of the container's border.
`LayoutManager`	`getLayout()`	Gets the layout manager for this container.
`<T extends EventListener> T[]`	`getListeners(Class<T> listenerType)`	Returns an array of all the objects currently registered as `FooListener`s upon this `Container`.
`Dimension`	`getMaximumSize()`	Returns the maximum size of this container.
`Dimension`	`getMinimumSize()`	Returns the minimum size of this container.
`Point`	`getMousePosition(boolean allowChildren)`	Returns the position of the mouse pointer in this `Container`'s coordinate space if the `Container` is under the mouse pointer, otherwise returns `null`.
`Dimension`	`getPreferredSize()`	Returns the preferred size of this container.
`Insets`	`insets()`	Deprecated. As of JDK version 1.1, replaced by `getInsets()`.
`void`	`invalidate()`	Invalidates the container.
`boolean`	`isAncestorOf(Component c)`	Checks if the component is contained in the component hierarchy of this container.
`boolean`	`isFocusCycleRoot()`	Returns whether this Container is the root of a focus traversal cycle.
`boolean`	`isFocusCycleRoot(Container container)`	Returns whether the specified Container is the focus cycle root of this Container's focus traversal cycle.
`final boolean`	`isFocusTraversalPolicyProvider()`	Returns whether this container provides focus traversal policy.
`boolean`	`isFocusTraversalPolicySet()`	Returns whether the focus traversal policy has been explicitly set for this Container.
`boolean`	`isValidateRoot()`	Indicates if this container is a validate root.
`void`	`list(PrintStream out, int indent)`	Prints a listing of this container to the specified output stream.
`void`	`list(PrintWriter out, int indent)`	Prints out a list, starting at the specified indentation, to the specified print writer.
`Component`	`locate(int x, int y)`	Deprecated. As of JDK version 1.1, replaced by `getComponentAt(int, int)`.
`Dimension`	`minimumSize()`	Deprecated. As of JDK version 1.1, replaced by `getMinimumSize()`.
`void`	`paint(Graphics g)`	Paints the container.
`void`	`paintComponents(Graphics g)`	Paints each of the components in this container.
`Dimension`	`preferredSize()`	Deprecated. As of JDK version 1.1, replaced by `getPreferredSize()`.
`void`	`print(Graphics g)`	Prints the container.
`protected void`	`processContainerEvent(ContainerEvent e)`	Processes container events occurring on this container by dispatching them to any registered ContainerListener objects.
`protected void`	`processEvent(AWTEvent e)`	Processes events on this container.
`void`	`remove(int index)`	Removes the component, specified by `index`, from this container.
`void`	`remove(Component comp)`	Removes the specified component from this container.
`void`	`removeAll()`	Removes all the components from this container.
`void`	`removeContainerListener(ContainerListener l)`	Removes the specified container listener so it no longer receives container events from this container.
`void`	`removeNotify()`	Makes this Container undisplayable by removing its connection to its native screen resource.
`void`	`setComponentZOrder(Component comp, int index)`	Moves the specified component to the specified z-order index in the container.
`void`	`setFocusCycleRoot(boolean focusCycleRoot)`	Sets whether this Container is the root of a focus traversal cycle.
`void`	`setFocusTraversalKeys(int id, Set<? extends AWTKeyStroke> keystrokes)`	Sets the focus traversal keys for a given traversal operation for this Container.
`void`	`setFocusTraversalPolicy(FocusTraversalPolicy policy)`	Sets the focus traversal policy that will manage keyboard traversal of this Container's children, if this Container is a focus cycle root.
`final void`	`setFocusTraversalPolicyProvider(boolean provider)`	Sets whether this container will be used to provide focus traversal policy.
`void`	`setFont(Font f)`	Sets the font of this container.
`void`	`transferFocusDownCycle()`	Transfers the focus down one focus traversal cycle.
`void`	`update(Graphics g)`	Updates the container.
`void`	`validate()`	Validates this container and all of its subcomponents.
`protected void`	`validateTree()`	Recursively descends the container tree and recomputes the layout for any subtrees marked as needing it (those marked as invalid).

Methods declared in class Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle

Modifier and Type	Method	Description
`boolean`	`action(Event evt, Object what)`	Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.
`void`	`add(PopupMenu popup)`	Adds the specified popup menu to the component.
`void`	`addComponentListener(ComponentListener l)`	Adds the specified component listener to receive component events from this component.
`void`	`addFocusListener(FocusListener l)`	Adds the specified focus listener to receive focus events from this component when this component gains input focus.
`void`	`addHierarchyBoundsListener(HierarchyBoundsListener l)`	Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes.
`void`	`addHierarchyListener(HierarchyListener l)`	Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes.
`void`	`addInputMethodListener(InputMethodListener l)`	Adds the specified input method listener to receive input method events from this component.
`void`	`addKeyListener(KeyListener l)`	Adds the specified key listener to receive key events from this component.
`void`	`addMouseListener(MouseListener l)`	Adds the specified mouse listener to receive mouse events from this component.
`void`	`addMouseMotionListener(MouseMotionListener l)`	Adds the specified mouse motion listener to receive mouse motion events from this component.
`void`	`addMouseWheelListener(MouseWheelListener l)`	Adds the specified mouse wheel listener to receive mouse wheel events from this component.
`Rectangle`	`bounds()`	Deprecated. As of JDK version 1.1, replaced by `getBounds()`.
`int`	`checkImage(Image image, int width, int height, ImageObserver observer)`	Returns the status of the construction of a screen representation of the specified image.
`int`	`checkImage(Image image, ImageObserver observer)`	Returns the status of the construction of a screen representation of the specified image.
`protected AWTEvent`	`coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)`	Potentially coalesce an event being posted with an existing event.
`boolean`	`contains(int x, int y)`	Checks whether this component "contains" the specified point, where `x` and `y` are defined to be relative to the coordinate system of this component.
`boolean`	`contains(Point p)`	Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
`Image`	`createImage(int width, int height)`	Creates an off-screen drawable image to be used for double buffering.
`Image`	`createImage(ImageProducer producer)`	Creates an image from the specified image producer.
`VolatileImage`	`createVolatileImage(int width, int height)`	Creates a volatile off-screen drawable image to be used for double buffering.
`VolatileImage`	`createVolatileImage(int width, int height, ImageCapabilities caps)`	Creates a volatile off-screen drawable image, with the given capabilities.
`void`	`disable()`	Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`protected final void`	`disableEvents(long eventsToDisable)`	Disables the events defined by the specified event mask parameter from being delivered to this component.
`final void`	`dispatchEvent(AWTEvent e)`	Dispatches an event to this component or one of its sub components.
`void`	`enable()`	Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`void`	`enable(boolean b)`	Deprecated. As of JDK version 1.1, replaced by `setEnabled(boolean)`.
`protected final void`	`enableEvents(long eventsToEnable)`	Enables the events defined by the specified event mask parameter to be delivered to this component.
`void`	`enableInputMethods(boolean enable)`	Enables or disables input method support for this component.
`protected void`	`firePropertyChange(String propertyName, boolean oldValue, boolean newValue)`	Support for reporting bound property changes for boolean properties.
`void`	`firePropertyChange(String propertyName, byte oldValue, byte newValue)`	Reports a bound property change.
`void`	`firePropertyChange(String propertyName, char oldValue, char newValue)`	Reports a bound property change.
`void`	`firePropertyChange(String propertyName, double oldValue, double newValue)`	Reports a bound property change.
`void`	`firePropertyChange(String propertyName, float oldValue, float newValue)`	Reports a bound property change.
`protected void`	`firePropertyChange(String propertyName, int oldValue, int newValue)`	Support for reporting bound property changes for integer properties.
`void`	`firePropertyChange(String propertyName, long oldValue, long newValue)`	Reports a bound property change.
`void`	`firePropertyChange(String propertyName, short oldValue, short newValue)`	Reports a bound property change.
`protected void`	`firePropertyChange(String propertyName, Object oldValue, Object newValue)`	Support for reporting bound property changes for Object properties.
`Color`	`getBackground()`	Gets the background color of this component.
`int`	`getBaseline(int width, int height)`	Returns the baseline.
`Component.BaselineResizeBehavior`	`getBaselineResizeBehavior()`	Returns an enum indicating how the baseline of the component changes as the size changes.
`Rectangle`	`getBounds()`	Gets the bounds of this component in the form of a `Rectangle` object.
`Rectangle`	`getBounds(Rectangle rv)`	Stores the bounds of this component into "return value" rv and return rv.
`ColorModel`	`getColorModel()`	Gets the instance of `ColorModel` used to display the component on the output device.
`ComponentListener[]`	`getComponentListeners()`	Returns an array of all the component listeners registered on this component.
`ComponentOrientation`	`getComponentOrientation()`	Retrieves the language-sensitive orientation that is to be used to order the elements or text within this component.
`Cursor`	`getCursor()`	Gets the cursor set in the component.
`DropTarget`	`getDropTarget()`	Gets the `DropTarget` associated with this `Component`.
`Container`	`getFocusCycleRootAncestor()`	Returns the Container which is the focus cycle root of this Component's focus traversal cycle.
`FocusListener[]`	`getFocusListeners()`	Returns an array of all the focus listeners registered on this component.
`boolean`	`getFocusTraversalKeysEnabled()`	Returns whether focus traversal keys are enabled for this Component.
`Font`	`getFont()`	Gets the font of this component.
`FontMetrics`	`getFontMetrics(Font font)`	Gets the font metrics for the specified font.
`Color`	`getForeground()`	Gets the foreground color of this component.
`Graphics`	`getGraphics()`	Creates a graphics context for this component.
`GraphicsConfiguration`	`getGraphicsConfiguration()`	Gets the `GraphicsConfiguration` associated with this `Component`.
`int`	`getHeight()`	Returns the current height of this component.
`HierarchyBoundsListener[]`	`getHierarchyBoundsListeners()`	Returns an array of all the hierarchy bounds listeners registered on this component.
`HierarchyListener[]`	`getHierarchyListeners()`	Returns an array of all the hierarchy listeners registered on this component.
`boolean`	`getIgnoreRepaint()`	Returns whether or not paint messages received from the operating system should be ignored.
`InputContext`	`getInputContext()`	Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
`InputMethodListener[]`	`getInputMethodListeners()`	Returns an array of all the input method listeners registered on this component.
`InputMethodRequests`	`getInputMethodRequests()`	Gets the input method request handler which supports requests from input methods for this component.
`KeyListener[]`	`getKeyListeners()`	Returns an array of all the key listeners registered on this component.
`Locale`	`getLocale()`	Gets the locale of this component.
`Point`	`getLocation()`	Gets the location of this component in the form of a point specifying the component's top-left corner.
`Point`	`getLocation(Point rv)`	Stores the x,y origin of this component into "return value" rv and return rv.
`Point`	`getLocationOnScreen()`	Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
`MouseListener[]`	`getMouseListeners()`	Returns an array of all the mouse listeners registered on this component.
`MouseMotionListener[]`	`getMouseMotionListeners()`	Returns an array of all the mouse motion listeners registered on this component.
`Point`	`getMousePosition()`	Returns the position of the mouse pointer in this `Component`'s coordinate space if the `Component` is directly under the mouse pointer, otherwise returns `null`.
`MouseWheelListener[]`	`getMouseWheelListeners()`	Returns an array of all the mouse wheel listeners registered on this component.
`String`	`getName()`	Gets the name of the component.
`Container`	`getParent()`	Gets the parent of this component.
`PropertyChangeListener[]`	`getPropertyChangeListeners()`	Returns an array of all the property change listeners registered on this component.
`PropertyChangeListener[]`	`getPropertyChangeListeners(String propertyName)`	Returns an array of all the listeners which have been associated with the named property.
`Dimension`	`getSize()`	Returns the size of this component in the form of a `Dimension` object.
`Dimension`	`getSize(Dimension rv)`	Stores the width/height of this component into "return value" rv and return rv.
`Toolkit`	`getToolkit()`	Gets the toolkit of this component.
`final Object`	`getTreeLock()`	Gets this component's locking object (the object that owns the thread synchronization monitor) for AWT component-tree and layout operations.
`int`	`getWidth()`	Returns the current width of this component.
`int`	`getX()`	Returns the current x coordinate of the components origin.
`int`	`getY()`	Returns the current y coordinate of the components origin.
`boolean`	`gotFocus(Event evt, Object what)`	Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
`boolean`	`handleEvent(Event evt)`	Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).
`boolean`	`hasFocus()`	Returns `true` if this `Component` is the focus owner.
`void`	`hide()`	Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`boolean`	`imageUpdate(Image img, int infoflags, int x, int y, int w, int h)`	Repaints the component when the image has changed.
`boolean`	`inside(int x, int y)`	Deprecated. As of JDK version 1.1, replaced by contains(int, int).
`boolean`	`isBackgroundSet()`	Returns whether the background color has been explicitly set for this Component.
`boolean`	`isCursorSet()`	Returns whether the cursor has been explicitly set for this Component.
`boolean`	`isDisplayable()`	Determines whether this component is displayable.
`boolean`	`isDoubleBuffered()`	Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later.
`boolean`	`isEnabled()`	Determines whether this component is enabled.
`boolean`	`isFocusable()`	Returns whether this Component can be focused.
`boolean`	`isFocusOwner()`	Returns `true` if this `Component` is the focus owner.
`boolean`	`isFocusTraversable()`	Deprecated. As of 1.4, replaced by `isFocusable()`.
`boolean`	`isFontSet()`	Returns whether the font has been explicitly set for this Component.
`boolean`	`isForegroundSet()`	Returns whether the foreground color has been explicitly set for this Component.
`boolean`	`isLightweight()`	A lightweight component doesn't have a native toolkit peer.
`boolean`	`isMaximumSizeSet()`	Returns true if the maximum size has been set to a non-`null` value otherwise returns false.
`boolean`	`isMinimumSizeSet()`	Returns whether or not `setMinimumSize` has been invoked with a non-null value.
`boolean`	`isOpaque()`	Returns true if this component is completely opaque, returns false by default.
`boolean`	`isPreferredSizeSet()`	Returns true if the preferred size has been set to a non-`null` value otherwise returns false.
`boolean`	`isShowing()`	Determines whether this component is showing on screen.
`boolean`	`isValid()`	Determines whether this component is valid.
`boolean`	`isVisible()`	Determines whether this component should be visible when its parent is visible.
`boolean`	`keyDown(Event evt, int key)`	Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
`boolean`	`keyUp(Event evt, int key)`	Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
`void`	`list()`	Prints a listing of this component to the standard system output stream `System.out`.
`void`	`list(PrintStream out)`	Prints a listing of this component to the specified output stream.
`void`	`list(PrintWriter out)`	Prints a listing to the specified print writer.
`Point`	`location()`	Deprecated. As of JDK version 1.1, replaced by `getLocation()`.
`boolean`	`lostFocus(Event evt, Object what)`	Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
`boolean`	`mouseDown(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseDrag(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
`boolean`	`mouseEnter(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseExit(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`boolean`	`mouseMove(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
`boolean`	`mouseUp(Event evt, int x, int y)`	Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
`void`	`move(int x, int y)`	Deprecated. As of JDK version 1.1, replaced by `setLocation(int, int)`.
`void`	`nextFocus()`	Deprecated. As of JDK version 1.1, replaced by transferFocus().
`void`	`paintAll(Graphics g)`	Paints this component and all of its subcomponents.
`boolean`	`postEvent(Event e)`	Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
`boolean`	`prepareImage(Image image, int width, int height, ImageObserver observer)`	Prepares an image for rendering on this component at the specified width and height.
`boolean`	`prepareImage(Image image, ImageObserver observer)`	Prepares an image for rendering on this component.
`void`	`printAll(Graphics g)`	Prints this component and all of its subcomponents.
`protected void`	`processComponentEvent(ComponentEvent e)`	Processes component events occurring on this component by dispatching them to any registered `ComponentListener` objects.
`protected void`	`processFocusEvent(FocusEvent e)`	Processes focus events occurring on this component by dispatching them to any registered `FocusListener` objects.
`protected void`	`processHierarchyBoundsEvent(HierarchyEvent e)`	Processes hierarchy bounds events occurring on this component by dispatching them to any registered `HierarchyBoundsListener` objects.
`protected void`	`processHierarchyEvent(HierarchyEvent e)`	Processes hierarchy events occurring on this component by dispatching them to any registered `HierarchyListener` objects.
`protected void`	`processInputMethodEvent(InputMethodEvent e)`	Processes input method events occurring on this component by dispatching them to any registered `InputMethodListener` objects.
`protected void`	`processKeyEvent(KeyEvent e)`	Processes key events occurring on this component by dispatching them to any registered `KeyListener` objects.
`protected void`	`processMouseEvent(MouseEvent e)`	Processes mouse events occurring on this component by dispatching them to any registered `MouseListener` objects.
`protected void`	`processMouseMotionEvent(MouseEvent e)`	Processes mouse motion events occurring on this component by dispatching them to any registered `MouseMotionListener` objects.
`void`	`remove(MenuComponent popup)`	Removes the specified popup menu from the component.
`void`	`removeComponentListener(ComponentListener l)`	Removes the specified component listener so that it no longer receives component events from this component.
`void`	`removeFocusListener(FocusListener l)`	Removes the specified focus listener so that it no longer receives focus events from this component.
`void`	`removeHierarchyBoundsListener(HierarchyBoundsListener l)`	Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component.
`void`	`removeHierarchyListener(HierarchyListener l)`	Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component.
`void`	`removeInputMethodListener(InputMethodListener l)`	Removes the specified input method listener so that it no longer receives input method events from this component.
`void`	`removeKeyListener(KeyListener l)`	Removes the specified key listener so that it no longer receives key events from this component.
`void`	`removeMouseListener(MouseListener l)`	Removes the specified mouse listener so that it no longer receives mouse events from this component.
`void`	`removeMouseMotionListener(MouseMotionListener l)`	Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
`void`	`removeMouseWheelListener(MouseWheelListener l)`	Removes the specified mouse wheel listener so that it no longer receives mouse wheel events from this component.
`void`	`removePropertyChangeListener(PropertyChangeListener listener)`	Removes a PropertyChangeListener from the listener list.
`void`	`removePropertyChangeListener(String propertyName, PropertyChangeListener listener)`	Removes a `PropertyChangeListener` from the listener list for a specific property.
`void`	`repaint()`	Repaints this component.
`void`	`repaint(int x, int y, int width, int height)`	Repaints the specified rectangle of this component.
`void`	`repaint(long tm)`	Repaints the component.
`void`	`repaint(long tm, int x, int y, int width, int height)`	Repaints the specified rectangle of this component within `tm` milliseconds.
`void`	`requestFocus()`	Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
`protected boolean`	`requestFocus(boolean temporary)`	Requests that this `Component` get the input focus, and that this `Component`'s top-level ancestor become the focused `Window`.
`protected boolean`	`requestFocus(boolean temporary, FocusEvent.Cause cause)`	Requests by the reason of `cause` that this `Component` get the input focus, and that this `Component`'s top-level ancestor become the focused `Window`.
`void`	`requestFocus(FocusEvent.Cause cause)`	Requests by the reason of `cause` that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
`boolean`	`requestFocusInWindow()`	Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
`protected boolean`	`requestFocusInWindow(boolean temporary)`	Requests that this `Component` get the input focus, if this `Component`'s top-level ancestor is already the focused `Window`.
`boolean`	`requestFocusInWindow(FocusEvent.Cause cause)`	Requests by the reason of `cause` that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
`void`	`reshape(int x, int y, int width, int height)`	Deprecated. As of JDK version 1.1, replaced by `setBounds(int, int, int, int)`.
`void`	`resize(int width, int height)`	Deprecated. As of JDK version 1.1, replaced by `setSize(int, int)`.
`void`	`resize(Dimension d)`	Deprecated. As of JDK version 1.1, replaced by `setSize(Dimension)`.
`void`	`revalidate()`	Revalidates the component hierarchy up to the nearest validate root.
`void`	`setBackground(Color c)`	Sets the background color of this component.
`void`	`setBounds(int x, int y, int width, int height)`	Moves and resizes this component.
`void`	`setBounds(Rectangle r)`	Moves and resizes this component to conform to the new bounding rectangle `r`.
`void`	`setComponentOrientation(ComponentOrientation o)`	Sets the language-sensitive orientation that is to be used to order the elements or text within this component.
`void`	`setCursor(Cursor cursor)`	Sets the cursor image to the specified cursor.
`void`	`setDropTarget(DropTarget dt)`	Associate a `DropTarget` with this component.
`void`	`setEnabled(boolean b)`	Enables or disables this component, depending on the value of the parameter `b`.
`void`	`setFocusable(boolean focusable)`	Sets the focusable state of this Component to the specified value.
`void`	`setFocusTraversalKeysEnabled(boolean focusTraversalKeysEnabled)`	Sets whether focus traversal keys are enabled for this Component.
`void`	`setForeground(Color c)`	Sets the foreground color of this component.
`void`	`setIgnoreRepaint(boolean ignoreRepaint)`	Sets whether or not paint messages received from the operating system should be ignored.
`void`	`setLocale(Locale l)`	Sets the locale of this component.
`void`	`setLocation(int x, int y)`	Moves this component to a new location.
`void`	`setLocation(Point p)`	Moves this component to a new location.
`void`	`setMaximumSize(Dimension maximumSize)`	Sets the maximum size of this component to a constant value.
`void`	`setMinimumSize(Dimension minimumSize)`	Sets the minimum size of this component to a constant value.
`void`	`setMixingCutoutShape(Shape shape)`	Sets a 'mixing-cutout' shape for this lightweight component.
`void`	`setName(String name)`	Sets the name of the component to the specified string.
`void`	`setPreferredSize(Dimension preferredSize)`	Sets the preferred size of this component to a constant value.
`void`	`setSize(int width, int height)`	Resizes this component so that it has width `width` and height `height`.
`void`	`setSize(Dimension d)`	Resizes this component so that it has width `d.width` and height `d.height`.
`void`	`setVisible(boolean b)`	Shows or hides this component depending on the value of parameter `b`.
`void`	`show()`	Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`void`	`show(boolean b)`	Deprecated. As of JDK version 1.1, replaced by `setVisible(boolean)`.
`Dimension`	`size()`	Deprecated. As of JDK version 1.1, replaced by `getSize()`.
`String`	`toString()`	Returns a string representation of this component and its values.
`void`	`transferFocus()`	Transfers the focus to the next component, as though this Component were the focus owner.
`void`	`transferFocusBackward()`	Transfers the focus to the previous component, as though this Component were the focus owner.
`void`	`transferFocusUpCycle()`	Transfers the focus up one focus traversal cycle.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details

SCROLLBARS_AS_NEEDED

public static final int SCROLLBARS_AS_NEEDED

Specifies that horizontal/vertical scrollbar should be shown only when the size of the child exceeds the size of the scrollpane in the horizontal/vertical dimension.

See Also:

SCROLLBARS_ALWAYS

public static final int SCROLLBARS_ALWAYS

Specifies that horizontal/vertical scrollbars should always be shown regardless of the respective sizes of the scrollpane and child.

See Also:

SCROLLBARS_NEVER

public static final int SCROLLBARS_NEVER

Specifies that horizontal/vertical scrollbars should never be shown regardless of the respective sizes of the scrollpane and child.

See Also:

Constructor Details

ScrollPane

public ScrollPane() throws HeadlessException

Create a new scrollpane container with a scrollbar display policy of "as needed".

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

See Also:

ScrollPane

@ConstructorProperties("scrollbarDisplayPolicy") public ScrollPane(int scrollbarDisplayPolicy) throws HeadlessException

Create a new scrollpane container.

Parameters:

scrollbarDisplayPolicy - policy for when scrollbars should be shown

Throws:

IllegalArgumentException - if the specified scrollbar display policy is invalid

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

See Also:

Method Details

addImpl

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

Adds the specified component to this scroll pane container. If the scroll pane has an existing child component, that component is removed and the new one is added.

Overrides:

addImpl in class Container

Parameters:

comp - the component to be added

constraints - not applicable

index - position of child component (must be <= 0)

See Also:

getScrollbarDisplayPolicy

public int getScrollbarDisplayPolicy()

Returns the display policy for the scrollbars.

Returns:: the display policy for the scrollbars

getViewportSize

public Dimension getViewportSize()

Returns the current size of the scroll pane's view port.

Returns:: the size of the view port in pixels

getHScrollbarHeight

public int getHScrollbarHeight()

Returns the height that would be occupied by a horizontal scrollbar, which is independent of whether it is currently displayed by the scroll pane or not.

Returns:: the height of a horizontal scrollbar in pixels

getVScrollbarWidth

public int getVScrollbarWidth()

Returns the width that would be occupied by a vertical scrollbar, which is independent of whether it is currently displayed by the scroll pane or not.

Returns:: the width of a vertical scrollbar in pixels

getVAdjustable

public Adjustable getVAdjustable()

Returns the ScrollPaneAdjustable object which represents the state of the vertical scrollbar. The declared return type of this method is Adjustable to maintain backward compatibility.

Returns:

the vertical scrollbar state

See Also:

getHAdjustable

public Adjustable getHAdjustable()

Returns the ScrollPaneAdjustable object which represents the state of the horizontal scrollbar. The declared return type of this method is Adjustable to maintain backward compatibility.

Returns:

the horizontal scrollbar state

See Also:

setScrollPosition

public void setScrollPosition(int x, int y)

Scrolls to the specified position within the child component. A call to this method is only valid if the scroll pane contains a child. Specifying a position outside of the legal scrolling bounds of the child will scroll to the closest legal position. Legal bounds are defined to be the rectangle: x = 0, y = 0, width = (child width - view port width), height = (child height - view port height). This is a convenience method which interfaces with the Adjustable objects which represent the state of the scrollbars.

Parameters:: x - the x position to scroll to; y - the y position to scroll to
Throws:: NullPointerException - if the scrollpane does not contain a child

setScrollPosition

public void setScrollPosition(Point p)

Scrolls to the specified position within the child component. A call to this method is only valid if the scroll pane contains a child and the specified position is within legal scrolling bounds of the child. Specifying a position outside of the legal scrolling bounds of the child will scroll to the closest legal position. Legal bounds are defined to be the rectangle: x = 0, y = 0, width = (child width - view port width), height = (child height - view port height). This is a convenience method which interfaces with the Adjustable objects which represent the state of the scrollbars.

Parameters:: p - the Point representing the position to scroll to
Throws:: NullPointerException - if p is null

getScrollPosition

public Point getScrollPosition()

Returns the current x,y position within the child which is displayed at the 0,0 location of the scrolled panel's view port. This is a convenience method which interfaces with the adjustable objects which represent the state of the scrollbars.

Returns:: the coordinate position for the current scroll position
Throws:: NullPointerException - if the scrollpane does not contain a child

setLayout

public final void setLayout(LayoutManager mgr)

Sets the layout manager for this container. This method is overridden to prevent the layout mgr from being set.

Overrides:

setLayout in class Container

Parameters:

mgr - the specified layout manager

See Also:

doLayout

public void doLayout()

Lays out this container by resizing its child to its preferred size. If the new preferred size of the child causes the current scroll position to be invalid, the scroll position is set to the closest valid position.

Overrides:

doLayout in class Container

See Also:

layout

@Deprecated public void layout()

Deprecated.

As of JDK version 1.1, replaced by doLayout().

Overrides:: layout in class Container

printComponents

public void printComponents(Graphics g)

Prints the component in this scroll pane.

Overrides:

printComponents in class Container

Parameters:

g - the specified Graphics window

See Also:

addNotify

public void addNotify()

Creates the scroll pane's peer.

Overrides:

addNotify in class Container

See Also:

paramString

public String paramString()

Returns a string representing the state of this ScrollPane. 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 Container
Returns:: the parameter string of this scroll pane

processMouseWheelEvent

protected void processMouseWheelEvent(MouseWheelEvent e)

Process mouse wheel events that are delivered to this ScrollPane by scrolling an appropriate amount.

Note that if the event parameter is null the behavior is unspecified and may result in an exception.

Overrides:

processMouseWheelEvent in class Component

Parameters:

e - the mouse wheel event

Since:

1.4

See Also:

eventTypeEnabled

protected boolean eventTypeEnabled(int type)

If wheel scrolling is enabled, we return true for MouseWheelEvents

Since:: 1.4

setWheelScrollingEnabled

public void setWheelScrollingEnabled(boolean handleWheel)

Enables/disables scrolling in response to movement of the mouse wheel. Wheel scrolling is enabled by default.

Parameters:

handleWheel - true if scrolling should be done automatically for a MouseWheelEvent, false otherwise.

Since:

1.4

See Also:

isWheelScrollingEnabled

public boolean isWheelScrollingEnabled()

Indicates whether or not scrolling will take place in response to the mouse wheel. Wheel scrolling is enabled by default.

Returns:

true if the wheel scrolling enabled; otherwise false

Since:

1.4

See Also:

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this ScrollPane. For scroll panes, the AccessibleContext takes the form of an AccessibleAWTScrollPane. A new AccessibleAWTScrollPane instance is created if necessary.

Specified by:: getAccessibleContext in interface Accessible
Overrides:: getAccessibleContext in class Component
Returns:: an AccessibleAWTScrollPane that serves as the AccessibleContext of this ScrollPane
Since:: 1.3

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Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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