Package org.ka2ddo.yaac.gui.util

Class ScrollableJLabel

java.lang.Object

java.awt.Component

java.awt.Container

javax.swing.JComponent

org.ka2ddo.yaac.gui.util.ScrollableJLabel

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable, Accessible, Scrollable

public class ScrollableJLabel
extends JComponent
implements Scrollable, Accessible

This widget adapts a JLabel to be displayable in a JScrollPane for multi-line read-only message displays.

Author:

Andrew Pavlin, KA2DDO

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	ScrollableJLabel.AccessibleScrollableLabel	The class used to obtain the accessible role for this object.

Nested classes/interfaces inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes/interfaces inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces inherited from class java.awt.Component

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

Field Summary

Fields inherited from class javax.swing.JComponent

listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

Constructors

Constructor	Description
ScrollableJLabel(String text)	Creates a JLabel instance with the specified text.

Method Summary

Modifier and Type	Method	Description
AccessibleContext	getAccessibleContext()	Returns the AccessibleContext associated with this JComponent.
Component	getLabelFor()	Get the component this is labelling.
Dimension	getPreferredScrollableViewportSize()	Returns the preferred size of the viewport for a view component.
Dimension	getPreferredSize()	If the preferredSize has been set to a non-null value just returns it.
int	getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)	Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.
boolean	getScrollableTracksViewportHeight()	Return true if a viewport should always force the height of this Scrollable to match the height of the viewport.
boolean	getScrollableTracksViewportWidth()	Return true if a viewport should always force the width of this Scrollable to match the width of the viewport.
int	getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)	Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation.
String	getText()	Returns the text string that the label displays.
protected void	paintComponent(Graphics g)	Draw the text of this label on the screen.
void	setLabelFor(Component c)	Set the component this is labelling.
void	setText(String text)	Defines the text this component will display.

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getUI, getUIClassID, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintImmediately, paintImmediately, paramString, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update, updateUI

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

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

Methods inherited from class java.lang.Object

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

Constructor Details

ScrollableJLabel

public ScrollableJLabel(String text)

Creates a JLabel instance with the specified text. The label is aligned against the leading edge of its display area, and centered vertically.

Parameters:

text - The text to be displayed by the label.

Method Details

setText

public void setText(String text)

Defines the text this component will display. If the value of text is null or empty string, nothing is displayed.

The default value of this property is null.

Parameters:

text - String to display on label

getText

public String getText()

Returns the text string that the label displays.

Returns:

a String

See Also:

• setText(java.lang.String)

paintComponent

protected void paintComponent(Graphics g)

Draw the text of this label on the screen.

Overrides:

paintComponent in class JComponent

Parameters:

g - the Graphics object to protect

getPreferredSize

public Dimension getPreferredSize()

If the preferredSize has been set to a non-null value just returns it. If the UI delegate's getPreferredSize method returns a non null value then return that; otherwise defer to the component's layout manager.

Overrides:

getPreferredSize in class JComponent

Returns:

the value of the preferredSize property

getPreferredScrollableViewportSize

public Dimension getPreferredScrollableViewportSize()

Returns the preferred size of the viewport for a view component. For example, the preferred size of a JList component is the size required to accommodate all of the cells in its list. However, the value of preferredScrollableViewportSize is the size required for JList.getVisibleRowCount rows. A component without any properties that would affect the viewport size should just return getPreferredSize here.

Specified by:

getPreferredScrollableViewportSize in interface Scrollable

Returns:

the preferredSize of a JViewport whose view is this Scrollable

See Also:

• JComponent.getPreferredSize()

getScrollableUnitIncrement

public int getScrollableUnitIncrement(Rectangle visibleRect,
 int orientation,
 int direction)

Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation. Ideally, components should handle a partially exposed row or column by returning the distance required to completely expose the item.

Scrolling containers, like JScrollPane, will use this method each time the user requests a unit scroll.

Specified by:

getScrollableUnitIncrement in interface Scrollable

Parameters:

visibleRect - The view area visible within the viewport

orientation - Either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL.

direction - Less than zero to scroll up/left, greater than zero for down/right.

Returns:

The "unit" increment for scrolling in the specified direction. This value should always be positive.

See Also:

• JScrollBar.setUnitIncrement(int)

getScrollableBlockIncrement

public int getScrollableBlockIncrement(Rectangle visibleRect,
 int orientation,
 int direction)

Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.

Scrolling containers, like JScrollPane, will use this method each time the user requests a block scroll.

Specified by:

getScrollableBlockIncrement in interface Scrollable

Parameters:

visibleRect - The view area visible within the viewport

orientation - Either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL.

direction - Less than zero to scroll up/left, greater than zero for down/right.

Returns:

The "block" increment for scrolling in the specified direction. This value should always be positive.

See Also:

• JScrollBar.setBlockIncrement(int)

getScrollableTracksViewportWidth

public boolean getScrollableTracksViewportWidth()

Return true if a viewport should always force the width of this Scrollable to match the width of the viewport. For example a normal text view that supported line wrapping would return true here, since it would be undesirable for wrapped lines to disappear beyond the right edge of the viewport. Note that returning true for a Scrollable whose ancestor is a JScrollPane effectively disables horizontal scrolling.

Scrolling containers, like JViewport, will use this method each time they are validated.

Specified by:

getScrollableTracksViewportWidth in interface Scrollable

Returns:

True if a viewport should force the Scrollables width to match its own.

getScrollableTracksViewportHeight

public boolean getScrollableTracksViewportHeight()

Return true if a viewport should always force the height of this Scrollable to match the height of the viewport. For example a columnar text view that flowed text in left to right columns could effectively disable vertical scrolling by returning true here.

Scrolling containers, like JViewport, will use this method each time they are validated.

Specified by:

getScrollableTracksViewportHeight in interface Scrollable

Returns:

True if a viewport should force the Scrollables height to match its own.

getLabelFor

public Component getLabelFor()

Get the component this is labelling.

Returns:

the Component this is labelling. Can be null if this does not label a Component. If the displayedMnemonic property is set and the labelFor property is also set, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

setLabelFor

public void setLabelFor(Component c)

Set the component this is labelling. Can be null if this does not label a Component. If the displayedMnemonic property is set and the labelFor property is also set, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

Parameters:

c - the Component this label is for, or null if the label is not the label for a component

getAccessibleContext

public AccessibleContext getAccessibleContext()

Returns the AccessibleContext associated with this JComponent. The method implemented by this base class returns null. Classes that extend JComponent should implement this method to return the AccessibleContext associated with the subclass.

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class Component

Returns:

the AccessibleContext of this JComponent