Class ActiveScrollPane
- java.lang.Object
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- java.awt.Component
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- java.awt.Container
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- java.awt.ScrollPane
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- org.jcsp.awt.ActiveScrollPane
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- All Implemented Interfaces:
java.awt.image.ImageObserver
,java.awt.MenuContainer
,java.io.Serializable
,javax.accessibility.Accessible
,CSProcess
public class ActiveScrollPane extends java.awt.ScrollPane implements CSProcess
java.awt.ScrollPane
with a channel interface.Process Diagram
Description
ActiveScrollPane is a process extension of java.awt.ScrollPane with channels for run-time configuration and event notification. The event channels should be connected to one or more application-specific server processes (instead of registering a passive object as a Listener to this component).All channels are optional. The configure channel is settable from a constructor. Event channels can be added to notify the occurrence of any type of Event the component generates (by calling the appropriate addXXXEventChannel method before the process is run). Messages can be sent down the configure channel at any time to configure the component. See the table below for details.
All channels are managed by independent internal handler processes. It is, therefore, safe for a serial application process both to service an event channel and configure the component -- no deadlock can occur.
IMPORTANT: it is essential that event channels from this process are always serviced -- otherwise the Java Event Thread will be blocked and the GUI will stop responding. A simple way to guarantee this is to use channels configured with overwriting buffers. For example:
final One2OneChannel myMouseEvent = Channel.one2one (new OverWriteOldestBuffer (n)); final ActiveScrollPane myScrollPane = new ActiveScrollPane (); myScrollPane.addMouseEventChannel (myMouseEvent.out ());
This will ensure that the Java Event Thread will never be blocked. Slow or inattentive readers may miss rapidly generated events, but the n most recent events will always be available.Channel Protocols
Input Channels configure ActiveScrollPane.Configure Invoke the user-defined Configure.configure method on the scrollPane. Output Channels containerEvent ContainerEvent See the addContainerEventChannel
method.componentEvent ComponentEvent See the addComponentEventChannel
method.focusEvent FocusEvent See the addFocusEventChannel
method.keyEvent KeyEvent See the addKeyEventChannel
method.mouseEvent MouseEvent See the addMouseEventChannel
method.mouseMotionEvent MouseEvent See the addMouseMotionEventChannel
method.Example
import java.awt.*; import java.awt.event.*; import org.jcsp.util.*; import org.jcsp.lang.*; import org.jcsp.awt.*; public class ActiveScrollPaneExample { public static void main (String argv[]) { final Frame root = new Frame ("ActiveScrollPane Example"); final One2OneChannel mouseEvent = Channel.one2one (new OverWriteOldestBuffer (10)); final ActiveScrollPane scrollPane = new ActiveScrollPane (); scrollPane.addMouseEventChannel (mouseEvent.out ()); root.add (scrollPane); root.setSize (400, 400); root.setVisible (true); new Parallel ( new CSProcess[] { scrollPane, new CSProcess () { public void run () { boolean running = true; while (running) { final MouseEvent event = (MouseEvent) mouseEvent.in ().read (); switch (event.getID ()) { case MouseEvent.MOUSE_ENTERED: System.out.println ("MOUSE_ENTERED"); break; case MouseEvent.MOUSE_EXITED: System.out.println ("MOUSE_EXITED"); break; case MouseEvent.MOUSE_PRESSED: System.out.println ("MOUSE_PRESSED"); break; case MouseEvent.MOUSE_RELEASED: System.out.println ("MOUSE_RELEASED"); break; case MouseEvent.MOUSE_CLICKED: if (event.getClickCount() > 1) { System.out.println ("MOUSE_DOUBLE_CLICKED ... goodbye!"); running = false; } else { System.out.println ("MOUSE_CLICKED ... *double* click to quit!"); } break; } } root.setVisible (false); System.exit (0); } } } ).run (); } }
- See Also:
ScrollPane
,ContainerEvent
,ComponentEvent
,FocusEvent
,KeyEvent
,MouseEvent
,OverWriteOldestBuffer
, Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description static interface
ActiveScrollPane.Configure
This enables general configuration of this component.-
Nested classes/interfaces inherited from class java.awt.ScrollPane
java.awt.ScrollPane.AccessibleAWTScrollPane
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Field Summary
Fields Modifier and Type Field Description private ChannelInput
configure
The channel from which configuration messages arrive.private java.util.Vector
vec
The Vector construct containing the handlers.-
Fields inherited from class java.awt.ScrollPane
SCROLLBARS_ALWAYS, SCROLLBARS_AS_NEEDED, SCROLLBARS_NEVER
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Constructor Summary
Constructors Constructor Description ActiveScrollPane()
Constructs a new ActiveScrollPane with a display policy of java.awt.ScrollPane.SCROLLBARS_AS_NEEDED and without a configure channel.ActiveScrollPane(int scrollbarDisplayPolicy)
Constructs a new ActiveScrollPane without a configure channel.ActiveScrollPane(int scrollbarDisplayPolicy, ChannelInput configure)
Constructs a new ActiveScrollPane.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addComponentEventChannel(ChannelOutput componentEvent)
Add a new channel to this component that will be used to notify that a ComponentEvent has occurred.void
addContainerEventChannel(ChannelOutput containerEvent)
Add a new channel to this component that will be used to notify that a ContainerEvent has occurred.void
addFocusEventChannel(ChannelOutput focusEvent)
Add a new channel to this component that will be used to notify that a FocusEvent has occurred.void
addKeyEventChannel(ChannelOutput keyEvent)
Add a new channel to this component that will be used to notify that a KeyEvent has occurred.void
addMouseEventChannel(ChannelOutput mouseEvent)
Add a new channel to this component that will be used to notify that a MouseEvent has occurred.void
addMouseMotionEventChannel(ChannelOutput mouseMotionEvent)
Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred.void
run()
The main body of this process.void
setConfigureChannel(ChannelInput configure)
Sets the configuration channel for this ActiveScrollPane.-
Methods inherited from class java.awt.ScrollPane
addImpl, addNotify, doLayout, eventTypeEnabled, getAccessibleContext, getHAdjustable, getHScrollbarHeight, getScrollbarDisplayPolicy, getScrollPosition, getVAdjustable, getViewportSize, getVScrollbarWidth, isWheelScrollingEnabled, layout, paramString, printComponents, processMouseWheelEvent, setLayout, setScrollPosition, setScrollPosition, setWheelScrollingEnabled
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Methods inherited from class java.awt.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
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Methods inherited from class java.awt.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, getPeer, 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, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
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Field Detail
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vec
private java.util.Vector vec
The Vector construct containing the handlers.
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configure
private ChannelInput configure
The channel from which configuration messages arrive.
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Constructor Detail
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ActiveScrollPane
public ActiveScrollPane()
Constructs a new ActiveScrollPane with a display policy of java.awt.ScrollPane.SCROLLBARS_AS_NEEDED and without a configure channel.
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ActiveScrollPane
public ActiveScrollPane(int scrollbarDisplayPolicy)
Constructs a new ActiveScrollPane without a configure channel.- Parameters:
scrollbarDisplayPolicy
- - policy for when scrollbars should be shown (java.awt.ScrollPane.SCROLLBARS_AS_NEEDED, SCROLLBARS_ALWAYS, SCROLLBARS_NEVER).
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ActiveScrollPane
public ActiveScrollPane(int scrollbarDisplayPolicy, ChannelInput configure)
Constructs a new ActiveScrollPane.- Parameters:
scrollbarDisplayPolicy
- - policy for when scrollbars should be shown (java.awt.ScrollPane.SCROLLBARS_AS_NEEDED, SCROLLBARS_ALWAYS, SCROLLBARS_NEVER).configure
- the channel for configuration events -- can be null if no configuration is required.
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Method Detail
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setConfigureChannel
public void setConfigureChannel(ChannelInput configure)
Sets the configuration channel for this ActiveScrollPane. This method overwrites any configuration channel set in the constructor.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.
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addContainerEventChannel
public void addContainerEventChannel(ChannelOutput containerEvent)
Add a new channel to this component that will be used to notify that a ContainerEvent has occurred. This should be used instead of registering a ContainerListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
containerEvent
- the channel down which to send ContainerEvents.
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addComponentEventChannel
public void addComponentEventChannel(ChannelOutput componentEvent)
Add a new channel to this component that will be used to notify that a ComponentEvent has occurred. This should be used instead of registering a ComponentListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
componentEvent
- the channel down which to send ComponentEvents.
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addFocusEventChannel
public void addFocusEventChannel(ChannelOutput focusEvent)
Add a new channel to this component that will be used to notify that a FocusEvent has occurred. This should be used instead of registering a FocusListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
focusEvent
- the channel down which to send FocusEvents.
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addKeyEventChannel
public void addKeyEventChannel(ChannelOutput keyEvent)
Add a new channel to this component that will be used to notify that a KeyEvent has occurred. This should be used instead of registering a KeyListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
keyEvent
- the channel down which to send KeyEvents.
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addMouseEventChannel
public void addMouseEventChannel(ChannelOutput mouseEvent)
Add a new channel to this component that will be used to notify that a MouseEvent has occurred. This should be used instead of registering a MouseListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
mouseEvent
- the channel down which to send MouseEvents.
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addMouseMotionEventChannel
public void addMouseMotionEventChannel(ChannelOutput mouseMotionEvent)
Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred. This should be used instead of registering a MouseMotionListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.NOTE: This method must be called before this process is run.
- Parameters:
mouseMotionEvent
- the channel down which to send MouseMotionEvents.
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