Class ActiveTextArea
- All Implemented Interfaces:
ImageObserver
,MenuContainer
,Serializable
,Accessible
,CSProcess
java.awt.TextArea
with a channel interface.
Process Diagram
Description
ActiveTextArea is a process extension of java.awt.TextArea 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 and event channels are settable from a constructor. The event channel delivers updated text whenever the ActiveTextArea is changed. Other event channels can be added to notify the occurrence of any other events 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 myTextAreaEvent = Channel.one2one (new OverWriteOldestBuffer (n)); final ActiveTextArea myTextArea = new ActiveTextArea (null, myTextAreaEvent.out (), "Edit Me", 5, 20);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 | ||
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configure | String | Append the string to the text in this ActiveTextArea |
Boolean |
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|
ActiveTextArea.Configure | Invoke the user-defined Configure.configure method on the textArea. | |
otherwise ... | Append the toString form of the object to the text in this ActiveTextArea. | |
Output Channels | ||
event | String | The text in the ActiveTextArea (whenever the text area is altered) |
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 org.jcsp.lang.*; import org.jcsp.util.*; import org.jcsp.awt.*; import java.awt.*; public class ActiveTextAreaExample { public static void main (String argv[]) { final ActiveClosingFrame frame = new ActiveClosingFrame ("ActiveTextAreaExample Example"); final Any2OneChannel event = Channel.any2one (new OverWriteOldestBuffer (10)); final String[] string = {"Entia Non Sunt Multiplicanda Praeter Necessitatem", "Everything we do, we do it to you", "Race Hazards - What Rice Hozzers?", "Cogito Ergo Occam"}; final String goodbye = "Goodbye World"; final ActiveTextArea[] activeText = new ActiveTextArea[string.length]; for (int i = 0; i invalid input: '<' string.length; i++) { activeText[i] = new ActiveTextArea (null, event.out (), string[i], 5, 40); } Panel panel = new Panel (new GridLayout (string.length/2, 2)); for (int i = 0; i invalid input: '<' string.length; i++) { panel.add (activeText[i]); } final Frame realFrame = frame.getActiveFrame (); realFrame.setBackground (Color.green); realFrame.add (panel); realFrame.pack (); realFrame.setVisible (true); new Parallel ( new CSProcess[] { frame, new Parallel (activeText), new CSProcess () { public void run () { boolean running = true; while (running) { String s = (String) event.in ().read (); System.out.println (s); running = (! s.equals (goodbye)); } realFrame.setVisible (false); System.exit (0); } } } ).run (); } }
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic interface
This enables general configuration of this component.Nested classes/interfaces inherited from class java.awt.TextArea
TextArea.AccessibleAWTTextArea
Nested classes/interfaces inherited from class java.awt.TextComponent
TextComponent.AccessibleAWTTextComponent
Nested classes/interfaces inherited from class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate ChannelInput
The channel from which configuration messages arrive.private Vector
The Vector construct containing the handlers.Fields inherited from class java.awt.TextArea
SCROLLBARS_BOTH, SCROLLBARS_HORIZONTAL_ONLY, SCROLLBARS_NONE, SCROLLBARS_VERTICAL_ONLY
Fields inherited from class java.awt.TextComponent
textListener
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
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Constructor Summary
ConstructorsConstructorDescriptionConstructs a new ActiveTextArea with scrollbars, but with no configuration or event channels or initial text or size.Constructs a new ActiveTextArea with scrollbars and initial text, but with no configuration or event channels or initial size.ActiveTextArea
(String s, int rows, int columns) Constructs a new ActiveTextArea with scrollbars and initial text and size, but with no configuration or event channels.ActiveTextArea
(String s, int rows, int columns, int scrollbars) Constructs a new ActiveTextArea with user-defined scrollbars and initial text and size, but with no configuration or event channels.ActiveTextArea
(ChannelInput configure, ChannelOutput event) Constructs a new ActiveTextArea with configuration and event channels and scrollbars, but with no initial text or size.ActiveTextArea
(ChannelInput configure, ChannelOutput event, String s) Constructs a new ActiveTextArea with configuration and event channels and scrollbars and initial text, but with no initial size.ActiveTextArea
(ChannelInput configure, ChannelOutput event, String s, int rows, int columns) Constructs a new ActiveTextArea with configuration and event channels and scrollbars and initial text and size.ActiveTextArea
(ChannelInput configure, ChannelOutput event, String s, int rows, int columns, int scrollbars) Constructs a new ActiveTextArea with configuration and event channels and user-defined scrollbars and initial text and size. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addComponentEventChannel
(ChannelOutput componentEvent) Add a new channel to this component that will be used to notify that a ComponentEvent 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 ActiveTextArea.Methods inherited from class java.awt.TextArea
addNotify, append, appendText, getAccessibleContext, getColumns, getMinimumSize, getMinimumSize, getPreferredSize, getPreferredSize, getRows, getScrollbarVisibility, insert, insertText, minimumSize, minimumSize, paramString, preferredSize, preferredSize, replaceRange, replaceText, setColumns, setRows
Methods inherited from class java.awt.TextComponent
addTextListener, enableInputMethods, getBackground, getCaretPosition, getInputMethodRequests, getListeners, getSelectedText, getSelectionEnd, getSelectionStart, getText, getTextListeners, isEditable, processEvent, processTextEvent, removeNotify, removeTextListener, select, selectAll, setBackground, setCaretPosition, setEditable, setSelectionEnd, setSelectionStart, setText
Methods inherited from class java.awt.Component
action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAlignmentX, getAlignmentY, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paint, paintAll, postEvent, prepareImage, prepareImage, print, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate
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Field Details
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vec
The Vector construct containing the handlers. -
configure
The channel from which configuration messages arrive.
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Constructor Details
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ActiveTextArea
public ActiveTextArea()Constructs a new ActiveTextArea with scrollbars, but with no configuration or event channels or initial text or size. -
ActiveTextArea
Constructs a new ActiveTextArea with scrollbars and initial text, but with no configuration or event channels or initial size.- Parameters:
s
- the initial text displayed in the area.
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ActiveTextArea
Constructs a new ActiveTextArea with scrollbars and initial text and size, but with no configuration or event channels.- Parameters:
s
- the initial text displayed in the area.rows
- the rows of the area.columns
- the columns of the area.
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ActiveTextArea
Constructs a new ActiveTextArea with user-defined scrollbars and initial text and size, but with no configuration or event channels.- Parameters:
s
- the initial text displayed in the area.rows
- the rows of the area.columns
- the columns of the area.scrollbars
- the columns of the area (java.awt.TextArea.SCROLLBARS_BOTH, java.awt.TextArea.SCROLLBARS_VERTICAL_ONLY, java.awt.TextArea.SCROLLBARS_HORIZONTAL_ONLY or java.awt.TextArea.SCROLLBARS_NONE).
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ActiveTextArea
Constructs a new ActiveTextArea with configuration and event channels and scrollbars, but with no initial text or size.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.event
- the current text will be output when the text area is changed -- can be null if no notification is required.
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ActiveTextArea
Constructs a new ActiveTextArea with configuration and event channels and scrollbars and initial text, but with no initial size.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.event
- the current text will be output when the text area is changed -- can be null if no notification is required.s
- the initial text displayed in the area.
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ActiveTextArea
Constructs a new ActiveTextArea with configuration and event channels and scrollbars and initial text and size.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.event
- the current text will be output when the text area is changed -- can be null if no notification is required.s
- the initial text displayed in the area.rows
- the rows of the area.columns
- the columns of the area.
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ActiveTextArea
public ActiveTextArea(ChannelInput configure, ChannelOutput event, String s, int rows, int columns, int scrollbars) Constructs a new ActiveTextArea with configuration and event channels and user-defined scrollbars and initial text and size.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.event
- the current text will be output when the text area is changed -- can be null if no notification is required.s
- the initial text displayed in the area.rows
- the rows of the area.columns
- the columns of the area.scrollbars
- the columns of the area (java.awt.TextArea.SCROLLBARS_BOTH, java.awt.TextArea.SCROLLBARS_VERTICAL_ONLY, java.awt.TextArea.SCROLLBARS_HORIZONTAL_ONLY or java.awt.TextArea.SCROLLBARS_NONE).
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Method Details
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setConfigureChannel
Sets the configuration channel for this ActiveTextArea. 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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addComponentEventChannel
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
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
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
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
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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run
public void run()The main body of this process.
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