Class VariableInput
- All Implemented Interfaces:
InputObject
,Tieable
,Value
,ImageObserver
,MenuContainer
,Serializable
,Accessible
Whenever checkInput is called, an error of type JCMError might be generated. If throwErrors is true, this error is thrown; if it is false, the error is caught, the value of the variable is set to Double.NaN, and no error is thrown. The error message associated with the error can be retrieved by calling getErrorMessage(), if desired. (This value is null if no error occurred the last time checkInput was called.)
A VariableInput is a Value, so it can be used directly where a Value object is needed.
An VariableInput will ordinarily be registered with a Controller in TWO ways: It's added to a Controller with the Controller's add() method. This makes the Controller call the VariableInput's checkInput() method during the Controller's compute() method. Secondly, a Controller is set as the "onUserAction" property. This causes the Controller's compute() method to be called when the user presses return in the VariableInput box. This is optional-- you might, for example, only want the Controller to compute() when a Compute button is pressed. You can also set the VariableInput's onTextChange property to a Controller that you want to compute every time the text in the box changes.
After the VariableInput is created, it is possible to specify the largest and smallest allowed values for the variable. It is also possible to specify what sytle of input is allowed. The style can be to allow any constant expression, constant real numbers only, or integers only. Set these parameters with setMin(), setMax(), and setInputStyle(). For setInputStyle(), the legal parameter values are VariableInput.EXPRESSION, VariableInput.REAL, and VariableInput.INTEGER. The default input style is EXPRESSION.
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class java.awt.TextField
TextField.AccessibleAWTTextField
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 TypeFieldDescriptionprotected String
Error message from the most recent time checkInput() as called.static final int
A constant for use in the setInputStyle() method.protected int
One of the constant values EXPRESSION, REAL, or INTEGER, specifying the style of input.static final int
A constant for use in the setInputStyle() method.protected double
Largest allowable value.protected double
Smallest allowable value.protected String
This is set to true if the text in the box has been changed since the last time the value of the variable was checked by checkInput().static final int
A constant for use in the setInputStyle() method.protected long
This serial number is increased each time the value of the variable changes.protected boolean
True if an error should be thrown when checkInput() is calles and the contents do not define a legal number.protected edu.hws.jcm.awt.VariableInput.VI
The Variable that represents the value of this input box.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
ConstructorsConstructorDescriptionCreate an unnamed VariableInput with initial contents "0".VariableInput
(String name, String initialString) Construct a VariableInput with the given name and initial String (which can both be null).VariableInput
(String name, String initialString, Parser parser) Create a VariableInput just as in the constructor VariableInput(String,String). -
Method Summary
Modifier and TypeMethodDescriptionvoid
A convenience method that registers this VariableInput's variable with Parser p (but only if both p and the name of the variable are non-null).void
Check whether the contents are valid, and change the value of the associated variable if the new contents do not match the current value.protected double
convertInput
(String num) Convert a string into a real value.Get error message from previous call to checkInput().int
Return the input style, which determines what types of things are allowed in the input box.double
getMax()
Return the maximum value that will be accepted in this VariableInput box.double
getMin()
Return the minimum value that will be accepted in this VariableInput box.Return the Controller, if any, that is notified when the text in this input box changesReturn the Controller, if any, that is notified when the user presses return in this text-input box.long
Return this object's serial number, which increases whenever the value of the associated variable changes.boolean
Return the value of the throwErrors property.double
getVal()
Return the value of the associated variable, which might not reflect the value of the contents of the input box.Get the associated variable for the VariableInput box.void
Method required by InputObject interface; in this class, it simply calls setOnUserAction(c).void
Overridden to call onUserAction.compute() if onUserAction is non-null.void
Overridden to call onUserAction.compute() if onUserAction is non-null.void
setInputStyle
(int style) Specify what types of things are allowed in the input box.void
setMax
(double max) Specify the largest allowed value for the content of this VariableInput box.void
setMin
(double min) Specify the smallest allowed value for the content of this VariableInput box.void
Set the name of the variable.void
If the Controller, cm is non-null, then its compute() method will be called whenever the text in this input box changes.void
If the Controller, c, is non-null, then its compute() method will be called whenever the user presses the return key while typing in this text-input box.void
This overrides the setText() method from the TextField class so that it will also force the contents to be checked the next time the checkInput() method is called.void
setThrowErrors
(boolean throwErrors) Set the throwErrors property.void
setVal
(double d) Set the value of the associated variable.void
Synchronize serial number and value with newest, unless this VariableInput is itself newest.Convenience method for creating a component containing this VariableInput together with a label of the form "= ". Convenience method for creating a component containing this VariableInput together with a label of the form "name = ".Methods inherited from class java.awt.TextField
addActionListener, addNotify, echoCharIsSet, getAccessibleContext, getActionListeners, getColumns, getEchoChar, getListeners, getMinimumSize, getMinimumSize, getPreferredSize, getPreferredSize, minimumSize, minimumSize, paramString, preferredSize, preferredSize, processEvent, removeActionListener, setColumns, setEchoChar, setEchoCharacter
Methods inherited from class java.awt.TextComponent
addTextListener, enableInputMethods, getBackground, getCaretPosition, getInputMethodRequests, getSelectedText, getSelectionEnd, getSelectionStart, getText, getTextListeners, isEditable, removeNotify, removeTextListener, select, selectAll, setBackground, setCaretPosition, setEditable, setSelectionEnd, setSelectionStart
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, 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, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate
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Field Details
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variable
protected edu.hws.jcm.awt.VariableInput.VI variableThe Variable that represents the value of this input box. (VI is a private nested class inside VariableInput.) -
throwErrors
protected boolean throwErrorsTrue if an error should be thrown when checkInput() is calles and the contents do not define a legal number. True by default. -
errorMessage
Error message from the most recent time checkInput() as called. Null if there was no error. -
serialNumber
protected long serialNumberThis serial number is increased each time the value of the variable changes. -
previousContents
This is set to true if the text in the box has been changed since the last time the value of the variable was checked by checkInput(). -
minValue
protected double minValueSmallest allowable value. -
maxValue
protected double maxValueLargest allowable value. -
inputStyle
protected int inputStyleOne of the constant values EXPRESSION, REAL, or INTEGER, specifying the style of input. -
EXPRESSION
public static final int EXPRESSIONA constant for use in the setInputStyle() method. Any constant expression is allowed.- See Also:
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REAL
public static final int REALA constant for use in the setInputStyle() method. Only real numbers are allowed.- See Also:
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INTEGER
public static final int INTEGERA constant for use in the setInputStyle() method. Only integers are allowed.- See Also:
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Constructor Details
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VariableInput
public VariableInput()Create an unnamed VariableInput with initial contents "0". -
VariableInput
Construct a VariableInput with the given name and initial String (which can both be null). If initialString is null, the string "0" is used. No error occurs in the constructor if the initialString does not represent a legal value (A string rather than a double is used for initialization since the initial content can be an expression such as "pi/2".) If name is not null, it is used as the name of the VariableInput component as well as the name of the associated variable. -
VariableInput
Create a VariableInput just as in the constructor VariableInput(String,String). Then, if both parser and name are non-null, register the associated variable with the parser.
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Method Details
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getVariable
Get the associated variable for the VariableInput box. You will need this, for example, if you want to register the variable with a Parser. -
withLabel
Convenience method for creating a component containing this VariableInput together with a label of the form "= ". This version uses default colors for the label, which are inherited from the containing component. -
withLabel
Convenience method for creating a component containing this VariableInput together with a label of the form "name = ". Uses the given background and foreground colors for the label and the panel. The colors can be null to use the defaults, which will be inherited from the containing Component. -
setName
Set the name of the variable. This should not be called while the variable is registered with a Parser. The name of the VariableInput Component is also set to name, if the name is non=null. -
addTo
A convenience method that registers this VariableInput's variable with Parser p (but only if both p and the name of the variable are non-null). -
setOnUserAction
If the Controller, c, is non-null, then its compute() method will be called whenever the user presses the return key while typing in this text-input box. -
getOnUserAction
Return the Controller, if any, that is notified when the user presses return in this text-input box. -
notifyControllerOnChange
Method required by InputObject interface; in this class, it simply calls setOnUserAction(c). This is meant to be called by JCMPanel.gatherInputs().- Specified by:
notifyControllerOnChange
in interfaceInputObject
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setOnTextChange
If the Controller, cm is non-null, then its compute() method will be called whenever the text in this input box changes. Furthermore, the throwErrors property will be set to false, to avoid throwing multiple errors while the user is typing. (You can change it back to true if you want by calling setThrowErrors(true).) -
getOnTextChange
Return the Controller, if any, that is notified when the text in this input box changes -
getVal
public double getVal()Return the value of the associated variable, which might not reflect the value of the contents of the input box. The value of the variable changes only when the checkInput() method is called, or when the setVal() method is called. Call checkInput() first, if you want to be sure of getting the same value that is currently shown in the box. -
setVal
public void setVal(double d) Set the value of the associated variable. Also sets the content of the input box. -
setThrowErrors
public void setThrowErrors(boolean throwErrors) Set the throwErrors property. If the value is true, then an error will be thrown by the checkInput() method when the contents of the VariableInput box are not legal. Otherwise, no error is thrown; the value of the variable is just set to Double.NaN. -
getThrowErrors
public boolean getThrowErrors()Return the value of the throwErrors property. -
setMin
public void setMin(double min) Specify the smallest allowed value for the content of this VariableInput box. -
getMin
public double getMin()Return the minimum value that will be accepted in this VariableInput box. -
setMax
public void setMax(double max) Specify the largest allowed value for the content of this VariableInput box. -
getMax
public double getMax()Return the maximum value that will be accepted in this VariableInput box. -
setInputStyle
public void setInputStyle(int style) Specify what types of things are allowed in the input box. The value of the parameter, style, must be one of the constants VariableInput.EXPRESSION, VariableInput.REAL, or VariableInput.INTEGER. If not, the call to setInputStyle is ignored. -
getInputStyle
public int getInputStyle()Return the input style, which determines what types of things are allowed in the input box. The returned value is one of the contstants EXPRESSION, REAL, or INTEGER -
getErrorMessage
Get error message from previous call to checkInput(). Returns null if there was no error. -
checkInput
public void checkInput()Check whether the contents are valid, and change the value of the associated variable if the new contents do not match the current value. This might throw an error of type JCMError, if throwErrors is true. This is usually called by a Controller.- Specified by:
checkInput
in interfaceInputObject
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getSerialNumber
public long getSerialNumber()Return this object's serial number, which increases whenever the value of the associated variable changes.- Specified by:
getSerialNumber
in interfaceTieable
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sync
Synchronize serial number and value with newest, unless this VariableInput is itself newest. This is required by the Tieable interface, and is usually called by an object of type Tie. -
convertInput
Convert a string into a real value. The parameter is taken from the input box when this method is called by VI.checkInput() Throw a JCMError if any error is found in the input.- Parameters:
num
- String to be converted- Returns:
- the real value.
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setText
This overrides the setText() method from the TextField class so that it will also force the contents to be checked the next time the checkInput() method is called. -
processActionEvent
Overridden to call onUserAction.compute() if onUserAction is non-null. This is not meant to be called directly.- Overrides:
processActionEvent
in classTextField
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processTextEvent
Overridden to call onUserAction.compute() if onUserAction is non-null. This is not meant to be called directly.- Overrides:
processTextEvent
in classTextComponent
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