Package edu.hws.jcm.draw
Class DraggablePoint
java.lang.Object
edu.hws.jcm.draw.Drawable
edu.hws.jcm.draw.DraggablePoint
- All Implemented Interfaces:
InputObject
,Draggable
,Serializable
A DraggablePoint can be added to a DisplayCanvas, where it appears as a small disk, square, or
cross. (The visual style is a settable property.) This object can be dragged with the mouse,
within the limits of the CoordinateRect that contains the DraggablePoint. Either the x- or
y-value of the point can be clamped to a specified Value. Typically, the y-value might
be given by some function of the x-value. In that case, the point is constrained to move
along the graph of the function. Or the x- or y-value can be clamped to a constant to make
the point move along a vertical or horizontal line. Two Variables are associated with
the DraggablePoint. These Variables represent the x- and y- values of the point. Each Variable
implements the Tieable interface, so it can be synchronized with other Tieable values such as
a VariableIput or VariableSlider.
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
A style constant that specifies the visual appearance of a DraggablePoint to be a cross.static final int
A style constant that specifies the visual appearance of a DraggablePoint to be a disk.static final int
A style constant that specifies the visual appearance of a DraggablePoint to be a square. -
Constructor Summary
ConstructorsConstructorDescriptionCreate a DraggablePoint with default values for style, radius, color.DraggablePoint
(int style) Create a DraggablePoint with specified visual style. -
Method Summary
Modifier and TypeMethodDescriptionvoid
This method is required by the InputObject interface.void
clampX
(double x) Clamp the x-value of the point to the constant x, so that the point is constrained to a vertical line.void
Clamp the x-value of the point to the function f, so that the point is constrained to move along the graph of x = f(y).void
Clamp the x-value of the point to v.void
clampY
(double y) Clamp the y-value of the point to the constant y, so that the point is constrained to a horizontal line.void
Clamp the y-value of the point to the function f, so that the point is constrained to move along the graph of y = f(x).void
Clamp the y-value of the point to v.void
continueDrag
(MouseEvent evt) Continue a drag operation begun in startDrag().void
This method, from the Drawable interface, draws the point.void
finishDrag
(MouseEvent evt) Finish a drag operation begun in startDrag().getColor()
Get the color used for drawing the point.Get the "ghostColor" of the point.Get the Controller that is notified when the user drags the point.int
Get the radius used for drawing the point.int
getStyle()
Get the visual style of the point, which must be one of the constants DraggablePoint.DISK, DraggablePoint.SQUARE, or DraggablePoint.CROSS.getXVar()
Get the variable that represents the current x-value of the point.getYVar()
Get the variable that represents the current y-value of the point.void
Method required by InputObject interface; in this class, it simply calls setOnUserAction(c).void
Set the color to be used for drawing the point.void
Set the ghoseColor to be used for drawing the point when it location is undefined or is outside the proper limits.void
setLocation
(double x, double y) Move the point to (x,y), then "clamp" the value of x or y, if a clamp Value has been set.void
Set the Controller that is to be notified when the user drags the point.void
setRadius
(int r) Set the radius that determines the size of the point when it is drawn.void
setStyle
(int style) Set the visual style of the point.boolean
startDrag
(MouseEvent evt) Check whether a mouse click (as specified in the MouseEvent parameter) is a click on this DraggablePoint.Methods inherited from class edu.hws.jcm.draw.Drawable
getVisible, needsRedraw, setOwnerData, setVisible
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Field Details
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DISK
public static final int DISKA style constant that specifies the visual appearance of a DraggablePoint to be a disk.- See Also:
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SQUARE
public static final int SQUAREA style constant that specifies the visual appearance of a DraggablePoint to be a square.- See Also:
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CROSS
public static final int CROSSA style constant that specifies the visual appearance of a DraggablePoint to be a cross.- See Also:
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Constructor Details
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DraggablePoint
public DraggablePoint()Create a DraggablePoint with default values for style, radius, color. The point appears as a dark gray disk of radius 4. -
DraggablePoint
public DraggablePoint(int style) Create a DraggablePoint with specified visual style. Radius is 4, color is darkGray, and ghostColor is lightGray.- Parameters:
style
- One of the style constants DraggablePoint.DISK, DraggablePoint.SQUARE, or DraggablePoint.CROSS.
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Method Details
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clampX
Clamp the x-value of the point to v. That is, if v is not null, then whenever the location of the point changes, its x-value is modified to v.getVal(). Note that if v is non-null then any clamp Value specified for y will be cleared since x and y cannot both be clamped. -
clampY
Clamp the y-value of the point to v. That is, if v is not null, then whenever the location of the point changes, its y-value is modified to v.getVal(). Note that if v is non-null then any clamp Value specified for x will be cleared since x and y cannot both be clamped. -
clampX
public void clampX(double x) Clamp the x-value of the point to the constant x, so that the point is constrained to a vertical line. -
clampY
public void clampY(double y) Clamp the y-value of the point to the constant y, so that the point is constrained to a horizontal line. -
clampX
Clamp the x-value of the point to the function f, so that the point is constrained to move along the graph of x = f(y). f must be a function of one variable. -
clampY
Clamp the y-value of the point to the function f, so that the point is constrained to move along the graph of y = f(x). f must be a function of one variable. -
getRadius
public int getRadius()Get the radius used for drawing the point. The point's height and width are given by two times the radius. -
setRadius
public void setRadius(int r) Set the radius that determines the size of the point when it is drawn. The point's height and width are given by two times the radius. -
setStyle
public void setStyle(int style) Set the visual style of the point. The style should be one of the constants DraggablePoint.DISK, DraggablePoint.SQUARE, or DraggablePoint.CROSS. If it is not, then nothing is done. -
getStyle
public int getStyle()Get the visual style of the point, which must be one of the constants DraggablePoint.DISK, DraggablePoint.SQUARE, or DraggablePoint.CROSS. -
getXVar
Get the variable that represents the current x-value of the point. (Note that this variable can be type-cast to type Tieable.) -
getYVar
Get the variable that represents the current y-value of the point. (Note that this variable can be type-cast to type Tieable.) -
getColor
Get the color used for drawing the point. -
setColor
Set the color to be used for drawing the point. If the specified Color value is null, then nothing is done. -
getGhostColor
Get the "ghostColor" of the point. This color is used for drawing the point when its x-value or y-value is undefined or outside the range of values on the CoordinateRect that contains the point. (This can happen because of clamping of values. It can also happen if the limits on the CoordinateRect are changed.) -
setGhostColor
Set the ghoseColor to be used for drawing the point when it location is undefined or is outside the proper limits. If the specified Color value is null, then nothing is done. -
setOnUserAction
Set the Controller that is to be notified when the user drags the point. (The compute() method of the Controller is called.) If the Controller value is null, then no notification is done. -
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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getOnUserAction
Get the Controller that is notified when the user drags the point. A null value means that no notification is done. -
setLocation
public void setLocation(double x, double y) Move the point to (x,y), then "clamp" the value of x or y, if a clamp Value has been set. -
checkInput
public void checkInput()This method is required by the InputObject interface. In this case, it just applies the clamping Values if any are specified.- Specified by:
checkInput
in interfaceInputObject
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draw
This method, from the Drawable interface, draws the point. It is not usually called directly.- Specified by:
draw
in classDrawable
- Parameters:
g
- The graphics context in which the Drawble is to be drawn. (The drawing can change the color in g, but should not permanently change font, painting mode, etc. Thus, every drawable is responsible for setting the color it wants to use.)coordsChanged
- Indicates whether the CoordinateRect has changed.
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startDrag
Check whether a mouse click (as specified in the MouseEvent parameter) is a click on this DraggablePoint. If so, return true, and start a drag operation. It is expected that the continueDrag() and finishDrag() will be called to complete the drag operation. This is only meant to be called from the checkDraggables() method in class CoordinateRect. -
continueDrag
Continue a drag operation begun in startDrag(). This is not meant to be called directly.- Specified by:
continueDrag
in interfaceDraggable
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finishDrag
Finish a drag operation begun in startDrag(). This is not meant to be called directly.- Specified by:
finishDrag
in interfaceDraggable
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