Class TLcdGXYCircleBy3PointsPainter

All Implemented Interfaces:
ILcdCloneable, ILcdPropertyChangeSource, ILcdGXYEditor, ILcdGXYEditorProvider, ILcdGXYPainter, ILcdGXYPainterProvider, ILcdGXYPathPainter, Serializable, Cloneable

public class TLcdGXYCircleBy3PointsPainter extends ALcdGXYAreaPainter implements ILcdGXYPathPainter, ILcdGXYEditorProvider, ILcdGXYEditor
Paints and locates ILcdCircleBy3Points objects and enables visual editing of ILcd2DEditableCircleBy3Points objects in an ILcdGXYView.
Since:
9.0
See Also:
  • Field Details

    • MIDDLE_OF_BOUNDS

      public static final int MIDDLE_OF_BOUNDS
      Constant value indicating that the anchor point should be chosen in the middle of the bounds, calculated by boundsSFCT.
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    • FOCUS_POINT

      public static final int FOCUS_POINT
      Constant value indicating that the anchor point should be chosen as the arc's focus point. If this point cannot be calculated, the MIDDLE_OF_BOUNDS method is used to calculate the anchor point.
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    • CENTER_POINT

      public static final int CENTER_POINT
      Constant value indicating that the anchor point should be chosen at the center of the circle.
      See Also:
    • MIDDLE_OF_CURVE

      public static final int MIDDLE_OF_CURVE
      Constant value indicating that the anchor point should be chosen at the middle of the curve if ILcdCurve is implemented. If ILcdCurve is not implemented, or if no valid anchor point can be found, the MIDDLE_OF_BOUNDS method is used.
      See Also:
    • START_OF_CURVE

      public static final int START_OF_CURVE
      Constant value indicating that the anchor point should be chosen at the start of the curve if ILcdCurve is implemented. If ILcdCurve is not implemented, or if no valid anchor point can be found, the MIDDLE_OF_BOUNDS method is used.
      See Also:
    • END_OF_CURVE

      public static final int END_OF_CURVE
      Constant value indicating that the anchor point should be chosen at the end of the curve if ILcdCurve is implemented. If ILcdCurve is not implemented, or if no valid anchor point can be found, the MIDDLE_OF_BOUNDS method is used.
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    • INTERMEDIATE_CONTROL_POINT

      public static final int INTERMEDIATE_CONTROL_POINT
      Constant value indicating that the anchor point should be chosen at the intermediate control point of the circle segment of the circle.
      See Also:
  • Constructor Details

    • TLcdGXYCircleBy3PointsPainter

      public TLcdGXYCircleBy3PointsPainter()
  • Method Details

    • setMinimumEditDelta

      public void setMinimumEditDelta(int aDelta)
      Sets the minimum pixel distance the input device (a mouse, for example) must move before editing the shape. A larger value ensures that the object easily "snaps" back in place, a small value allows fine editing.
      Parameters:
      aDelta - the minimum pixel distance the input device should move in either the X or Y direction
    • getMinimumEditDelta

      public int getMinimumEditDelta()
      Returns the minimum pixel distance the input device (a mouse, for example) must move before editing the shape. A larger value ensures that the object easily "snaps" back in place, a small value allows fine editing. The default value is 3 pixels.
      Returns:
      the minimum pixel distance the input device should move in either the X or Y direction
    • setDrawCenter

      public void setDrawCenter(boolean aDrawCenter)
      Sets whether the center point of the arc should be displayed or not. The default value of this property is false. This setting has an influence on the methods boundsSFCT, isTouched and snapping.
      Parameters:
      aDrawCenter - A flag indicating whether the center point should be displayed or not.
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    • isDrawCenter

      public boolean isDrawCenter()
      Returns whether the center point of the arc should be displayed.
      Returns:
      whether the center point of the arc should be displayed.
      See Also:
    • setDrawCenterWhenSelected

      public void setDrawCenterWhenSelected(boolean aDrawCenterWhenSelected)
      Sets whether the center point of the arc should be displayed when it is painted in selected mode or not. The default value of this property is true. This setting has an influence on the methods boundsSFCT, isTouched and snapping. Regardless of this setting, the center point is always displayed in HANDLES mode to allow editing.
      Parameters:
      aDrawCenterWhenSelected - A flag indicating whether the center point should be displayed when it is painted in selected mode or not.
      See Also:
    • isDrawCenterWhenSelected

      public boolean isDrawCenterWhenSelected()
      Returns whether the center point of the arc should be displayed when it is painted in selected mode.
      Returns:
      whether the center point of the arc should be displayed when it is painted in selected mode.
      See Also:
    • setCenterIcon

      public void setCenterIcon(ILcdIcon aIcon)
      Sets the icon for the center point's default representation, if isDrawCenter() returns true.
      Parameters:
      aIcon - the icon for the center point's default representation
      See Also:
    • getCenterIcon

      public ILcdIcon getCenterIcon()
      Returns the icon for the center point's default representation, used if isDrawCenter() returns true.
      Returns:
      the icon for the center point's default representation
    • setCenterIconWhenSelected

      public void setCenterIconWhenSelected(ILcdIcon aIcon)
      Sets the icon for the center point's selected representation, if isDrawCenterWhenSelected() returns true.
      Parameters:
      aIcon - the icon for the center point's selected representation
      See Also:
    • getCenterIconWhenSelected

      public ILcdIcon getCenterIconWhenSelected()
      Returns the icon for the center point's selected representation, used if isDrawCenterWhenSelected() returns true.
      Returns:
      the icon for the center point's selected representation
    • setPaintCache

      public void setPaintCache(boolean aPaintCache)
      Turns caching of the representation of the object on or off. Caching greatly reduces the time to paint an object but requires more memory. The representation of an object can only be cached for objects which implement ILcdCache. By default, caching is turned on.
      Parameters:
      aPaintCache - A flag indicating whether to use caching when painting an object.
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    • getPaintCache

      public boolean getPaintCache()
      Returns whether caching is used when painting this painter's object.
      Returns:
      true if caching is used to paint this painter's object, false otherwise.
      See Also:
    • setSnapToInvisiblePoints

      public void setSnapToInvisiblePoints(boolean aSnapToInvisiblePoints)
      Sets whether the other shapes can snap to invisible points of this shape. The default value is false.
      Parameters:
      aSnapToInvisiblePoints - A flag indicating whether snapping to the invisible points is allowed.
      See Also:
    • isSnapToInvisiblePoints

      public boolean isSnapToInvisiblePoints()
      Returns whether the painter allows snapping to the invisible points of the shape.
      Returns:
      whether the painter allows snapping to the invisible points of the shape.
      See Also:
    • setSnapIcon

      public void setSnapIcon(ILcdIcon aSnapIcon)
      Sets the icon that marks snap targets of the object currently set to this painter. This icon is painted when the paint method is called with the render mode ILcdGXYPainter.SNAPS.
      Parameters:
      aSnapIcon - The icon that should be used to paint snap target points.
      See Also:
    • getSnapIcon

      public ILcdIcon getSnapIcon()
      Returns the icon that is used to paint snap target points of the object set to this painter.
      Returns:
      the icon that is used to paint snap target points of the object set to this painter.
      See Also:
    • getAnchorPointLocation

      public int getAnchorPointLocation()
      Returns the location of the anchor point (by default: MIDDLE_OF_BOUNDS).
      Returns:
      one of MIDDLE_OF_BOUNDS, FOCUS_POINT, CENTER_POINT, MIDDLE_OF_CURVE, START_OF_CURVE, END_OF_CURVE, INTERMEDIATE_CONTROL_POINT.
    • setAnchorPointLocation

      public void setAnchorPointLocation(int aAnchorPointLocation)
      Sets the preferred anchor point location.
      Parameters:
      aAnchorPointLocation - one of MIDDLE_OF_BOUNDS, FOCUS_POINT, CENTER_POINT, MIDDLE_OF_CURVE, START_OF_CURVE, END_OF_CURVE, INTERMEDIATE_CONTROL_POINT.
    • setObject

      public void setObject(Object aObject)
      Description copied from interface: ILcdGXYPainter
      Sets the Object for which the representation shall be handled by this painter.

      Setting the object on the painter may have an effect on the internal state of the painter, for example, the color to use.

      When the object is set to a painter, the context parameter in subsequent calls to methods in this class must contain a layer that contains this object and for which the painter for this object is this painter.

      Specified by:
      setObject in interface ILcdGXYEditor
      Specified by:
      setObject in interface ILcdGXYPainter
      Parameters:
      aObject - the object for which the representation shall be handled by this painter.
      See Also:
    • getObject

      public Object getObject()
      Description copied from interface: ILcdGXYPainter
      Returns the Object for which the representation is currently being handled by this painter.
      Specified by:
      getObject in interface ILcdGXYEditor
      Specified by:
      getObject in interface ILcdGXYPainter
      Returns:
      the Object for which the representation is currently being handled by this painter.
      See Also:
    • paint

      public void paint(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Displays the representation of the object in the given mode on the Graphics passed, taking into account the supplied context.

      The visual representation of an object depends on the context. Depending on the context (e.g. is the location covered by the view), an object may or may not have a representation. The context contains:

      • transformations which allow to compute the location in view space of points and bounds given in model, space
      • a pen which can connect points with a line or create arcs around a point,
      • the view for which the object's representation must be painted. This can be useful when the painted object depends on the scale of the view, or the presence of other layers in the view.
      • the current location(s) of the mouse or input device and the last location(s) the mouse or input device was pressed.

      The mode passed in this method indicates what part of the object must be painted, whether it should be painted as selected or not, and whether user interaction (via mouse movements) must be taken into account.

      When the mode passed contains either TRANSLATING, RESHAPING or CREATING, this method is also responsible for interpreting interaction on the representation of an object and modifying the representation of the object accordingly. The painter is not responsible for modifying the object itself, this is done by a corresponding ILcdGXYEditor . Implementations of ILcdGXYPainter and ILcdGXYEditor interfaces must be consistent for an object: the painter must display the result of the user interaction on the object, while the editor is responsible for modifying the object as a result of the user interaction. A good practice to ensure a consistent implementation is to implement both the ILcdGXYPainter and ILcdGXYEditor interfaces in a single class.

      When the mode passed includes SNAPS, the part of the representation which corresponds to the object returned as snap target by the method snapTarget must be painted in order to provide the user with a visual indication of the snap target.

      The Graphics passed in this method can be different from the Graphics returned by a view due to techniques such as double buffering (as applied in Swing). Basic drawing operations must always be performed on the Graphics passed as an argument in this method.

      Specified by:
      paint in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation).
      aGXYContext - the ILcdGXYContext the drawing depends on.
    • boundsSFCT

      public void boundsSFCT(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext, ILcd2DEditableBounds aBoundsSFCT) throws TLcdNoBoundsException
      Description copied from interface: ILcdGXYPainter
      Sets the supplied bounds (in view coordinates, pixels) so that it encompasses the representation of the object in the given mode taking into account the given context.

      If this method returns without exception the bounds argument must encompass the representation of the object. A point outside the bounds will not be contained within the painted object.

      The bounds returned in this method can be seen as the equivalent in the view space of the bounds in the model space for ILcdBounded objects.

      Specified by:
      boundsSFCT in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation). For example, an object may be represented differently in SELECTED mode compared to DEFAULT mode. The returned bounds of the representation must take this different representation into account.
      aGXYContext - the context for which the representation of the object is painted. It contains amongst others the transformations from model to world and world to view.
      aBoundsSFCT - the bounds that must be adapted to encompass the representation of the object in the given mode and context. These bounds must not be taken into account when the method has thrown an exception.
      Throws:
      TLcdNoBoundsException - if no bounds can be determined for the representation of the object. This can happen when the object does not have a representation in the given context, for example when it is located in a part of the world which is not visible in the current view.
      See Also:
    • isTouched

      public boolean isTouched(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Checks if the representation of the object in the given mode is touched at the location as defined in the supplied context.

      The location that must be taken into account to check whether the representation is touched can be retrieved from the context passed with the methods ILcdGXYContext.getX() and ILcdGXYContext.getY(). If the check is part of an ongoing operation of user interaction, for example, when the mouse is being dragged, the location of the start of the operation can also be taken into account using the methods ILcdGXYContext.getDeltaX() and ILcdGXYContext.getDeltaY(). The context contains the transformations required to convert this location into the equivalent location in model space. Implementations of this interface usually follow either of the following patterns:

      • transform the location of the interaction back to model space and compare the coordinates with the object in model space.
      • transform the location to world space and compare with a world representation of the object. This forces the painter into caching a world representation of the object. Caching a view representation of an object is not very practical as it would have to change whenever the view's scale changes or when it is panned. A world representation of an object only changes when the view's XYWorldReference changes, which happens less frequently.

      As the mode influences the way an object is represented, it must also be taken into account when checking whether that representation is being touched. When the mode contains CREATING, RESHAPING or TRANSLATING which indicate that the object must be represented in a state for an ongoing operation, the location of the start of the operation may be taken into account as mentioned above. The painting result can take into account multiple locations, to respond to, for example, multi-touch input. When the mode contains SELECTED, the painter should also check if the non-selected representation is touched, since these are always painted on top of each other.

      The boundsSFCT is often used to speed up the performance of this method as a location outside these bounds can never touch the representation of the object.

      Note that this method does not give an indication of what part of the object is touched. It is up to the painter implementations to provide methods to make this distinction. The method does also not indicate what sensitivity must be applied when checking if an object is touched. It is up to the implementation to decide what should be the maximum distance between the location given in the context and the closest relevant point or area of the representation of the object.

      Specified by:
      isTouched in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in
      aGXYContext - contains the location of the interaction and the transformations to convert this location into model coordinates
      Returns:
      true if the representation of the object in the given mode is touched by the location as defined in the context passed, false otherwise
      See Also:
    • anchorPointSFCT

      public void anchorPointSFCT(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext, Point aPointSFCT) throws TLcdNoBoundsException
      Description copied from class: ALcdGXYPainter
      Implements ILcdGXYPainter.anchorPointSFCT. aPointSFCT will be set to the center of the bounds calculated by boundsSFCT.
      Specified by:
      anchorPointSFCT in interface ILcdGXYPainter
      Overrides:
      anchorPointSFCT in class ALcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is painted in (see class documentation)
      aGXYContext - the context for which the representation of the object is painted. It contains amongst others the transformations from model to world and world to view.
      aPointSFCT - the point that has to be moved to the location of the anchor point of the representation of the object. This point must not be taken into account when the method has thrown a TLcdNoBoundsException.
      Throws:
      TLcdNoBoundsException - if no anchor point can be determined for the representation of the object. This can be when the object does not have a representation in the given context, for example when it is located in a part of the world which is not visible in the projection as set in the views world reference.
      See Also:
    • supportSnap

      public boolean supportSnap(Graphics aGraphics, ILcdGXYContext aGXYContext)
      Description copied from class: ALcdGXYPainter
      Override this method to support snapping. This implementation does not support snapping.
      Specified by:
      supportSnap in interface ILcdGXYPainter
      Overrides:
      supportSnap in class ALcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aGXYContext - the context in which this object is represented and in which the editing of an object occurs.
      Returns:
      false.
    • snapTarget

      public Object snapTarget(Graphics aGraphics, ILcdGXYContext aGXYContext)
      Description copied from class: ALcdGXYPainter
      Override this method to support snapping. This implementation does not support snapping.
      Specified by:
      snapTarget in interface ILcdGXYPainter
      Overrides:
      snapTarget in class ALcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aGXYContext - the context in which this object is represented and in which the editing of an object occurs.
      Returns:
      null.
      See Also:
    • getCursor

      public Cursor getCursor(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from class: ALcdGXYPainter
      Override this method to return a cursor. This implementation returns null.
      Specified by:
      getCursor in interface ILcdGXYPainter
      Overrides:
      getCursor in class ALcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the rendering mode to return the cursor for.
      aGXYContext - the context in which the rendering occurs.
      Returns:
      null.
    • appendAWTPath

      public boolean appendAWTPath(ILcdGXYContext aGXYContext, int aRenderMode, ILcdAWTPath aAWTPathSFCT)
      Description copied from interface: ILcdGXYPathPainter
      Appends a discretized representation in view coordinates to the given path.
      Specified by:
      appendAWTPath in interface ILcdGXYPathPainter
      Parameters:
      aGXYContext - the graphics context
      aRenderMode - the rendering mode
      aAWTPathSFCT - the path to append to
      Returns:
      true if a discretization of the shape could be successfully appended to the path
    • appendGeneralPath

      public boolean appendGeneralPath(ILcdGXYContext aGXYContext, int aRenderMode, ILcdGeneralPath aGeneralPathSFCT)
      Description copied from interface: ILcdGXYPathPainter
      Appends a discretized representation in world coordinates to the given path.
      Specified by:
      appendGeneralPath in interface ILcdGXYPathPainter
      Parameters:
      aGXYContext - the graphics context
      aRenderMode - the rendering mode
      aGeneralPathSFCT - the path to append to
      Returns:
      true if a discretization of the shape could be successfully appended to the path
    • edit

      public boolean edit(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYEditor
      Defines how an object shall be edited by this editor, taking into account the mode and the context passed.

      The mode passed indicates how the interaction should be interpreted. It can be one of the following:

      • TRANSLATED
      • RESHAPED
      • START_CREATION
      • CREATING
      • END_CREATION

      The first two modes designate that the object should be modified, the last three modes are passed when initializing an object. From an implementation point of view there is no difference between TRANSLATED and RESHAPED. These constants only differ in semantics. For ILcdShape objects TRANSLATED can be seen as the mode that will be passed when the shape as a whole is moved. RESHAPED is used more often for moving part of a shape.

      The context contains information on the user interaction at hand. The methods getX and getY contain the location(s) of the user interaction. The methods getDeltaX and getDeltaY contain the distance(s) over which the user interaction is taking place. For example, getX and getY may contain the current mouse location while getDeltaX and getDeltaY contain the distance over which the mouse has been dragged. The editing behavior can take into account multiple locations, to respond to, for example, multi-touch input.

      When a snap target is accepted, the implementation of this method should take that fact into account when editing or initializing an object.

      Specified by:
      edit in interface ILcdGXYEditor
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - indicates how the user interaction should be interpreted. Is one of the following:
      • TRANSLATED,
      • RESHAPED,
      • START_CREATION,
      • CREATING,
      • END_CREATION.
      aGXYContext - contains information on the user interaction and the transformations to transform from view space to the object model space.
      Returns:
      true if the object has changed when this method returns, false otherwise.
      See Also:
    • getCreationClickCount

      public int getCreationClickCount()
      Description copied from interface: ILcdGXYEditor
      Returns the number user interactions required to complete the initialization of an object set to this editor. For example, for a circle this can be two: one to determine the center point of the circle and one to determine the radius of the circle. A negative number indicates that there is no upper limit to the number of user interactions. For example, for a polyline this could be -2: it requires a minimum of two clicks to establish a polyline, but there is no upper limit on the number of polyline points.
      Specified by:
      getCreationClickCount in interface ILcdGXYEditor
      Returns:
      the number of user interactions required to initialize the object set to this editor.
    • acceptSnapTarget

      public boolean acceptSnapTarget(Graphics aGraphics, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYEditor
      Returns whether the object set to the editor can be edited so that (part of) the object snaps to the object passed as snap target in the context. If the snap target is accepted, a call to the edit method with this context passed should edit the object so that (part of) the object snaps to the object passed as snap target in the context.

      The context contains information on the user interaction at hand: the current location of the user interaction, given by its X and Y coordinates, and the distance in X direction and distance in Y direction over which the user interaction is taking place. For example, getX and getY may contain the current mouse location while getDeltaX and getDeltaY contain the distance over which the mouse has been dragged. The context also contains the candidate snap target and the layer the snap target is contained in.

      Specified by:
      acceptSnapTarget in interface ILcdGXYEditor
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aGXYContext - the context containing the information on the user interaction and the snap target.
      Returns:
      whether the object set to the editor can be edited so that (part of) the object snaps to the object passed as snap target in the context.
      See Also:
    • getGXYEditor

      public ILcdGXYEditor getGXYEditor(Object aObject)
      Description copied from interface: ILcdGXYEditorProvider
      Finds an ILcdGXYEditor that can be used to edit the object passed.

      The editor provider is responsible for setting the object to the editor before returning the editor. An implementation should therefore have the following structure:

      
       public ILcdGXYEditor getGXYEditor(Object aObject) {
         ILcdGXYEditor editor = ... // find the editor for the object
         editor.setObject( aObject );
         return editor;
       }
       

      Specified by:
      getGXYEditor in interface ILcdGXYEditorProvider
      Parameters:
      aObject - the object to find an editor for
      Returns:
      an editor that can be used to edit the object.
    • clone

      public Object clone()
      Description copied from interface: ILcdCloneable

      Makes Object.clone() public.

      When for example extending from java.lang.Object, it can be implemented like this:
      
       public Object clone() {
         try {
           return super.clone();
         } catch ( CloneNotSupportedException e ) {
           // Cannot happen: extends from Object and implements Cloneable (see also Object.clone)
           throw new RuntimeException( e );
         }
       }
       
      Specified by:
      clone in interface ILcdCloneable
      Specified by:
      clone in interface ILcdGXYEditorProvider
      Specified by:
      clone in interface ILcdGXYPainterProvider
      Overrides:
      clone in class ALcdGXYAreaPainter
      Returns:
      a clone of this painter provider.
      See Also: