com.luciad.create.geometries

Class PolylineRingCreator

java.lang.Object

com.luciad.create.geometries.PolylineRingCreator

All Implemented Interfaces:

IGeometryCreator, AutoCloseable

public final class PolylineRingCreator
extends Object
implements AutoCloseable, IGeometryCreator

This class can create (2D) polyline ring instances.

It reacts on input events to create polyline rings. The event handling behavior can be restricted based on the currently set line creation mode.

The events handled in Click mode are:

• Click events to append one point, and start inserting a new one. This results in changes that are ChangeStatus#InProgressKeyPoint, or ChangeStatus#Finished when reaching the maximum point count.
• Mouse move events to position the next individual point. This results in changes that are ChangeStatus#InProgress.
• Double click or long touch press events to append a point, and finish creation. Long touch press events are only reacted upon if points were previously added via touch tap. This results in changes that are ChangeStatus#Finished, or ChangeStatus#InProgressKeyPoint when the maximum point count is not reached yet.

The events handled in Freehand mode are:

• Drag events to continuously add points. Creation starts, with points being added as long as the drag event is ongoing, and creation is finished when dragging stops. Points are not added on every Drag event, indeed a heuristic is used to only add a point when the distance to the previous point or the curvature is high enough.
• This results in changes that are ChangeStatus#InProgressKeyPoint if a new point is added, ChangeStatus#InProgress if the drag move does not trigger a new point (i.e. the wannabee point is too close to the previous one), or ChangeStatus#Finished when the drag ends.

In Automatic mode (the default creation mode), the first event since creation is started determines how polyline points are added. If the first event is a mouse click or touch tap, events are added in Click mode. If a drag event is initiated, points are added in Freehand mode.

It is possible to constrain polyline creation using:

• A minimum point count
• A maximum point count
• A constraint

This class does not allow you to interactively choose the elevation of the points. The elevation will by default be set to 0.

Constructor Summary

Constructors

Constructor and Description
PolylineRingCreator(CoordinateReference reference) Creates a new polyline ring creator instance.

Method Summary

Modifier and Type	Method and Description
void	close()
protected void	finalize()
IPolylineRingConstraint	getConstraint()
LineCreationMode	getLineCreationMode()
LineInterpolationType	getLineInterpolationType()
long	getMaxPointCount()
long	getMinPointCount()
EventResult	onEvent(IInputEvent inputEvent, FeatureCreateContext context) Handles the given event, and returns if the event was handled or not.
void	setConstraint(IPolylineRingConstraint constraint) Sets the constraint to use during creation.
void	setLineCreationMode(LineCreationMode mode) The line creation mode is Automatic by default.
void	setLineInterpolationType(LineInterpolationType lineInterpolationType) Sets the line interpolation that is used for the geometry.
void	setMaxPointCount(long maxPointCount) Sets the maximum amount of points a polyline ring can have.
void	setMinPointCount(long minPointCount) Sets the minimum amount of points a polyline ring can have.
void	start(IGeometryCreateCallback callback, FeatureCreateContext context) This method is called to start creation.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolylineRingCreator

public PolylineRingCreator(@NotNull
                           CoordinateReference reference)

Creates a new polyline ring creator instance.

Parameters:

reference - the reference of the created polyline ring

Method Detail

finalize

protected void finalize()

Overrides:

finalize in class Object

close

public void close()

Specified by:

close in interface AutoCloseable

start

public void start(@NotNull
                  IGeometryCreateCallback callback,
                  @NotNull
                  FeatureCreateContext context)
           throws NullPointerException

This method is called to start creation.

After this call, IGeometryCreator#onEvent can be called.

When a IGeometryCreator was started, it can not be started again until it has finished. Implementations of this method are encouraged to throw an exception in that case to signal a programming error by the caller of this method.

Specified by:

start in interface IGeometryCreator

Parameters:

callback - the callback to signal geometry changes, and whether creation for the geometry has finished, cannot be null.

context - the context, cannot be null

Throws:

NullPointerException - when null is passed.

onEvent

@NotNull
public EventResult onEvent(@NotNull
                                    IInputEvent inputEvent,
                                    @NotNull
                                    FeatureCreateContext context)
                             throws NullPointerException

Handles the given event, and returns if the event was handled or not.

Specified by:

onEvent in interface IGeometryCreator

Parameters:

inputEvent - an event, cannot be null

context - the context, cannot be null

Returns:

if the event was consumed or not

Throws:

NullPointerException - when null is passed.

setConstraint

public void setConstraint(@Nullable
                          IPolylineRingConstraint constraint)

Sets the constraint to use during creation.

The default is no constraint.

The constraint behavior is as follows:

• Initially the first 3 points are added and positioned. This results in calls to the constraint without a PolylineChange.
• After positioning the first 3 points, additional points are inserted and positioned, until creation is ended. This results in calls to the constraint with a change containing 1 point insert.

Constraints are not allowed to change the point count during creation. Doing this will result in an exception.

Parameters:

constraint - the constraint. Can be null.

getConstraint

@Nullable
public IPolylineRingConstraint getConstraint()

Returns:

the constraint that is used during creation. Can be null.

See Also:

setConstraint

setLineInterpolationType

public void setLineInterpolationType(@NotNull
                                     LineInterpolationType lineInterpolationType)

Sets the line interpolation that is used for the geometry.

The default is LineInterpolationType#Geodesic.

Parameters:

lineInterpolationType - the line interpolation to use

getLineInterpolationType

@NotNull
public LineInterpolationType getLineInterpolationType()

Returns:

the line interpolation that is used for the geometry

setMinPointCount

public void setMinPointCount(long minPointCount)
                      throws IllegalArgumentException

Sets the minimum amount of points a polyline ring can have.

The creator cannot finish creation before the created polyline ring has at least this minimum point count. By default, this value is 3.

If the creation mode is LineCreationMode#Freehand, the feature creation is always finished when when the final DragEvent is received. If not enough point were generated prior to it, the created polylinering is filled with the needed amount of points at the last received location.

Parameters:

minPointCount - the minimum number of points allowed.

Throws:

IllegalArgumentException - if minPointCount is lower than 3, or higher than the current max point count.

getMinPointCount

public long getMinPointCount()

Returns:

the minimum amount of points a polyline ring can have.

See Also:

setMinPointCount

setMaxPointCount

public void setMaxPointCount(long maxPointCount)
                      throws IllegalArgumentException

Sets the maximum amount of points a polyline ring can have.

The creator automatically finishes creation when the polyline ring reaches this maximum point count. By default, this value is the maximum value of long, which realistically corresponds to "no maximum".

Parameters:

maxPointCount - the maximum number of points allowed.

Throws:

IllegalArgumentException - if maxPointCount is lower than the current min point count.

getMaxPointCount

public long getMaxPointCount()

Returns:

the maximum amount of points a polyline ring can have.

See Also:

setMaxPointCount

setLineCreationMode

public void setLineCreationMode(@NotNull
                                LineCreationMode mode)

The line creation mode is Automatic by default.

Parameters:

mode - the creation mode that is used.

See Also:

LineCreationMode

getLineCreationMode

@NotNull
public LineCreationMode getLineCreationMode()

Returns:

the creation mode that is used.

See Also:

LineCreationMode