Package edu.cnu.mdi.mapping.item

Class AMapMultiPointItem

java.lang.Object

edu.cnu.mdi.item.AItem

edu.cnu.mdi.mapping.item.AMapItem

edu.cnu.mdi.mapping.item.AMapMultiPointItem

All Implemented Interfaces:

IFeedbackProvider, IDrawable, EventListener

Direct Known Subclasses:

MapPolygonItem, MapPolylineItem

public abstract class AMapMultiPointItem
extends AMapItem

Abstract base for map-native items whose geometry is an ordered array of geographic vertices (longitude/latitude in radians).

Shared behaviour

Provides vertex storage, modification lifecycle (drag / vertex resize), hit-testing, bounds, selection handles, projection caching, and feedback. Subclasses (MapPolylineItem, MapPolygonItem) supply only AItem.drawItem(java.awt.Graphics2D, edu.cnu.mdi.container.IContainer) and the buildShape(edu.cnu.mdi.mapping.container.MapContainer) factory method.

Vertex indexing

Vertices are in _latLons in construction order. For a closed polygon the path is implicitly closed — no duplicate of vertex 0 is stored.

Drag

Raw lon/lat delta from drag-start to current cursor is applied to all vertices from their snapshot positions (no incremental accumulation). Same high-latitude caveat as MapLineItem: at high latitudes a purely northward drag may introduce a small longitudinal error.

Resize

Moves the vertex at ItemModification.getSelectIndex() to the current geographic cursor location.

Rotation

Rotation is silently ignored for arbitrary multi-vertex geographic shapes because there is no single unambiguous spherical rotation centre or "bearing change" for non-line shapes. Subclasses with a well-defined centre (e.g. a geodesic circle) may override modify() to add it.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static final class	AMapMultiPointItem.MultiPointStartState	Immutable snapshot of all vertex positions at drag-start.

Field Summary

Fields

Modifier and Type	Field	Description
protected Point2D.Double[]	_latLons	Geographic vertices in radians (x = longitude, y = latitude).
protected MapGraphics.ProjectedMapShape	_projectedShape	Cached projected shape.

Fields inherited from class edu.cnu.mdi.item.AItem

_connectable, _deletable, _dirty, _displayName, _doubleClickable, _draggable, _enabled, _focus, _FOCUSFILL, _lastDrawnPolygon, _layer, _line, _locked, _modification, _path, _popupMenu, _resizable, _resizePolicy, _rightClickable, _rotatable, _selectable, _selected, _style, _styleEditable, _visible, rotateIcon, RPSIZE, RPSIZE2, SPSIZE, SPSIZE2

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AMapMultiPointItem(Layer layer, Point2D.Double[] latLons, Object... keyVals)

Method Summary

Modifier and Type	Method	Description
protected abstract MapGraphics.ProjectedMapShape	buildShape(MapContainer mc)	Build the projected shape from the current vertices.
boolean	contains(IContainer container, Point screenPoint)	Test whether this item, as rendered, contains the given screen point.
protected boolean	containsPoint(MapGraphics.ProjectedMapShape shape, Point screenPoint)	Tests whether a screen point hits the projected shape.
protected static Point2D.Double[]	copyVertices(Point2D.Double[] src)	Deep defensive copy of a vertex array.
protected void	ensureProjectedShape(IContainer container)	Rebuilds _projectedShape if null.
Rectangle	getBounds(IContainer container)	Return the screen-coordinate bounding rectangle of this item.
void	getFeedbackStrings(IContainer container, Point pp, Point2D.Double wp, List<String> feedbackStrings)	Populate the feedback string list with information about this item.
Point2D.Double[]	getLatLons()
Point[]	getSelectionPoints(IContainer container)	Returns all vertices projected to device-space handles, omitting any that are off-map (non-finite projection result).
int	getVertexCount()
Rectangle2D.Double	getWorldBounds()	Return the world-coordinate bounding rectangle of this item.
protected Point2D.Double	localToLatLon(MapContainer mc, Point p)	Converts a device-space point to geographic lon/lat in radians.
void	modify()	Update this item's geometry in response to a mouse movement during an active modification.
void	prepareForRemoval()	Prepare this item for removal from its layer.
protected Point	projectLatLon(MapContainer mc, Point2D.Double latLon)	Projects a geographic point to device pixels.
void	setDirty(boolean dirty)	Set the dirty flag.
void	setLatLons(Point2D.Double[] latLons)	Replace all vertices and mark dirty.
boolean	shouldDraw(Graphics2D g2, IContainer container)	Return true if this item should be drawn on the current frame.
void	startModification()	Classify and begin a drag, resize, or rotate modification.
void	translateWorld(double dx, double dy)	Translate this item by (dx, dy) in world coordinates.
protected void	updateFocus()	Recomputes the focus as the geographic mean of all vertices.

Methods inherited from class edu.cnu.mdi.mapping.item.AMapItem

getFocusPoint

Methods inherited from class edu.cnu.mdi.item.AItem

acceptModification, applyGeometryProperties, applyProperties, applyStyleProperties, createPopupMenu, doubleClicked, draw, drawItem, drawSelections, enclosed, equals, focusFill, geometryChanged, getAzimuth, getContainer, getDisplayName, getFocus, getItemModification, getLastDrawnPolygon, getLayer, getLine, getPath, getPopupMenu, getResizePolicy, getRotatePoint, getStyle, getStyleSafe, getView, hashCode, inASelectRect, inRotatePoint, inSelectPoint, isConnectable, isDeletable, isDirty, isDoubleClickable, isDraggable, isEnabled, isLocked, isResizable, isRightClickable, isRotatable, isSelectable, isSelected, isStyleEditable, isTrackable, isVisible, modificationRejected, prepareForPopup, setAzimuth, setConnectable, setDeletable, setDisplayName, setDoubleClickable, setDraggable, setEnabled, setFillFocus, setFocus, setLocked, setModification, setResizable, setResizePolicy, setRightClickable, setRotatable, setSelectable, setSelected, setStyle, setStyleEditable, setVisible, stopModification, translateLocal

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface edu.cnu.mdi.graphics.drawable.IDrawable

getName

Field Details

_latLons

protected Point2D.Double[] _latLons

Geographic vertices in radians (x = longitude, y = latitude). Never null after construction; length ≥ 2.

_projectedShape

protected transient MapGraphics.ProjectedMapShape _projectedShape

Cached projected shape. Cleared by setDirty(boolean) and rebuilt lazily by ensureProjectedShape(edu.cnu.mdi.container.IContainer).

Constructor Details

AMapMultiPointItem

protected AMapMultiPointItem(Layer layer,
 Point2D.Double[] latLons,
 Object... keyVals)

Parameters:

layer - the layer; must not be null

latLons - geographic vertices in radians; must not be null, length ≥ 2

keyVals - optional PropertyUtils key/value pairs

Throws:

IllegalArgumentException - if latLons has fewer than 2 points

Method Details

getLatLons

public Point2D.Double[] getLatLons()

Returns:

a defensive copy of the vertex array; never null

setLatLons

public void setLatLons(Point2D.Double[] latLons)

Replace all vertices and mark dirty.

Parameters:

latLons - new vertices; must not be null, length ≥ 2

getVertexCount

public int getVertexCount()

Returns:

number of vertices (≥ 2)

buildShape

protected abstract MapGraphics.ProjectedMapShape buildShape(MapContainer mc)

Build the projected shape from the current vertices.

Use MapGraphics.buildProjectedPolyline(edu.cnu.mdi.mapping.container.MapContainer, java.awt.geom.Point2D.Double[]) for open items, MapGraphics.buildProjectedPolygon(edu.cnu.mdi.mapping.container.MapContainer, java.awt.geom.Point2D.Double[]) for closed items.

Parameters:

mc - the owning map container

Returns:

projected shape; never null

shouldDraw

public boolean shouldDraw(Graphics2D g2,
 IContainer container)

Description copied from class: AItem

Return true if this item should be drawn on the current frame.

This is a secondary visibility check beyond the simple AItem._visible flag. A typical implementation checks whether the item's screen bounds intersect the current clip rectangle.

Specified by:

shouldDraw in class AItem

Parameters:

g2 - the graphics context (may be used to read clip bounds)

container - the container being rendered

Returns:

true if AItem.drawItem(java.awt.Graphics2D, edu.cnu.mdi.container.IContainer) should be called

getBounds

public Rectangle getBounds(IContainer container)

Description copied from class: AItem

Return the screen-coordinate bounding rectangle of this item.

The default implementation returns null. Subclasses should override to return a meaningful bounding box used for hit-testing and rubber-band selection.

Overrides:

getBounds in class AItem

Parameters:

container - the container rendering this item

Returns:

the pixel bounding rectangle, or null if unavailable

contains

public boolean contains(IContainer container,
 Point screenPoint)

Description copied from class: AItem

Test whether this item, as rendered, contains the given screen point.

Priority order:

1. AItem._lastDrawnPolygon — exact hit test.
2. AItem.getBounds(IContainer) — axis-aligned bounding rectangle.
3. AItem.inASelectRect(edu.cnu.mdi.container.IContainer, java.awt.Point) — selection/rotation handle rectangles.

Overrides:

contains in class AItem

Parameters:

container - the container rendering this item

screenPoint - the pixel point to test

Returns:

true if the item contains screenPoint

containsPoint

protected boolean containsPoint(MapGraphics.ProjectedMapShape shape,
 Point screenPoint)

Tests whether a screen point hits the projected shape.

Default: 6-pixel proximity (correct for open polylines). MapPolygonItem overrides to also test interior containment.

Parameters:

shape - projected shape (may be null)

screenPoint - device-space test point

Returns:

true if the point hits the shape

getSelectionPoints

public Point[] getSelectionPoints(IContainer container)

Returns all vertices projected to device-space handles, omitting any that are off-map (non-finite projection result).

Overrides:

getSelectionPoints in class AItem

Parameters:

container - the container rendering this item

Returns:

handle positions, or null if none are visible

startModification

public void startModification()

Classify and begin a drag, resize, or rotate modification.

Priority: rotate (if start point is in rotation handle) → resize (if start point is in a selection handle) → drag (otherwise).

This method is a no-op if AItem._modification is null.

Stores a AMapMultiPointItem.MultiPointStartState snapshot of all vertex positions in the modification's user-object slot.

Overrides:

startModification in class AItem

modify

public void modify()

Update this item's geometry in response to a mouse movement during an active modification.

Called repeatedly while the user is dragging, resizing, or rotating. The current mouse position is available through AItem._modification.

DRAG: shifts all vertices by the lon/lat delta from the start snapshot. RESIZE: moves the selected vertex to the cursor. ROTATE: silently ignored.

Specified by:

modify in class AItem

getWorldBounds

public Rectangle2D.Double getWorldBounds()

Return the world-coordinate bounding rectangle of this item.

Returns the axis-aligned lon/lat bounding box of the vertex set. May under-estimate arcs that bulge beyond the chord; use getBounds(IContainer) for exact pixel bounds.

Specified by:

getWorldBounds in class AItem

Returns:

the world-coordinate bounding rectangle

translateWorld

public void translateWorld(double dx,
 double dy)

Translate this item by (dx, dy) in world coordinates.

Applies raw lon/lat offsets to all vertices. See MapLineItem for the high-latitude caveat.

Specified by:

translateWorld in class AItem

Parameters:

dx - the world-coordinate offset along the X axis

dy - the world-coordinate offset along the Y axis

getFeedbackStrings

public void getFeedbackStrings(IContainer container,
 Point pp,
 Point2D.Double wp,
 List<String> feedbackStrings)

Populate the feedback string list with information about this item. The default implementation is a no-op.

Adds vertex count and total great-circle perimeter when the cursor is over the item.

Specified by:

getFeedbackStrings in interface IFeedbackProvider

Overrides:

getFeedbackStrings in class AItem

Parameters:

container - the container rendering this item

pp - the current mouse position in screen coordinates

wp - the corresponding world-coordinate position

feedbackStrings - the list to add strings to

updateFocus

protected void updateFocus()

Recomputes the focus as the geographic mean of all vertices.

Overrides:

updateFocus in class AMapItem

setDirty

public void setDirty(boolean dirty)

Description copied from class: AItem

Set the dirty flag. Setting to true also clears AItem._lastDrawnPolygon.

Specified by:

setDirty in interface IDrawable

Overrides:

setDirty in class AItem

Parameters:

dirty - new dirty state

prepareForRemoval

public void prepareForRemoval()

Description copied from class: AItem

Prepare this item for removal from its layer.

Performs two operations:

1. Feedback de-registration. The item unregisters itself from the container's FeedbackControl so that it is no longer polled after removal. The container reference is captured before AItem._layer is nulled.
2. Reference nulling. Heavyweight references are set to null to assist garbage collection and to cause fast, obvious NullPointerExceptions if the item is used after removal.

Subclasses holding additional heavyweight references should override this method, null those fields, and call super.prepareForRemoval() either first or last.

Specified by:

prepareForRemoval in interface IDrawable

Overrides:

prepareForRemoval in class AItem

ensureProjectedShape

protected void ensureProjectedShape(IContainer container)

Rebuilds _projectedShape if null.

projectLatLon

protected Point projectLatLon(MapContainer mc,
 Point2D.Double latLon)

Projects a geographic point to device pixels.

Returns:

device-space point, or null if off-map

localToLatLon

protected Point2D.Double localToLatLon(MapContainer mc,
 Point p)

Converts a device-space point to geographic lon/lat in radians.

Returns:

geographic point, or null if either argument is null

copyVertices

protected static Point2D.Double[] copyVertices(Point2D.Double[] src)

Deep defensive copy of a vertex array.