Package edu.cnu.mdi.mapping.item

Class MapTextItem

java.lang.Object

edu.cnu.mdi.item.AItem

edu.cnu.mdi.mapping.item.AMapItem

edu.cnu.mdi.mapping.item.MapTextItem

All Implemented Interfaces:

IFeedbackProvider, IDrawable, ITextEditable, EventListener

public class MapTextItem
extends AMapItem
implements ITextEditable

A map-native text label whose anchor is stored as a geographic coordinate (longitude/latitude in radians).

Distinction from TextItem

TextItem anchors its bounding box to a world-space (projection-space) point. When the map projection changes or the view recenters, the text box drifts because the anchor is in a coordinate system that moves relative to the Earth's surface. MapTextItem stores the anchor as a geographic point; the anchor is re-projected on every draw so the label stays above the same geographic feature regardless of the active projection.

Rendering model

The text box is always axis-aligned in screen space. Only the anchor moves with the projection; the box itself is a screen-space rectangle computed from font metrics on each draw, exactly as in TextItem. This means rotation of the text box is not supported (and is meaningless for a geographic label).

Drag

Drag converts both the start and current mouse positions independently to geographic coordinates and moves the anchor by the difference. This is exact at all latitudes (no raw lon/lat approximation).

Resize

Not applicable — the box size is determined by the font and text content. ResizePolicy.SCALEONLY is set so that shift+drag scales rather than attempting a shape-preserving reshape.

Rotation

Not supported. Geographic labels are conventionally upright; rotating a text label relative to the map surface has no standard geographic meaning.

Focus

AItem._focus holds the geographic anchor (x = longitude, y = latitude in radians). AMapItem.getFocusPoint(edu.cnu.mdi.container.IContainer) projects it to device pixels for the selection indicator. The bounding box is then built screen-space around that pixel anchor, matching TextItem's screen-space round-trip.

Field Summary

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

Constructor	Description
MapTextItem(Layer layer, Point2D.Double location, Font font, String text, Color lineColor, Color fillColor, Color textColor)	Creates a map-native text label.

Method Summary

Modifier and Type	Method	Description
void	drawItem(Graphics2D g2, IContainer container)	Projects the geographic anchor to device pixels and draws the text box (background fill, border, and text) in screen space around that pixel.
void	edit()	Opens the text-edit dialog and applies the result.
int	getAlignment()
Rectangle	getBounds(IContainer container)	Returns the screen-space bounding rectangle of the text box.
void	getFeedbackStrings(IContainer container, Point pp, Point2D.Double wp, List<String> feedbackStrings)	Populate the feedback string list with information about this item.
Font	getFont()	Returns the current display font.
String	getText()	Returns the full text content as a single string with embedded newlines.
Rectangle2D.Double	getWorldBounds()	Return the world-coordinate bounding rectangle of this item.
void	modify()	Update this item's geometry in response to a mouse movement during an active modification.
void	setAlignment(int align)
void	setFocus(Point2D.Double location)	Set the world-coordinate focus of this item.
void	setFont(Font font)	Sets the display font.
void	setText(String text)	Sets the text content, replacing special characters via UnicodeUtils.specialCharReplace(java.lang.String).
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.

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

getFocusPoint, updateFocus

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

acceptModification, applyGeometryProperties, applyProperties, applyStyleProperties, contains, createPopupMenu, doubleClicked, draw, drawSelections, enclosed, equals, focusFill, geometryChanged, getAzimuth, getContainer, getDisplayName, getFocus, getItemModification, getLastDrawnPolygon, getLayer, getLine, getPath, getPopupMenu, getResizePolicy, getRotatePoint, getSelectionPoints, getStyle, getStyleSafe, getView, hashCode, inASelectRect, inRotatePoint, inSelectPoint, isConnectable, isDeletable, isDirty, isDoubleClickable, isDraggable, isEnabled, isLocked, isResizable, isRightClickable, isRotatable, isSelectable, isSelected, isStyleEditable, isTrackable, isVisible, modificationRejected, prepareForPopup, prepareForRemoval, setAzimuth, setConnectable, setDeletable, setDirty, setDisplayName, setDoubleClickable, setDraggable, setEnabled, setFillFocus, 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

Methods inherited from interface edu.cnu.mdi.item.ITextEditable

getStyle, setStyle

Constructor Details

MapTextItem

public MapTextItem(Layer layer,
 Point2D.Double location,
 Font font,
 String text,
 Color lineColor,
 Color fillColor,
 Color textColor)

Creates a map-native text label.

Parameters:

layer - the layer; must not be null

location - geographic anchor in radians (x = longitude, y = latitude)

font - font to use; if null the default font is used

text - text to display; must not be null or empty

lineColor - border color; null for no border

fillColor - background color; null for transparent background

textColor - text foreground color; null defaults to black

Method Details

drawItem

public void drawItem(Graphics2D g2,
 IContainer container)

Projects the geographic anchor to device pixels and draws the text box (background fill, border, and text) in screen space around that pixel.

Returns immediately if the anchor is off-map (non-finite projection). No path-based geometry is maintained; the bounding box is rebuilt from font metrics on every draw.

Specified by:

drawItem in class AItem

Parameters:

g2 - the graphics context

container - the rendering container; must be a MapContainer

shouldDraw

public boolean shouldDraw(Graphics2D g2,
 IContainer container)

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.

Returns false if the anchor is unplaced or the bounding rectangle does not intersect the visible component area.

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)

Returns the screen-space bounding rectangle of the text box.

Computed from font metrics centred on the projected anchor. Returns null if the anchor is off-map.

Overrides:

getBounds in class AItem

Parameters:

container - the rendering container

Returns:

bounding rectangle in device coordinates, or null

getWorldBounds

public Rectangle2D.Double getWorldBounds()

Return the world-coordinate bounding rectangle of this item.

Returns null — a geographic label has no world-space extent.

Specified by:

getWorldBounds in class AItem

Returns:

the world-coordinate bounding rectangle

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.

Records the geographic start anchor and its screen projection for subsequent drag computation.

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: independently inverse-projects the start and current mouse positions to geographic coordinates and shifts the anchor by the difference. This is exact at all latitudes. RESIZE / ROTATE: silently ignored.

Specified by:

modify in class AItem

translateWorld

public void translateWorld(double dx,
 double dy)

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

Moves the geographic anchor by raw lon/lat offsets. See MapLineItem for the high-latitude caveat. A no-op if the anchor is unplaced.

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

setFocus

public void setFocus(Point2D.Double location)

Set the world-coordinate focus of this item.

Stores the geographic location directly. NaN coordinates represent an unplaced label.

Overrides:

setFocus in class AItem

Parameters:

location - the new focus; may be null to clear

edit

public void edit()

Opens the text-edit dialog and applies the result.

Rebuilding the path (as TextItem does for rotation) is unnecessary here because MapTextItem has no stored path.

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.

Reports the text content and geographic anchor when the cursor is over the label.

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

getAlignment

public int getAlignment()

Returns:

the current text alignment

setAlignment

public void setAlignment(int align)

Parameters:

align - text alignment constant from SwingConstants

getFont

public Font getFont()

Description copied from interface: ITextEditable

Returns the current display font.

Specified by:

getFont in interface ITextEditable

Returns:

the current font

setFont

public void setFont(Font font)

Sets the display font.

Specified by:

setFont in interface ITextEditable

Parameters:

font - the font to use; if null the default font is restored

getText

public String getText()

Returns the full text content as a single string with embedded newlines.

Specified by:

getText in interface ITextEditable

Returns:

the text; never null

setText

public void setText(String text)

Sets the text content, replacing special characters via UnicodeUtils.specialCharReplace(java.lang.String).

Specified by:

setText in interface ITextEditable

Parameters:

text - the new text; null is treated as an empty string