Client API. The Codename One framework your app is built on: this runs on the device, not in a backend.

public final class VectorMapEngine

Object
VectorMapEngine

The pure-Codename One map renderer behind MapView (and the NativeMap fallback).

It maintains the camera (center + fractional zoom), pulls tiles from a TileSource, rasterizes vector tiles once into 256px buffers (or decodes raster tiles), caches them in an LRU TileCache, and on each paint blits the visible buffers scaled to the fractional zoom and places labels with the LabelEngine. All drawing uses the framework Graphics API – there is no native peer.

A vector map zooms past the deepest level its source serves: beyond it the deepest tile’s geometry is drawn again for each smaller area on screen (“overzoom”), the way vector map renderers reach street level from data that stops at zoom 14.

Constructors

public VectorMapEngine(TileSource source, MapStyle style) Creates an engine over source, styled by style.

Methods

`public void setRepaintCallback(Runnable r)`	Sets the callback invoked (on the EDT) whenever a tile finishes loading and the map needs to repaint.
`public void setSource(TileSource source)`	Replaces the tile source, clearing cached tiles.
`public` `TileSource getSource()`	The active tile source.
`public void setStyle(MapStyle style)`	Replaces the style, clearing rendered tiles so they redraw.
`public` `MapStyle getStyle()`	The active style.
`public void setCenter(LatLng center)`	Recenters the camera at `center`, keeping the current zoom.
`public` `LatLng getCenter()`	The geographic coordinate at the center of the viewport.
`public void setZoom(double zoom)`	Sets the zoom level, clamped to the source’s min/max.
`public double getZoom()`	The current fractional zoom level.
`public double getMinZoom()`	The smallest zoom level the tile source serves.
`public double getMaxZoom()`	The largest zoom level the camera can reach.
`public void setViewport(int width, int height)`	Sets the pixel size of the viewport (called by the host component on layout before painting and coordinate conversion).
`public void setPixelRatio(double ratio)`	Sets the device pixel ratio: physical pixels per logical (256px) map pixel.
`public double getPixelRatio()`	The current device pixel ratio (see `setPixelRatio(double)`).
`public boolean hasPendingTiles()`	Whether any tile requested for the current view is still loading (i.e. the basemap is not yet fully rendered).
`public boolean hasRenderedVisibleTiles()`	True when the currently visible tile set has been requested and every visible tile has finished loading/decoding/rendering into the tile cache.
`public` `Point latLngToScreen(LatLng coord)`	Geographic to component-relative pixel.
`public void panPixels(double dx, double dy)`	Pans the camera by a pixel delta (used for drag gestures).
`public void zoomAround(double newZoom, int sx, int sy)`	Zooms to `newZoom` while keeping the geographic point currently under the component pixel `sx,sy` fixed (used for pinch and double-tap).
`public` `LatLng screenToLatLng(int x, int y)`	Component-relative pixel to geographic.
`public` `MapBounds getVisibleBounds()`	The geographic bounds currently visible, or null before layout.
`public void fitBounds(MapBounds bounds, int padding)`	Moves the camera so `bounds` fits the viewport inset by `padding`.
`public void paint(Graphics g, int originX, int originY, int width, int height)`	Paints the basemap and labels into `g`, offset by `originX,originY`.
`public void paintTiles(Graphics g, int originX, int originY, int width, int height)`	Paints the basemap without its labels, and remembers the labels in view for the next `paintLabels` call.
`public void paintLabels(Graphics g)`	Draws the labels of the basemap painted by the last `paintTiles` call.
`public void clearCache()`	Drops all cached tiles (e.g. on low memory).

Inherited methods

From Object

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

Constructor details

VectorMapEngine

public VectorMapEngine(TileSource source, MapStyle style)

Creates an engine over source, styled by style.

Method details

setRepaintCallback

public void setRepaintCallback(Runnable r)

Sets the callback invoked (on the EDT) whenever a tile finishes loading and the map needs to repaint.

setSource

public void setSource(TileSource source)

Replaces the tile source, clearing cached tiles.

getSource

public TileSource getSource()

The active tile source.

setStyle

public void setStyle(MapStyle style)

Replaces the style, clearing rendered tiles so they redraw.

getStyle

public MapStyle getStyle()

The active style.

setCenter

public void setCenter(LatLng center)

Recenters the camera at center, keeping the current zoom.

getCenter

public LatLng getCenter()

The geographic coordinate at the center of the viewport.

setZoom

public void setZoom(double zoom)

Sets the zoom level, clamped to the source’s min/max.

getZoom

public double getZoom()

The current fractional zoom level.

getMinZoom

public double getMinZoom()

The smallest zoom level the tile source serves.

getMaxZoom

public double getMaxZoom()

The largest zoom level the camera can reach. For a vector source this is six levels past the deepest level the source serves (see the class notes), up to zoom 22; a source that serves deeper tiles than that keeps its own deepest level. A raster source stops at its own deepest level, since stretching a bitmap only blurs it.

setViewport

public void setViewport(int width, int height)

Sets the pixel size of the viewport (called by the host component on layout before painting and coordinate conversion).

setPixelRatio

public void setPixelRatio(double ratio)

Sets the device pixel ratio: physical pixels per logical (256px) map pixel. On a 3x retina screen pass 3 so a tile spans 768 device pixels and the map shows the same area it would on a 1x screen. Values <= 0 are ignored. Changing it discards rendered tiles so they re-rasterize at the new resolution.

getPixelRatio

public double getPixelRatio()

The current device pixel ratio (see setPixelRatio(double)).

hasPendingTiles

public boolean hasPendingTiles()

Whether any tile requested for the current view is still loading (i.e. the basemap is not yet fully rendered). Goes true after the first paint that needs uncached tiles and back to false once they have all arrived. Best-effort readiness signal (tile bookkeeping happens on the EDT).

hasRenderedVisibleTiles

public boolean hasRenderedVisibleTiles()

True when the currently visible tile set has been requested and every visible tile has finished loading/decoding/rendering into the tile cache. Calling this may request missing visible tiles, so it can be used as a deterministic readiness probe before the first paint has run.

latLngToScreen

public Point latLngToScreen(LatLng coord)

Geographic to component-relative pixel.

panPixels

public void panPixels(double dx, double dy)

Pans the camera by a pixel delta (used for drag gestures). A positive dx moves the map content to the right.

zoomAround

public void zoomAround(double newZoom, int sx, int sy)

Zooms to newZoom while keeping the geographic point currently under the component pixel sx,sy fixed (used for pinch and double-tap).

screenToLatLng

public LatLng screenToLatLng(int x, int y)

Component-relative pixel to geographic.

getVisibleBounds

public MapBounds getVisibleBounds()

The geographic bounds currently visible, or null before layout.

fitBounds

public void fitBounds(MapBounds bounds, int padding)

Moves the camera so bounds fits the viewport inset by padding.

paint

public void paint(Graphics g, int originX, int originY, int width, int height)

Paints the basemap and labels into g, offset by originX,originY. The caller is responsible for clipping to the component bounds and for drawing overlays (markers/shapes) afterwards.

This is paintTiles followed by paintLabels; call those two instead to draw shapes such as a route between them, so the route does not cover the street names, as on familiar street maps.

paintTiles

public void paintTiles(Graphics g, int originX, int originY, int width, int height)

Paints the basemap without its labels, and remembers the labels in view for the next paintLabels call.

paintLabels

public void paintLabels(Graphics g)

Draws the labels of the basemap painted by the last paintTiles call. Does nothing before one.

clearCache

public void clearCache()

Drops all cached tiles (e.g. on low memory).