com.luciad.maps

Class Map

java.lang.Object

com.luciad.maps.Map

All Implemented Interfaces:

AutoCloseable

public final class Map
extends Object
implements AutoCloseable

A map for showing geo-spatial data.

Data

Data can be added to the map using its LayerList. For rendering, all data is transformed to a common coordinate reference for display. As a consequence, many different types of data can be visualized at the same time: raster data (imagery and elevation) and vector data (Feature instances).

The following article shows, among others, how you can add data to the map: Create your first map application

Navigation

You can navigate the map using MapNavigator. If you want to fully customize map navigation, you can set the Camera directly.

Related articles:

• How to scale, pan, rotate, and fit a map with the MapNavigator API
• How to manipulate the camera of a Map with the camera API

Interacting with Features data

To support interaction with Feature data, it is possible to query which features are present in a given pixel bounds. Feature states, such as selection, can be tracked by the Map's FeatureStateManager .

Threading

Note that Map and its Map.Renderer track on which thread they are constructed. This is done so that, in subsequent calls, they can verify that the same threads are used consistently. When an inconsistency is detected, an assertion is triggered. This means that:

• All functions on Map, except getRenderer() must be called on the thread on which the Map was constructed (the "UI" thread).
• All functions on Map.Renderer must be called on the thread on which getRenderer() was called the first time (the "Render" thread).

Related article: Threading rules for the Map

DPI and display scaling

To make sure the Map can be rendered on screens with different DPI's, it is possible to configure:

• The DPI: see Map#setDpi
• The display scale: see Map#setDisplayScale

Related article: Support high-resolution (HiDPI) displays

Integrating the map with your UI toolkit

The map can only be made visible on the screen when integrating it with a UI toolkit. The samples show how this can be done. Next to that, the following article demonstrates how this is done for Qt: Integrate with Qt.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Map.Builder
static class	Map.FeatureQuery A query specifies which features you are interested in.
static class	Map.HeightProvider A height provider based on the map layers order and visibility.
static interface	Map.IRendererCallback This callback can be used to execute tasks on the render thread right before or right after the Map is painted by Map.Renderer.
static class	Map.LocationMode Used to determine how the Map::getViewToMapTransformation method determines the point in Map coordinates that corresponds to a given view location.
static class	Map.Renderer The Map renderer.
static class	Map.ViewMapTransformation This class allows to transform between view (pixel coordinates on the screen) and map coordinates.

Method Summary

Modifier and Type	Method and Description
void	addRendererCallback(Map.IRendererCallback rendererCallback) Adds the given callback to the Map.
void	close()
void	deliverNotifications() Delivers any pending notifications.
void	destroy() Disposes the Map.
protected void	finalize()
AnimationManager	getAnimationManager() Important notice regarding multi-threading:
android.graphics.Color	getBackgroundColor() Returns the background color of the map.
Camera	getCamera() Returns the camera that is currently used.
IController	getController() Returns the current active controller of the map.
MouseCursor	getCursor() Returns the current cursor of the map.
double	getDisplayScale() Gets the display scale currently used to render the map.
double	getDpi() Gets the DPI value used to calculate map scales.
GraphicsEffects	getEffects()
FeatureStateManager	getFeatureStateManager() Returns the FeatureStateManager that keeps track of the feature state (for example selection) for this map.
long	getHeight()
Map.HeightProvider	getHeightProvider()
LayerList	getLayerList()
MapNavigator	getMapNavigator()
CoordinateReference	getReference() Returns the reference of this Map.
Map.Renderer	getRenderer() Retrieves the Renderer for this Map.
Map.ViewMapTransformation	getViewMapTransformation() Returns a transformation that can transform view coordinates to map coordinates and vice-versa.
long	getWidth()
boolean	is3D() Returns whether this Map is visualized in 3D.
static Map.Builder	newBuilder()
void	queryFeatures(Map.FeatureQuery query, IMapQueryFeaturesCallback callback) Queries the features under the given pixel bounds, and passes the result to the given callback.
void	removeRendererCallback(Map.IRendererCallback rendererCallback) Removes the given callback from the Map.
void	resize(long width, long height) To be called when the host widget resizes, so that the map can adapt its camera, and graphics related resources.
void	setBackgroundColor(android.graphics.Color color) Sets the background color of the map.
void	setCamera(Camera camera) Set the camera that is used by the renderer.
void	setController(IController controller) Activate a controller, so that it can interact with the map.
void	setCursor(MouseCursor cursor) Change the map's cursor.
void	setDisplayScale(double displayScale) Specifies the display scale to allow the renderer to scale the graphics on high DPI displays.
void	setDpi(double dpi) Sets the DPI value that will be used to calculate map scales.
void	setMapInvalidationCallback(IInvalidationCallback mapInvalidationCallback) Sets the given IInvalidationCallback.
void	setMouseCursorCallback(IMouseCursorCallback mouseCursorCallback) Sets the given IMouseCursorCallback.

Methods inherited from class java.lang.Object

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

Method Detail

finalize

protected void finalize()

Overrides:

finalize in class Object

close

public void close()

Specified by:

close in interface AutoCloseable

newBuilder

@NotNull
public static Map.Builder newBuilder()

destroy

public void destroy()

Disposes the Map.

This method cleans all observers and controllers from the map. This method needs to be called before the Map instance is deleted. If this method is not called, some objects will keep a reference on the map, preventing it to be deleted properly.

setMapInvalidationCallback

public void setMapInvalidationCallback(@Nullable
                                       IInvalidationCallback mapInvalidationCallback)

Sets the given IInvalidationCallback.

This callback is called when the map has changed, and needs to be repainted. Can be null. The callback is owned by the calling code, i.e. typically code that integrates the Map in a UI framework. Beware that this callback should not call (directly or indirectly) the map (for example Map::paint) because it can be called on any thread.

Parameters:

mapInvalidationCallback - a callback that is called when the map has changed.

getRenderer

@NotNull
public Map.Renderer getRenderer()

Retrieves the Renderer for this Map.

The Renderer owns the OpenGL resources related to this Map. It can only be interacted with while the OpenGL context is current.

Returns:

the renderer

deliverNotifications

public void deliverNotifications()

Delivers any pending notifications.

The map buffers up notifications for delivery to the user on the UI thread. However, as the map does not have a way to schedule any actions on the UI thread, the user himself should call this function on the appropriate thread. For example, this could be done when the UI toolkit or framework indicates that the widget containing this map should be updated.

resize

public void resize(long width,
                   long height)

To be called when the host widget resizes, so that the map can adapt its camera, and graphics related resources.

Parameters:

width - The new map's width expressed in device independent pixels.

height - The new map's height expressed in device independent pixels.

getWidth

public long getWidth()

Returns:

the width of the Map in device independent pixels

getHeight

public long getHeight()

Returns:

the height of the Map in device independent pixels

getLayerList

@NotNull
public LayerList getLayerList()

Returns:

the list of Layer instances that are visualized in this Map. The methods offered on this class can be used to add/move/remove layers.

getReference

@NotNull
public CoordinateReference getReference()

Returns the reference of this Map.

This reference determines how the Map is visualized. When a projected (2D) reference is used, all data on the map is painted in this reference. When a (3D) geocentric reference is used, the Map is painted in 3D, and all data is pointed on the globe.

Returns:

the reference of this Map.

getMapNavigator

@NotNull
public MapNavigator getMapNavigator()

Returns:

a MapNavigator instance that can manipulate the Camera of this map

setCamera

public void setCamera(@NotNull
                      Camera camera)
               throws NullPointerException

Set the camera that is used by the renderer.

This method is only needed when you want to navigate in a different way than using MapNavigator.

You can call this method on any thread, but its behavior is slightly different:

• when called on the render thread, the camera is immediately updated. You can for example get access to the render thread using the animation manager, which performs animation updated on the render thread.
• when called on an other thread, the camera will be updated on the next repaint. This is done to prevent camera changes while painting the map.

See the threading article for a more detailed explanation on the threading behavior.

Parameters:

camera - the new camera. Cannot be null.

Throws:

NullPointerException - when the camera is null.

getCamera

@NotNull
public Camera getCamera()

Returns the camera that is currently used.

You can call this method on any thread.

See also setCamera for more information.

Warning: this method will return the camera instance that was last used by the map renderer. This means that if you call setCamera on a different thread than the render thread, a call to getCamera immediately after will not necessarily result in the same camera. See the threading article for a more detailed explanation.

Returns:

the camera currently used by the renderer.

getFeatureStateManager

@NotNull
public FeatureStateManager getFeatureStateManager()

Returns the FeatureStateManager that keeps track of the feature state (for example selection) for this map.

Apart from inspecting the feature state, you can use the returned object to change the feature state.

Returns:

the FeatureStateManager that keeps track of the feature state for this map.

queryFeatures

public void queryFeatures(@NotNull
                          Map.FeatureQuery query,
                          @NotNull
                          IMapQueryFeaturesCallback callback)
                   throws NullPointerException

Queries the features under the given pixel bounds, and passes the result to the given callback.

All visible layers are taken into account. The features are sorted using the following criteria:

3D:

• Labels
• Top Most feature (unless draped)
• Layer order
• Feature Z order in the layer
• Unspecified Order

2D:

• Labels
• Layer order
• Feature Z order in the layer
• Unspecified Order

It is possible that the same feature appears multiple times in the result list, once for each part of the feature. When a feature is for example painted using 2 draw calls, all 2 parts of the feature can be returned if they are hit. A typical example is a feature is painted using both a geometry on the map and a label. It is up to the caller of this method to filter out duplicate feature hits if needed.

Parameters:

query - the feature query containing the parameters to use to query the visible features

callback - a callback which can handle the result of the query operation. Cannot be null.

Throws:

NullPointerException - when the call back is null.

getViewMapTransformation

@NotNull
public Map.ViewMapTransformation getViewMapTransformation()

Returns a transformation that can transform view coordinates to map coordinates and vice-versa.

Returns:

the view <> map transformation.

setBackgroundColor

public void setBackgroundColor(@NotNull
                               android.graphics.Color color)

Sets the background color of the map.

Parameters:

color - the new background color.

getBackgroundColor

@NotNull
public android.graphics.Color getBackgroundColor()

Returns the background color of the map.

Returns:

the color that is used to render the map background.

setController

public void setController(@Nullable
                          IController controller)

Activate a controller, so that it can interact with the map.

When a controller is set, the map will call IController#onActivate to let the controller know it is activated. The previous controller if present will first receive a call to IController#onDeactivate.

Parameters:

controller - The new active controller. If null is given, that will only deactivate the previous one. Given that, no further interaction will be possible on the map until a controller is set again.

getController

@Nullable
public IController getController()

Returns the current active controller of the map.

No default behavior is

Returns:

null if no controller has been set.

getAnimationManager

@NotNull
public AnimationManager getAnimationManager()

Important notice regarding multi-threading:

• You can start and stop animations with the AnimationManager from the UI thread.
• The onStart/onUpdate/onStop methods of IAnimation will be invoked from the render thread. Because of this, animations are for example suitable to animate and update the map's camera.

See the related article: Threading rules for the Map

Returns:

the AnimationManager attached to this map.

setCursor

public void setCursor(@NotNull
                      MouseCursor cursor)

Change the map's cursor.

Changing the cursor triggers a call to the mouse cursor callback if set.

Parameters:

cursor - the new cursor.

See Also:

Map#setMouseCursorCallback

getCursor

@NotNull
public MouseCursor getCursor()

Returns the current cursor of the map.

The default value is MouseCursor#defaultCursor.

See Also:

Map#setCursor

setMouseCursorCallback

public void setMouseCursorCallback(@Nullable
                                   IMouseCursorCallback mouseCursorCallback)

Sets the given IMouseCursorCallback.

This callback is called when the map's cursor has changed. Can be null. The callback is owned by the calling code, i.e. typically code that integrates the Map in a UI framework. Beware that this callback should not call (directly or indirectly) the map (for example Map::paint) because it can be called on any thread.

Parameters:

mouseCursorCallback - a callback that is called when the map has changed.

is3D

public boolean is3D()

Returns whether this Map is visualized in 3D.

Currently, this will only be true if the map reference is geocentric.

Having a 2D map limits the navigation, for example the camera can not be tilted and will always be top-down.

Currently, 3D maps always use a perspective camera and 2D maps always use an orthographic camera.

Returns:

whether this Map is visualized in 3D.

getDisplayScale

public double getDisplayScale()

Gets the display scale currently used to render the map.

Returns:

the current display scale, will be 1.0 if setDisplayScale has never been called

setDisplayScale

public void setDisplayScale(double displayScale)

Specifies the display scale to allow the renderer to scale the graphics on high DPI displays.

• display scale > 1: all features are enlarged
• display scale < 1: all features are made smaller
• display scale == 1: all features remain unscaled

When a feature is scaled by the display scale, it means that pixel distances are scale. For example:

• the icon size on the screen is scaled
• line widths change

This method must be called every time the display or its display scale changes to ensure proper rendering.

You can call this method on any thread, but its behavior is slightly different:

• when called on the render thread, the DPI is immediately updated.
• when called on an other thread, the DPI will be updated on the next repaint.

See the threading article for a more detailed explanation on the threading behavior.

The default is 1.0;

Parameters:

displayScale - the display scale. A value of 1.0 corresponds with a display scale of 100%.

getDpi

public double getDpi()

Gets the DPI value used to calculate map scales.

Returns:

the current dpi value

setDpi

public void setDpi(double dpi)

Sets the DPI value that will be used to calculate map scales.

By default, the map uses the default DPI of your platform (96 on Windows/Linux, 72 on MacOS, 160 on Android). The DPI value should be set to the physical DPI value of the display to get accurate results.

You can call this method on any thread, but its behavior is slightly different:

• when called on the render thread, the DPI is immediately updated.
• when called on an other thread, the DPI will be updated on the next repaint.

See the threading article for a more detailed explanation on the threading behavior.

Parameters:

dpi - the dpi value

addRendererCallback

public void addRendererCallback(@NotNull
                                Map.IRendererCallback rendererCallback)
                         throws NullPointerException

Adds the given callback to the Map.

After calling this method, the Map.Renderer#paint will start calling the given callback instance.

Parameters:

rendererCallback - a renderer callback instance. Cannot be null.

Throws:

NullPointerException - when the renderer call back is null.

removeRendererCallback

public void removeRendererCallback(@NotNull
                                   Map.IRendererCallback rendererCallback)
                            throws NullPointerException

Removes the given callback from the Map.

After calling this method, the Map.Renderer#paint will stop calling the given callback instance.

Parameters:

rendererCallback - a renderer callback instance. Cannot be null.

Throws:

NullPointerException - when the renderer call back is null.

getEffects

@NotNull
public GraphicsEffects getEffects()

Returns:

a GraphicsEffects instance that can apply graphics effects on this map. Have a look at GraphicsEffects for a list of effects that are available.

getHeightProvider

@NotNull
public Map.HeightProvider getHeightProvider()

Returns:

a Map based height provider.

Since:

2023.0