// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.data.osm.visitor.paint;
import static org.openstreetmap.josm.tools.I18n.tr;
import java.awt.Graphics2D;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.gui.NavigatableComponent;
import org.openstreetmap.josm.plugins.PluginHandler;
import org.openstreetmap.josm.tools.CheckParameterUtil;
/**
* <p>MapRendererFactory manages a list of map renderer classes and associated
* meta data (display name, description).</p>
*
* <p>Plugins can implement and supply their own map renderers.</p>
* <strong>Sample code in a plugin</strong>
* <pre>
* public class MyMapRenderer extends AbstractMapRenderer {
* // ....
* }
*
* // to be called when the plugin is created
* MapRendererFactory factory = MapRendererFactory.getInstance();
* factory.register(MyMapRenderer.class, "My map renderer", "This is is a fast map renderer");
* factory.activate(MyMapRenderer.class);
*
* </pre>
* @since 4087
*/
public final class MapRendererFactory {
/** preference key for the renderer class name. Default: class name for {@link StyledMapRenderer}
*
*/
public static final String PREF_KEY_RENDERER_CLASS_NAME = "mappaint.renderer-class-name";
public static class MapRendererFactoryException extends RuntimeException {
public MapRendererFactoryException(String message, Throwable cause) {
super(message, cause);
}
public MapRendererFactoryException(String message) {
super(message);
}
public MapRendererFactoryException(Throwable cause) {
super(cause);
}
}
public static class Descriptor {
private final Class<? extends AbstractMapRenderer> renderer;
private final String displayName;
private final String description;
public Descriptor(Class<? extends AbstractMapRenderer> renderer, String displayName, String description) {
this.renderer = renderer;
this.displayName = displayName;
this.description = description;
}
public Class<? extends AbstractMapRenderer> getRenderer() {
return renderer;
}
public String getDisplayName() {
return displayName;
}
public String getDescription() {
return description;
}
}
private static MapRendererFactory instance;
/**
* Replies the unique instance
* @return instance of map rending class
*/
public static synchronized MapRendererFactory getInstance() {
if (instance == null) {
instance = new MapRendererFactory();
}
return instance;
}
private static Class<?> loadRendererClass(String className) {
for (ClassLoader cl : PluginHandler.getResourceClassLoaders()) {
try {
return Class.forName(className, true, cl);
} catch (final NoClassDefFoundError | ClassNotFoundException e) {
Main.trace(e);
}
}
Main.error(tr("Failed to load map renderer class ''{0}''. The class wasn''t found.", className));
return null;
}
private final List<Descriptor> descriptors = new ArrayList<>();
private Class<? extends AbstractMapRenderer> activeRenderer;
private MapRendererFactory() {
registerDefaultRenderers();
String rendererClassName = Main.pref.get(PREF_KEY_RENDERER_CLASS_NAME, null);
if (rendererClassName != null) {
activateMapRenderer(rendererClassName);
} else {
activateDefault();
}
}
private void activateMapRenderer(String rendererClassName) {
Class<?> c = loadRendererClass(rendererClassName);
if (c == null) {
Main.error(tr("Can''t activate map renderer class ''{0}'', because the class wasn''t found.", rendererClassName));
Main.error(tr("Activating the standard map renderer instead."));
activateDefault();
} else if (!AbstractMapRenderer.class.isAssignableFrom(c)) {
Main.error(tr("Can''t activate map renderer class ''{0}'', because it isn''t a subclass of ''{1}''.",
rendererClassName, AbstractMapRenderer.class.getName()));
Main.error(tr("Activating the standard map renderer instead."));
activateDefault();
} else {
Class<? extends AbstractMapRenderer> renderer = c.asSubclass(AbstractMapRenderer.class);
if (!isRegistered(renderer)) {
Main.error(tr("Can''t activate map renderer class ''{0}'', because it isn''t registered as map renderer.", rendererClassName));
Main.error(tr("Activating the standard map renderer instead."));
activateDefault();
} else {
activate(renderer);
}
}
}
private void registerDefaultRenderers() {
register(
WireframeMapRenderer.class,
tr("Wireframe Map Renderer"),
tr("Renders the map as simple wire frame.")
);
register(
StyledMapRenderer.class,
tr("Styled Map Renderer"),
tr("Renders the map using style rules in a set of style sheets.")
);
}
/**
* <p>Replies true, if {@code Renderer} is already a registered map renderer class.</p>
*
* @param renderer the map renderer class. Must not be null.
* @return true, if {@code Renderer} is already a registered map renderer class
* @throws IllegalArgumentException if {@code renderer} is null
*/
public boolean isRegistered(Class<? extends AbstractMapRenderer> renderer) {
CheckParameterUtil.ensureParameterNotNull(renderer);
for (Descriptor d: descriptors) {
if (d.getRenderer().equals(renderer)) return true;
}
return false;
}
/**
* <p>Registers a map renderer class.</p>
*
* @param renderer the map renderer class. Must not be null.
* @param displayName the display name to be displayed in UIs (i.e. in the preference dialog)
* @param description the description
* @throws IllegalArgumentException if {@code renderer} is null
* @throws IllegalStateException if {@code renderer} is already registered
*/
public void register(Class<? extends AbstractMapRenderer> renderer, String displayName, String description) {
CheckParameterUtil.ensureParameterNotNull(renderer);
if (isRegistered(renderer))
throw new IllegalStateException(
// no I18n - this is a technical message
MessageFormat.format("Class ''{0}'' already registered a renderer", renderer.getName())
);
Descriptor d = new Descriptor(renderer, displayName, description);
descriptors.add(d);
}
/**
* <p>Unregisters a map renderer class.</p>
*
* <p>If the respective class is also the active renderer, the renderer is reset
* to the default renderer.</p>
*
* @param renderer the map renderer class. Must not be null.
*
*/
public void unregister(Class<? extends AbstractMapRenderer> renderer) {
if (renderer == null) return;
if (!isRegistered(renderer)) return;
Iterator<Descriptor> it = descriptors.iterator();
while (it.hasNext()) {
Descriptor d = it.next();
if (d.getRenderer().equals(renderer)) {
it.remove();
break;
}
}
if (activeRenderer != null && activeRenderer.equals(renderer)) {
activateDefault();
}
}
/**
* <p>Activates a map renderer class.</p>
*
* <p>The renderer class must already be registered.</p>
*
* @param renderer the map renderer class. Must not be null.
* @throws IllegalArgumentException if {@code renderer} is null
* @throws IllegalStateException if {@code renderer} isn't registered yet
*/
public void activate(Class<? extends AbstractMapRenderer> renderer) {
CheckParameterUtil.ensureParameterNotNull(renderer);
if (!isRegistered(renderer))
throw new IllegalStateException(
// no I18n required
MessageFormat.format("Class ''{0}'' not registered as renderer. Can''t activate it.", renderer.getName())
);
this.activeRenderer = renderer;
Main.pref.put(PREF_KEY_RENDERER_CLASS_NAME, activeRenderer.getName());
}
/**
* <p>Activates the default map renderer.</p>
*
* @throws IllegalStateException if the default renderer {@link StyledMapRenderer} isn't registered
*/
public void activateDefault() {
Class<? extends AbstractMapRenderer> defaultRenderer = StyledMapRenderer.class;
if (!isRegistered(defaultRenderer))
throw new IllegalStateException(
MessageFormat.format("Class ''{0}'' not registered as renderer. Can''t activate default renderer.",
defaultRenderer.getName())
);
activate(defaultRenderer);
}
/**
* <p>Creates an instance of the currently active renderer.</p>
* @param g Graphics
* @param viewport Navigatable component
* @param isInactiveMode {@code true} if the paint visitor shall render OSM objects such that they look inactive
* @return an instance of the currently active renderer
*
* @throws MapRendererFactoryException if creating an instance fails
* @see AbstractMapRenderer#AbstractMapRenderer(Graphics2D, NavigatableComponent, boolean)
*/
public AbstractMapRenderer createActiveRenderer(Graphics2D g, NavigatableComponent viewport, boolean isInactiveMode) {
try {
Constructor<?> c = activeRenderer.getConstructor(new Class<?>[]{Graphics2D.class, NavigatableComponent.class, boolean.class});
return AbstractMapRenderer.class.cast(c.newInstance(g, viewport, isInactiveMode));
} catch (NoSuchMethodException | IllegalArgumentException | InstantiationException | IllegalAccessException e) {
throw new MapRendererFactoryException(e);
} catch (InvocationTargetException e) {
Main.debug(e);
throw new MapRendererFactoryException(e.getCause());
}
}
/**
* <p>Replies the (unmodifiable) list of map renderer descriptors.</p>
*
* @return the descriptors
*/
public List<Descriptor> getMapRendererDescriptors() {
return Collections.unmodifiableList(descriptors);
}
/**
* <p>Replies true, if currently the wireframe map renderer is active. Otherwise, false.</p>
*
* <p>There is a specific method for {@link WireframeMapRenderer} for legacy support.
* Until 03/2011 there were only two possible map renderers in JOSM: the wireframe
* renderer and the styled renderer. For the time being there are still UI elements
* (menu entries, etc.) which toggle between these two renderers only.</p>
*
* @return true, if currently the wireframe map renderer is active. Otherwise, false
*/
public boolean isWireframeMapRendererActive() {
return WireframeMapRenderer.class.equals(activeRenderer);
}
}