Java tutorial
/* * This is part of Geomajas, a GIS framework, http://www.geomajas.org/. * * Copyright 2008-2013 Geosparc nv, http://www.geosparc.com/, Belgium. * * The program is available in open source according to the GNU Affero * General Public License. All contributions in this program are covered * by the Geomajas Contributors License Agreement. For full licensing * details, see LICENSE.txt in the project root. */ package org.geomajas.gwt.client.map.layer; import org.geomajas.annotation.Api; import org.geomajas.configuration.client.ClientLayerInfo; import org.geomajas.gwt.client.gfx.PainterVisitor; import org.geomajas.gwt.client.map.MapModel; import org.geomajas.gwt.client.map.event.HasLayerChangedHandlers; import org.geomajas.gwt.client.map.event.LayerChangedHandler; import org.geomajas.gwt.client.map.event.LayerLabeledEvent; import org.geomajas.gwt.client.map.event.LayerShownEvent; import org.geomajas.gwt.client.map.event.LayerStyleChangedHandler; import org.geomajas.gwt.client.spatial.Bbox; import com.google.gwt.event.shared.HandlerManager; import com.google.gwt.event.shared.HandlerRegistration; /** * <p> * An abstract layer implements common behavior and data for all layers. Since we will want to paint layers on the map, * it must implement the {@link org.geomajas.gwt.client.gfx.Paintable} interface. * </p> * * @param <T> * layer info {@link ClientLayerInfo} * * @author Pieter De Graef * @author Jan De Moerloose * @author Frank Wynants * @since 1.10.0 */ @Api public abstract class AbstractLayer<T extends ClientLayerInfo> implements Layer<T>, HasLayerChangedHandlers { private T layerInfo; /** The model behind a map. Every layer belongs to such a model. */ protected MapModel mapModel; private boolean showing; private boolean selected; private boolean labeled; private boolean visible; protected HandlerManager handlerManager; // ------------------------------------------------------------------------- // Constructor: // ------------------------------------------------------------------------- protected AbstractLayer(MapModel mapModel, T layerInfo) { this.mapModel = mapModel; this.layerInfo = layerInfo; this.visible = layerInfo.isVisible(); this.updateShowing(false); handlerManager = new HandlerManager(this); } // ------------------------------------------------------------------------- // Public methods: // ------------------------------------------------------------------------- /** * Add a handler that registers changes in layer status. * * @param handler * The new handler to be added. */ public HandlerRegistration addLayerChangedHandler(LayerChangedHandler handler) { return handlerManager.addHandler(LayerChangedHandler.TYPE, handler); } /** * Add a handler that registers changes in layer style. * * @param handler * The new handler to be added. */ public HandlerRegistration addLayerStyleChangedHandler(LayerStyleChangedHandler handler) { return handlerManager.addHandler(LayerStyleChangedHandler.TYPE, handler); } /** * Return the layer information. * * @return the layer info * @since 1.10.0 */ @Api public T getLayerInfo() { return layerInfo; } /** * The PainterVisitor accept function, that determines how this object should be rendered. */ public abstract void accept(PainterVisitor visitor, Object group, Bbox bounds, boolean recursive); /** * Is this layer currently selected or not? * * @return true if selected, false otherwise */ public boolean isSelected() { return selected; } @Override public void updateShowing() { updateShowing(true); } /** * Update showing state. * * @param fireEvents Should events be fired if state changes? */ protected void updateShowing(boolean fireEvents) { double scale = mapModel.getMapView().getCurrentScale(); if (visible) { boolean oldShowing = showing; showing = scale >= layerInfo.getMinimumScale().getPixelPerUnit() && scale <= layerInfo.getMaximumScale().getPixelPerUnit(); if (oldShowing != showing && fireEvents) { handlerManager.fireEvent(new LayerShownEvent(this, true)); } } else { showing = false; } } // ------------------------------------------------------------------------- // Getters and setters: // ------------------------------------------------------------------------- /** * Return this layer's client ID as defined in the configuration. * * @return id of the client layer * @since 1.10.0 */ @Api public String getId() { return layerInfo.getId(); } /** * Return this layer's server ID as defined in the configuration. * * @return id of the server layer * @since 1.10.0 */ @Api public String getServerLayerId() { return layerInfo.getServerLayerId(); } /** * Returns a nice name for the group to use in the DOM, not necessarily unique. * * @return name */ public String getGroupName() { return layerInfo.getId(); } @Override public MapModel getMapModel() { return mapModel; } /** * Get the layer label as defined in the configuration. * * @return layer label * @since 1.10.0 */ @Api public String getLabel() { return layerInfo.getLabel(); } /** * Returns true if labels are visible (This does not necessarily mean that * the labels are currently showing on the map!). * * @return true when labels are enable * @since 1.10.0 */ @Api public boolean isLabelsVisible() { return labeled; } /** * Returns true if labels are currently showing (eg. isShowing == true && isLabelsVisible == true). * * @return true when labels are enabled and the layer is showing * @since 1.10.0 */ @Api public boolean isLabelsShowing() { return isLabelsVisible() && isShowing(); } /** * @deprecated replaced by {@link #isLabelsShowing()}. */ @Deprecated public boolean isLabeled() { return showing && labeled; } public double getMinimumScale() { return layerInfo.getMinimumScale().getPixelPerUnit(); } public double getMaximumScale() { return layerInfo.getMaximumScale().getPixelPerUnit(); } @Override public void setLabeled(boolean labeled) { this.labeled = labeled; handlerManager.fireEvent(new LayerLabeledEvent(this)); } @Override public void setSelected(boolean selected) { this.selected = selected; } @Override public boolean isShowing() { return showing; } /** * Return whether the layer is visible. * * @return true when layer is visible * @since 1.10.0 */ @Api public boolean isVisible() { return visible; } /** * Make the layer visible or invisible. * * @param visible * the visible to set * @since 1.10.0 */ @Api public void setVisible(boolean visible) { if (visible != this.visible) { this.visible = visible; updateShowing(false); handlerManager.fireEvent(new LayerShownEvent(this)); } } }