group layers sample

src/main/java/com/esri/samples/grouplayers/group_layers/GroupLayersSample.java

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+/*
+ * Copyright 2019 Esri.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.esri.samples.grouplayers.group_layers;
+
+import java.util.Arrays;
+import java.util.List;
+
+import javafx.application.Application;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.TreeItem;
+import javafx.scene.control.TreeView;
+import javafx.scene.layout.StackPane;
+import javafx.stage.Stage;
+
+import com.esri.arcgisruntime.data.ServiceFeatureTable;
+import com.esri.arcgisruntime.layers.ArcGISSceneLayer;
+import com.esri.arcgisruntime.layers.FeatureLayer;
+import com.esri.arcgisruntime.layers.GroupLayer;
+import com.esri.arcgisruntime.layers.Layer;
+import com.esri.arcgisruntime.loadable.LoadStatus;
+import com.esri.arcgisruntime.mapping.ArcGISScene;
+import com.esri.arcgisruntime.mapping.ArcGISTiledElevationSource;
+import com.esri.arcgisruntime.mapping.Basemap;
+import com.esri.arcgisruntime.mapping.Surface;
+import com.esri.arcgisruntime.mapping.view.Camera;
+import com.esri.arcgisruntime.mapping.view.SceneView;
+
+public class GroupLayersSample extends Application {
+
+  private SceneView sceneView;
+
+  @Override
+  public void start(Stage stage) {
+
+    try {
+
+      // set the title and size of the stage and show it
+      StackPane stackPane = new StackPane();
+      Scene fxScene = new Scene(stackPane);
+      stage.setTitle("Group Layers Sample");
+      stage.setWidth(800);
+      stage.setHeight(700);
+
+      // create a JavaFX scene with a stackpane and set it to the stage
+      stage.setScene(fxScene);
+      stage.show();
+
+      // create a scene view and add it to the stack pane
+      sceneView = new SceneView();
+      stackPane.getChildren().add(sceneView);
+
+      // create a scene with a basemap and add it to the scene view
+      ArcGISScene scene = new ArcGISScene();
+      scene.setBasemap(Basemap.createImagery());
+      sceneView.setArcGISScene(scene);
+
+      // set the base surface with world elevation
+      Surface surface = new Surface();
+      surface.getElevationSources().add(new ArcGISTiledElevationSource("http://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"));
+      scene.setBaseSurface(surface);
+
+      // create different types of layers
+      ArcGISSceneLayer devOne = new ArcGISSceneLayer("https://scenesampleserverdev.arcgis.com/arcgis/rest/services/Hosted/DevA_Trees/SceneServer/layers/0");
+      ArcGISSceneLayer devTwo = new ArcGISSceneLayer("https://scenesampleserverdev.arcgis.com/arcgis/rest/services/Hosted/DevA_Pathways/SceneServer/layers/0");
+      ArcGISSceneLayer devThree = new ArcGISSceneLayer("https://scenesampleserverdev.arcgis.com/arcgis/rest/services/Hosted/DevA_BuildingShell_Textured/SceneServer/layers/0");
+      ArcGISSceneLayer nonDevOne = new ArcGISSceneLayer("https://scenesampleserverdev.arcgis.com/arcgis/rest/services/Hosted/PlannedDemo_BuildingShell/SceneServer/layers/0");
+      FeatureLayer nonDevTwo = new FeatureLayer(new ServiceFeatureTable("https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/DevelopmentProjectArea/FeatureServer/0"));
+
+      // create a group layer from scratch by adding the layers as children
+      GroupLayer groupLayer = new GroupLayer();
+      groupLayer.setName("Group: Dev A");
+      groupLayer.getLayers().addAll(Arrays.asList(devOne, devTwo, devThree));
+
+      // add the group layer and other layers to the scene as operational layers
+      scene.getOperationalLayers().addAll(Arrays.asList(groupLayer, nonDevOne, nonDevTwo));
+
+      // zoom to the extent of the group layer when the child layers are loaded
+      groupLayer.getLayers().forEach(childLayer ->
+        childLayer.addDoneLoadingListener(() -> {
+          if (childLayer.getLoadStatus() == LoadStatus.LOADED) {
+            sceneView.setViewpointCamera(new Camera(groupLayer.getFullExtent().getCenter(), 700, 0, 60, 0));
+          }
+        })
+      );
+
+      // create a JavaFX tree view to show the layers in the scene
+      TreeView<Layer> layerTreeView = new TreeView<>();
+      layerTreeView.setMaxSize(250, 200);
+      TreeItem<Layer> rootTreeItem = new TreeItem<>();
+      layerTreeView.setRoot(rootTreeItem);
+      layerTreeView.setShowRoot(false);
+      StackPane.setAlignment(layerTreeView, Pos.TOP_RIGHT);
+      StackPane.setMargin(layerTreeView, new Insets(10));
+      stackPane.getChildren().add(layerTreeView);
+
+      // display each layer with a custom tree cell
+      layerTreeView.setCellFactory(p -> new LayerTreeCell());
+
+      // recursively build the table of contents from the scene's operational layers
+      buildLayersView(rootTreeItem, scene.getOperationalLayers());
+
+    } catch (Exception e) {
+      // on any error, display the stack trace.
+      e.printStackTrace();
+    }
+  }
+
+  /**
+   * Recursively builds a tree from a parent tree item using a list of operational layers (including group layers).
+   *
+   * @param parentItem tree item to build tree from
+   * @param operationalLayers a list of operational layers
+   */
+  private void buildLayersView(TreeItem<Layer> parentItem, List<Layer> operationalLayers) {
+    for (Layer layer : operationalLayers) {
+      // load each layer before adding to ensure all metadata is ready for display
+      layer.loadAsync();
+      layer.addDoneLoadingListener(() -> {
+        // add a tree item for the layer to the parent tree item
+        if (layer.canShowInLegend()) {
+          TreeItem<Layer> layerItem = new TreeItem<>(layer);
+          layerItem.setExpanded(true);
+          parentItem.getChildren().add(layerItem);
+          // if the layer is a group layer, continue building with its children
+          if (layer instanceof GroupLayer && ((GroupLayer) layer).isShowChildrenInLegend()) {
+            buildLayersView(layerItem, ((GroupLayer) layer).getLayers());
+          }
+        }
+      });
+    }
+  }
+
+  /**
+   * Stops and releases all resources used in application.
+   */
+  @Override
+  public void stop() {
+
+    if (sceneView != null) {
+      sceneView.dispose();
+    }
+  }
+
+  /**
+   * Opens and runs application.
+   *
+   * @param args arguments passed to this application
+   */
+  public static void main(String[] args) {
+
+    Application.launch(args);
+  }
+
+}

src/main/java/com/esri/samples/grouplayers/group_layers/LayerTreeCell.java

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+package com.esri.samples.grouplayers.group_layers;
+
+import javafx.scene.control.CheckBox;
+import javafx.scene.control.TreeCell;
+
+import com.esri.arcgisruntime.layers.Layer;
+
+/**
+ * A custom tree cell for displaying a layer in a tree view. Includes a check box for toggling the layer's visibility.
+ */
+public class LayerTreeCell extends TreeCell<Layer> {
+
+  @Override
+  public void updateItem(Layer layer, boolean empty) {
+    super.updateItem(layer, empty);
+    if (!empty) {
+      // use the layer's name for the text
+      setText(layer.getName());
+
+      // add a check box to allow the user to change the visibility of the layer
+      CheckBox checkBox = new CheckBox();
+      setGraphic(checkBox);
+
+      // toggle the layer's visibility when the check box is toggled
+      checkBox.setSelected(layer.isVisible());
+      checkBox.selectedProperty().addListener(e -> layer.setVisible(checkBox.isSelected()));
+    } else {
+      setText(null);
+      setGraphic(null);
+    }
+  }
+}

src/main/java/com/esri/samples/grouplayers/group_layers/README.md

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+<h1>Group layers</h1>
+
+<p>Group a collection of layers together and toggle their visibility as a group.</p>
+
+<p><img src="GroupLayers.png"/></p>
+
+<h2>Use case</h2>
+
+<p>Group layers communicate to the user that layers are related and can be managed together.</p>
+
+<p>In a land development project, you might group layers according to the phase of development.</p>
+
+<h2>How to use the sample</h2>
+
+<p>The layers in the map will be displayed in a table of contents. Toggle the checkbox next to a layer's name to change its visibility.</p>
+
+<h2>How it works</h2>
+
+<ol>
+<li>Create an empty <code>GroupLayer</code>.</li>
+
+<li>Add a child layer to the group layer's layers collection.</li>
+
+<li>To toggle the visibility of the group, simply change the group layer's visibility property.</li>
+</ol>
+
+<h2>Relevant API</h2>
+
+<ul>
+<li>GroupLayer</li>
+</ul>
+
+<h2>Additional information</h2>
+
+<p>The full extent of a group layer may change when child layers are added/removed. Group layers do not have a spatial reference, but the full extent will have the spatial reference of the first child layer.</p>
+
+<p>Group layers can be saved to web scenes. In web maps, group layers will be flattened in the web map's operational layers.</p>
+
+<p>The implementation shown here makes use of a custom tree cell for displaying layers in a tree view. In the custom 
+tree cell, toggling the checkbox of the group layer cell does not also toggle the child cell's checkbox. If you 
+desire this behavior, use or extend JavaFX's <code>CheckBoxTreeCell</code> and <code>CheckBoxTreeItem</code>.
+
+<h2 id="tags">Tags</h2>
+
+<p>Layers, group layer</p>