Group a collection of layers together and toggle their visibility as a group.
Use case
Group layers communicate to the user that layers are related and can be managed together.
In a land development project, you might group layers according to the phase of development.
How to use the sample
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. Turning a group layer's visibility off will override the visibility of its child layers.
How it works
- Create an empty
GroupLayer
. - Create a new layer and add it to the group layer's layers collection.
- Set the group layer's
GroupVisibilityMode
to change its behavior:
GroupVisibilityMode::Independent
allows each sublayer to change its visibility independently.GroupVisibilityMode::Exclusive
allows only one sublayer to be visible at a time.GroupVisibilityMode::Inherited
treats the group layer as if it is one merged layer.
- Create a ListView and bind the model the the scene's operational layer list model.
- Create a delegate for the group layer and and another delegate for all other layers. The group layer delegate will have nested checkboxes.
- Check that the layer is a group layer. If true, load the group layer delegate. If false, load the other delegate.
- Each delegate will use the
name
andlayerVisible
roles exposed on theLayerListModel
. - To toggle the visibility of the group, simply change the group layer's visibility property.
Relevant API
- GroupLayer
Additional information
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.
Tags
group layer
Sample Code
// [WriteFile Name=GroupLayers, Category=Layers]
// [Legal]
// 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.
// [Legal]
#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD
#include "GroupLayers.h"
#include "ArcGISTiledElevationSource.h"
#include "Scene.h"
#include "SceneQuickView.h"
#include "GroupLayer.h"
#include "ArcGISSceneLayer.h"
#include "FeatureLayer.h"
#include "ServiceFeatureTable.h"
#include "Viewpoint.h"
#include "Envelope.h"
using namespace Esri::ArcGISRuntime;
GroupLayers::GroupLayers(QObject* parent /* = nullptr */):
QObject(parent),
m_scene(new Scene(BasemapStyle::ArcGISImageryStandard, this))
{
// create a new elevation source from Terrain3D REST service
ArcGISTiledElevationSource* elevationSource = new ArcGISTiledElevationSource(
QUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"), this);
// add the elevation source to the scene to display elevation
m_scene->baseSurface()->elevationSources()->append(elevationSource);
// Create layers and append to a group layer
ArcGISSceneLayer* layer1 = new ArcGISSceneLayer(QUrl("https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/DevA_BuildingShells/SceneServer"), this);
ArcGISSceneLayer* layer2 = new ArcGISSceneLayer(QUrl("https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/DevB_BuildingShells/SceneServer"), this);
GroupLayer* groupLayer = new GroupLayer(QList<Layer*>{layer1, layer2}, this);
groupLayer->setName("Buildings group");
groupLayer->setVisibilityMode(GroupVisibilityMode::Exclusive);
// Create additional layers
ArcGISSceneLayer* layer3 = new ArcGISSceneLayer(QUrl("https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/DevA_Trees/SceneServer"), this);
ServiceFeatureTable* ft1 = new ServiceFeatureTable(QUrl("https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/DevelopmentProjectArea/FeatureServer/0"), this);
FeatureLayer* layer4 = new FeatureLayer(ft1, this);
ServiceFeatureTable* ft2 = new ServiceFeatureTable(QUrl("https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/DevA_Pathways/FeatureServer/1"), this);
FeatureLayer* layer5 = new FeatureLayer(ft2, this);
// Add layers to the scene
m_scene->operationalLayers()->append(groupLayer);
m_scene->operationalLayers()->append(layer3);
m_scene->operationalLayers()->append(layer4);
m_scene->operationalLayers()->append(layer5);
connect(m_scene, &Scene::doneLoading, this, [this](Error e)
{
if (!e.isEmpty())
return;
m_layerListModel = m_scene->operationalLayers();
emit layerListModelChanged();
});
}
GroupLayers::~GroupLayers() = default;
void GroupLayers::init()
{
// Register classes for QML
qmlRegisterType<SceneQuickView>("Esri.Samples", 1, 0, "SceneView");
qmlRegisterType<GroupLayers>("Esri.Samples", 1, 0, "GroupLayersSample");
qmlRegisterUncreatableType<LayerListModel>("Esri.Samples", 1, 0, "AbstractListModel", "AbstractListModel is uncreateable");
}
SceneQuickView* GroupLayers::sceneView() const
{
return m_sceneView;
}
// Set the view (created in QML)
void GroupLayers::setSceneView(SceneQuickView* sceneView)
{
if (!sceneView || sceneView == m_sceneView)
{
return;
}
m_sceneView = sceneView;
m_sceneView->setArcGISScene(m_scene);
// create initial viewpoint
Geometry env = Geometry::fromJson(R"({"spatialReference":{
"wkid":4326
},
"xmax":-122.67960721754773,
"xmin":-122.68647066116789,
"ymax":45.53584958588318,
"ymin":45.531539857343745
})");
// zoom to viewpoint
m_sceneView->setViewpoint(Viewpoint(env.extent()));
emit sceneViewChanged();
}
LayerListModel* GroupLayers::getGroupLayerListModel(int layerId)
{
if (!m_scene)
return nullptr;
GroupLayer* groupLayer = static_cast<GroupLayer*>(m_scene->operationalLayers()->at(layerId));
if (groupLayer)
return groupLayer->layers();
return nullptr;
}