Use annotation sublayers to gain finer control of annotation layer subtypes.
Use case
Annotation, which differs from labels by having a fixed place and size, is typically only relevant at particular scales. Annotation sublayers allow for finer control of annotation by allowing properties (like visibility in the map and legend) to be set and others to be read (like name) on subtypes of an annotation layer.
An annotation dataset which marks valves as "Opened" or "Closed", might be set to display the "Closed" valves over a broader range of scales than the "Opened" valves, if the "Closed" data is considered more relevant by the map's author. Regardless, the user can be given a manual option to set visibility of annotation sublayers on and off, if required.
How to use the sample
Start the sample and take note of the visibility of the annotation. Zoom in and out to see the annotation turn on and off based on scale ranges set on the data.
Use the checkboxes to manually set "Open" and "Closed" annotation sublayers visibility to on or off.
How it works
- Load a
MobileMapPackage
that containsAnnotationSublayer
. - Get the sublayers from the map package's layers by calling
sublayer::subLayerContents()[i]
. - You can toggle the visibility of each sublayer manually using
sublayer::setVisible()
. - To determine if a sublayer is visible at the current scale of the
MapView
, usesublayer::isVisibleAtScale()
, by passing in the map's current scale.
Relevant API
- AnnotationLayer
- AnnotationSublayer
- LayerContent
Offline Data
Read more about how to set up the sample's offline data here.
Link | Local Location |
---|---|
Gas Device Anno Mobile Map Package | <userhome>/ArcGIS/Runtime/Data/mmpk/GasDeviceAnno.mmpk |
About the data
The scale ranges were set by the map's author using ArcGIS Pro:
- The "Open" annotation sublayer has its maximum scale set to 1:500 and its minimum scale set to 1:2000.
- The "Closed" annotation sublayer has no minimum or maximum scales set, so will be drawn at all scales.
Tags
annotation, scale, text, utilities, visualization
Sample Code
// [WriteFile Name=ControlAnnotationSublayerVisibility, Category=DisplayInformation]
// [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 "ControlAnnotationSublayerVisibility.h"
#include "Map.h"
#include "MapQuickView.h"
#include "MobileMapPackage.h"
#include "AnnotationLayer.h"
#include "AnnotationSublayer.h"
#include <QDir>
#include <QtCore/qglobal.h>
#ifdef Q_OS_IOS
#include <QStandardPaths>
#endif // Q_OS_IOS
using namespace Esri::ArcGISRuntime;
// helper method to get cross platform data path
namespace
{
QString defaultDataPath()
{
QString dataPath;
#ifdef Q_OS_ANDROID
dataPath = "/sdcard";
#elif defined Q_OS_IOS
dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
#else
dataPath = QDir::homePath();
#endif
return dataPath;
}
// sample MMPK location
const QString sampleFileAnno {"/ArcGIS/Runtime/Data/mmpk/GasDeviceAnno.mmpk"};
} // namespace
ControlAnnotationSublayerVisibility::ControlAnnotationSublayerVisibility(QObject* parent /* = nullptr */):
QObject(parent)
{
const QString dataPath = defaultDataPath() + sampleFileAnno;
// connect to the Mobile Map Package instance to know when errors occur
connect(MobileMapPackage::instance(), &MobileMapPackage::errorOccurred,
[](Error error)
{
if (error.isEmpty())
return;
qDebug() << QString("Error: %1 %2").arg(error.message(), error.additionalMessage());
});
// Load the MMPK
createMapPackage(dataPath);
}
ControlAnnotationSublayerVisibility::~ControlAnnotationSublayerVisibility() = default;
void ControlAnnotationSublayerVisibility::init()
{
// Register the map view for QML
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<ControlAnnotationSublayerVisibility>("Esri.Samples", 1, 0, "ControlAnnotationSublayerVisibilitySample");
}
MapQuickView* ControlAnnotationSublayerVisibility::mapView() const
{
return m_mapView;
}
// Set the view (created in QML)
void ControlAnnotationSublayerVisibility::setMapView(MapQuickView* mapView)
{
if (!mapView || mapView == m_mapView)
return;
m_mapView = mapView;
m_mapView->setMap(m_map);
connect(m_mapView, &MapQuickView::mapScaleChanged, this, [this]()
{
m_mapScale = m_mapView->mapScale();
emit mapScaleChanged();
if (!m_annotationSubLayerOpen)
return;
m_visibleAtCurrentExtent = m_annotationSubLayerOpen->isVisibleAtScale(m_mapScale);
emit visibleAtCurrentExtentChanged();
});
emit mapViewChanged();
}
// create map package
void ControlAnnotationSublayerVisibility::createMapPackage(const QString& path)
{
//! [open mobile map package cpp snippet]
// instatiate a mobile map package
m_mobileMapPackage = new MobileMapPackage(path, this);
// wait for the mobile map package to load
connect(m_mobileMapPackage, &MobileMapPackage::doneLoading, this, [this](Error error)
{
if (!error.isEmpty())
{
qDebug() << QString("Package load error: %1 %2").arg(error.message(), error.additionalMessage());
return;
}
if (!m_mobileMapPackage || !m_mapView || m_mobileMapPackage->maps().isEmpty())
return;
// The package contains a list of maps that could be shown in the UI for selection.
// For simplicity, obtain the first map in the list of maps.
// set the map on the map view to display
m_mapView->setMap(m_mobileMapPackage->maps().at(0));
m_layerListModel = mapView()->map()->operationalLayers();
for (Layer* layer : *m_layerListModel)
{
if (layer->layerType() == LayerType::AnnotationLayer)
{
m_annoLayer = layer;
connect(m_annoLayer, &Layer::doneLoading, this, [this](Error error)
{
if (!error.isEmpty())
{
qDebug() << QString("Package load error: %1 %2").arg(error.message(), error.additionalMessage());
return;
}
const auto contents = m_annoLayer->subLayerContents();
m_annotationSubLayerClosed = dynamic_cast<AnnotationSublayer*>(contents[0]);
m_annotationSubLayerOpen = dynamic_cast<AnnotationSublayer*>(contents[1]);
m_closedLayerText = m_annotationSubLayerClosed->name();
m_openLayerText = QString("%1 (1:%2 - 1:%3)").arg(m_annotationSubLayerOpen->name()).arg(m_annotationSubLayerOpen->maxScale()).arg(m_annotationSubLayerOpen->minScale());
emit openLayerTextChanged();
emit closedLayerTextChanged();
});
layer->load();
}
}
});
m_mobileMapPackage->load();
//! [open mobile map package cpp snippet]
}
void ControlAnnotationSublayerVisibility::openLayerVisible()
{
if (!m_annotationSubLayerOpen)
return;
m_annotationSubLayerOpen->setVisible(!m_annotationSubLayerOpen->isVisible());
}
void ControlAnnotationSublayerVisibility::closedLayerVisible()
{
if (!m_annotationSubLayerClosed)
return;
m_annotationSubLayerClosed->setVisible(!m_annotationSubLayerClosed->isVisible());
}