Display an alert message when a graphic is clicked.
Use case
A user may wish to select a graphic on a map to view relevant information about it.
How to use the sample
Select a graphic to identify it. You will see an alert message displayed.
How it works
- Create a
GraphicsOverlayand add it to theMapView. - Add a
Graphicalong with aSimpleFillSymbolto the graphics overlay. - Create a
Pointfrom the location clicked on the map view by the user from theMapQuickView::mouseClickedsignal. - Identify the graphic on the map view with
identifyGraphicsOverlayAsync(GraphicsOverlay*, QPointF, double, bool, int).
Relevant API
- Graphic
- GraphicsOverlay
- MapView
Tags
graphics, identify
Sample Code
// [WriteFile Name=IdentifyGraphics, Category=DisplayInformation] // [Legal] // Copyright 2016 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 // sample headers #include "IdentifyGraphics.h" // ArcGIS Maps SDK headers #include "Geometry.h" #include "Graphic.h" #include "GraphicListModel.h" #include "GraphicsOverlay.h" #include "GraphicsOverlayListModel.h" #include "IdentifyGraphicsOverlayResult.h" #include "Map.h" #include "MapQuickView.h" #include "MapTypes.h" #include "PolygonBuilder.h" #include "SimpleFillSymbol.h" #include "SimpleRenderer.h" #include "SpatialReference.h" #include "SymbolTypes.h" // Qt headers #include <QFuture> #include <QList> #include <QMouseEvent> #include <QUuid> // STL headers #include <memory> using namespace Esri::ArcGISRuntime; IdentifyGraphics::IdentifyGraphics(QQuickItem* parent) : QQuickItem(parent) { } IdentifyGraphics::~IdentifyGraphics() = default; void IdentifyGraphics::init() { qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView"); qmlRegisterType<IdentifyGraphics>("Esri.Samples", 1, 0, "IdentifyGraphicsSample"); } void IdentifyGraphics::componentComplete() { QQuickItem::componentComplete(); // find QML MapView component m_mapView = findChild<MapQuickView*>("mapView"); // Create a map using the topographic basemap m_map = new Map(BasemapStyle::ArcGISTopographic, this); // set map on the map view m_mapView->setMap(m_map); // create a new graphics overlay m_graphicsOverlay = new GraphicsOverlay(this); // assign a renderer to the graphics overlay SimpleFillSymbol* simpleFillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle::Solid, QColor(255, 255, 0, 180), this); SimpleRenderer* simpleRenderer = new SimpleRenderer(simpleFillSymbol, this); m_graphicsOverlay->setRenderer(simpleRenderer); // add the overlay to the mapview m_mapView->graphicsOverlays()->append(m_graphicsOverlay); // add polygon graphics addPolygonGraphic(); // connect signals connectSignals(); } // create the polygon geometry and graphic void IdentifyGraphics::addPolygonGraphic() { // create the polygon using the builder class PolygonBuilder polygonBuilder(SpatialReference::webMercator()); polygonBuilder.addPoint(-20e5, 20e5); polygonBuilder.addPoint(20e5, 20e5); polygonBuilder.addPoint(20e5, -20e5); polygonBuilder.addPoint(-20e5, -20e5); // create the graphic and add to the graphics overlay Graphic* graphic = new Graphic(polygonBuilder.toGeometry(), this); m_graphicsOverlay->graphics()->append(graphic); } void IdentifyGraphics::connectSignals() { //! [identify graphics api snippet] // connect to the mouse clicked signal on the MapQuickView connect(m_mapView, &MapQuickView::mouseClicked, this, [this](QMouseEvent& mouseEvent) { // call identify on the map view constexpr double tolerance = 5.0; constexpr bool returnPopupsOnly = false; constexpr int maximumResults = 1; m_mapView->identifyGraphicsOverlayAsync(m_graphicsOverlay, mouseEvent.position(), tolerance, returnPopupsOnly, maximumResults).then(this, [this](IdentifyGraphicsOverlayResult* rawIdentifyResult) { // Delete rawIdentifyResult on leaving scope. auto identifyResult = std::unique_ptr<IdentifyGraphicsOverlayResult>(rawIdentifyResult); if (identifyResult) { m_identifiedGraphicsCount = identifyResult->graphics().size(); emit identifiedGraphicsCountChanged(); } }); }); //! [identify graphics api snippet] } int IdentifyGraphics::identifiedGraphicsCount() { return m_identifiedGraphicsCount; }