Display common symbols for all graphics in a graphics overlay with a renderer.
Use case
Graphics are often used to display data that changes location regularly because they are held in memory instead of being persisted to the map. When a number of graphics are required to share the same style, a simple renderer can be applied to the graphics overlay containing the graphics. For example, the location of mobile taxis from a same company could be plotted on a map with each taxi marked by a relevant symbol.
How to use the sample
The sample loads with a predefined simple renderer, which displays a red cross simple marker symbol for the graphics in the graphics overlay.
How it works
- Create a
GraphicsOverlay
. - Create a number of
Point
objects with x, y and spatial reference parameters. - Create a
SimpleMarkerSymbol
passing in aSimpleMarkerSymbolStyle
, color and size as parameters. - Create a simple renderer with
SimpleRenderer(simpleMarkerSymbol)
. - Set the simple renderer to the graphics overlay using
graphicsOverlay::setRenderer(simpleRenderer)
. - Create a number of
Graphic
objects with the points initiated in step 2. - Add the graphics to the graphics overlay with
graphicsOverlay::graphics()::append(graphic)
.
Relevant API
- Graphic
- GraphicsOverlay
- Point
- SimpleMarkerSymbol
- SimpleRenderer
Additional information
Renderers are used to display graphics that don't already have a symbol set. A renderer will not override a graphic's symbol if one has been set.
Tags
graphics, marker, renderer, symbol, symbolize, symbology
Sample Code
// [WriteFile Name=Simple_Renderer, 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
#include "Simple_Renderer.h"
#include "Map.h"
#include "MapQuickView.h"
#include "Point.h"
#include "Viewpoint.h"
#include "GraphicsOverlay.h"
#include "Graphic.h"
#include "SimpleMarkerSymbol.h"
#include "SimpleRenderer.h"
#include "SpatialReference.h"
using namespace Esri::ArcGISRuntime;
Simple_Renderer::Simple_Renderer(QQuickItem* parent) :
QQuickItem(parent)
{
}
Simple_Renderer::~Simple_Renderer() = default;
void Simple_Renderer::init()
{
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<Simple_Renderer>("Esri.Samples", 1, 0, "Simple_RendererSample");
}
void Simple_Renderer::componentComplete()
{
QQuickItem::componentComplete();
// find QML MapView component
m_mapView = findChild<MapQuickView*>("mapView");
m_mapView->setWrapAroundMode(WrapAroundMode::Disabled);
// Create a map using the imagery basemap
m_map = new Map(BasemapStyle::ArcGISImageryStandard, this);
// create graphics overlay
m_graphicsOverlay = new GraphicsOverlay(this);
// create red cross SimpleMarkerSymbol
SimpleMarkerSymbol* crossSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle::Cross, QColor("red"), 12, this);
// create renderer and set symbol to crossSymbol
SimpleRenderer* simpleRenderer = new SimpleRenderer(crossSymbol, this);
// set the SimpleRenderer to the GraphicsOverlay
m_graphicsOverlay->setRenderer(simpleRenderer);
// create points to render
Point oldFaithfulPoint(-110.828140, 44.460458, SpatialReference::wgs84());
Point cascadeGeyserPoint(-110.829004, 44.462438, SpatialReference::wgs84());
Point plumeGeyserPoint(-110.829381, 44.462735, SpatialReference::wgs84());
// create graphics using points and add them to GraphicsOverlay
addPoint(oldFaithfulPoint);
addPoint(cascadeGeyserPoint);
addPoint(plumeGeyserPoint);
// Set map to map view
m_mapView->setMap(m_map);
// set viewpoint using the two farthest points as an envelope with padding
m_mapView->setViewpointGeometry(Envelope(oldFaithfulPoint, plumeGeyserPoint), 50);
// add GraphicsOverlay to MapView
m_mapView->graphicsOverlays()->append(m_graphicsOverlay);
}
void Simple_Renderer::addPoint(Point &point)
{
// create graphic
Graphic* graphic = new Graphic(point, this);
// add graphic to Graphic Overlay
m_graphicsOverlay->graphics()->append(graphic);
}