Restrict zooming between specific scale ranges.
Use case
Data may only appear at a certain scale on a map, and may be visually lost if zooming too far in or out. Setting the minimum and maximum scales ensures the zoom extents are appropriately limited for the purposes of the map.
How to use the sample
Zoom in and out of the map. The zoom extents of the map are limited between the given minimum and maximum scales.
How it works
- Create a
Map
object. - Set min and max scales of map with
setMaxScale()
andsetMinScale()
. - Set the map to a
MapView
object.
Relevant API
- Map
- Basemap
- MapView
- ViewPoint
Tags
area of interest, level of detail, maximum, minimum, scale, viewpoint
Sample Code
// [WriteFile Name=MinMaxScale, Category=Maps]
// [Legal]
// Copyright 2018 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 "MinMaxScale.h"
#include "Map.h"
#include "MapQuickView.h"
using namespace Esri::ArcGISRuntime;
MinMaxScale::MinMaxScale(QQuickItem* parent /* = nullptr */):
QQuickItem(parent)
{
}
void MinMaxScale::init()
{
// Register the map view for QML
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<MinMaxScale>("Esri.Samples", 1, 0, "MinMaxScaleSample");
}
void MinMaxScale::componentComplete()
{
QQuickItem::componentComplete();
// find QML MapView component
m_mapView = findChild<MapQuickView*>("mapView");
// Create a map using the streets basemap
m_map = new Map(BasemapStyle::ArcGISStreets, this);
// Establish the minimum and maximum scales for the map
m_map->setMaxScale(2000);
m_map->setMinScale(8000);
// Set map to map view
m_mapView->setMap(m_map);
Point edinburgh(-3.1927,55.9515, SpatialReference(4326));
m_mapView->setViewpointCenter(edinburgh);
}