如何在Swift中实现GMUClusterRenderer

Question

我正在使用适用于iOS的Google Maps API,并希望使用标记群集实用程序.我想出了如何显示聚类标记,但我想自定义标记.有人可以解释如何设置/更改每个标记或聚类标记的图标和标题吗？示例代码非常有用.

class POIItem: NSObject, GMUClusterItem {
    var position: CLLocationCoordinate2D
    var name: String!

    init(position: CLLocationCoordinate2D, name: String) {
        self.position = position
        self.name = name
    }
}

class MyRenderer: NSObject, GMUClusterRenderer {
    var mapView: GMSMapView
    var clusterIconGenerator: GMUClusterIconGenerator
    var clusterManager: GMUClusterManager

    init(mapView: GMSMapView, clusterIconGenerator: GMUClusterIconGenerator, clusterManager: GMUClusterManager) {
        self.mapView = mapView
        self.clusterIconGenerator = clusterIconGenerator
        self.clusterManager = clusterManager
    }

    func renderClusters(clusters: [GMUCluster]) {

    }

    func update() {

    }
}

这就是我到目前为止所拥有的.我不知道如何处理renderClusters和更新函数.

Answer 1

我在Swift 4上为集群标记找到了一个干净的解决方案,使用集群内部集群数量的自定义映像:

class MapClusterIconGenerator: GMUDefaultClusterIconGenerator {

    override func icon(forSize size: UInt) -> UIImage {
        let image = textToImage(drawText: String(size) as NSString,
                                inImage: UIImage(named: "cluster")!,
                                font: UIFont.systemFont(ofSize: 12))
        return image
    }

    private func textToImage(drawText text: NSString, inImage image: UIImage, font: UIFont) -> UIImage {

        UIGraphicsBeginImageContext(image.size)
        image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))

        let textStyle = NSMutableParagraphStyle()
        textStyle.alignment = NSTextAlignment.center
        let textColor = UIColor.black
        let attributes=[
            NSAttributedStringKey.font: font,
            NSAttributedStringKey.paragraphStyle: textStyle,
            NSAttributedStringKey.foregroundColor: textColor]

        // vertically center (depending on font)
        let textH = font.lineHeight
        let textY = (image.size.height-textH)/2
        let textRect = CGRect(x: 0, y: textY, width: image.size.width, height: textH)
        text.draw(in: textRect.integral, withAttributes: attributes)
        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return result!
    }

}

比集群管理器的设置:

private func setupClustering() {
    guard let mapView = self.mapView else { return }

    let iconGenerator = MapClusterIconGenerator()
    let renderer = MapClusterRenderer(mapView: mapView, clusterIconGenerator: iconGenerator)
    let algorithm = GMUNonHierarchicalDistanceBasedAlgorithm()
    clusterManager = GMUClusterManager(map: mapView, algorithm: algorithm, renderer: renderer)
}

我还使用了自定义群集渲染器MapClusterRenderer.

Answer 2

我设法找到"干净"的解决方案,即使它仍然令人困惑.但它的确有效!

1)创建.h文件"MarkerManager"

    #import <Foundation/Foundation.h>
@import CoreLocation;
#import "GMUClusterItem.h"
#import <GoogleMaps/GoogleMaps.h>


@interface MarkerManager: NSObject

@property (nonatomic) CLLocationCoordinate2D location;
@property (nonatomic, strong) GMSMarker *marker;

@end

2)转到Google-Maps-iOS-Utils文件夹中的GMUDefaultClusterRenderer类,导入MarkerManager.h类查找并更改此方法:

// Returns a marker at final position of |position| with attached |userData|.
// If animated is YES, animates from the closest point from |points|.
- (GMSMarker *)markerWithPosition:(CLLocationCoordinate2D)position
                             from:(CLLocationCoordinate2D)from
                         userData:(id)userData
                      clusterIcon:(UIImage *)clusterIcon
                         animated:(BOOL)animated {
  GMSMarker *marker = [self markerForObject:userData];
  CLLocationCoordinate2D initialPosition = animated ? from : position;
  marker.position = initialPosition;
  marker.userData = userData;
  if (clusterIcon != nil) {
    marker.icon = clusterIcon;
    marker.groundAnchor = CGPointMake(0.5, 0.5);
  }
  //added
  else {
      MarkerManager *data = userData;
      if(data != nil) {
          marker.icon = data.marker.icon;
      }
  }
  //ends here

  marker.zIndex = _zIndex;

  if ([_delegate respondsToSelector:@selector(renderer:willRenderMarker:)]) {
    [_delegate renderer:self willRenderMarker:marker];
  }
  marker.map = _mapView;

  if (animated) {
    [CATransaction begin];
    [CATransaction setAnimationDuration:kGMUAnimationDuration];
    marker.layer.latitude = position.latitude;
    marker.layer.longitude = position.longitude;
    [CATransaction commit];
  }

  if ([_delegate respondsToSelector:@selector(renderer:didRenderMarker:)]) {
    [_delegate renderer:self didRenderMarker:marker];
  }
  return marker;
}

3)创建新的swift类,POIItem:

class POIItem: NSObject, GMUClusterItem {
var position: CLLocationCoordinate2D
@objc var marker: GMSMarker!


init(position: CLLocationCoordinate2D, marker: GMSMarker) {
    self.position = position
    self.marker = marker
}
}

4)扩展GMUDefaultClusterRenderer类并覆盖markerWithPosition方法:

import Foundation
import UIKit

class CustomMarkers: GMUDefaultClusterRenderer {
    var mapView:GMSMapView?
    let kGMUAnimationDuration: Double = 0.5

    override init(mapView: GMSMapView, clusterIconGenerator iconGenerator: GMUClusterIconGenerator) {

        super.init(mapView: mapView, clusterIconGenerator: iconGenerator)
    }

    func markerWithPosition(position: CLLocationCoordinate2D, from: CLLocationCoordinate2D, userData: AnyObject, clusterIcon: UIImage, animated: Bool) -> GMSMarker {
        let initialPosition = animated ? from : position
        let marker = GMSMarker(position: initialPosition)
        marker.userData! = userData
        if clusterIcon.cgImage != nil {
            marker.icon = clusterIcon
        }
        else {
            marker.icon = self.getCustomTitleItem(userData: userData)

        }
        marker.map = mapView
        if animated
        {
            CATransaction.begin()
            CAAnimation.init().duration = kGMUAnimationDuration
            marker.layer.latitude = position.latitude
            marker.layer.longitude = position.longitude
            CATransaction.commit()
        }
        return marker
    }

    func getCustomTitleItem(userData: AnyObject) -> UIImage {
        let item = userData as! POIItem
        return item.marker.icon!
    }
}

5)在generateClusterItems方法中的MapViewController init POIItem中:

private func generateClusterItems() {

        for object in DataManager.sharedInstance.mapItemsArray {

            let doubleLat = Double(object.latitude)
            let doubleLong = Double(object.longitude)
            let latitude = CLLocationDegrees(doubleLat!)
            let longitude = CLLocationDegrees(doubleLong!)
            let position = CLLocationCoordinate2DMake(latitude, longitude)
            let marker = GMSMarker(position: position)
            let item = POIItem(position: position, marker: marker)
            self.clusterManager.add(item)                
            item.mapItem = object

        }
    }

在for循环中你可以调用:

marker.icon = UIImage(named:"YOUR_IMAGE_NAME")

现在,您可以将逻辑设置为具有多个自定义标记.