无论你在哪里捏缩放android,都要保持地图居中

Question

我正在寻找类似Uber处理捏缩放事件的方式.无论您在屏幕上捏什么,它都会使地图居中并放大中心位置.有没有办法在地图片段上没有某种叠加的情况下做到这一点？或者我应该只禁用地图的事件,在地图片段上创建叠加层,并处理叠加层中的所有缩放/其他事件？

Answer 1

我花了大约3天的时间在谷歌上搜索后,我已经建立了完整的解决方案.我的答案是从/sf/answers/2291410551/编辑的.

public class CustomMapView extends MapView {

    private int fingers = 0;
    private GoogleMap googleMap;
    private long lastZoomTime = 0;
    private float lastSpan = -1;
    private Handler handler = new Handler();

    private ScaleGestureDetector scaleGestureDetector;
    private GestureDetector gestureDetector;

    public CustomMapView(Context context) {
        super(context);
    }

    public CustomMapView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomMapView(Context context, AttributeSet attrs, int style) {
        super(context, attrs, style);
    }

    public CustomMapView(Context context, GoogleMapOptions options) {
        super(context, options);
    }

    public void init(GoogleMap map) {
        scaleGestureDetector = new ScaleGestureDetector(getContext(), new ScaleGestureDetector.OnScaleGestureListener() {
            @Override
            public boolean onScale(ScaleGestureDetector detector) {
                if (lastSpan == -1) {
                    lastSpan = detector.getCurrentSpan();
                } else if (detector.getEventTime() - lastZoomTime >= 50) {
                    lastZoomTime = detector.getEventTime();
                    googleMap.animateCamera(CameraUpdateFactory.zoomBy(getZoomValue(detector.getCurrentSpan(), lastSpan)), 50, null);
                    lastSpan = detector.getCurrentSpan();
                }
                return false;
            }

            @Override
            public boolean onScaleBegin(ScaleGestureDetector detector) {
                lastSpan = -1;
                return true;
            }

            @Override
            public void onScaleEnd(ScaleGestureDetector detector) {
                lastSpan = -1;

            }
        });
        gestureDetector = new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() {
            @Override
            public boolean onDoubleTapEvent(MotionEvent e) {

                disableScrolling();
                googleMap.animateCamera(CameraUpdateFactory.zoomIn(), 400, null);

                return true;
            }
        });
        googleMap = map;
    }

    private float getZoomValue(float currentSpan, float lastSpan) {
        double value = (Math.log(currentSpan / lastSpan) / Math.log(1.55d));
        return (float) value;
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        gestureDetector.onTouchEvent(ev);
        switch (ev.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_POINTER_DOWN:
                fingers = fingers + 1;
                break;
            case MotionEvent.ACTION_POINTER_UP:
                fingers = fingers - 1;
                break;
            case MotionEvent.ACTION_UP:
                fingers = 0;
                break;
            case MotionEvent.ACTION_DOWN:
                fingers = 1;
                break;
        }
        if (fingers > 1) {
            disableScrolling();
        } else if (fingers < 1) {
            enableScrolling();
        }
        if (fingers > 1) {
            return scaleGestureDetector.onTouchEvent(ev);
        } else {
            return super.dispatchTouchEvent(ev);
        }
    }

    private void enableScrolling() {
        if (googleMap != null && !googleMap.getUiSettings().isScrollGesturesEnabled()) {
            handler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    googleMap.getUiSettings().setAllGesturesEnabled(true);
                }
            }, 50);
        }
    }

    private void disableScrolling() {
        handler.removeCallbacksAndMessages(null);
        if (googleMap != null && googleMap.getUiSettings().isScrollGesturesEnabled()) {
            googleMap.getUiSettings().setAllGesturesEnabled(false);
        }
    }
}

并自定义MapFragment

public class CustomMapFragment extends Fragment {

        CustomMapView view;
        Bundle bundle;
        GoogleMap map;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            bundle = savedInstanceState;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View v = inflater.inflate(R.layout.fragment_map, container, false);

            view = (CustomMapView) v.findViewById(R.id.mapView);
            view.onCreate(bundle);
            view.onResume();

            map = view.getMap();
            view.init(map);

            MapsInitializer.initialize(getActivity());

            return v;
        }

        public GoogleMap getMap() {
            return map;
        }

        @Override
        public void onResume() {
            super.onResume();
            view.onResume();
        }

        @Override
        public void onPause() {
            super.onPause();
            view.onPause();
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            view.onDestroy();
        }

        @Override
        public void onLowMemory() {
            super.onLowMemory();
            view.onLowMemory();
        }
    }

最后,在您的活动中:

....
<fragment
    android:id="@+id/map"
    class="yourpackage.CustomMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>
...

我已经在Android 4.1(API 16)和后者上进行了测试,它运行良好且流畅.(关于API <16,我没有任何设备可以测试).

Answer 2

这是MechEthan想到的代码.

1. 首先,您必须在叠加视图上检测到双击.

   public class TouchableWrapper extends FrameLayout {
       private final GestureDetector.SimpleOnGestureListener mGestureListener
               = new GestureDetector.SimpleOnGestureListener() {
           @Override
           public boolean onDoubleTap(MotionEvent e) {
   
               //Notify the event bus (I am using Otto eventbus of course) that you have just received a double-tap event on the map, inside the event bus event listener
               EventBus_Singleton.getInstance().post(new EventBus_Poster("double_tapped_map"));
   
               return true;
           }
       };
   
       public TouchableWrapper(Context context) {
           super(context);
           mGestureDetector = new GestureDetectorCompat(context, mGestureListener);
       }
   
       @Override
       public boolean onInterceptTouchEvent(MotionEvent ev) {
           mGestureDetector.onTouchEvent(ev);
   
           return super.onInterceptTouchEvent(ev);
       }
   }
   

2. 无论您在哪里抓取mapView,都要将mapView包装在上面创建的TouchableWrapper中.这就是我这样做的原因,因为我有需要将mapFragment添加到另一个片段的问题所以我需要一个自定义的SupportMapFragment来执行此操作

   public class CustomMap_Fragment extends SupportMapFragment {
   
       TouchableWrapper mTouchView;
   
       public CustomMap_Fragment() {
           super();
       }
   
       public static CustomMap_Fragment newInstance() {
           return new CustomMap_Fragment();
       }
   
       @Override
       public View onCreateView(LayoutInflater arg0, ViewGroup arg1, Bundle arg2) {
           View mapView = super.onCreateView(arg0, arg1, arg2);
   
           Fragment fragment = getParentFragment();
           if (fragment != null && fragment instanceof OnMapReadyListener) {
               ((OnMapReadyListener) fragment).onMapReady();
           }
   
           mTouchView = new TouchableWrapper(getActivity());
           mTouchView.addView(mapView);
   
           return mTouchView;
       }
   
       public static interface OnMapReadyListener {
           void onMapReady();
       }
   }
   

3. 在我的Map_Fragment中(最终将位于支持导航抽屉和片段事务以切换视图的活动中的FrameLayout内)

   mMapFragment = CustomMap_Fragment.newInstance();
   getChildFragmentManager().beginTransaction().replace(R.id.map_container, mMapFragment).commit();
   

4. 现在终于在我刚拿到我的地图的同一片段中,EventBus接收器在收到"double_tapped_map"时会执行以下操作:

   @Subscribe public void eventBus_ListenerMethod(AnswerAvailableEvent event) {
       //Construct a CameraUpdate object that will zoom into the exact middle of the map, with a zoom of currentCameraZoom + 1 unit
      zoomInUpdate = CameraUpdateFactory.zoomIn();
      //Run that with a speed of 400 ms.
      map.animateCamera(zoomInUpdate, 400, null);
   }
   

注意:为了完美实现这一点,你可以在地图上禁用zoomGestures(意思是你这样做myMap.getUiSettings().setZoomGesturesEnabled(false);.如果你不这样做,你将能够在地图上快速双击,你会看到它会从中心缩放因为双击的实现与我发布的第一个答案完全相同,也就是说它们从前一个分接时间中减去当前时间,因此在该窗口中你可以在第三个分接头滑动,它不会触发事件总线事件和谷歌地图将捕捉它;所以禁用缩放手势.

但是,你会看到捏合/熄灭将不再起作用,你也必须处理捏,我也已经完成了但是还需要1个小时而我还没有时间去做但是100%我当我这样做时会更新答案.

提示:优步已禁用地图上的旋转手势.map.getUiSettings().setRotateGesturesEnabled(false);