问题

I am trying to make my overlay image to do following things:

onClick / onDrag of map , show a constant image at the middle of map which is a pin
onTouchUp , change marker image to Loading marker and once data loading complete change loading image to new image with text.

Here is a pretty similar solution to my problem:

What i have done so far ?

Placed an imageview over my google map in the middle , and got loacation of that imageView using mMap.getCameraPosition().target which gives approx middle position coordinates using setOnCameraChanged , i know that's deprecated, well have a better solution?.
Rest of the part i can't figure out , though i have read several SO questions claiming they have implemented it wrapping framelayout over fragment of google map, and applying onTouch on that, but cannot find an authentic answer to that one too.

my xml of fragment where all this is happening looks like this :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragments.MovableMapFragment">

    <fragment
        android:id="@+id/map_frag_fmm"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/tablayout_global_tabs"
        android:layout_alignParentTop="true" />
<! -- long xml ahead -->

Someone know how to achieve this kind of behavior ?

回答1:

The best solution would be to use RxJava/RxAndroid and do background tasks with it, but I can't post a solution using rx without seeing your code and there's already an example from @user27799 also @Manas Chaudhari provided a great explanation of the logic (down below).

//bunch of imports
import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;

public class MapsActivity extends AppCompatActivity implements OnMapReadyCallback
{

  private GoogleMap mGoogleMap;
  private FrameLayout frameLayout, circleFrameLayout;
  private ProgressBar progress;
  private TextView textView;
  private int circleRadius;
  private boolean isMoving = false;
  private SupportMapFragment mapFragment;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    initViews();
  }

  private void initViews() {

    frameLayout = (FrameLayout) findViewById(R.id.map_container);

    circleFrameLayout = (FrameLayout) frameLayout.findViewById(R.id.pin_view_circle);
    textView = (TextView) circleFrameLayout.findViewById(R.id.textView);
    progress = (ProgressBar) circleFrameLayout.findViewById(R.id.profile_loader);

    mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

}

  private void moveMapCamera() {
    if (mGoogleMap == null) {
        return;
    }

    CameraUpdate center = CameraUpdateFactory
            .newLatLng(new LatLng(40.76793169992044, -73.98180484771729));
    CameraUpdate zoom = CameraUpdateFactory.zoomTo(15);

    mGoogleMap.moveCamera(center);
    mGoogleMap.animateCamera(zoom);
}

  @Override
  public void onMapReady(GoogleMap googleMap) {
    mGoogleMap = googleMap;

    mGoogleMap.setOnCameraMoveStartedListener(new GoogleMap.OnCameraMoveStartedListener() {

        /* User starts moving map - change your pin's image here 
        */
        @Override
        public void onCameraMoveStarted(int i) {
            isMoving = true;
            textView.setVisibility(View.GONE);
            progress.setVisibility(View.GONE);
            Drawable mDrawable;
            if (Build.VERSION.SDK_INT >= 21)
                mDrawable = getApplicationContext().getResources().getDrawable(R.drawable.circle_background_moving, null);
            else
                mDrawable = getApplicationContext().getResources().getDrawable(R.drawable.circle_background_moving);

            circleFrameLayout.setBackground(mDrawable);
            resizeLayout(false);
        }
    });

    /*User stoped moving map -> retrieve location and do your background task */
    mGoogleMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
        @Override
        public void onCameraIdle() {

            isMoving = false;
            textView.setVisibility(View.INVISIBLE);
            progress.setVisibility(View.VISIBLE);
            resizeLayout(true);

            /* this is just an example that simulates data loading
               you shoud substitute it with your logic
            */
            new Handler().postDelayed(new Runnable() {
                public void run() {

                    Drawable mDrawable;
                    if (Build.VERSION.SDK_INT >= 21)
                        mDrawable = getApplicationContext().getResources().getDrawable(R.drawable.circle_background, null);
                    else
                        mDrawable = getApplicationContext().getResources().getDrawable(R.drawable.circle_background);

                    if (!isMoving) {
                        circleFrameLayout.setBackground(mDrawable);
                        textView.setVisibility(View.VISIBLE);
                        progress.setVisibility(View.GONE);
                    }
                }
            }, 1500);
        }
    });

    MapsInitializer.initialize(this);
    moveMapCamera();
  }

  //resing circle pin
  private void resizeLayout(boolean backToNormalSize){
    FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) circleFrameLayout.getLayoutParams();

    ViewTreeObserver vto = circleFrameLayout.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            circleFrameLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            circleRadius = circleFrameLayout.getMeasuredWidth();
        }
    });

    if (backToNormalSize) {
        params.width = WRAP_CONTENT;
        params.height = WRAP_CONTENT;
        params.topMargin = 0;

    } else {
        params.topMargin = (int) (circleRadius * 0.3);
        params.height = circleRadius - circleRadius / 3;
        params.width = circleRadius - circleRadius / 3;
    }

    circleFrameLayout.setLayoutParams(params);
  }

}

Layout file with pin in the center of the screen:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:id="@+id/map_container"
         android:layout_width="match_parent"
         android:layout_height="match_parent">

<fragment xmlns:tools="http://schemas.android.com/tools"
          android:id="@+id/map"
          android:name="com.google.android.gms.maps.SupportMapFragment"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          tools:context="com.example.mapstest.MapsActivity" />

<FrameLayout
    android:id="@+id/pin_view_line"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="@dimen/line_top_margin"
    android:background="@drawable/line_background"/>

<FrameLayout
    android:id="@+id/pin_view_circle"
    android:layout_gravity="center"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/circle_background">

    <TextView
        android:id="@+id/textView"
        android:layout_margin="@dimen/inner_circle_margin"
        android:layout_width="@dimen/inner_circle_radius"
        android:layout_height="@dimen/inner_circle_radius"
        android:layout_gravity="top|center_horizontal"
        android:gravity="center"
        android:text="12 min"
        android:textSize="@dimen/text_size"
        android:textColor="@android:color/white"/>

    <ProgressBar
        android:id="@+id/profile_loader"
        android:layout_margin="@dimen/inner_circle_margin"
        android:layout_width="@dimen/inner_circle_radius"
        android:layout_height="@dimen/inner_circle_radius"
        android:indeterminate="true"
        android:layout_gravity="top|center_horizontal"
        android:visibility="gone"
        android:contentDescription="@null"/>

</FrameLayout>

Circle background when not moving:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="oval">    
<solid android:color="@android:color/holo_green_dark"/>
<stroke
    android:width="@dimen/stroke_width"
    android:color="@android:color/black"/>
<size
    android:width="@dimen/circle_radius"
    android:height="@dimen/circle_radius"/>
</shape>

Circle background when map is moving:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="oval">    
<solid android:color="@android:color/black"/>
<size
    android:width="@dimen/circle_radius"
    android:height="@dimen/circle_radius"/>
</shape>

Line background file:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">    
<solid android:color="@android:color/black"/>
<size
    android:width="@dimen/line_width"
    android:height="@dimen/line_height"/>
</shape>

Dimensions:

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <dimen name="circle_radius">48dp</dimen>
  <dimen name="line_width">4dp</dimen>
  <dimen name="line_height">40dp</dimen>
  <dimen name="stroke_width">4dp</dimen>
  <dimen name="text_size">10sp</dimen>
  <dimen name="inner_circle_radius">40dp</dimen>
  <dimen name="inner_circle_margin">4dp</dimen>
  <dimen name="line_top_margin">20dp</dimen>
</resources>

I hope it helps you, but if you have any questions feel free to ask or if you see areas that you'd improve - edit my solution.

Cheers.

回答2:

Put you layout in FrameLayout and draw picture over Map. When GoogleMap ready (My code use RxJava):

Observable.<Void>create(subscriber -> {
        mMap.setOnCameraIdleListener(() -> subscriber.onNext(null));
    })
            .debounce(1, TimeUnit.SECONDS)
            .subscribeOn(AndroidSchedulers.mainThread())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(aVoid -> {
                LatLng newPos = mMap.getProjection().fromScreenLocation(new Point(mBinding.googleMap.getWidth() / 2, mBinding.googleMap.getHeight() / 2));

                makeServerRequest(newPos);
            });

回答3:

Layout

Markers are meant to be positioned at specific coordinates on Map. Thus, they move when you change the Map.

As your pin is always in the middle of the map, its not suitable to create it using Marker. Instead, you can place it outside the map fragment at the center of the map container. So your XML should look as follows:

<RelativeLayout>
  <fragment 
    android:id="@+id/map_fragment" />

  <RelativeLayout
    android:id="@+id/pin_view"
    android:centerInParent="true" />
</RelativeLayout>

You can add children to pin_view to implement animations as per your requirement.

Pin States

Based on the gif provided by you, there can be three states for the pin.

Empty
Loading
Loaded

Listeners

You can trigger the animations by setting these listeners:

setOnCameraMoveStartedListener
- Previous value needs to be invalidated. Change pin's state to Empty
- Cancel any ongoing requests
setOnCameraIdleListener
- Get coordinates using map.getCameraPosition()
- Change pin's state to 'Loading'
- Trigger a network call to fetch data. In the callback
  - Change pin's state to 'Loaded' and display the value Note that callback won't get executed, if user moves before api completes, as we will cancel the request as soon as user moves. So, this scenario will also be taken care of

来源：https://stackoverflow.com/questions/39821038/create-overlay-imageview-animation-google-map

标签

android