android - (谷歌地图)检查 LatLng 是否在可见区域经度的 80% 以内

Question

我有一个 android 布局，它有一个谷歌地图布局，底部覆盖有一个小的 LinearLayout。当用户选择 map 上的标记时，这个小布局就会变得可见。现在，我想知道选中的标记是否在选中时被小布局覆盖，比如它是否在 map 经度可见区域的前 80% 以内。我玩过 maps.getProjection().getVisibleRegion() 但我不确定我从这里去哪里。提前致谢

Answer 1

要检查 80%(或更多)的标记是否被您的小布局重叠，最好使用屏幕坐标，而不是 LatLng。您应该获取标记的屏幕 y 坐标、标记 height 和“小布局”的 height，然后检查 y 标记的坐标比小布局顶部的 y 坐标高 80%。

所以像这样:

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {

    private static final String TAG = MainActivity.class.getSimpleName();

    static final LatLng KYIV = new LatLng(50.450000, 30.523610);

    private GoogleMap mGoogleMap;
    private SupportMapFragment mMapSupportedFragment;
    private LinearLayout mSmallLinearLayout;
    private RelativeLayout mRootLayout;
    private Marker mMarker;
    private int mRootLayoutHeight;
    private int mSmallLayoutHeight;
    private int mMarkerWidth = 100;
    private int mMarkerHeight = 100;


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

        mRootLayout = (RelativeLayout) findViewById(R.id.root_layout);
        mSmallLinearLayout = (LinearLayout) findViewById(R.id.small_bottom_layout);

        mMapSupportedFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map_fragment);
        mMapSupportedFragment.getMapAsync(MainActivity.this);

    }

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

        mRootLayout.post(new Runnable() {
            @Override
            public void run() {
                mRootLayoutHeight = mRootLayout.getHeight();
            }
        });

        mSmallLinearLayout.post(new Runnable() {
            @Override
            public void run() {
                mSmallLayoutHeight = mSmallLinearLayout.getHeight();
            }
        });

        mMarker = mGoogleMap.addMarker(new MarkerOptions()
                .position(KYIV)
                .icon(getMarkerIcon(mMarkerWidth, mMarkerHeight)));

        mGoogleMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
            @Override
            public void onCameraIdle() {
                if (isMarkerOverlayed()) {
                    // do you magic here:
                    Toast.makeText(MainActivity.this, "Overlapped", Toast.LENGTH_SHORT).show();
                };
            }
        });

    }

    private boolean isMarkerOverlayed() {
        boolean overlayed = false;

        LatLng markerLocation = mMarker.getPosition();
        Projection projection = mGoogleMap.getProjection();
        Point markerScreenPosition = projection.toScreenLocation(markerLocation);

        int smallLayoutTopY = mRootLayoutHeight - mSmallLayoutHeight;

        // 0.8 is 80% of marker height
        if (markerScreenPosition.y >= smallLayoutTopY + 0.8 * mMarkerHeight &&
            markerScreenPosition.y < mRootLayoutHeight) {
            overlayed = true;
        }

        return overlayed;
    }

    private BitmapDescriptor getMarkerIcon(int width, int height) {

        final Drawable iconDrawable = getResources().getDrawable(R.drawable.ic_marker);
        final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        iconDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        iconDrawable.draw(canvas);

        return BitmapDescriptorFactory.fromBitmap(bitmap);
    }

}

你有这样的东西: