Google Maps API. Projection

Question

I'm trying to drag ImageView to google map and drop it as a marker. Map is in FrameLayout:

   <FrameLayout
        android:id="@+id/map_frg"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="2">

I've set to this FrameLayout OnDragListener:

private class PinDragListener implements View.OnDragListener {

        private GoogleMap map;

        public PinDragListener(GoogleMap map) {
            this.map = map;
        }

        @Override
        public boolean onDrag(View v, DragEvent event) {
            switch (event.getAction()) {
                case DragEvent.ACTION_DROP:
                    MarkerOptions markerOptions = new MarkerOptions()
                            .draggable(true)
                            .anchor(0.0f, 1.0f);
                    int[] coords = new int[2];
                    v.getLocationOnScreen(coords);
                    Projection projection = map.getProjection();
                    LatLng latLng = projection.fromScreenLocation(new Point(coords[0], coords[1]));
                    markerOptions.position(latLng);
                    markerOptions.visible(true);
                    map.addMarker(markerOptions);
                    break;
                default:
                    break;
            }
            return true;
        }
    }

But when image was dropped somewhere marker placed in the left corner again and again. What can be wrong?

UPDATE:

I've passed dragged view via listener

private class PinTouchListener implements OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_DOWN) {
                ClipData data = ClipData.newPlainText("", "");
                DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(v);
                v.startDrag(data, shadowBuilder, v, 0);
                dragPinListener.onViewTouched(v);
                return true;
            } else {
                return false;
            }
        }
    }

and I've got such coordinates every time I dropped marker

x = 0 | y = 1234
 Lat = 65.96291676309829 | Lng = -18.548969998955727

score 1 · Answer 1 · answered Mar 04 '16 at 11:20

The OnDragListener.onDrag() method will get called for each specific event that occurs during the drag-and-drag process, passing in a DragEvent to describe the specifics of each event. Each DragEvent will have one of the following actions:

ACTION_DRAG_LOCATION : Sent to a view between ACTION_DRAG_ENTERED and　ACTION_DRAG_EXITED with the current location of the drag inside that view. ・ The location can be obtained with getX() and getY().

How It Works Here are example of the drag-and-drop functionality, We have created a custom ImageView that implements the OnDragListener interface.

Please refer to the following this link: http://www.tutorialspoint.com/android/android_drag_and_drop.htm https://github.com/wada811/Android-View-Drag-And-Drop-Sample/blob/master/app/src/main/java/com/wada811/android_view_drag_and_drop_sample/DragAndDropFrameLayout.java

Hope it helps.

score 0 · Accepted Answer · answered Mar 03 '16 at 09:55

0

I need to use event.getX() and event.getY() in onDrag method in OnDragListener to retrieve current view screen location.

answered Mar 03 '16 at 09:55

Lay'O

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Google Maps API. Projection

2 Answers2