Make GoogleMaps marker draggabe and detect moving marker

To make GoogleMaps marker draggabe and detect moving marker:
- Modify MapsActivity to implement GoogleMap.OnMarkerDragListener
- Override onMarkerDragStart(Marker marker), onMarkerDrag(Marker marker) and onMarkerDragEnd(Marker marker), to handle the MarkerDrag events.
- Assign OnMarkerDragListener by calling mMap.setOnMarkerDragListener(this).
- Set markers draggable by calling markerOptions.draggable(true).


Modify MapsActivity.java from last post "Detect touch on GoogleMap, onMapClick() and onMapLongClick()".

MapsActivity.java

package com.blogspot.android_er.androidstudiomapapp;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.InputType;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.Toast;

import com.google.android.gms.common.GoogleApiAvailability;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends AppCompatActivity implements OnMapReadyCallback,
 GoogleMap.OnMapClickListener, GoogleMap.OnMapLongClickListener,
 GoogleMap.OnMarkerDragListener {

 private GoogleMap mMap;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_maps);
 // Obtain the SupportMapFragment and get notified when the map is ready to be used.
 SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
 .findFragmentById(R.id.map);
 mapFragment.getMapAsync(this);

 }

 /**
 * Manipulates the map once available.
 * This callback is triggered when the map is ready to be used.
 * This is where we can add markers or lines, add listeners or move the camera. In this case,
 * we just add a marker near Sydney, Australia.
 * If Google Play services is not installed on the device, the user will be prompted to install
 * it inside the SupportMapFragment. This method will only be triggered once the user has
 * installed Google Play services and returned to the app.
 */
 @Override
 public void onMapReady(GoogleMap googleMap) {
 mMap = googleMap;
 mMap.setOnMapClickListener(this);
 mMap.setOnMapLongClickListener(this);
 mMap.setOnMarkerDragListener(this);
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
 getMenuInflater().inflate(R.menu.activity_main, menu);
 return super.onCreateOptionsMenu(menu);
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
 switch (item.getItemId()) {
 case R.id.menu_addmarkers:
 addMarker();
 return true;
 case R.id.maptypeHYBRID:
 if(mMap != null){
 mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
 return true;
 }
 case R.id.maptypeNONE:
 if(mMap != null){
 mMap.setMapType(GoogleMap.MAP_TYPE_NONE);
 return true;
 }
 case R.id.maptypeNORMAL:
 if(mMap != null){
 mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
 return true;
 }
 case R.id.maptypeSATELLITE:
 if(mMap != null){
 mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
 return true;
 }
 case R.id.maptypeTERRAIN:
 if(mMap != null){
 mMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
 return true;
 }
 case R.id.menu_legalnotices:
 String LicenseInfo = GoogleApiAvailability
 .getInstance()
 .getOpenSourceSoftwareLicenseInfo(MapsActivity.this);
 AlertDialog.Builder LicenseDialog =
 new AlertDialog.Builder(MapsActivity.this);
 LicenseDialog.setTitle("Legal Notices");
 LicenseDialog.setMessage(LicenseInfo);
 LicenseDialog.show();
 return true;
 case R.id.menu_about:
 AlertDialog.Builder aboutDialogBuilder =
 new AlertDialog.Builder(MapsActivity.this);
 aboutDialogBuilder.setTitle("About Me")
 .setMessage("http://android-er.blogspot.com");

 aboutDialogBuilder.setPositiveButton("visit",
 new DialogInterface.OnClickListener() {
 @Override
 public void onClick(DialogInterface dialog, int which) {
 String url = "http://android-er.blogspot.com";
 Intent i = new Intent(Intent.ACTION_VIEW);
 i.setData(Uri.parse(url));
 startActivity(i);
 }
 });

 aboutDialogBuilder.setNegativeButton("Dismiss",
 new DialogInterface.OnClickListener() {
 @Override
 public void onClick(DialogInterface dialog, int which) {
 dialog.cancel();
 }
 });

 AlertDialog aboutDialog = aboutDialogBuilder.create();
 aboutDialog.show();

 return true;
 }
 return super.onOptionsItemSelected(item);
 }

 private void addMarker(){
 if(mMap != null){

 //create custom LinearLayout programmatically
 LinearLayout layout = new LinearLayout(MapsActivity.this);
 layout.setLayoutParams(new LinearLayout.LayoutParams(
 LinearLayout.LayoutParams.MATCH_PARENT,
 LinearLayout.LayoutParams.WRAP_CONTENT));
 layout.setOrientation(LinearLayout.VERTICAL);

 final EditText titleField = new EditText(MapsActivity.this);
 titleField.setHint("Title");

 final EditText latField = new EditText(MapsActivity.this);
 latField.setHint("Latitude");
 latField.setInputType(InputType.TYPE_CLASS_NUMBER
 | InputType.TYPE_NUMBER_FLAG_DECIMAL
 | InputType.TYPE_NUMBER_FLAG_SIGNED);

 final EditText lonField = new EditText(MapsActivity.this);
 lonField.setHint("Longitude");
 lonField.setInputType(InputType.TYPE_CLASS_NUMBER
 | InputType.TYPE_NUMBER_FLAG_DECIMAL
 | InputType.TYPE_NUMBER_FLAG_SIGNED);

 layout.addView(titleField);
 layout.addView(latField);
 layout.addView(lonField);

 AlertDialog.Builder builder = new AlertDialog.Builder(this);
 builder.setTitle("Add Marker");
 builder.setView(layout);
 AlertDialog alertDialog = builder.create();

 builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
 @Override
 public void onClick(DialogInterface dialog, int which) {
 boolean parsable = true;
 Double lat = null, lon = null;

 String strLat = latField.getText().toString();
 String strLon = lonField.getText().toString();
 String strTitle = titleField.getText().toString();

 try{
 lat = Double.parseDouble(strLat);
 }catch (NumberFormatException ex){
 parsable = false;
 Toast.makeText(MapsActivity.this,
 "Latitude does not contain a parsable double",
 Toast.LENGTH_LONG).show();
 }

 try{
 lon = Double.parseDouble(strLon);
 }catch (NumberFormatException ex){
 parsable = false;
 Toast.makeText(MapsActivity.this,
 "Longitude does not contain a parsable double",
 Toast.LENGTH_LONG).show();
 }

 if(parsable){

 LatLng targetLatLng = new LatLng(lat, lon);
 MarkerOptions markerOptions =
 new MarkerOptions().position(targetLatLng).title(strTitle);

 markerOptions.draggable(true);

 mMap.addMarker(markerOptions);
 mMap.moveCamera(CameraUpdateFactory.newLatLng(targetLatLng));

 }
 }
 });
 builder.setNegativeButton("Cancel", null);

 builder.show();
 }else{
 Toast.makeText(MapsActivity.this, "Map not ready", Toast.LENGTH_LONG).show();
 }
 }

 @Override
 public void onMapClick(LatLng latLng) {
 Toast.makeText(MapsActivity.this,
 "onMapClick: " + latLng.latitude + " : " + latLng.longitude,
 Toast.LENGTH_LONG).show();
 }

 @Override
 public void onMapLongClick(LatLng latLng) {
 Toast.makeText(MapsActivity.this,
 "onMapLongClick: " + latLng.latitude + " : " + latLng.longitude,
 Toast.LENGTH_LONG).show();

 //Add marker on LongClick position
 MarkerOptions markerOptions =
 new MarkerOptions().position(latLng).title(latLng.toString());
 markerOptions.draggable(true);

 mMap.addMarker(markerOptions);
 }


 @Override
 public void onMarkerDragStart(Marker marker) {
 marker.setTitle(marker.getPosition().toString());
 marker.showInfoWindow();
 marker.setAlpha(0.5f);
 }

 @Override
 public void onMarkerDrag(Marker marker) {
 marker.setTitle(marker.getPosition().toString());
 marker.showInfoWindow();
 marker.setAlpha(0.5f);
 }

 @Override
 public void onMarkerDragEnd(Marker marker) {
 marker.setTitle(marker.getPosition().toString());
 marker.showInfoWindow();
 marker.setAlpha(1.0f);
 }
}

reference: https://developers.google.com/maps/documentation/android-api/marker

Next: - Custom InfoWindow for Google Maps Android API v2

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~ Step-by-step of Android Google Maps Activity using Google Maps Android API v2, on Android Studio

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