package com.example.mansi.busezon;

    import android.Manifest;
    import android.content.Intent;
    import android.content.pm.PackageManager;
    import android.support.design.widget.FloatingActionButton;
    import android.support.v4.app.ActivityCompat;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.GridLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.view.View;

    import com.example.mansi.busezon.adapters.ImagesAdapter;
    import com.haresh.multipleimagepickerlibrary.MultiImageSelector;

    import java.util.ArrayList;
    import java.util.List;

    public class MainActivity extends AppCompatActivity {

        public void sendMess(View view)
        {
            Intent intent = new Intent(MainActivity.this, SELL_BUY.class);
            startActivity(intent);
        }

        private FloatingActionButton floatingActionButton;
        private RecyclerView recyclerViewImages;
        private GridLayoutManager gridLayoutManager;

        private ArrayList<String> mSelectedImagesList = new ArrayList<>();
        private final int MAX_IMAGE_SELECTION_LIMIT=100;
        private static final int REQUEST_ID_MULTIPLE_PERMISSIONS = 401;
        private final int REQUEST_IMAGE=301;

        private MultiImageSelector mMultiImageSelector;
        private ImagesAdapter mImagesAdapter;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            floatingActionButton = (FloatingActionButton) findViewById(R.id.fab);
            recyclerViewImages = (RecyclerView) findViewById(R.id.recycler_view_images);
            gridLayoutManager = new GridLayoutManager(this, 4);
            recyclerViewImages.setHasFixedSize(true);
            recyclerViewImages.setLayoutManager(gridLayoutManager);


            mMultiImageSelector = MultiImageSelector.create();

            floatingActionButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    if(checkAndRequestPermissions()) {
                        mMultiImageSelector.showCamera(true);
                        mMultiImageSelector.count(MAX_IMAGE_SELECTION_LIMIT);
                        mMultiImageSelector.multi();
                        mMultiImageSelector.origin(mSelectedImagesList);
                        mMultiImageSelector.start(MainActivity.this, REQUEST_IMAGE);

    //                mMultiImageSelector.showCamera(true);
    //                mMultiImageSelector.single();
    //                mMultiImageSelector.origin(mSelectedImagesList);
    //                mMultiImageSelector.start(MainActivity.this, REQUEST_IMAGE);
                    }
                }
            });

        }


        @Override
        public void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if(requestCode == REQUEST_IMAGE){
                try {
                    mSelectedImagesList = data.getStringArrayListExtra(MultiImageSelector.EXTRA_RESULT);
                    mImagesAdapter = new ImagesAdapter(this,mSelectedImagesList);
                    recyclerViewImages.setAdapter(mImagesAdapter);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

        private boolean checkAndRequestPermissions() {
            int externalStoragePermission = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);

            List<String> listPermissionsNeeded = new ArrayList<>();
            if (externalStoragePermission != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
            }

            if (!listPermissionsNeeded.isEmpty()) {
                ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), REQUEST_ID_MULTIPLE_PERMISSIONS);
                return false;
            }
            return true;
        }

        @Override
        public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
            if (requestCode == REQUEST_ID_MULTIPLE_PERMISSIONS) {
                floatingActionButton.performClick();
            }
        }


    }

=================

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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="com.example.mansi.busezon.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:tint="@android:color/white"
        app:srcCompat="@android:drawable/ic_input_add" />
</android.support.constraint.ConstraintLayout>

============

<?xml version="1.0" encoding="utf-8"?>
<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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.mansi.busezon.Add_product"
    tools:showIn="@layout/activity_main">
   <android.support.v7.widget.RecyclerView
       android:id="@+id/recycler_view_images"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:layout_margin="@dimen/fab_margin"/>

</RelativeLayout>

========================

<?xml version="1.0" encoding="utf-8"?>
<com.haresh.multipleimagepickerlibrary.views.SquareFrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="5dp">

    <com.e.multipleimagepickerlibrary.views.SquaredImageView
        android:id="@+id/image_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerInside"
        android:src="@drawable/default_error"/>


</com.haresh.multipleimagepickerlibrary.views.SquareFrameLayout>