sample app

app/build.gradle

@@ -31,4 +31,5 @@ dependencies {
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
     implementation project(':draw')
+    implementation 'com.android.support:design:27.1.1'
 }

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.divyanshu.androiddraw">
 
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/com/divyanshu/androiddraw/DrawAdapter.kt

@@ -0,0 +1,31 @@
+package com.divyanshu.androiddraw
+
+import android.content.res.Resources
+import android.net.Uri
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ImageView
+
+class DrawAdapter(private val filePath: ArrayList<String>) : RecyclerView.Adapter<DrawAdapter.ViewHolder>(){
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
+        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_view,parent,false)
+        return ViewHolder(view)
+    }
+
+    override fun getItemCount(): Int {
+        return filePath.size
+    }
+
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+        val path = filePath[holder.adapterPosition]
+        holder.drawImage.setImageURI(Uri.parse(path))
+    }
+
+    class ViewHolder(itemView: View):RecyclerView.ViewHolder(itemView) {
+        val drawImage: ImageView = itemView.findViewById(R.id.image_draw)
+    }
+
+}

app/src/main/java/com/divyanshu/androiddraw/MainActivity.kt

@@ -1,17 +1,70 @@
 package com.divyanshu.androiddraw
 
+import android.app.Activity
 import android.content.Intent
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.net.Uri
 import android.support.v7.app.AppCompatActivity
 import android.os.Bundle
+import android.os.Environment
+import android.support.v7.widget.GridLayoutManager
 import com.divyanshu.draw.activity.DrawingActivity
+import kotlinx.android.synthetic.main.activity_main.*
+import java.io.File
+import java.io.FileOutputStream
+import java.util.*
+import kotlin.collections.ArrayList
+
+private const val REQUEST_CODE_DRAW = 101
 
 class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
-        startActivity(Intent(this, DrawingActivity::class.java))
+        recycler_view.layoutManager = GridLayoutManager(this,2)
+        recycler_view.adapter = DrawAdapter(getFilePath())
+
+        fab_add_draw.setOnClickListener {
+            val intent = Intent(this, DrawingActivity::class.java)
+            startActivityForResult(intent, REQUEST_CODE_DRAW)
+        }
+    }
+
+    private fun getFilePath(): ArrayList<String>{
+        val resultList = ArrayList<String>()
+        val imageDir = "${Environment.DIRECTORY_PICTURES}/Android Draw/"
+        val path = Environment.getExternalStoragePublicDirectory(imageDir)
+        val imageList = path.listFiles()
+        for (imagePath in imageList){
+            resultList.add(imagePath.absolutePath)
+        }
+        return resultList
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        if (data != null && resultCode == Activity.RESULT_OK) {
+            when(requestCode){
+                REQUEST_CODE_DRAW -> {
+                    val result= data.getByteArrayExtra("bitmap")
+                    val bitmap = BitmapFactory.decodeByteArray(result, 0, result.size)
+                    saveImage(bitmap)
+                }
+            }
+        }
+    }
 
+    private fun saveImage(bitmap: Bitmap) {
+        val imageDir = "${Environment.DIRECTORY_PICTURES}/Android Draw/"
+        val path = Environment.getExternalStoragePublicDirectory(imageDir)
+        val file = File(path, UUID.randomUUID().toString()+".png")
+        path.mkdirs()
+        file.createNewFile()
+        val outputStream = FileOutputStream(file)
+        bitmap.compress(Bitmap.CompressFormat.PNG,100,outputStream)
+        outputStream.flush()
+        outputStream.close()
     }
 }

app/src/main/res/layout/activity_main.xml

@@ -6,13 +6,21 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
-    <TextView
+    <android.support.v7.widget.RecyclerView
+        android:id="@+id/recycler_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        />
+
+    <android.support.design.widget.FloatingActionButton
+        android:id="@+id/fab_add_draw"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Hello World!"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        android:layout_margin="16dp"
+        android:src="@android:drawable/ic_input_add"
+        android:tint="@color/color_white" />
 
 </android.support.constraint.ConstraintLayout>

app/src/main/res/layout/item_view.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <ImageView
+        android:id="@+id/image_draw"
+        android:layout_width="match_parent"
+        android:layout_height="240dp"
+        android:scaleType="centerCrop" />
+
+</android.support.constraint.ConstraintLayout>

app/src/main/res/values/colors.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="colorPrimary">#000</color>
-    <color name="colorPrimaryDark">#000</color>
-    <color name="colorAccent">#1976D2</color>
+    <color name="colorPrimary">#FFFFFF</color>
+    <color name="colorPrimaryDark">#CCCCCC</color>
+    <color name="colorAccent">#000</color>
+    <color name="titleColor">#212121</color>
 </resources>

app/src/main/res/values/styles.xml

@@ -1,7 +1,7 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+    <style name="AppTheme" parent="Theme.AppCompat.Light">
         <!-- Customize your theme here. -->
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>