Pick Color From Image with TouchEvents in Android
Last Updated :
25 Aug, 2021
In this article, we are going to learn how to get touched pixel color on an image. A Screenshot is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Kotlin language.
Step by Step Implementation
Step 1: To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.
Step 2: Set any image in the layout
Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.
XML
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--Image form which we will pick color-->
<ImageView
android:id="@+id/pickColorImage"
android:layout_width="match_parent"
android:layout_height="255dp"
android:layout_marginTop="10dp"
android:contentDescription="Image to pick color"
android:scaleType="fitStart"
android:src="@drawable/gfg"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:layout_marginTop="20dp"
android:orientation="horizontal"
app:layout_constraintTop_toBottomOf="@id/pickColorImage">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Picked Color: "
android:textColor="@color/black"
android:textSize="20sp" />
<!-- color name in Hexadecimal -->
<TextView
android:id="@+id/colorInHex"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#fffffff"
android:textSize="20sp" />
<!-- show the picked color -->
<View
android:id="@+id/fillColor"
android:layout_width="match_parent"
android:layout_height="20dp"
android:layout_marginStart="8dp"
app:layout_constraintTop_toBottomOf="@id/pickColorImage" />
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
Step 3: Working with the MainActivity.kt file
Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.
Kotlin
import android.annotation.SuppressLint
import android.graphics.Bitmap
import android.graphics.Color
import android.os.Bundle
import android.view.MotionEvent
import android.view.View
import android.widget.ImageView
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
lateinit var image: ImageView
lateinit var bitmap: Bitmap
lateinit var colorView: View
lateinit var colorString: TextView
@SuppressLint("ClickableViewAccessibility")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
image = findViewById(R.id.pickColorImage)
colorView = findViewById(R.id.fillColor)
colorString = findViewById(R.id.colorInHex)
image.isDrawingCacheEnabled = true
image.buildDrawingCache(true)
// on touch listener on image view
image.setOnTouchListener { _, event ->
if (event.action == MotionEvent.ACTION_DOWN || event.action == MotionEvent.ACTION_MOVE) {
bitmap = image.drawingCache
// get touched pixel
val pixel = bitmap.getPixel(event.x.toInt(), event.y.toInt())
// get RGB values from the touched pixel
val r = Color.red(pixel)
val g = Color.green(pixel)
val b = Color.blue(pixel)
// color name in Hexadecimal(#RRGGBB)
colorString.text = "#${Integer.toHexString(pixel)}"
// fill the color in the view
colorView.setBackgroundColor(Color.rgb(r, g, b))
}
true
}
}
}
Now, run the app
Output:
Source Code: Click Here