MainActivity.kt
package com.cfsuman.kotlintutorials
import android.app.Activity
import android.content.Context
import android.graphics.*
import android.os.Bundle
import android.widget.*
import java.io.IOException
import kotlin.math.min
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// get the widgets reference from XML layout
val imageView = findViewById<ImageView>(R.id.imageView)
val imageView2 = findViewById<ImageView>(R.id.imageView2)
// get the bitmap from assets folder
val bitmap = assetsToBitmap("flower103.jpg")
bitmap?.apply {
// show original bitmap in first image view
imageView.setImageBitmap(this)
// crop circular area from bitmap
imageView2.setImageBitmap(cropCircularArea())
}
}
}
// extension function to get bitmap from assets
fun Context.assetsToBitmap(fileName:String):Bitmap?{
return try {
val stream = assets.open(fileName)
BitmapFactory.decodeStream(stream)
} catch (e: IOException) {
e.printStackTrace()
null
}
}
// extension function to crop circular area from bitmap
fun Bitmap.cropCircularArea():Bitmap?{
val bitmap = Bitmap.createBitmap(
width, // width in pixels
height, // height in pixels
Bitmap.Config.ARGB_8888
)
val canvas = Canvas(bitmap)
// create a circular path
val path = Path()
val radius = min(width/2f,height/2f)
path.apply {
addCircle(
width/2f,
height/2f,
radius,
Path.Direction.CCW
)
}
// draw circular bitmap on canvas
canvas.clipPath(path)
canvas.drawBitmap(this,0f,0f,null)
val diameter = (radius*2).toInt()
val x = (width - diameter)/2
val y = (height - diameter)/2
// return cropped circular bitmap
return Bitmap.createBitmap(
bitmap, // source bitmap
x, // x coordinate of the first pixel in source
y, // y coordinate of the first pixel in source
diameter, // width
diameter // height
)
}
activity_main.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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rootLayout"
android:background="#DCDCDC"
android:padding="24dp">
<ImageView
android:id="@+id/imageView"
android:layout_width="0dp"
android:layout_height="250dp"
android:layout_marginTop="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text="Original Bitmap"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@+id/imageView"
app:layout_constraintTop_toBottomOf="@+id/imageView" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="0dp"
android:layout_height="250dp"
android:layout_marginTop="24dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text="Bitmap Crop Circular Area"
app:layout_constraintEnd_toEndOf="@+id/imageView2"
app:layout_constraintStart_toStartOf="@+id/imageView2"
app:layout_constraintTop_toBottomOf="@+id/imageView2" />
</androidx.constraintlayout.widget.ConstraintLayout>
- android kotlin - BitmapShader example
- android kotlin - Bitmap tint solid color
- android kotlin - Bitmap mask
- android kotlin - Bitmap crop square
- android kotlin - Rounded corners bitmap
- android kotlin - Circular bitmap with border
- android kotlin - Bitmap add border
- android kotlin - Draw rectangle on bitmap
- android kotlin - Draw line on bitmap
- android kotlin - Draw circle on bitmap
- android kotlin - Bitmap remove transparency
- android kotlin - Bitmap color balance
- android kotlin - Bitmap blur effect
- android kotlin - Bitmap change saturation
- android kotlin - Bitmap rotate color axis