Wednesday, February 19, 2020

android kotlin ktx - Scale bitmap example

MainActivity.kt 

package com.example.jetpack

import android.graphics.BitmapFactory
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.core.graphics.scale
import kotlinx.android.synthetic.main.activity_main.*


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // get bitmap from drawable resource
        val bitmap = BitmapFactory.decodeResource(resources,R.drawable.cfsuman)

        // scale bitmap using android ktx
        val scaledBitmap = bitmap.scale(
            300, // width
            300, // height
            false // filter
        )

        imageView.setImageBitmap(bitmap)
        imageView2.setImageBitmap(scaledBitmap)
    }
}
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"
    tools:context=".MainActivity">
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@tools:sample/avatars[4]" />
    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView"
        tools:srcCompat="@tools:sample/avatars[13]" />
</androidx.constraintlayout.widget.ConstraintLayout>
build.gradle dependencies[add] 

// android ktx
implementation 'androidx.core:core-ktx:1.2.0'
build.gradle [add] 

android {
    kotlinOptions {
        jvmTarget = JavaVersion.VERSION_1_8.toString()
    }
}
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