How to Resize and Reposition 'ImageView' by Screen Scale remain its ratio

Question

🌟Text Code of MainActivity.java and activity_main.xml exist at the bottom of the article🌟

I am going to set Images that have the same ratio (16:9) to ImageView, But I met up with a small problem.

I want to set My ImageView remain 16:9 ratio, which of the picture being handed over(1920 * 1080)

if I use wrap_content, it remains ratio of the given picture, But I can't resize the size of ImageView.

.

if I use fixed numbers that remain 16:9 ratio like 400dp * 225dp
I can resize the size I want, and modify the position by Screen scale by using app:layout_constraintHorizontal_bias= and app:layout_constraintVertical_bias=

But in other Device, the Size of ImageView is too small or too big for its Screen Space. because the value is fixed

So, I Want to set ImageView Size and Position by Device's Screen Scale with remaining its ratio(16:9) How can I do it?

I've looked at a number of questions, but I've found a way "to match the imageView ratio to the picture" not "to set the size of ImageView relative to the size of the screen" cause my poor at searching.

Is there any method way to express as follows? this is not real code, it is just pseudo-code to explain easily what I really want to make.

android:layout_width="wrapcontent * 0.8"
android:layout_height="wrapcontent * 0.8"  //<!-- same as "layout_width * 9 / 16 " because ratio of give picture will be always 16 : 9 -->

app:layout_constraintHorizontal_bias=" ((Screen_width - ImageView_width) / 2) / 100 " //<!-- pseudo percentage that to stay in Screen's center -->
app:layout_constraintVertical_bias= "0.3" //<!-- pseudo percentage that to stay in Screen's custom upper part-->

I apologize for the confusion in your explanation and hope you have a peaceful day. MainActivity.The code for java and activity_main.xml is below.

MainActivity.java

package com.example.catexample;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // I Want to Resize and Reposition 'ImageView' by Screen Scale remain its ratio( 16 : 9)
        ImageView imageView = findViewById(R.id.kitti_DD);
    }

}

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/kitti_DD"
        android:layout_width="400dp"
        android:layout_height="225dp"
        android:adjustViewBounds="true"
        android:scaleType="fitCenter"

        app:layout_constraintHorizontal_bias="0.1"
        app:layout_constraintVertical_bias="0.3"

        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"

        app:srcCompat="@drawable/kittisaurus_dd" />

</androidx.constraintlayout.widget.ConstraintLayout>

kittisaurus_dd.jpg

ps.The cute cat's name used as an example is DD and it originated from a video of a 크집사 ,not 크림히어로즈.

Thank you from the bottom of my heart for reading the long article!😻

Answer 1

Set the width and height to 0dp and add the app:layout_constraintDimensionRatio attribute and set its value to your desired aspect ratio, e.g.: 4:3, 16:9, etc.