Develop Reference

Full height square element in android

I would like to have a square (same width as height) GridView fill the full height of the screen in landscape orientation. The Gridview is a chessboard (8 by 8 squares) with the xml:
<com.example.jens.jchess2.view.MyGridView
android:id="#+id/chessboard"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="0dp"
android:numColumns="8"
android:verticalSpacing="0dp"
android:horizontalSpacing="0dp">
</com.example.jens.jchess2.view.MyGridView>
and the elements of the grid are:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/square"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#000080"
android:orientation="vertical"
android:padding="0pt">
<ImageView
android:id="#+id/square_background"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:padding="0pt" />
<ImageView
android:id="#+id/piece"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:adjustViewBounds="true"
android:padding="0pt" />
</FrameLayout>
, where the ImageViews correspond to the squares and pieces (both from png images) of the board.
In the custom MyGridView I override onMeasure as follows:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = getContext().getResources().getDisplayMetrics().heightPixels;
if (width > height) {
super.onMeasure(
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY)
);
} else {
super.onMeasure(
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY)
);
}
}
which gives me a square GridView in both portrait and landscape orientation. In portrait mode it fills the full width and everything is fine. In landscape mode however it extends below the screen because the height (=width) of the GridView/board is too large. It is too large by the height of the toolbar and the height of the statusbar. How can I get the proper size for the GridView, i.e. screen height minus status bar height minus toolbar height?

Start with two versions of your layout file:
/res/layout/grid.xml
...
<!-- full width -->
<com.example.MyGridView
android:layout_width="match_parent"
android:layout_height="wrap_content"
...
/>
...
/res/layout-land/grid.xml
...
<!-- full height -->
<com.example.MyGridView
android:layout_width="wrap_content"
android:layout_height="match_parent"
...
/>
...
You probably already have something like this.
Now in your onMeasure() override, the match_parent dimension will have a MeasureSpec mode of EXACTLY and the wrap_content dimension will have a MeasureSpec mode of AT_MOST. You can use this to achieve your desired layout.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (widthMode == MeasureSpec.EXACTLY && heightMode == MeasureSpec.AT_MOST) {
// portrait
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
} else if (heightMode == MeasureSpec.EXACTLY && widthMode == MeasureSpec.AT_MOST) {
// landscape
super.onMeasure(heightMeasureSpec, heightMeasureSpec);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
EDIT: I found out that both modes can be AT_MOST depending on the ViewGroup container. Please see my other answer for updated measuring code.

Ah. Now I see that this is for a game.
Sometimes it's better to have layouts and child views, but in most cases with game boards you are better off creating a single View subclass that represents the game view.
For instance, what if your users say they want the ability to pinch-zoom into one quadrant of the game board? You can't do that with a GridView.
I whipped up a simple app to show you how this can work. I simplified the onMeasure() code I posted before, and instead of a GridView, a single View subclass renders the game board.
The MainActivity simply sets up the content view.
/res/layout/activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.gameboard.MainActivity">
<com.example.gameboard.GameBoardView
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
/res/layout-land/activity_main.xml:
Notice match_parent and wrap_content are switched for width and height.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.gameboard.MainActivity">
<com.example.gameboard.GameBoardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true" />
</RelativeLayout>
GameBoardView.java:
public class GameBoardView extends View {
private Paint mPaint;
public GameBoardView(Context context) {
super(context);
}
public GameBoardView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public GameBoardView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public GameBoardView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int size = Math.min(width, height);
int sizeMeasureSpec = MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY);
super.onMeasure(sizeMeasureSpec, sizeMeasureSpec);
mPaint = new Paint();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int w = getWidth() / 8;
int h = getHeight() / 8;
for (int row = 0; row < 8; row++) {
for (int col = 0; col < 8; col++) {
// choose black or white depending on the square
mPaint.setColor((row + col) % 2 == 0 ? 0xFFFFFFFF : 0xFF000000);
canvas.drawRect(w * col, h * row, w * (col + 1), h * (row + 1), mPaint);
}
}
}
}
Here I'm just drawing the squares right in the view. Now, if I were making a chess game, I would also create a Drawable subclass that would take the game model and render it. Having a separate Drawable for rendering the game makes it easy to scale to the correct size. For example, your Drawable could render at a fixed constant size, then be scaled by the View subclass to fit. The View subclass would function mostly as a controller, interpreting touch events and updating the game model.

ImageView height relative to width

I have this layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
style="#style/AppTheme.Widgets.Box"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:layout_width="match_parent"
android:layout_height="2dp"
android:scaleType="centerCrop"
android:background="#eee"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="7dp"
android:gravity="center"/>
</LinearLayout>
So, I am loading remote images into ImageView from web. I know the dimensions of the image so i know width:height ratio. Now I need to somehow apply this ration when I am initializing my layout so it doesnt jump like crazy later in the app.

For such case I've created a custom ImageView that maintains it's height relative to width. It has the custom attribute 'height_ratio' that's multiplied by width to get height:
DynamicHeightImageView.java:
/**
* An {#link android.widget.ImageView} layout that maintains a consistent width to height aspect ratio.
*/
public class DynamicHeightImageView extends ImageView {
private float mHeightRatio;
public DynamicHeightImageView(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.DynamicHeightImageView, 0, 0);
try {
mHeightRatio = ta.getFloat(R.styleable.DynamicHeightImageView_height_ratio, 0.0f);
} finally {
ta.recycle();
}
}
public DynamicHeightImageView(Context context) {
super(context);
}
public void setHeightRatio(float ratio) {
if (ratio != mHeightRatio) {
mHeightRatio = ratio;
requestLayout();
}
}
public double getHeightRatio() {
return mHeightRatio;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (mHeightRatio > 0.0f) {
// set the image views size
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = (int) (width * mHeightRatio);
setMeasuredDimension(width, height);
}
else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
attrs.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="DynamicHeightImageView">
<attr name="height_ratio" format="float"/>
</declare-styleable>
</resources>
Usage:
<com.melnykov.android.views.DynamicHeightImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
custom:height_ratio="0.6"/>

If you use CENTER_INSIDE as scale type, the image will be scaled so that the aspect ratio is preserved and the image fits into the "frame" of the image view that you have defined with layout_width and layout_height. But are you sure that you want your image 2dp high at maximum?

Since you know the dimensions of your image. You can set the image view's dimension programmatically converting pixels into dp
Refer this Convert Pixels to DP

As an improvement (as I see it) to makovkastar's answer:
I've tried to make the whole thing a little more simple, wrote it in Kotlin and made it so that the height and width aspects are set as integers as to be more precise by using fractions instead of floating point numbers:
/**
* An [android.widget.ImageView] layout that maintains a consistent width to height aspect ratio.
*/
class DynamicHeightImageView #JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : ImageView(context, attrs, defStyleAttr) {
private var heightFactor : Int
private var widthFactor : Int
init {
context.theme.obtainStyledAttributes(attrs, R.styleable.DynamicHeightImageView, 0, 0).apply {
heightFactor = getInt(R.styleable.DynamicHeightImageView_heightFactor, 1)
widthFactor = getInt(R.styleable.DynamicHeightImageView_widthFactor, 1)
}
}
/**
* Adjusts the [getHeight] relative to the [getWidth], according to [heightFactor] and [widthFactor].
*/
override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
super.onLayout(changed, left, top, right, bottom)
layoutParams.height = (width.toFloat() * heightFactor / widthFactor).toInt()
}
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="DynamicHeightImageView">
<attr name="heightFactor" format="integer"/>
<attr name="widthFactor" format="integer"/>
</declare-styleable>
</resources>

How to scale ImageView width

This is my layout file
<LinearLayout ...
<ImageView
android:id="#+id/feed_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
android:adjustViewBounds="true"
android:contentDescription="#string/image_content_description" />
But ImageView width does not match parent width. (width is image source width)
Image Source loaded Lazy-loading from url.
How to scale the width of image view regadless image source ?
I want
Width = match(or fill) parent.
Height = auto-scaled

You can achieve this in two ways:
If your image is larger than the ImageView you can use xml only
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="fitCenter"
android:adjustViewBounds="true"/>
If your image is smaller than the ImageView
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="fitXY"
android:adjustViewBounds="true"/>
With the second option you have to measure the width and height of the image and set the height of the ImageView in your code, according to the actual width of the image view (same ratio).

You can use android:scaletype="fitXY" property of imageview
2.default Android will scale your image down to fit the ImageView, maintaining the aspect ratio. However, make sure you're setting the image to the ImageView using android:src="..." rather than android:background="...". src= makes it scale the image maintaining aspect ratio, but background= makes it scale and distort the image to make it fit exactly to the size of the ImageView. (You can use a background and a source at the same time though, which can be useful for things like displaying a frame around the main image, using just one ImageView.)

If you want to fit the image in view use android:scaleType="fitXY"

You can achieve this with this, create new AspectRatioImageView that extends imageView:
public class AspectRatioImageView extends ImageView {
public AspectRatioImageView(Context context) {
super(context);
}
public AspectRatioImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public AspectRatioImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable drw = getDrawable();
if (null == drw || drw.getIntrinsicWidth() <= 0) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
} else {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = width * drw.getIntrinsicHeight() / drw.getIntrinsicWidth();
setMeasuredDimension(width, height);
}
}
}
And then in your layout xml use :
<my.app.AspectRatioImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/ar_imageview"/>

<ImageView
android:id="#+id/idImage"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="fitXY"/>
calculate the height according to the aspect ratio that you want
Display display = getActivity().getWindowManager().getDefaultDisplay();
int height = (display.getWidth() * 9) /16; // in this case aspect ratio 16:9
ImageView image = (ImageView) findViewById(R.id.idImage);
image.getLayoutParams().height = height;

Android ImageView: Fit Width

I download image and set it as a screen background dynamically using Imageview. I have tried ScaleType, to scale the image.
If image height is larger than width then ScaleTypes fitStart, fitEnd and fitCenter don't work. Android scale down the photo and fit it based on the height, but I see some extra blank space as part of the width.
I want to scale down the photo based on the width so that it fits the width and I don't care if there's some extra blank space as part of the height or if height is too long it is fine if it's going out of the view(if that's possible?).
ScaleType.XY scale the photo and fit everything in the ImageView and doesn't care about image height/weight ratio.
<ImageView
android:id="#+id/background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="fitStart"
/>

I ended up using this code:
<ImageView
android:id="#+id/background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"
android:src="#drawable/name"
/>
Make sure you set the image using src instead of background.

android:adjustViewBounds="true" does the job!

This elegant solution found here will work like a charm for you.
Basically you just have to create a small class that extends ImageView and simply override the onMeasure method to adjust the width and height as you want. Here it scales to fit width by using:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
setMeasuredDimension(width, height);
}
You would use this special ImageView like this:
<your.activity.package.AspectRatioImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_vertical"
android:src="#drawable/test" />

There is a simple method if you simply want to fill the width of screen and have height proportional (and know the ratio of the image) you can do this in OnCreate():
setContentView(R.layout.truppview_activity);
trupImage = (ImageView) findViewById(R.id.trupImage);
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics();
display.getMetrics(outMetrics);
float scWidth = outMetrics.widthPixels;
trupImage.getLayoutParams().width = (int) scWidth;
trupImage.getLayoutParams().height = (int) (scWidth * 0.6f);
Where 0.6 is the ratio adjustment (you could also calc automatically of course if you know the w & h of image).
PS:
Here is the XML side:
<ImageView
android:id="#+id/trupImage"
android:layout_width="match_parent"
android:background="#color/orange"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="fitCenter" />

if you want to fit the image whole parent block
it will stretch the image
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
And if you want to fit image whole parent with original ratio of image
it will crop out some part of image
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"

This works for me.
Create a class extends ImageView
package com.yourdomain.utils;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
public class ResizableImageView extends ImageView {
public ResizableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable d = getDrawable();
if (d != null) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
setMeasuredDimension(width, height);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
In xml use the following instead of ImageView
<com.yourdomain.utils.ResizableImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="#drawable/test" />

I think you cant do it only with XML, you need to resize yourself, the bitmap
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
try {
((ImageView) findViewById(R.id.background))
.setImageBitmap(ShrinkBitmap(width));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
then
private Bitmap ShrinkBitmap(int width)
throws FileNotFoundException {
BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
bmpFactoryOptions.inJustDecodeBounds = true;
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.img, bmpFactoryOptions);
int widthRatio = (int) android.util.FloatMath
.ceil(bmpFactoryOptions.outWidth / (float) width);
bmpFactoryOptions.inSampleSize = widthRatio;
if (bmpFactoryOptions.inSampleSize <= 0)
bmpFactoryOptions.inSampleSize = 0;
bmpFactoryOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;
bmpFactoryOptions.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.img, bmpFactoryOptions);
return bitmap;
}
And the layout
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/background"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

Fixed aspect ratio View

How would I go implementing a fixed aspect ratio View? I'd like to have items with 1:1 aspect ratio in a GridView. I think it's better to subclass the children than the GridView?
EDIT: I assume this needs to be done programmatically, that's no problem. Also, I don't want to limit the size, only the aspect ratio.

I implemented FixedAspectRatioFrameLayout, so I can reuse it and have any hosted view be with fixed aspect ratio:
public class FixedAspectRatioFrameLayout extends FrameLayout
{
private int mAspectRatioWidth;
private int mAspectRatioHeight;
public FixedAspectRatioFrameLayout(Context context)
{
super(context);
}
public FixedAspectRatioFrameLayout(Context context, AttributeSet attrs)
{
super(context, attrs);
init(context, attrs);
}
public FixedAspectRatioFrameLayout(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
init(context, attrs);
}
private void init(Context context, AttributeSet attrs)
{
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FixedAspectRatioFrameLayout);
mAspectRatioWidth = a.getInt(R.styleable.FixedAspectRatioFrameLayout_aspectRatioWidth, 4);
mAspectRatioHeight = a.getInt(R.styleable.FixedAspectRatioFrameLayout_aspectRatioHeight, 3);
a.recycle();
}
// **overrides**
#Override protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)
{
int originalWidth = MeasureSpec.getSize(widthMeasureSpec);
int originalHeight = MeasureSpec.getSize(heightMeasureSpec);
int calculatedHeight = originalWidth * mAspectRatioHeight / mAspectRatioWidth;
int finalWidth, finalHeight;
if (calculatedHeight > originalHeight)
{
finalWidth = originalHeight * mAspectRatioWidth / mAspectRatioHeight;
finalHeight = originalHeight;
}
else
{
finalWidth = originalWidth;
finalHeight = calculatedHeight;
}
super.onMeasure(
MeasureSpec.makeMeasureSpec(finalWidth, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(finalHeight, MeasureSpec.EXACTLY));
}
}

For new users, here's a better non-code solution :
A new support library called Percent Support Library is available in Android SDK v22 (MinAPI is 7 me thinks, not sure) :
src : android-developers.blogspot.in
The Percent Support Library provides percentage based dimensions and margins and, new to this release, the ability to set a custom aspect ratio via app:aspectRatio. By setting only a single width or height and using aspectRatio, the PercentFrameLayout or PercentRelativeLayout will automatically adjust the other dimension so that the layout uses a set aspect ratio.
To include add this to your build.gradle :
compile 'com.android.support:percent:23.1.1'
Now wrap your view (the one that needs to be square) with a PercentRelativeLayout / PercentFrameLayout :
<android.support.percent.PercentRelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
app:layout_aspectRatio="100%"
app:layout_widthPercent="100%"/>
</android.support.percent.PercentRelativeLayout>
You can see an example here.

To not use third-party solution and considering the fact that both PercentFrameLayout and PercentRelativeLayout were deprecated in 26.0.0, I'd suggest you to consider using ConstraintLayout as a root layout for your grid items.
Your item_grid.xml might look like:
<android.support.constraint.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="wrap_content">
<ImageView
android:id="#+id/imageview_item"
android:layout_width="0dp"
android:layout_height="0dp"
android:scaleType="centerCrop"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintDimensionRatio="H,1:1" />
</android.support.constraint.ConstraintLayout>
As a result you get something like this:

I recently made a helper class for this very problem and wrote a blog post about it.
The meat of the code is as follows:
/**
* Measure with a specific aspect ratio<br />
* <br />
* #param widthMeasureSpec The width <tt>MeasureSpec</tt> passed in your <tt>View.onMeasure()</tt> method
* #param heightMeasureSpec The height <tt>MeasureSpec</tt> passed in your <tt>View.onMeasure()</tt> method
* #param aspectRatio The aspect ratio to calculate measurements in respect to
*/
public void measure(int widthMeasureSpec, int heightMeasureSpec, double aspectRatio) {
int widthMode = MeasureSpec.getMode( widthMeasureSpec );
int widthSize = widthMode == MeasureSpec.UNSPECIFIED ? Integer.MAX_VALUE : MeasureSpec.getSize( widthMeasureSpec );
int heightMode = MeasureSpec.getMode( heightMeasureSpec );
int heightSize = heightMode == MeasureSpec.UNSPECIFIED ? Integer.MAX_VALUE : MeasureSpec.getSize( heightMeasureSpec );
if ( heightMode == MeasureSpec.EXACTLY && widthMode == MeasureSpec.EXACTLY ) {
/*
* Possibility 1: Both width and height fixed
*/
measuredWidth = widthSize;
measuredHeight = heightSize;
} else if ( heightMode == MeasureSpec.EXACTLY ) {
/*
* Possibility 2: Width dynamic, height fixed
*/
measuredWidth = (int) Math.min( widthSize, heightSize * aspectRatio );
measuredHeight = (int) (measuredWidth / aspectRatio);
} else if ( widthMode == MeasureSpec.EXACTLY ) {
/*
* Possibility 3: Width fixed, height dynamic
*/
measuredHeight = (int) Math.min( heightSize, widthSize / aspectRatio );
measuredWidth = (int) (measuredHeight * aspectRatio);
} else {
/*
* Possibility 4: Both width and height dynamic
*/
if ( widthSize > heightSize * aspectRatio ) {
measuredHeight = heightSize;
measuredWidth = (int)( measuredHeight * aspectRatio );
} else {
measuredWidth = widthSize;
measuredHeight = (int) (measuredWidth / aspectRatio);
}
}
}

I created a layout library using TalL's answer. Feel free to use it.
RatioLayouts
Installation
Add this to the top of the file
repositories {
maven {
url "http://dl.bintray.com/riteshakya037/maven"
}
}
dependencies {
compile 'com.ritesh:ratiolayout:1.0.0'
}
Usage
Define 'app' namespace on root view in your layout
xmlns:app="http://schemas.android.com/apk/res-auto"
Include this library in your layout
<com.ritesh.ratiolayout.RatioRelativeLayout
android:id="#+id/activity_main_ratio_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:fixed_attribute="WIDTH" // Fix one side of the layout
app:horizontal_ratio="2" // ratio of 2:3
app:vertical_ratio="3">
Update
With introduction of ConstraintLayout you don't have to write either a single line of code or use third-parties or rely on PercentFrameLayout which were deprecated in 26.0.0.
Here's the example of how to keep 1:1 aspect ratio for your layout using ConstraintLayout:
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginEnd="0dp"
android:layout_marginStart="0dp"
android:layout_marginTop="0dp"
android:background="#android:color/black"
app:layout_constraintDimensionRatio="H,1:1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</LinearLayout>
</android.support.constraint.ConstraintLayout>

I've used and liked Jake Wharton's implementation of ImageView (should go similarly for other views), others might enjoy it too:
AspectRatioImageView.java - ImageView that respects an aspect ratio applied to a specific measurement
Nice thing it's styleable in xml already.

Simply override onSizeChanged and calculate ratio there.
Formula for aspect ratio is:
newHeight = original_height / original_width x new_width
this would give you something like that:
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
//3:5 ratio
float RATIO = 5/3;
setLayoutParams(new LayoutParams((int)RATIO * w, w));
}
hope this helps!

The ExoPlayer from Google comes with an AspectRatioFrameLayout that you use like this:
<com.google.android.exoplayer2.ui.AspectRatioFrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:resize_mode="fixed_width">
<!-- https://exoplayer.dev/doc/reference/com/google/android/exoplayer2/ui/AspectRatioFrameLayout.html#RESIZE_MODE_FIXED_WIDTH -->
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</com.google.android.exoplayer2.ui.AspectRatioFrameLayout>
Then you must set the aspect ratio programmatically:
aspectRatioFrameLayout.setAspectRatio(16f/9f)
Note that you can also set the resize mode programmatically with setResizeMode.
Since you are obviously not going to grab the whole ExoPlayer library for this single class, you can simply copy-paste the file from GitHub to your project (it's open source):
https://github.com/google/ExoPlayer/blob/release-v2/library/ui/src/main/java/com/google/android/exoplayer2/ui/AspectRatioFrameLayout.java
Don't forget to grab the attribute resize_mode too:
https://github.com/google/ExoPlayer/blob/release-v2/library/ui/src/main/res/values/attrs.xml#L18-L25
<attr name="resize_mode" format="enum">
<enum name="fit" value="0"/>
<enum name="fixed_width" value="1"/>
<enum name="fixed_height" value="2"/>
<enum name="fill" value="3"/>
<enum name="zoom" value="4"/>
</attr>

You may find third-party libraries. Instead of using them, use constraint layout.
Below code sets the aspect ratio of ImageView as 16:9 regardless of the screen size and orientation.
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:scaleType="fitXY"
android:src="#drawable/mat3"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintDimensionRatio="H,16:9"/>
</androidx.constraintlayout.widget.ConstraintLayout>
app:layout_constraintDimensionRatio="H,16:9". Here, height is set with respect to the width of the layout.
For your question, set android:layout_width="match_parent" and use app:layout_constraintDimensionRatio="H,1:1" in your view.

I have used in this way.
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/imageView_home_one"
android:layout_width="0dp"
android:layout_height="0dp"
android:scaleType="centerCrop"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintDimensionRatio="H,4:3"
android:layout_marginTop="#dimen/_5sdp"
android:visibility="gone"
tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>