Develop Reference

Custom Square Layout not working as expected

I stumbled across this problem when working with custom Square Layout : by extending the Layout and overriding its onMeasure() method to make the dimensions = smaller of the two (height or width).
Following is the custom Layout code :
public class CustomSquareLayout extends RelativeLayout{
public CustomSquareLayout(Context context) {
super(context);
}
public CustomSquareLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomSquareLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
#RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public CustomSquareLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//Width is smaller
if(widthMeasureSpec < heightMeasureSpec)
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
//Height is smaller
else
super.onMeasure(heightMeasureSpec, heightMeasureSpec);
}
}
The custom Square Layout works fine, until in cases where the custom layout goes out of bound of the screen. What should have automatically adjusted to screen dimensions though, doesn't happen. As seen below, the CustomSquareLayout actually extends below the screen (invisible). What I expect is for the onMeasure to handle this, and give appropriate measurements. But that is not the case. Note of interest here is that even thought the CustomSquareLayout behaves weirdly, its child layouts all fall under a Square shaped layout that is always placed on the Left hand side.
<!-- XML for above image -->
<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"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="300dp"
android:text="Below is the Square Layout"
android:gravity="center"
android:id="#+id/text"
/>
<com.app.application.CustomSquareLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/text"
android:background="#color/colorAccent" #PINK
android:layout_centerInParent="true"
android:id="#+id/square"
android:padding="16dp"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true" #Note this
android:background="#color/colorPrimaryDark" #BLUE
>
</RelativeLayout>
</com.app.application.CustomSquareLayout>
</RelativeLayout>
Normal case : (Textview is in Top)
Following are few links I referenced:
Custom Square LinearLayout. How?
Simple way to do dynamic but square layout
Hope to find a solution to this, using onMeasure or any other function when extending the layout (so that even if some extends the Custom Layout, the Square property remains)
Edit 1 : For further clarification, the expected result for 1st case is shown
Edit 2 : I gave a preference to onMeasure() or such functions as the need is for the layout specs (dimensions) to be decided earlier (before rendering). Otherwise changing the dimensions after the component loads is simple, but is not requested.

You can force a square view by checking for "squareness" after layout. Add the following code to onCreate().
final View squareView = findViewById(R.id.square);
squareView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
squareView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
if (squareView.getWidth() != squareView.getHeight()) {
int squareSize = Math.min(squareView.getWidth(), squareView.getHeight());
RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) squareView.getLayoutParams();
lp.width = squareSize;
lp.height = squareSize;
squareView.requestLayout();
}
}
});
This will force a remeasurement and layout of the square view with a specified size that replaces MATCH_PARENT. Not incredibly elegant, but it works.
You can also add a PreDraw listener to your custom view.
onPreDraw
boolean onPreDraw ()
Callback method to be invoked when the view tree is about to be drawn. At this point, all views in the tree have been measured and given a frame. Clients can use this to adjust their scroll bounds or even to request a new layout before drawing occurs.
Return true to proceed with the current drawing pass, or false to cancel.
Add a call to an initialization method in each constructor in the custom view:
private void init() {
this.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
if (getWidth() != getHeight()) {
int squareSize = Math.min(getWidth(), getHeight());
RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) getLayoutParams();
lp.width = squareSize;
lp.height = squareSize;
requestLayout();
return false;
}
return true;
}
});
}
The XML can look like the following:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="300dp"
android:gravity="center"
android:text="Below is the Square Layout" />
<com.example.squareview.CustomSquareLayout
android:id="#+id/square"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/text"
android:background="#color/colorAccent"
android:padding="16dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:background="#color/colorPrimaryDark" />
</com.example.squareview.CustomSquareLayout>
</RelativeLayout>

There is a difference between the view's measured width and the view's width (same for height). onMeasure is only setting the view's measured dimensions. There is still a different part of the drawing process that constrains the view's actual dimensions so that they don't go outside the parent.
If I add this code:
final View square = findViewById(R.id.square);
square.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
System.out.println("measured width: " + square.getMeasuredWidth());
System.out.println("measured height: " + square.getMeasuredHeight());
System.out.println("actual width: " + square.getWidth());
System.out.println("actual height: " + square.getHeight());
}
});
I see this in the logs:
09-05 10:19:25.768 4591 4591 I System.out: measured width: 579
09-05 10:19:25.768 4591 4591 I System.out: measured height: 579
09-05 10:19:25.768 4591 4591 I System.out: actual width: 768
09-05 10:19:25.768 4591 4591 I System.out: actual height: 579
How to solve it by creating a custom view? I don't know; I never learned. But I do know how to solve it without having to write any Java code at all: use ConstraintLayout.
ConstraintLayout supports the idea that children should be able to set their dimensions using an aspect ratio, so you can simply use a ratio of 1 and get a square child. Here's my updated layout (the key piece is the app:layout_constraintDimensionRatio attr):
<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="match_parent">
<TextView
android:id="#+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="300dp"
android:gravity="center"
android:text="Below is the Square Layout"
app:layout_constraintTop_toTopOf="parent"/>
<RelativeLayout
android:id="#+id/square"
android:layout_width="match_parent"
android:layout_height="0dp"
android:padding="16dp"
android:background="#color/colorAccent"
app:layout_constraintTop_toBottomOf="#+id/text"
app:layout_constraintDimensionRatio="1">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:background="#color/colorPrimaryDark">
</RelativeLayout>
</RelativeLayout>
</android.support.constraint.ConstraintLayout>
And screenshots:

You cannot compare the two measure specs, as they are not simply a size. You can see a very good explanation in this answer. This answer is for a custom view, but measure specs are the same. You need to get the mode and the size to compute final sizes, and compare the end results for both dimensions.
In the second example you shared, the right question is this one (third answer). Is written for Xamarin in C#, but is easy to understand.
The case that is failing for you is because you're finding an AT_MOST mode (when the view is hitting the bottom of the screen), that's why comparisons are failing in this case.
That should be the final method (can contain typos, I have been unable to test it:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int width, height;
switch (widthMode) {
case MeasureSpec.EXACTLY:
width = widthSize;
break;
case MeasureSpec.AT_MOST:
width = Math.min(widthSize, heightSize);
break;
default:
width = 100;
break;
}
switch (heightMode) {
case MeasureSpec.EXACTLY:
height = heightSize;
break;
case MeasureSpec.AT_MOST:
height = Math.min(widthSize, heightSize);
break;
default:
height = 100;
break;
}
var size = Math.min(width, height);
var newMeasureSpec = MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY);
super.onMeasure(newMeasureSpec, newMeasureSpec);
}
I expect the end result to be roughly like this (maybe centered, but this dimensions):
Notice that this is a made up image done with Gimp.

try this. You can use on measure method to make a custom view. Check the link below for more details.
http://codecops.blogspot.in/2017/06/how-to-make-responsive-imageview-in.html

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.

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;

ImageView in ListView that expands maximum width

I have a ListView whose items are ImageViews, for the sake of discussion. I want the image to scale to the width of the ListView's rows, and maintain it's aspect ratio. here's a simplified version of the ListView's item layout,
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:padding="4dp" >
<FrameLayout
android:id="#+id/page_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="visible" >
<ImageView
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:src="#drawable/some_image" />
</FrameLayout>
</FrameLayout>
</LinearLayout>
the ImageView's width is match_parent, and all ancestors of it are the same. Layout designer shows that the ImageView's dimensions span the entire width, but the image inside does not.
The image is scaling correctly. The problem is that the height of the list view row is such that the width can't scale to the right size. If I use fitXY, it does scale the width, but then the aspect ratio is incorrect.
Any ideas?

I couldn't find any way to accomplish this without creating a custom view. in a nutshell, the custom view sets it's own dimensions to the real (not scaled) dimensions of the drawable behind it.
public class ResizableImageView extends ImageView {
public static interface OnSizeChangedListener {
void onSizeChanged(int width, int height);
}
private OnSizeChangedListener onSizeChangedListener = null;
public ResizableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = width * getDrawable().getIntrinsicHeight() / getDrawable().getIntrinsicWidth();
setMeasuredDimension(width, height);
if (onSizeChangedListener != null) {
onSizeChangedListener.onSizeChanged(width, height);
}
}
public void setOnSizeChangedListener(OnSizeChangedListener listener) {
this.onSizeChangedListener = listener;
}
}
In my case I needed to obtain the resized value in order to size the other views, hence the listener interface.

If what you want is to maintain the aspect ratio, according to the Android API Guide, I think that you have to change android:scaleType="fitCenter" for android:scaleType="centerInside" or maybe android:scaleType="centerCrop" as fitCenter doesn't maintain the aspect ratio of the image.

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"
/>