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

Custom LinearLayout - childs not visible

I build customView extending LinearLayout and having simple 3 childrens(2 TextView and ImageView). I create this view dynamically in code and adding it to parent LinearLayout. This view has background, so I can easily spot on the screen, that it is inflated correctly in its place, but any of child is not visible. I checked LayoutInspector and it shows that everything is setted correctly(text values to TextViews and picture to ImageView), but somehow when I try to locate them on inspector they are shown as little dot over my customView:
My CustomView is called DayTileView and this is square with gray background. As you can see on inspector on the left childrens are filled with content. Layout of View:
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<merge>
<TextView
android:id="#+id/day"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:textColor="#android:color/white"
/>
<TextView
android:id="#+id/dayName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:textColor="#android:color/white"
/>
<ImageView
android:id="#+id/padlock"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:src="#drawable/ic_padlock"
/>
</merge>
</layout>
And its code:
public class DayTileView extends LinearLayout {
private DayTileBinding mBinding;
public DayTileView(Context context) {
super(context);
init();
}
public DayTileView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
init();
}
public DayTileView(Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mBinding = DataBindingUtil.inflate(LayoutInflater.from(getContext()), R.layout.day_tile, this, true);
setOrientation(VERTICAL);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
setMeasuredDimension(width, width);
}
public void setDay(int day, int month, int year) {
DateTime settedDay = new DateTime().withYear(year).withMonthOfYear(month).withDayOfMonth(day);
mBinding.day.setText(String.valueOf(day));
String dayName = settedDay.dayOfWeek().getAsText();
mBinding.dayName.setText(dayName);
boolean isWeekend = settedDay.dayOfWeek().get() == 6 || settedDay.dayOfWeek().get() == 7;
setBackgroundColor(ContextCompat.getColor(getContext(), isWeekend ? R.color.weekend_bg : R.color.weekday_bg));
}
}
Its use in another CustomView which is also LinearLayout but wiht horizontal orientation (PlannedDayView on inspector):
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<merge>
<*.customViews.DayTileView
android:id="#+id/dayTile"
android:layout_width="0dp"
android:layout_weight="0.2"
android:layout_height="wrap_content"/>
<LinearLayout
android:id="#+id/container"
android:orientation="vertical"
android:layout_weight="1.2"
android:layout_width="0dp"
android:layout_height="wrap_content"/>
</merge>
</layout>
Has anyone any idea what could be casuing this (childs out of view)? When I replace merge for LinearLayout with vertical orientation and same background everything in Design mode of layout is visible correctly, so it should work.
EDIT:
I found out, that if I set during View initalization Padding Top to 10px then dot is moving down. So it looks like from some reasons Android didn't made to inflate correctly TextViews and ImageView

I found out what was the problem:
I overrided onMeasure and didn't measure child Views. Earlier I was using such code to make square View not square ViewGroup.
Corrected code:
final int width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
setMeasuredDimension(width, width);
super.onMeasure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY));
After setting correct width and height for View I must measure whole view with new MeasureSpec

How to set RecyclerView Max Height

I want to set Max Height of RecylerView.I am able to set max height using below code.Below code makes height 60% of current screen.
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int a = (displaymetrics.heightPixels * 60) / 100;
recyclerview1.getLayoutParams().height = a;
But now problem is that, if it have no item then also its height is 60%.
So I want to set its height 0 when no item in it.
I want to achieve like something.
if(recyclerview's height > maxHeight)
then set recyclerview's height to maxHeight
else dont change the height of recyclerview.
How can i set it?
Please help me, I am stuck with it

ConstraintLayout offers maximum height for its children.
<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">
<ListView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:scrollbars="vertical"
app:layout_constrainedHeight="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHeight_max="300dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

Here is something, you need. Subclass the RecyclerView and override onMeasure as following:
#Override
protected void onMeasure(int widthSpec, int heightSpec) {
heightSpec = MeasureSpec.makeMeasureSpec(Utils.dpsToPixels(240), MeasureSpec.AT_MOST);
super.onMeasure(widthSpec, heightSpec);
}
Make sure, you give proper number of pixels as the first argument in makeMeasureSpec(). I personally needed RecyclerView, that is 240dps at most.

I think this will work at least it worked for me
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/Id_const_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/Id_my_recycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/margin_top_space"
android:scrollbars="vertical"
app:layout_constrainedHeight="true"
app:layout_constraintBottom_toBottomOf="#+id/Id_const_layout"
app:layout_constraintEnd_toEndOf="#+id/Id_const_layout"
app:layout_constraintHeight_max="150dp"
app:layout_constraintHeight_min="30dp"
app:layout_constraintStart_toStartOf="#+id/Id_const_layout"
app:layout_constraintTop_toTopOf="#+id/Id_const_layout"
>
</androidx.recyclerview.widget.RecyclerView>
</androidx.constraintlayout.widget.ConstraintLayout>
You can change the constraintHeight_max and constraintHeight_min according to your needs.

We can optimize #Fattum 's method a little bit.
We can use app:maxHeight to set the maxHeight. One can use dp or px as you like.
public class MaxHeightRecyclerView extends RecyclerView {
private int mMaxHeight;
public MaxHeightRecyclerView(Context context) {
super(context);
}
public MaxHeightRecyclerView(Context context, AttributeSet attrs) {
super(context, attrs);
initialize(context, attrs);
}
public MaxHeightRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initialize(context, attrs);
}
private void initialize(Context context, AttributeSet attrs) {
TypedArray arr = context.obtainStyledAttributes(attrs, R.styleable.MaxHeightScrollView);
mMaxHeight = arr.getLayoutDimension(R.styleable.MaxHeightScrollView_maxHeight, mMaxHeight);
arr.recycle();
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (mMaxHeight > 0) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(mMaxHeight, MeasureSpec.AT_MOST);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
values/attrs.xml
<declare-styleable name="MaxHeightScrollView">
<attr name="maxHeight" format="dimension" />
</declare-styleable>

After trying way too many complicated suggestions, I finally figured this out through trial and error.
First, wrap the RecyclerView in some sort of layout. In my case, I used a constraint layout, and I even had other elements in that layout above and below the RecyclerView. Set the height of the layout to auto adjust by setting it to 0dp, then set the default layout height constraint as wrap and define a layout max height constraint.
Then, on your RecyclerView, set the height to wrap_content and layout_constrainedHeight to true.
Here is what it should look like:
<android.support.constraint.ConstraintLayout
android:layout_width="600px"
android:layout_height="0dp"
app:layout_constraintHeight_default="wrap"
app:layout_constraintHeight_max="450px">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constrainedHeight="true"
app:layout_constraintTop_ToTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
Hope this helps!

write this statements inside if else
and let me know ,
ViewGroup.LayoutParams params=recyclerview.getLayoutParams();
params.height=100;
recyclerview.setLayoutParams(params);

ill add my 2 cents i needed a recycler view with a max height and min height and wrap content between the 2
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:id="#+id/group_card_recycler_view_holder"
app:layout_constraintHeight_default="wrap"
app:layout_constraintHeight_max="#dimen/group_recycler_view_height"
app:layout_constraintHeight_min="#dimen/card_sentence_height"
android:layout_marginTop="#dimen/activity_horizontal_margin_8dp"
app:layout_constraintTop_toBottomOf="#id/group_name_container"
app:layout_constraintBottom_toTopOf="#id/myButtonLayout">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="true"
android:id="#+id/group_card_recycler_view"/>
</androidx.constraintlayout.widget.ConstraintLayout>

You can use WRAP_CONTENT in your RecyclerView. It will auto measure your recyclerview according to its content.
You can also calculate current height and set max height. So Recyclerview will use wrap_content attribute value until max height.
public static void getTotalHeightofRecyclerView(RecyclerView recyclerView) {
RecyclerView.Adapter mAdapter = recyclerView.getAdapter();
int totalHeight = 0;
for (int i = 0; i < mAdapter.getItemCount(); i++) {
View mView = recyclerView.findViewHolderForAdapterPosition(i).itemView
mView.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
totalHeight += mView.getMeasuredHeight();
}
if (totalHeight > 100) {
ViewGroup.LayoutParams params = recyclerView.getLayoutParams();
params.height = 100;
recyclerView.setLayoutParams(params);
}
}

The simplest way is to use ConstraintLayout and setting height constraint on Recycleview.
<android.support.constraint.ConstraintLayout
android:id="#+id/CL_OUTER_RV_Choose_Categories "
android:layout_width="match_parent"
android:layout_height="200dp">
<android.support.v7.widget.RecyclerView
android:id="#+id/RV_Choose_Categories"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_constrainedHeight="true" >
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
Please note that before Lollipop, the recycleview will not scroll. As a solution, add the below code in the activity's oncreate.
if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
ConstraintLayout CL_OUTER_RV_Choose_Categories = findViewById(R.id.CL_OUTER_RV_Choose_Categories);
LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) CL_OUTER_RV_Choose_Categories.getLayoutParams();
lp.height = LinearLayout.LayoutParams.WRAP_CONTENT;
}
This will ensure that height is fixed only on supported devices, and the complete recycle view is shown on older devices.
Do let me know if there is any better way.

If you have a RecyclerView designed to hold items of equal physical size and you want a no-brainer way to limit its height without extending RecyclerView, try this:
int maxRecyclerViewHeightPixels = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
MAX_RECYCLERVIEW_HEIGHT_DP,
getResources().getDisplayMetrics()
);
MyRecyclerViewAdapter myRecyclerViewAdapter = new MyRecyclerViewAdapter(getContext(), myElementList);
myRecyclerView.setAdapter(myRecyclerViewAdapter);
ViewGroup.LayoutParams params = myRecyclerView.getLayoutParams();
if (myElementList.size() <= MAX_NUMBER_OF_ELEMENTS_TO_DISPLAY_AT_ONE_TIME) {
myRecyclerView.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
//LinearLayout must be replaced by whatever layout type encloses your RecyclerView
}
else {
params.height = maxRecyclerViewHeightPixels;
myRecyclerView.setLayoutParams(params);
}
This works both for Linear and Grid RecyclerViews, you just need to play with the numbers a bit to suit your taste. Don't forget to set the height to WRAP_CONTENT after you populate the RecyclerView.
You may also have to set the height again every time the size of myElementList changes, but that's not a big issue.

I just had this same problem, and wanted to share a new, up-to-date answer. This one works on at least Android 9 and Android Studio v. 4.0.
Wrap the RecyclerView in a ConstraintLayout, as some of the answers here have suggested. But it does not appear you can set the maximum height of that layout in XML. Instead, you must set it in code, as follows: Give the ConstraintLayout an ID, and then, in your onCreate or onViewCreated method for the activity or fragment, respectively, in question - for example, to set a max height of 200 dp:
findViewById<ConstraintLayout>(R.id.[YOUR ID]).maxHeight = 200 // activity
view.findViewById<ConstraintLayout>(R.id.[YOUR ID]).maxHeight = 200 // fragment
Annoyingly, ConstraintLayout does expose an XML attribute android:minHeight but no android:maxHeight.
Even more annoyingly, RecyclerView itself apparently comes with an XML attribute named android:maxHeight, but that attribute does not work.

You can just set a specific height to any value in the xml code and set the visibility to gone. Then you set the visibility to Visible in Java, when you want to inflate it. Here is an example;
.xml
android:visibility="gone"
.java
recyclerView.setVisibility(View.VISIBLE);

Square layout on GridLayoutManager for RecyclerView

I try to make a grid-layout with square images. I thought that it must be possible to manipulate the GridLayoutManager by manipulating onMeasure to do a
super.onMeasure(recycler, state, widthSpec, widthSpec);
instead of
super.onMeasure(recycler, state, widthSpec, heightSpec);
but unfortunately, that didn't work.
Any ideas?

To have the square elements in my RecyclerView, I provide a simple wrapper for my root View element; I use the following SquareRelativeLayout in place of RelativeLayout.
package net.simplyadvanced.widget;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.RelativeLayout;
/** A RelativeLayout that will always be square -- same width and height,
* where the height is based off the width. */
public class SquareRelativeLayout extends RelativeLayout {
public SquareRelativeLayout(Context context) {
super(context);
}
public SquareRelativeLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SquareRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
#TargetApi(VERSION_CODES.LOLLIPOP)
public SquareRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Set a square layout.
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
}
}
Then, in my XML layout for the adapter, I've just referenced the custom view as shown in the following. Though, you can do this programmatically also.
<?xml version="1.0" encoding="utf-8"?>
<net.simplyadvanced.widget.SquareRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/elementRootView"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<!-- More widgets here. -->
</net.simplyadvanced.widget.SquareRelativeLayout>
Note: Depending on which orientation your grid is, then you may want to have the width based off of height (GridLayoutManager.HORIZONTAL) instead of the height being based off the width (GridLayoutManager.VERTICAL).

Constraint layout solves this problem. Use app:layout_constraintDimensionRatio="H,1:1"
recyclerview_grid_layout.xml
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ImageView
android:id="#+id/imageview"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintDimensionRatio="H,1:1"
android:scaleType="centerCrop"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
</android.support.constraint.ConstraintLayout>
EDIT
Set ImageView width to 0dp. match_parent is now deprecated for ConstraintLayout.

In case someone would like to scale the view differently - this is how you do it:
private static final double WIDTH_RATIO = 3;
private static final double HEIGHT_RATIO = 4;
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = (int) (HEIGHT_RATIO / WIDTH_RATIO * widthSize);
int newHeightSpec = MeasureSpec.makeMeasureSpec(heightSize, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, newHeightSpec);
}

Starting API 26 (Support Library 26.0), one can use ConstraintLayout that exposes aspect ratio property to force views to be squared:
https://developer.android.com/training/constraint-layout/index.htm
android {
compileSdkVersion 26
buildToolsVersion '26.0.2'
...
}
...
dependencies {
compile 'com.android.support:appcompat-v7:26.0.2'
compile 'com.android.support.constraint:constraint-layout:1.1.0-beta1' //use whatever version is current
}
Example of layout I'm using in GridLayoutManager:
<?xml version="1.0" encoding="utf-8"?>
<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"
android:layout_margin="#dimen/margin_small"
android:background="#drawable/border_gray"
android:gravity="center">
<android.support.constraint.ConstraintLayout
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintDimensionRatio="h,1:1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<!-- place your content here -->
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
app:layout_constraintDimensionRatio="h,1:1" is the key attribute here

A small update for ConstraintLayout for androidx.
Include this line to your build.gradle:
implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
I wanted to get a RecycleView with GridLayoutManager with square CardViews and I used such a layout for items:
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:card_view="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="8dp"
>
<androidx.cardview.widget.CardView
android:id="#+id/cardView"
android:layout_width="0dp"
android:layout_height="0dp"
card_view:cardElevation="4dp"
app:layout_constraintDimensionRatio="H,1:1"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
>
On the ConstraintLayout
layout_width="match_parent" is important to let the item fill as much space as RecyclerView provides
layout_height="wrap_content" do not let the item to fill all the height given by RecyclerView, but use the constrained height, provided by ConstraintLayout. In my case, when I used FrameLayout or LinearLayout, the items were "tall".
On the child node, in my case CardView
limiting size to zero is important: layout_width="0dp" and layout_height="0dp" it means, that width and height are contrained
layout_constraintDimensionRatio="H,1:1" makes the desired effect, by setting H you define that height is to be constrained 1:1 is the ratio.
See some detailed explanations on the offsite.

Please, try this extension of the FrameLayout. It performs double measuring to improve consistency. It also supports custom XML properties to set-up required aspect ration from layouts
public class StableAspectFrameLayout extends FrameLayout {
private int aspectWidth = 1;
private int aspectHeight = 1;
public StableAspectFrameLayout(Context context) {
this(context, null, 0);
}
public StableAspectFrameLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public StableAspectFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
extractCustomAttrs(context, attrs);
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public StableAspectFrameLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
extractCustomAttrs(context, attrs);
}
private void extractCustomAttrs(Context context, AttributeSet attrs) {
if (attrs == null) return;
TypedArray a = context.getResources().obtainAttributes(attrs, R.styleable.StableAspectFrameLayout);
try {
aspectWidth = a.getInteger(R.styleable.StableAspectFrameLayout_aspect_width, 1);
aspectHeight = a.getInteger(R.styleable.StableAspectFrameLayout_aspect_height, 1);
} finally {
a.recycle();
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int newSpecWidth = MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY);
int newH = Math.round(((float) getMeasuredWidth()) * aspectHeight / aspectWidth);
int newSpecHeigh = MeasureSpec.makeMeasureSpec(newH, MeasureSpec.EXACTLY);
super.onMeasure(newSpecWidth, newSpecHeigh);
}
}
And the content fo the attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- StableAspectFrameLayout -->
<declare-styleable name="StableAspectFrameLayout">
<attr name="aspect_width" format="integer"/>
<attr name="aspect_height" format="integer"/>
</declare-styleable>
</resources>

Once again, I recommend the relatively recent 'percent' layouts. Using the dependency 'com.android.support:percent:25.2.0', you can do something like this:
<android.support.percent.PercentFrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/image"
app:layout_widthPercent="100%"
app:layout_aspectRatio="100%"
android:padding="10dp"
android:scaleType="centerCrop"
android:cropToPadding="true"
tools:background="#efdbed"
/>
</android.support.percent.PercentFrameLayout>
It's probably much faster than ConstraintLayout, though someday we probably won't care anymore.

I don't like chosen answer so let me provide mine: Instead of wrapping entire item layout in SomeDammyLayoutWithFixedAspectRatio you can hack GridLayoutManager and rewrite code inside measureChild. I've replaced these lines:
if (mOrientation == VERTICAL) {
wSpec = getChildMeasureSpec(availableSpaceInOther, otherDirParentSpecMode,
horizontalInsets, lp.width, false);
hSpec = getChildMeasureSpec(mOrientationHelper.getTotalSpace(), getHeightMode(),
verticalInsets, lp.height, true);
} else {
hSpec = getChildMeasureSpec(availableSpaceInOther, otherDirParentSpecMode,
verticalInsets, lp.height, false);
wSpec = getChildMeasureSpec(mOrientationHelper.getTotalSpace(), getWidthMode(),
horizontalInsets, lp.width, true);
}
to:
if (mOrientation == VERTICAL) {
wSpec = getChildMeasureSpec(availableSpaceInOther, otherDirParentSpecMode,
horizontalInsets, lp.width, false);
hSpec = wSpec;
} else {
hSpec = getChildMeasureSpec(availableSpaceInOther, otherDirParentSpecMode,
verticalInsets, lp.height, false);
wSpec = hSpec;
}
It seems to work fine.
Don't get me wrong, this is quite messy too, but at least this solution doesn't hurt app performance by extending view hierarchy

I had similar problem and I had to inflate the view which would be square in Grid of recycler view. Below is my way of doing it.
Inside onCreateViewHolder method I used the ViewTreeObserver and GlobalLayoutListener to get the measured width of the layout. The layout has match_parent value in the width attribute. Any my recycler view has layout in center horizontal.
final View view = LayoutInflater.from(mActivity).inflate(R.layout.list_item_deals, parent, false);
view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
int side = view.getMeasuredWidth();
ViewGroup.LayoutParams lp = view.getLayoutParams();
lp.width = side;
lp.height = side;
view.setLayoutParams(lp);
}
});
reference image

center children in a custom RelativeLayout

I have defined a custom relative layout to force a square view in my layout. But I am having trouble centering the children in that relative layout.
My custom RelativeLayout is defined as follows:
public class SquareView extends RelativeLayout {
public SquareView(Context context) {
super(context);
}
public SquareView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SquareView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int size;
size = Math.min(widthSize, heightSize);
setMeasuredDimension(size, size);
int finalMeasureSpec = MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY);
super.onMeasure(finalMeasureSpec, finalMeasureSpec);
}
}
and my xml is as follows:
<com.mypackage.SquareView
android:id="#+id/gameboard_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:gravity="center_horizontal"
android:padding="0dp" >
<LinearLayout
android:id="#+id/gameboard"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:background="#drawable/xmlgameboard"
android:gravity="center_horizontal"
android:orientation="vertical" >
</LinearLayout>
</com.mypackage.SquareView>
When I view the xml file in graphical view I see the SquareView (gameboard_container) filling all available space (not square), but the child LinearLayout (gameboard) is square.
However, the child LinearLayout (gameboard) is also left justified, where as I require it to be centered.
How would I fix this?
Thank you.

After 3 days of struggling with this I've managed to solve it. The solution was to simply nest my SquareView inside a frame layout. Then I could centre the SquareView using
android:layout_gravity="center_horizontal"