Related
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.
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
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"
I create my own class for the square layout:
public class SquareLayout extends LinearLayout{
public SquareLayout(Context context) {
super(context);
}
public SquareLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public SquareLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int size = width > height ? height : width;
setMeasuredDimension(size, size);
}
Then, in my xml:
...
<com.myApp.SquareLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal"
android:orientation="horizontal" >
<ImageView
android:id="#+id/cellImageView"
android:adjustViewBounds="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="2dp"
android:padding="2dp"
android:scaleType="centerCrop"
android:src="#drawable/image" />
</com.myApp.SquareLayout>
...
Nothing written more in my java code.
But instead if my layout and my Image, I see only a white rectangle...
What am I wrong?
// you forget to call super.onMeasure(widthMeasureSpec, widthMeasureSpec);
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int size = width > height ? height : width;
setMeasuredDimension(size, size);
}
// xml file
<com.example.testapplication.SquareLayout
android:id="#+id/layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal"
android:orientation="horizontal" >
<ImageView
android:id="#+id/cellImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="2dp"
android:adjustViewBounds="true"
android:padding="2dp"
android:scaleType="centerCrop"
android:src="#drawable/ic_launcher" />
</com.example.testapplication.SquareLayout>
I had problems calling setMeasuredDimension directly when applying the same technique to a RelativeLayout. I was unable to correctly align against the bottom edge. Changing to instead call up to super.onMeasure() with a new measure spec worked better.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int size = Math.min(width, height);
super.onMeasure(MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(size, MeasureSpec.EXACTLY));
}
Edit:
The solution below has now been deprecated, as ConstraintLayout has become the new standard and provides this functionality.
Original Answer:
Turns out the Android team gave us the solution, but nobody knows about it! Check out these two classes from the Percent Support Library:
PercentFrameLayout
PercentRelativeLayout
If you want to impose the ratio of a view, you have to place it within one of these layouts. So in this case, you have to place a standard LinearLayout, not your subclass, within one of these layouts with the right aspect ratio. Example if you want to use a PercentFrameLayout:
<android.support.percent.PercentFrameLayout
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">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_aspectRatio="100%">
<!-- Whatever subviews you want here -->
</LinearLayout>
</android.support.percent.PercentFrameLayout>
And there you go, all your views will be contained within a square linear
layout!
don't forget to add the gradle dependency compile 'com.android.support:percent:23.3.0' Adjust the version number as required
View's have a minHeight but somehow are lacking a maxHeight:
What I'm trying to achieve is having some items (views) filling up a ScrollView. When there are 1..3 items I want to display them directly. Meaning the ScrollView has the height of either 1, 2 or 3 items.
When there are 4 or more items I want the ScrollView to stop expanding (thus a maxHeight) and start providing scrolling.
However, there is unfortunately no way to set a maxHeight. So I probably have to set my ScrollView height programmatically to either WRAP_CONTENT when there are 1..3 items and set the height to 3*sizeOf(View) when there are 4 or more items.
Can anyone explain why there is no maxHeight provided, when there is already a minHeight?
(BTW: some views, like ImageView have a maxHeight implemented.)
None of these solutions worked for what I needed which was a ScrollView set to wrap_content but having a maxHeight so it would stop expanding after a certain point and start scrolling. I just simply overrode the onMeasure method in ScrollView.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(300, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
This might not work in all situations, but it certainly gives me the results needed for my layout. And it also addresses the comment by madhu.
If some layout present below the scrollview then this trick wont work – madhu Mar 5 at 4:36
In order to create a ScrollView or ListView with a maxHeight you just need to create a Transparent LinearLayout around it with a height of what you want the maxHeight to be. You then set the ScrollView's Height to wrap_content. This creates a ScrollView that appears to grow until its height is equal to the parent LinearLayout.
This worked for me to make it customizable in xml:
MaxHeightScrollView.java:
public class MaxHeightScrollView extends ScrollView {
private int maxHeight;
private final int defaultHeight = 200;
public MaxHeightScrollView(Context context) {
super(context);
}
public MaxHeightScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
if (!isInEditMode()) {
init(context, attrs);
}
}
public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
if (!isInEditMode()) {
init(context, attrs);
}
}
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
if (!isInEditMode()) {
init(context, attrs);
}
}
private void init(Context context, AttributeSet attrs) {
if (attrs != null) {
TypedArray styledAttrs = context.obtainStyledAttributes(attrs, R.styleable.MaxHeightScrollView);
//200 is a defualt value
maxHeight = styledAttrs.getDimensionPixelSize(R.styleable.MaxHeightScrollView_maxHeight, defaultHeight);
styledAttrs.recycle();
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
attr.xml
<declare-styleable name="MaxHeightScrollView">
<attr name="maxHeight" format="dimension" />
</declare-styleable>
example layout
<blah.blah.MaxHeightScrollView android:layout_weight="1"
app:maxHeight="90dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<EditText android:id="#+id/commentField"
android:hint="Say Something"
android:background="#FFFFFF"
android:paddingLeft="8dp"
android:paddingRight="8dp"
android:gravity="center_vertical"
android:maxLines="500"
android:minHeight="36dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</blah.blah.MaxHeightScrollView>
(I know this does not directly answer the question but might be helpful to others looking for maxHeight functionality)
ConstraintLayout offers maximum height for its children via
app:layout_constraintHeight_max="300dp"
app:layout_constrainedHeight="true"
or
app:layout_constraintWidth_max="300dp"
app:layout_constrainedWidth="true"
Sample usage here.
I would have commented on whizzle's answer if I could, but thought it useful to note that in order for me to solve this problem in the context of multi-window mode in Android N, I needed to change the code slightly to this:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if(MeasureSpec.getSize(heightMeasureSpec) > maxHeight) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
This allows for the layout to resize to be smaller than the max height, but also prevent it from being larger than the max height. I used this is a layout class that Overrides RelativeLayout and this allowed me to create a custom dialog with a ScrollView as the child of MaxHeightRelativeLayout that does not expand the full height of the screen and also shrinks to fit within the smallest widow size in multi-window for Android N.
As mentioned above, ConstraintLayout offers maximum height for its children via:
app:layout_constraintHeight_max="300dp"
app:layout_constrainedHeight="true"
Besides, if maximum height for one ConstraintLayout's child is uncertain until App running, there still has a way to make this child automatically adapt a mutable height no matter where it was placed in the vertical chain.
For example, we need to show a bottom dialog with a mutable header TextView, a mutable ScrollView and a mutable footer TextView. The dialog's max height is 320dp，when total height not reach 320dp ScrollView act as wrap_content, when total height exceed ScrollView act as "maxHeight=320dp - header height - footer height".
We can achieve this just through xml layout file:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="320dp">
<TextView
android:id="#+id/tv_header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/black_10"
android:gravity="center"
android:padding="10dp"
app:layout_constraintBottom_toTopOf="#id/scroll_view"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1"
app:layout_constraintVertical_chainStyle="packed"
tools:text="header" />
<ScrollView
android:id="#+id/scroll_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/black_30"
app:layout_constrainedHeight="true"
app:layout_constraintBottom_toTopOf="#id/tv_footer"
app:layout_constraintHeight_max="300dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/tv_header">
<LinearLayout
android:id="#+id/ll_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/tv_sub1"
android:layout_width="match_parent"
android:layout_height="160dp"
android:gravity="center"
android:textColor="#color/orange_light"
tools:text="sub1" />
<TextView
android:id="#+id/tv_sub2"
android:layout_width="match_parent"
android:layout_height="160dp"
android:gravity="center"
android:textColor="#color/orange_light"
tools:text="sub2" />
</LinearLayout>
</ScrollView>
<TextView
android:id="#+id/tv_footer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/black_50"
android:gravity="center"
android:padding="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/scroll_view"
tools:text="footer" />
</android.support.constraint.ConstraintLayout>
Most import code is short:
app:layout_constraintVertical_bias="1"
app:layout_constraintVertical_chainStyle="packed"
app:layout_constrainedHeight="true"
Horizontal maxWidth usage is quite the same.
There is no way to set maxHeight. But you can set the Height.
To do that you will need to discovery the height of each item of you scrollView. After that just set your scrollView height to numberOfItens * heightOfItem.
To discovery the height of an item do that:
View item = adapter.getView(0, null, scrollView);
item.measure(0, 0);
int heightOfItem = item.getMeasuredHeight();
To set the height do that:
// if the scrollView already has a layoutParams:
scrollView.getLayoutParams().height = heightOfItem * numberOfItens;
// or
// if the layoutParams is null, then create a new one.
scrollView.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, heightOfItem * numberOfItens));
Wrap your ScrollView around your a plainLinearLayout with layout_height="max_height", this will do a perfect job. In fact, I have this code in production from last 5 years with zero issues.
<LinearLayout
android:id="#+id/subsParent"
android:layout_width="match_parent"
android:layout_height="150dp"
android:gravity="bottom|center_horizontal"
android:orientation="vertical">
<ScrollView
android:id="#+id/subsScroll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:layout_marginEnd="15dp"
android:layout_marginStart="15dp">
<TextView
android:id="#+id/subsTv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/longText"
android:visibility="visible" />
</ScrollView>
</LinearLayout>
My MaxHeightScrollView custom view
public class MaxHeightScrollView extends ScrollView {
private int maxHeight;
public MaxHeightScrollView(Context context) {
this(context, null);
}
public MaxHeightScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs);
}
private void init(Context context, AttributeSet attrs) {
TypedArray styledAttrs =
context.obtainStyledAttributes(attrs, R.styleable.MaxHeightScrollView);
try {
maxHeight = styledAttrs.getDimensionPixelSize(R.styleable.MaxHeightScrollView_mhs_maxHeight, 0);
} finally {
styledAttrs.recycle();
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (maxHeight > 0) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
style.xml
<declare-styleable name="MaxHeightScrollView">
<attr name="mhs_maxHeight" format="dimension" />
</declare-styleable>
Using
<....MaxHeightScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:mhs_maxHeight="100dp"
>
...
</....MaxHeightScrollView>
I have an answer here:
https://stackoverflow.com/a/29178364/1148784
Just create a new class extending ScrollView and override it's onMeasure method.
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (maxHeight > 0){
int hSize = MeasureSpec.getSize(heightMeasureSpec);
int hMode = MeasureSpec.getMode(heightMeasureSpec);
switch (hMode){
case MeasureSpec.AT_MOST:
heightMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(hSize, maxHeight), MeasureSpec.AT_MOST);
break;
case MeasureSpec.UNSPECIFIED:
heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
break;
case MeasureSpec.EXACTLY:
heightMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(hSize, maxHeight), MeasureSpec.EXACTLY);
break;
}
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
In case anyone needs it:
app:layout_constraintHeight_max="300dp"
It forces the View (that is inside a ConstraintLayout) to be 300dp as a max height. For those who want to do this programmatically, it goes like this:
val totalScreenHeight = displayMetrics.heightPixels
val layoutParams: ConstraintLayout.LayoutParams = viewThatIsInsideAConstraintLayout.layoutParams as ConstraintLayout.LayoutParams
layoutParams.matchConstraintMaxHeight = totalScreenHeight/2
viewThatIsInsideAConstraintLayout.layoutParams = layoutParams
Have you tried using the layout_weight value? If you set one it to a value greater than 0, it will stretch that view into the remaining space available.
If you had multiple views that needed to be stretched, then the value will become a weight between them.
So if you had two views both set to a layout_weight value of 1, then they would both stretch to fill in the space but they would both stretch to an equal amount of space. If you set one of them to the value of 2, then it would stretch twice as much as the other view.
Some more info here listed under Linear Layout.
i think u can set the heiht at runtime for 1 item just scrollView.setHeight(200px), for 2 items scrollView.setheight(400px) for 3 or more scrollView.setHeight(600px)
As we know devices running android can have different screen sizes. As we further know views should adjust dynamically and become the space which is appropriate.
If you set a max height you maybe force the view not to get enough space or take to less space. I know that sometimes it seems to be practically to set a max height. But if the resolution will ever change dramatically, and it will!, then the view, which has a max height, will look not appropriate.
i think there is no proper way to exactly do the layout you want. i would recommend you to think over your layout using layout managers and relative mechanisms. i don't know what you're trying to achieve but it sounds a little strange for me that a list should only show three items and then the user has to scroll.
btw. minHeight is not guaranteed (and maybe shouldn't exist either). it can have some benefit to force items to be visible while other relative items get smaller.
If anyone is considering using exact value for LayoutParams e.g.
setLayoutParams(new LayoutParams(Y, X );
Do remember to take into account the density of the device display otherwise you might get very odd behaviour on different devices. E.g:
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics d = new DisplayMetrics();
display.getMetrics(d);
setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, (int)(50*d.density) ));
First get the item height in pixels
View rowItem = adapter.getView(0, null, scrollView);
rowItem.measure(0, 0);
int heightOfItem = rowItem.getMeasuredHeight();
then simply
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics displayMetrics = new DisplayMetrics();
display.getMetrics(displayMetrics);
scrollView.getLayoutParams().height = (int)((heightOfItem * 3)*displayMetrics .density);
if you guys want to make a non-overflow scrollview or listview, just but it on a RelativeLayout with a topview and bottomview on top and bottom for it:
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/topview"
android:layout_below="#+id/bottomview" >
I used a custom ScrollView made in Kotlin which uses maxHeight. Example of use:
<com.antena3.atresplayer.tv.ui.widget.ScrollViewWithMaxHeight
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxHeight="100dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</com.antena3.atresplayer.tv.ui.widget.ScrollViewWithMaxHeight>
Here is the code of ScrollViewWidthMaxHeight:
import android.content.Context
import android.util.AttributeSet
import android.widget.ScrollView
import timber.log.Timber
class ScrollViewWithMaxHeight #JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : ScrollView(context, attrs, defStyleAttr) {
companion object {
var WITHOUT_MAX_HEIGHT_VALUE = -1
}
private var maxHeight = WITHOUT_MAX_HEIGHT_VALUE
init {
val a = context.obtainStyledAttributes(
attrs, R.styleable.ScrollViewWithMaxHeight,
defStyleAttr, 0
)
try {
maxHeight = a.getDimension(
R.styleable.ScrollViewWithMaxHeight_android_maxHeight,
WITHOUT_MAX_HEIGHT_VALUE.toFloat()
).toInt()
} finally {
a.recycle()
}
}
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
var heightMeasure = heightMeasureSpec
try {
var heightSize = MeasureSpec.getSize(heightMeasureSpec)
if (maxHeight != WITHOUT_MAX_HEIGHT_VALUE) {
heightSize = maxHeight
heightMeasure = MeasureSpec.makeMeasureSpec(heightSize, MeasureSpec.AT_MOST)
} else {
heightMeasure = MeasureSpec.makeMeasureSpec(heightSize, MeasureSpec.UNSPECIFIED)
}
layoutParams.height = heightSize
} catch (e: Exception) {
Timber.e(e, "Error forcing height")
} finally {
super.onMeasure(widthMeasureSpec, heightMeasure)
}
}
fun setMaxHeight(maxHeight: Int) {
this.maxHeight = maxHeight
}
}
which needs also this declaration in values/attrs.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ScrollViewWithMaxHeight">
<attr name="android:maxHeight" />
</declare-styleable>
</resources>