How to set layout_gravity programmatically?

Question

My question is simple,

How to set my buttons layout_gravity programmatically?

I found this on internet, but it simply throws me a Nullpointer exception:

 Button MyButton = new Button(this);

    LinearLayout.LayoutParams  lllp=(LinearLayout.LayoutParams)MyButton.getLayoutParams();
    lllp.gravity=Gravity.RIGHT;
    MyButton.setLayoutParams(lllp); 


    MyLinearLayout.addView(MyButton);

Any solution?

I believe you need to add the view to its parent before it will have LayoutParams that are not null. — Rich Morey, Apr 07 '17 at 18:19

score 623 · Accepted Answer · edited Mar 22 '23 at 12:48

623

Java

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
params.weight = 1.0f;
params.gravity = Gravity.TOP;

button.setLayoutParams(params);

Kotlin

val params = LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.WRAP_CONTENT,
    LinearLayout.LayoutParams.WRAP_CONTENT
).apply {
    weight = 1.0f
    gravity = Gravity.TOP
}
button.setLayoutParams(params)

For gravity values and how to set gravity check Gravity.

Basically, you should choose the LayoutParams depending on the parent. It can be RelativeLayout, LinearLayout etc...

edited Mar 22 '23 at 12:48

Community

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answered Nov 08 '11 at 11:44

Karthi

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For some reasons params.gravity = 80 (It should be BOTTOM, by te Docs) is just not working. I got some space betwen the bottom of the View and the Text. Its not so Bottom-aligned... – Adam Varhegyi Nov 10 '11 at 13:09
@AdamVarhegyi Without seeing your layout xml I'm not certain what your remaining problem is. But that space you're talking about may be due to padding. Try to [`setPadding()`](http://developer.android.com/reference/android/view/View.html#setPadding%28int,%20int,%20int,%20int%29) on your `View` to 0 for the bottom. – Tony Chan Nov 16 '11 at 03:23
53

Taking the constant value from the documentation is simply wrong, please use Gravity.TOP – Maragues Sep 22 '12 at 11:02
52

this is "gravity" and he asked for "layout_gravity" ?? – M. Usman Khan Mar 04 '16 at 14:02
15

@usman no, this is about `layout_gravity` (that is `LayoutParams.gravity`). The `gravity` would be `button.setGravity()` – Floern Nov 23 '16 at 17:06
10

There is a lot of wrong information about gravity and layout_gravity here on SO. Many ppl think that `setGravity()` is the layout_gravity, but this is wrong. I can approve that this answer is correct for setting layout_gravity programmatically. – Bevor Nov 28 '16 at 09:36
I think it is called gravity and not layoutGravity because it already is inside LayoutParams. – Michał Powłoka Apr 17 '18 at 09:33

score 61 · Answer 2 · edited May 29 '23 at 16:14

I'd hate to be resurrecting old threads but this is a problem that is not answered correctly and moreover I've run into this problem myself.

Here's the long bit, if you're only interested in the answer, please scroll all the way down to the code:

android:gravity and android:layout_gravity work differently. Here's an article I've read that helped me.

GIST of article: gravity affects view after height/width is assigned. So gravity centre will not affect a view that is done MATCH_PARENT (think of it as auto margin). layout_gravity centre WILL affect view that is MATCH_PARENT (think of it as auto pad).

Basically, android:layout_gravity CANNOT be access programmatically, only android:gravity. In the OP's case and my case, the accepted answer does not place the button vertically centre.

To improve on Karthi's answer:

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

params.gravity = Gravity.CENTER;
button.setLayoutParams(params);

Link to LinearLayout.LayoutParams.

android:layout_gravity shows "No related methods" meaning cannot be accessed programatically. Whereas gravity is a field in the class.

Also to add on that gravity auto-margins (for lack of a better term) based on the LinearLayout parent's orientation. The article link provided will help. — Uknight, Nov 12 '12 at 10:25

score 23 · Answer 3 · answered Jul 27 '13 at 05:47

23

I had a similar problem with programmatically setting layout_gravity on buttons in a GridLayout.

The trick was to set gravity on the button layoutParams AFTER the button was added to a parent (GridLayout), otherwise the gravity would be ignored.

grid.addView(button)
((GridLayout.LayoutParams)button.getLayoutParams()).setGravity(int)

answered Jul 27 '13 at 05:47

owjsub

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How do I change the layout_gravity for the whole GridLayout? – Iqbal Feb 08 '16 at 12:48
Still true in 2020! Why? – Thomas Oct 31 '20 at 20:55
Thank you SO MUCH. Still true in 2021 (nearly 2022 btw) – sparkhead95 Dec 03 '21 at 19:18

Yashwanth Kumar · Answer 4 · 2012-08-06T11:58:55.447

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MyButton.setGravity(Gravity.RIGHT);

For layout_gravity use the answer stated by "karthi". This method sets gravity to place the children inside the view.

edited Aug 06 '12 at 11:58

answered Nov 08 '11 at 11:25

Yashwanth Kumar

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It just gravity, not layout_gravity. – Adam Varhegyi Nov 08 '11 at 11:27
Okay then tell me if layout_gravity equals setGravity, then how I set the gravity? – Adam Varhegyi Nov 08 '11 at 11:30
http://developer.android.com/reference/android/widget/TextView.html#setGravity(int) , look at this.. – Yashwanth Kumar Nov 08 '11 at 11:31
6

Posting an enormous Document is not solution sorry, – Adam Varhegyi Nov 08 '11 at 11:59
look for setGravity method in the link.., somehow the redirection to the exact method is not working.. – Yashwanth Kumar Nov 08 '11 at 12:03
If the asker is refering to `layout_gravity` of the view within its container, and not `gravity` of the content of the view, then Karthi's answer below is the correct one. – Tony Chan Nov 16 '11 at 03:15
This did not work (at least not in API 7). Using LayoutParams works perfectly (see other answers). – JRomero Jul 26 '12 at 04:21

score 18 · Answer 5 · answered May 16 '17 at 16:56

18

layoutParams2.gravity = Gravity.RIGHT|Gravity.BOTTOM;

use this to add mor than one gravity

answered May 16 '17 at 16:56

Omar Alnajjar

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Nope, that's how: `gravity = Gravity.END or Gravity.BOTTOM` – Oleksandr Nos Oct 08 '20 at 15:39
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@OleksandrNos What you wrote is the Kotlin syntax, what Omar wrote is the java syntax. – Tamim Attafi Jan 25 '21 at 16:48

score 17 · Answer 6 · edited May 26 '23 at 15:54

17

If you want to change the layout_gravity of an existing view, do this:

((FrameLayout.LayoutParams) view.getLayoutParams()).gravity = Gravity.BOTTOM;

Remember to use the right LayoutParams based on the Layout type your view is in. Ex:

LinearLayout.LayoutParams

edited May 26 '23 at 15:54

bighugedev

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answered Apr 27 '15 at 07:48

vovahost

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score 11 · Answer 7 · edited Mar 01 '19 at 09:08

11

KOTLIN setting more than one gravity on FrameLayout without changing size:

     // assign more than one gravity,Using the operator "or"
    var gravity = Gravity.RIGHT or Gravity.CENTER_VERTICAL
     // update gravity
    (pagerContainer.layoutParams as FrameLayout.LayoutParams).gravity = gravity
     // refresh layout
     pagerContainer.requestLayout()

edited Mar 01 '19 at 09:08

BertKing

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answered Jan 29 '19 at 14:17

Hitesh Sahu

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It 's save my time... THX – BertKing Mar 01 '19 at 07:08
requestLayout() saved me ^_^ – Master Zzzing Jun 29 '22 at 07:39

score 10 · Answer 8 · answered Jun 11 '12 at 14:12

10

This question is old but I just had the same problem and solved it like this

LayoutParams lay = new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT)
lay.gravity = Gravity.CENTER;

answered Jun 11 '12 at 14:12

CodeFlakes

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@Muzikant.. ok.. i didnt noticed first.. but now its clear to me..Thanks – Noman Jul 18 '12 at 09:51
Does this only work by specifying what kind of layout it is first? Like RelativeLayout.LayoutParams ... instead of just LayoutParams – shecodesthings Oct 31 '12 at 18:48
RelativeLayout.LayoutParams use other flags to set gravity of the view (rightOf, centerInParent, centerVertical). This workaround is for LinearLayouts childrens – noni Sep 24 '13 at 20:41

score 5 · Answer 9 · edited Aug 26 '18 at 16:30

If you want to put a view in the center of parent, you can do with following code..

public class myLayout extends LinearLayout {

    public myLayout(Context context) {
      super(context);

      RelativeLayout vi = (RelativeLayout) ((LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(
            R.layout.activity_main, null);
      LinearLayout.LayoutParams cc = new LinearLayout.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
      cc.gravity = Gravity.CENTER;
      this.setGravity(Gravity.CENTER);
      this.addView(vi);
  }
}

these code section make LinearLayout put the first view elements in the center of parent. So, we system don't consider the initial width and high to arrange view in the center . I do the code section well.

score 5 · Answer 10 · answered Sep 05 '14 at 07:45

I use someting like that: (Xamarin and C# code)

  LinearLayout linLayout= new LinearLayout(this); 
    linLayout.SetGravity(GravityFlags.Center);

    TextView txtView= new TextView(this);  
     linLayout.AddView(txtView);

the SetGravity puts my textView in the center of the layout. So SetGravity layout property refer to layout content

score 5 · Answer 11 · answered Sep 06 '14 at 13:56

In case you need to set Gravity for a View use the following

Button b=new Button(Context);
b.setGravity(Gravity.CENTER);

For setting layout_gravity for the Button use gravity field for the layoutparams as

LayoutParams lp=new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
lp.gravity=Gravity.CENTER;

try this hope this clears thanks

score 3 · Answer 12 · edited Dec 16 '15 at 17:32

The rest of the answers are right, I want to add more explaination. The layout_gravity is about how to position the view in parent view.

You must set gravity **after method parentView.addView() ** was called. We can see the code:

public void setLayoutParams(ViewGroup.LayoutParams params) {
    if (params == null) {
        throw new NullPointerException("Layout parameters cannot be null");
    }
    mLayoutParams = params;
    resolveLayoutParams();
    if (mParent instanceof ViewGroup) {
        ((ViewGroup) mParent).onSetLayoutParams(this, params);
    }
    requestLayout();
}

And the problem of null pointer is because it's not calling addView before getLayoutParams().

The annotation was already said "This method may return null if this View is not attached to a parent ViewGroup or {@link#setLayoutParams(android.view.ViewGroup.LayoutParams)} was not invoked successfully. When a View is attached to a parent ViewGroup, this method must not return null."

This bit me too...it's not obvious you have to set gravity after the addView() is called. You'd think you'd set everything up on the new view and then add it so this is unintuitive :-P — kenyee, Aug 14 '16 at 03:23

score 3 · Answer 13 · answered Feb 02 '21 at 06:20

3

Modify the existing layout params and set layout params again

//Get the current layout params and update the Gravity
(iv.layoutParams as FrameLayout.LayoutParams).gravity = Gravity.START
//Set layout params again (this updates the view)
iv.layoutParams = layoutParams

answered Feb 02 '21 at 06:20

Sai

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In my case there is LinearLayout inside FrameLayout, and gravity for LinearLayout works only if I cast it to FrameLayout, example: `@BindingAdapter("android:stateLayoutGravity") fun LinearLayout.setStateLayoutGravity(gravity: Int) { (this.layoutParams as FrameLayout.LayoutParams).apply { this.gravity = gravity } }` – bene25 Jun 29 '23 at 11:32

score 2 · Answer 14 · answered Jul 21 '16 at 12:16

2

to RelativeLayout, try this code , it works for me: yourLayoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);

answered Jul 21 '16 at 12:16

michael wang

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score 2 · Answer 15 · answered Jul 11 '17 at 07:19

Perfectly Working!!! None of the above answer works for me. In Xml file setting gravity and setting layout_gravity is different. Check out the below code

// here messageLL is the linear layout in the xml file
// Before adding any view just remove all views
   messageLL.removeAllViews();
// FrameLayout is the parent for LinearLayout
FrameLayout.LayoutParams params = new 
   FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
   params.gravity = Gravity.CENTER|Gravity.CENTER_VERTICAL;
   messageLL.setLayoutParams(params);
   messageText.setVisibility(View.GONE);
   messageNoText.setVisibility(View.VISIBLE);
   messageLL.addView(messageNoText);

Also check This,where you can find clear explanation about gravity and layout_gravity .

score 2 · Answer 16 · answered Aug 29 '19 at 12:12

Most of above answer are right, so written a helper methods, so you can use it directly in you project .

set layout_gravity programmtically

// gravity types : Gravity.BOTTOM, Gravity.START etc.
// view : can be any view example : button, textview, linearlayout, image etc.

// for single view
   public static void setLayoutGravity(int gravity, View view){
     ((LinearLayout.LayoutParams) view.getLayoutParams()).gravity = gravity;
    }


// for mulitple views
  public static void setLayoutGravity(int gravity, View ...view){
        for(View item : view)
            ((LinearLayout.LayoutParams) item.getLayoutParams()).gravity = gravity;
    }

score 0 · Answer 17 · answered Jun 25 '15 at 20:35

I switched from LinearLayout.LayoutParams to RelativeLayout.LayoutParams to finally get the result I was desiring on a custom circleview I created.

But instead of gravity you use addRule

RelativeLayout.LayoutParams mCircleParams = new RelativeLayout.LayoutParams(circleheight,circleheight);

    mCircleParams.addRule(RelativeLayout.CENTER_IN_PARENT);

score 0 · Answer 18 · answered Aug 28 '18 at 09:47

 int width=getResources().getDisplayMetrics().widthPixels; 
 LinearLayout.LayoutParams params = new LinearLayout.LayoutParams
                    (width, width);

            params.gravity = Gravity.CENTER;

           iv_main_text = new HTextView(getContext());
            iv_main_text.setLayoutParams(params);
            iv_main_text.setBackgroundColor(Color.BLUE);
            iv_main_text.setTextSize(60);
            iv_main_text.setGravity(Gravity.CENTER);
            iv_main_text.setTextColor(Color.BLACK);

score 0 · Answer 19 · answered Aug 09 '19 at 08:05

FloatingActionButton sendFab = new FloatingActionButton(this);
    FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    layoutParams.setMargins(32, 32, 32, 32);
    layoutParams.gravity = Gravity.END|Gravity.BOTTOM;
    sendFab.setLayoutParams(layoutParams);
    sendFab.setImageResource(android.R.drawable.ic_menu_send);

score -1 · Answer 20 · answered Jul 07 '17 at 09:38

-1

Try this code

    Button btn = new Button(YourActivity.this);
    btn.setGravity(Gravity.CENTER | Gravity.TOP);
    btn.setText("some text");

or

    btn.setGravity(Gravity.TOP);

answered Jul 07 '17 at 09:38

Fakhriddin Abdullaev

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OP asks for `layout_gravity` not `gravitiy`. – alizeyn Jul 01 '18 at 12:04

How to set layout_gravity programmatically?

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