How to place center of a view inside FrameLayout - android

I have a FrameLayout which already holds a child view, and I know its width and height in pixels. I want to programmatically add a new view so that its center is at the specific point of the frame layout. Size of the view is not known and its FrameLayout.LayoutParams is set to WRAP_CONTENT, WRAP_CONTENT. How can I do it?

Say you want to position a TextView in the middle of a FrameLayout.
TextView text = (TextView)frame.findViewById(R.id.text);
FrameLayout frame = (FrameLayout)findViewById(R.id.frame1);
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
Now add your TextView to your FrameLayout and set gravity to center
frame.addView(text);
params.gravity=Gravity.CENTER;
I haven't tried it but I think it should work.

In KOTLIN
viewToADD?.layoutParams = FrameLayout.LayoutParams
(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT).
apply {gravity = Gravity.CENTER and Gravity.CENTER_VERTICAL}
frameLayout.addView(viewToADD)

Related

TextureView Align Parent Right Programmatically

I have a customView extending from TextureView. I want this customView to always align_parent_right.
My method inside customView has the following code:
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams();
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
setLayoutParams(layoutParams);
However, customeView is still aligned left and not right. How can it be change to align right?
Add this way
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams();
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
layoutParams.addRule(RelativeLayout.LEFT_OF, R.id.leftViewIdHere);
setLayoutParams(layoutParams);

Aligning ImageView to LinearLayout programmatically

I need to programmatically align an ImageView to the bottom of a LinearLayout.
I, of course, already tried to add the ImageView as a child of the LinearLayout, but the image get shrinked (cause the LinearLayout is smaller than the image), and I need the image not be resized, only bottom-aligned.
I also tried this :
RelativeLayout main_layout = (RelativeLayout) view.findViewById(R.id.main_layout);
LinearLayout line_0_layout = (LinearLayout) view.findViewById(R.id.line_0_layout);
ImageView horse_img = new ImageView(getActivity());
horse_img.setImageResource(R.drawable.horse);
RelativeLayout.LayoutParams layout_params = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layout_params.addRule(RelativeLayout.ALIGN_BOTTOM, line_0_layout.getId());
horse_img.setLayoutParams(layout_params);
main_layout.addView(horse_img);
but it doesn't work : the image is added to the view but not aligned to the LinearLayout.
It seems simple question, but it's not.
Thanks in advance for your help.
layout_params.addRule(RelativeLayout.BELOW, line_0_layout.getId());

Set framelayout margin and its children width, height and position

I am currently having a programatically created framelayout with a imageview and a text view. By original layout is relative layout.
RelativeLayout layout = (RelativeLayout) findViewById(R.id.rel);
FrameLayout fr = new FrameLayout(this);
fr.setBackgroundResource(R.drawable.question_bar_icon);
ImageView b1 = new ImageView(this);
TextView b2 = new TextView(this);
b1.setBackgroundResource(R.drawable.mcq);
fr.addView(b1);
fr.addView(b2);
layout.addView(fr);
Now i am unable to resize the imageview and the button, also m unable to position them, in the sence textview in the center and imageview in the verticle center and left positioned.
I tried layout params, but not working, any help would be greatly appreciated!
Try using the overloaded version of addView that takes a LayoutParameter as well in every case you are programatically adding a view, otherwise it is inserted to the ViewGroup with default layout parameters. (P.S. you can also control the order of insertion).
For example for the ImageView you wanted to be in the center of the frame layout:
int width = FrameLayout.LayoutParams.WRAP_CONTENT; //or whatever you want
int height= FrameLayout.LayoutParams.WRAP_CONTENT; //or whatever you want
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(width, height, Gravity.CENTER);
fr.addView(b1,lp);
Do the same for the other view, and most importantly, do the same, using RelativeLayout.LayoutParams for inserting the frame element itself into your RelativeLayout.

How do I set MarginTop property in javacode?

I created LinearLayout and Button via class not via XML. I know how to inflate layout view and button view dont know how to set margins of them. I need to set margins of my button and my linearlayout. If I use XML, it is very simple: <android:marginLeft="10px">.
But, what should I do if I want to set margin by class not by XML?
In this we have linear layout in main.xml named lyt1 and we add edittext at runtime and set
left margin value
please use bleow code :
lyt = (LinearLayout)findViewById(R.id.lyt1);
EditText txt = new EditText(WvActivity.this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
lp.leftMargin = 10;
txt.setLayoutParams(lp);
lyt.addView(txt);
lyt.invalidate();
Use:
LinearLayout.LayoutParams params=new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
params.setMargins(left, top, right, bottom);

How to set layout_gravity programmatically?

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?
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
}
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...
I'd hate to be resurrecting old threads but this is a problem that is not answered correctly and moreover I've ran 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 works 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 FILL_PARENT (think of it as auto margin). layout_gravity centre WILL affect view that is FILL_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(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.CENTER;
button.setLayoutParams(params);
Link to LinearLayout.LayoutParams.
android:layout_gravity shows "No related methods" meaning cannot be access programatically.
Whereas gravity is a field in the class.
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)
MyButton.setGravity(Gravity.RIGHT);
For layout_gravity use the answer stated by "karthi". This method sets gravity to place the children inside the view.
layoutParams2.gravity = Gravity.RIGHT|Gravity.BOTTOM;
use this to add mor than one gravity
If you want to change the layou_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
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()
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;
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
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
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.
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."
to RelativeLayout, try this code , it works for me:
yourLayoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
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 .
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;
}
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
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);
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);
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);
Try this code
Button btn = new Button(YourActivity.this);
btn.setGravity(Gravity.CENTER | Gravity.TOP);
btn.setText("some text");
or
btn.setGravity(Gravity.TOP);

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