Develop Reference

Dynamically added TextInputLayout is not shown in LinearLayout

I am adding a View in a LinearLayout, this way:
LinearLayout ll=(LinearLayout)findViewById(R.id.linearlayout);
TextInputLayout til=new TextInputLayout(MainActivity.this);
til.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
Log.i("TAG","BEFORE: "+ll.getChildCount());
ll.addView(til);
Log.i("TAG","AFTER: "+ll.getChildCount());
This way, the til object is not shown, but it IS added, because in the second log I see the number has incremented by one, the view I just added.
Why can't I see it? how to show the new view in the layout?
Thank you.

I think what you are forgetting is to add an EditText or a TextInputEditText to the TextInputLayout.
The android documentation says:
[TextInputLayout is a] Layout which wraps an EditText (or descendant) to show a floating label when the hint is hidden due to the user inputting text.
EditText editText = new EditText(this);
RelativeLayout.LayoutParams editTextParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
editText.setLayoutParams(editTextParams);
editText.setTextSize(16);
editText.setTextColor(getResources().getColor(R.color.black));
editText.setHint("hint");
editText.setHintTextColor(getResources().getColor(R.color.gray));
textInputLayout.addView(editText, editTextParams);

TextInputLayout is nothing without having EditText as child.
Create a layout file text_input_layout.xml as below:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.TextInputLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.TextInputLayout>
Now, to add, simply inflate this layout and addView() to LinearLayout as below:
LinearLayout linearLayout = (LinearLayout) findViewById(R.id.linearlayout);
TextInputLayout textInputLayout = (TextInputLayout) LayoutInflator.from(this).inflate(R.layout.text_input_layout, null);
linearLayout.addView(textInputLayout);
Hope this helps...
Note: You can also have TextInputEditText as Child of TextInputLayout

The til has zero height. Use this instead:
til.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));

How to remove layout anchor_property of fab in programmatically?

I have added layout_anchor property on fab in layout xml. After clicking a button the fab should position on end of the screen. To achieve that I am thinking to add gravity property. But how do i remove layout_anchor property programmatically.
layout.xml
<com.samsoft.sam.Fab
android:id="#+id/fab"
app:layout_anchor="#id/asd"
app:layout_anchorGravity="top|end"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
The above is my fab code and it positions perfectly, now I need to replace layout anchor property with android:gravity="top|end" programmatically. Please help me.

I assume you mean you want the FloatingActionButton's layout_gravity to end up as top|end.
You can do this by getting the FloatingActionButton's CoordinatorLayout.LayoutParams, clearing the anchor's ID, setting the gravity field as needed, and then setting the LayoutParams back on the FloatingActionButton.
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) fab.getLayoutParams();
lp.setAnchorId(View.NO_ID);
lp.gravity = Gravity.TOP | GravityCompat.END;
fab.setLayoutParams(lp);

((CoordinatorLayout.LayoutParams) floatingActionButton.getLayoutParams()).setAnchorId(View.NO_ID);
This is the code you are looking for. Happy coding :)

Adding a widget in scrollView programmatically

I am having trouble adding a view in the scrollview. The structure of my xml is
// xml_layout.xml
<ScrollView>
<LinearLayout
android:id="#+id/container"
>
<LinearLayout>
<ListView
...
/>
</LinearLayout>
******Here I am trying to add an item *********
</LinearLayout>
</ScrollView>
I am trying to add a textview at the bottom programmatically as follows.
TextView v = new TextView(getActivity());
ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
v.setText("TEST View");
v.setLayoutParams(params);
LinearLayout container = (LinearLayout) LayoutInflater.from(getActivity()).inflate(R.layout.xml_layout, null).findViewById(R.id.container);
container.addView(v, 1);
The goal I am trying to achieve is making a tablelayout that contains two columns with the title and listview in the second column. Before I do this, I tried to display a simple textview so that I know I can add a widget. I have tried many different ways but did not work. Is there something wrong with my code??

you must first verify that your LinearLayout 'container' is 'vertical ' orientation, and...
LinearLayout container = (LinearLayout) findViewById(R.id.container);
container.addView(v);

Configure CoordinatorLayout from code

I'm dynamically injecting a content view into the CoordinatorLayout and would now like to apply a layout_below property to the injected view so that it isn't hidden behind the AppBar.
Is there any way to do this at runtime from code instead of xml properties of the annotation?

Taking one step back and building the entire view in plain xml, I realized that layout_below is not the property I needed for my use case: placing the content view below the app bar. I did not make this clear in my question though, as I assumed layout_below would be the proper option for that.
In fact, to insert a non scrolling view into the CoordinatorLayout it should first be wrapped with a android.support.v4.widget.NestedScrollView. Then, to avoid its content being hidden behind the app bar, it is necessary to update its behavior to android.support.design.widget.AppBarLayout.ScrollingViewBehavior. Otherwise a default behavior is used which will hide behind the app bar.
val viewToInsert = getLayoutInflater.inflate( id, coordinatorWrapper, false )
val p = viewToInsert.getLayoutParams.asInstanceOf[Coordinator.LayoutParams]
p.setBehavior( new ScrollingViewBehavior )
coordinatorWrapper.addView( viewToInsert, 1, p )

You could try setting an anchor.
ContentView view = getContentView(); //your view
CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) view.getLayoutParams();
params.setAnchorId(R.id.app_bar_layout);
params.anchorGravity = Gravity.BOTTOM; //we will anchor to the bottom line of the appbar
params.gravity = Gravity.BOTTOM; //we want to be BELOW that line
view.setLayoutParams(params);

Android: Retrieve layout_marginBottom programmatically?

In my a LinearLayout I have set android:layout_marginBottom in my XML. I just want to retrieve that value.
Just LayoutParams doesn't give me access to bottomMargin . I tried to typecast :
row1 = (LinearLayout) findViewById(R.id.mainrow1);
LinearLayout.LayoutParams row1Params = (android.widget.LinearLayout.LayoutParams) row1.getLayoutParams();
but this gives me Runtime exception ClassCastException.
The main aim is I got buttons in nested LinearLayouts & I want to set height/width of LinearLayout programmatically that will inturn auto set height of buttons. I have added bottomMargin after 1st layout - so there is space between 2 rows.

Change Your layout of Button according to following logic,
set Layout_Width to 0dip
set Layout_Weight to 1
set Layout_Height to Wrap_Content

try this. When you get layout, R.layout. is best option. It is working for me.
row1 = (LinearLayout) findViewById(R.layout.mainrow1);