Develop Reference

RecyclerView (wrap_content) inside of a BottomSheetDialogFragment

I'm facing a tricky situation here and I don't know how to solve this problem.
In my project I have a custom BottomSheetDialogFragment and in the layout a FrameLayout to add or replace Fragments.
Now I have a Fragment and inside I have a RecyclerView with the height:="wrap_content" because I want the BottomSheetDialogFragment only use the necessary space. Everything looks great, the problem appear when I put another view inside of the same layout and set the RecyclerView bellow or above of that view.
The RecyclerView ignores the size of the other view (or views) and always grows to the max screen size, and then it's no possible to see a few elements and even scroll.
I saw a solution, some developers are suggesting to add paddingBottom equals to the height of the view. But in my case doesn't works because I want to have a dynamic solution.
Above I'll share a few images of the problem and GitHub Repository with a sample.
Thanks for your attention!

I've manage to do what you need just need to use this as your fragment_sample.xml:
<LinearLayout 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="wrap_content"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/rclItems"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
app:layoutManager="android.support.v7.widget.LinearLayoutManager"/>
<Button
android:id="#+id/btnAddMoreItems"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/rclItems"
android:text="#string/add_1_item"/>
</LinearLayout>
Explanation
Using a LinearLayout gives you the ability to work with weight, and the vertical orientation allows you to place an item below the other. The weight on the recyclerview will increase the height of it as needed until filling the screen. The next item you add would be added to the recyclerview but you'll need to scroll the list to see it

The android developers blog says that :-
The scrolling containers in your bottom sheet must support nested scrolling .
Try changing your fragment_sample.xml as below to make the recyclerview scroll working and to make the add button persistent.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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="wrap_content">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:id="#+id/next"
android:layout_above="#id/btnAddMoreItems"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/rclItems"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</android.support.v4.widget.NestedScrollView>
<Button
android:id="#+id/btnAddMoreItems"
android:layout_width="match_parent"
android:layout_alignParentBottom="true"
android:layout_height="wrap_content"
android:text="#string/add_1_item"/>
</RelativeLayout>
Note: making bottomsheet layout a child view of CoordinatorLayout will allow you to get the implement BottomSheetBehavior and recieve its transitions callbacks .

Filling a view that has `wrap_content` as height

So I'm using a RecyclerView, with some cards. I want to get an overlay on the card when it's clicked, which should cover all contents, but not change the size of the view. Hardcoding the size of the card is not possible, since the contents have different dimensions.
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!--contents and stuff-->
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000" />
</RelativeLayout>
The example above is pretty much what I'm trying to achieve, but this obviously won't work, since the View's and RelativeLayout's height refer to each other.
How can I make the View cover everything inside the RelativeLayout?
Edit
Clarification: The issue I'm having has nothing to do with clicking, covering or anything like that. I'm having issues with just covering the RelativeLayout.

Credits go to thunder413 for suggesting the FrameLayout in the comments.
Basically, all I had to do was encapsulating the RelativeLayout (as shown in my question) in a FrameLayout, and move the View out of the RelativeLayout into the FrameLayout
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<!--contents and stuff-->
</RelativeLayout>
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000" />
</FrameLayout>

Android/XML - How to align an immobile layout to top of parent and have scrollview below?

Please refer to example below. I want to have the top layout (below encased in red) to be unmoving in a scrollview in my activity. I have a scrollview as the parent layout and then I thought having a relative layout for the top one would work, and align it to the top, but that didn't really work out as it still remained within the scrollview. I would like to have the users have the red-layout box remain static when they scroll down.
I figure I would also have to put in a topMargin at the top of the scrollview or something in order to fit the redbox layout in.
XML Code posted here: http://pastebin.com/bxdREbeG

Do something like this (hand code, for reference only):
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/YourTopStaticView"
android:layout_width="match_parent"
android:layout_height="48dp"> //Or any other height you want
//Contents of the top view
</RelativeLyout>
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/YourTopStaticView">
//Contents of the ScrollView
</ScrollView>
</RelativeLayout>
As a side note, do not hardcode children into the ScrollView like that. Use the RecyclerView (which is an updated, modern replacement for ListView), which you will be expected to know how to use if you want to move into serious Android programming. It is actually super easy to use, once you get the hang of it :-)

You should use the ScrollView with only one child (official documentation - http://developer.android.com/reference/android/widget/ScrollView.html). According to your xml, your ScrollView is very complicated with a lot of child widgets.
The best option for you is to use a LinearLayout as the root for the whole container, a LinearLayout( or Relative) for the top layout containing the Reset and Save buttons, and a ListView for the long list that you have. ListView takes care of it's own scrolling. So you don't have to worry about that.
This will improve your code performance as well.

This should suit your needs:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout android:id="#+id/topPanel"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp">
<TextView android:id="#+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:text="Multi TTS Implementation"/>
<Button android:id="#+id/save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:text="SAVE"/>
<Button android:id="#+id/resetAll"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="#id/save"
android:layout_centerVertical="true"
android:text="RESET ALL"/>
</RelativeLayout>
<ScrollView android:id="#id/scroll"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_below="#id/topPanel"
android:layout_alignParentBottom="true"
android:padding="5dp">
<!-- Your scrollable content here -->
</ScrollView>
</RelativeLayout>

Putting two child layout inside a parent layout with equal weight distribution in Android

I want to use two child layout (one linear layout and one relative layout) inside a parent layout (relative layout) in such a way that both of the child layout will take exactly half of the screen and items inside of each child layout will not cause one child layout to get more width than another one!

It is pretty easy, use parameter layout_weight in children of LinearLayout, something like this:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent">
</RelativeLayout>
<RelativeLayout
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent">
</RelativeLayout>
</LinearLayout>

If I understand correctly from your illustration, the red box is a RelativeLayout, whereas the green boxes are a LinearLayout and a RelativeLayout.
A simple solution would be to center an empty View inside the RelativeLayout and align the two child Views against it:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_toLeftOf="#+id/v_center" />
<View
android:id="#+id/v_center"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_centerInParent="true" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_toRightOf="#+id/v_center" />
</RelativeLayout>
A nice little bonus here is that you can provide some spacing between the two by specifying the View's dimensions.
Beware, however, that RelativeLayouts aren't very efficient, and nesting them is an especially bad idea. I suggest using the hierarchy viewer tool to inspect the layout timings to make sure it's relatively fast, and to try to avoid nesting the layouts in this fashion.

LinearLayout, RelativeLayout, etc. margins do not work as expected

Margins in group layouts do not seem to work.
For example,
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_margin="40dip"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="I'm a button" />
</LinearLayout>
should display a button with 40p margins on all sides. However, it has 80p margins on the right and bottom.
Am I doing something wrong?
Is this a bug?
A workaround would be to use gravity, but this only works with even margins.
BTW, there is a similar question posted here but has not been answered.

android:padding="40dp" on the LinearLayout or android:layout_margin="40dp" on the Button will give you the effect you want. Padding defines the space between a views edges and its content, layout margin defines extra space on the sides of a view.

The problem is actually the way FrameLayout interprets margins. setContentView() attaches your "main" layout to a FrameLayout, which is the actual root of the view hierarchy (you can see that with Hierarchy Viewer) and is offered to you by the phone.
Margins are managed by the parent layout, so in this case that main FrameLayout. I don't know if it's a feature or a bug, but that's how this layout interprets margins.
So well, the solution was already posted while I was typing: use padding instead.

if you need set margin for a layout, simply wrap it with another linear or relative layout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout android:layout_margin="40dip"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="I'm a button" />
</LinearLayout>
</LinearLayout>

Wrapping the Linear Layout with another layout is the best strategy.