Develop Reference

Android remove border hover from FloatActionbutton

current situation
So as you can see on the picture there is a shadow on the border of my button. Is there a way to remove the shadow so that that the color of the button corresponds with the color of my action bar. right know it looks ugly because you can see the shadow. This is my code:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout 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="wrap_content"
android:orientation="horizontal"
>
<TableRow
android:gravity="end">
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/logInButton"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:borderWidth="0dp"
app:backgroundTint="#color/faviconColor"
app:srcCompat="#drawable/ic_person_black_24dp" />
</TableRow>
</TableLayout>

Try setting android:elevation="0dp" to your floatingaction button.
Nevertheless, why even use a FloatingActionButton, and not just a normal button? FloatingActionButtons are afaik not made to be used like this, and if you need e.g. a round ripple effect, there are more elegant ways to do this.
EDIT:
If this does not work (as sometimes) use app:elevation="0dp" instead

Android: Strange gap between buttons

I am just beginning with Android. I am making a layout with buttons, but a very strange thing is happening — there is a small gap between them. Setting margin and padding to 0 is also not helping.
Here is my simple layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical">
<Button
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
<Button
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
</LinearLayout>
It is looking like this:

Make your own flat Button style with ripple effect [lollipop] and without it [pre-lollipop]:
https://gist.github.com/dmytrodanylyk/3513e42839ae4309d2b5

You have to use android:background to change the background of button. For example if you use android:background = "#FFFFFF" your visual problem is fixed. In reality , there is no space between the buttons, their background creates an "illusion"

Overlay over an ImageView on Android

So I have a list of images that come from the web, I don't know which color are they and I want to place a text over the ImageView.
My idea is to place the ImageView, an image overlay with transparency gradient over that ImageView and the text above it. I want to mimic this behaviour:
Is there anyway to do this via XML?

When you write the XML for your list items which get inflated in the getView(...) of whatever ListAdapter you've written you can surely do this.
Something like this for the list item:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="320dp"
android:layout_height="240dp"
android:background="#ACACAC"/>
<RelativeLayout
android:layout_width="320dp"
android:layout_height="240dp"
android:background="#drawable/gradient">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Here is your text"
android:textColor="#000000"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
</RelativeLayout>
Then you create that drawable/gradient. For that you can recycle the answer from here.

Thanks to adityajones I managed to get there :)
So although this is my right answer, I'll mark his as the correct one!
<?xml version="1.0" encoding="utf-8"?>
<ImageView
android:layout_width="fill_parent"
android:layout_height="200dp"
android:scaleType="centerCrop"
android:src="#drawable/image" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="200dp"
android:background="#drawable/gradient_image" >
<TextView
android:id="#+id/text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_margin="6dp"
android:layout_marginBottom="18dp"
android:shadowColor="#000"
android:shadowRadius="7.0"
android:text="This is some random text"
android:textColor="#color/white"
android:textSize="22sp" />
</RelativeLayout>

I'd use a FrameLayout or RelativeLayout. The first View you add to either should be the background ImageView, then obviously you'll need some TextViews and Other ImageViews [or Buttons, or ImageButtons, etc]
Seems like a reasonable layout: a background image, and then one additional view in each corner.
For the gradient, you'll probably want a separate Layout/View at the bottom with a gradient drawable as the background, although I can imagine you might be able to get away with setting the background of one of your TextViews as the gradient.

You do not have to use a gradient drawable file or set it in your xml..
you can do this pragmatically using GradientDrawable Class as explained in this related Question (Create a radial gradient programmatically) then set it as a background for a layout that covers your ImageView, this gives you ability to use different colors and orientations

Change background color dynamically and use a border

I have the following template
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#drawable/borders" >
<RelativeLayout
android:id="#+id/layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp">
<ImageView
android:id="#+id/category_starred_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/rating_not_important"
android:contentDescription="#string/app_name" />
<TextView
android:id="#+id/category_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/category_starred_icon"
android:textIsSelectable="false"
android:textSize="18sp"
android:paddingLeft="5dp"
android:paddingTop="5dp"
android:paddingRight="5dp"
android:textColor="#android:color/white"
android:hint="#string/category" />
</RelativeLayout>
</LinearLayout>
i get a warning This RelativeLayout layout or its LinearLayout parent is possibly useless; transfer the background
attribute to the other view, i want solve it, but i have the follow problem i have a border in the LinearLayout is like a drop shadow but when i change the background color in my code
mLayout.setBackgroundColor(Color.paseColor(mColorString));
i lost the border, how i can solve the warning witout lose the border, the main problem is the background colors are dynamically

Have a look at this: http://developer.android.com/guide/topics/resources/drawable-resource.html#LayerList
This is an drawable that organizes other drawables in a layer list (one on top of the other). With it, you can use other drawables, like shape, to define the borders and the background the way you want.
I can't make a complete answer now, but if you search for this, I'm sure you can do it. When I have more time, I may come back to help you, if you haven't found out how to solve this yet.

Radio Button Text over Button

I'm trying to create a view in android that looks like:
Text
Radio Button 1
...
...
I thought it was simple enough but at least in the layout preview and emulator I'm seeing the text for the RadioButton appear on top of the actual radio button (the circle), see the attached screen shot. I'm guessing this is something very trivial but I'm messed around with gravity and every other setting I can think of and nothing. Android 3.1 if that matters.
Here's my layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#color/white"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="#+id/question_text"
android:textColor="#color/primary_gray"
android:layout_width="match_parent"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
android:layout_height="wrap_content"/>
<RadioGroup android:id="#+id/multiple_choice_one_answer_group"
android:background="#color/white"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RadioButton
android:background="#color/primary_gray"
android:textColor="#color/black"
android:textSize="10sp"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" />
</RadioGroup>
</LinearLayout>
Screenshot:

The problem is setting the background. If you remove the background from the RadioButton and keep it on the RadioGroup, it has the effect you're looking for. In general, setting the background of a Button to everything removes the button look; try it on a regular Button and you'll see. This is because the background for a Button is already set to something, and you're replacing it with a flat color.
Try this instead:
<RadioGroup android:id="#+id/multiple_choice_one_answer_group"
android:background="#color/primary_gray"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RadioButton
android:textColor="#color/black"
android:textSize="10sp"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" />
</RadioGroup>

Setting the background in the java code instead of the layout solves this as well.