Develop Reference

How to add an transparent background image in android studio irrespective of transparency of data in the page?

enter image description hereIn linear layout I'm using image view, text view and also the edit text irrespective of the linear layout I'm thinking to add an image in the background which should be transparent when ever I try to use transparency then the whole activity is changing.However, need only the background image is transparent not the whole page.

According to what, I understood........
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:background="#drawable/download"
android:weightSum="2"
android:layout_height="match_parent">
<ImageView
android:layout_gravity="center"
android:src="#drawable/download"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="0dp" />
<LinearLayout
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="0dp">
<TextView
android:text="#string/dummy_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>

In my opinion, your design is not really appealing.
In your example, the text is not readable, it makes no sense to have an image twice in the same screen, the background picture is stretched and the front image is so small.
I would suggest you use something like this:
If you like it this way, here yo have the XML definition:
<?xml version="1.0" encoding="utf-8"?>
<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="match_parent"
android:orientation="vertical"
android:padding="10dp">
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Taj Mahal"
android:layout_marginBottom="5dp"
android:textSize="24sp"/>
<View
android:layout_height="2dp"
android:layout_width="match_parent"
android:background="#aaaaaa"/>
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:padding="10dp"
android:scaleType="fitXY"
app:srcCompat="#drawable/taj_mahal"/>
<View
android:layout_height="2dp"
android:layout_width="match_parent"
android:background="#aaaaaa"/>
<TextView
android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="The Taj Mahal is an ivory-white marble mausoleum on the south bank of the Yamuna river in the Indian city of Agra. It was commissioned in 1632 by the Mughal emperor, Shah Jahan (reigned 1628–1658), to house the tomb of his favourite wife."
android:textSize="18sp"/>
</LinearLayout>

Elevation not working for BottomSheet inside Coordinator layout

I am trying to use a BottomSheet in my layout.
The root view is an CoordinatorLayout and I want to set Elevation on top for the Bottom Sheet so i am setting it with a high value (50dp), however it is not showing when the app runs but it appears on android studio design tool.
I have tried to set background for the sheet with a solid color instead of gradient but it still did work. I also tried to use Shadow shapes but it does not give the same elevation appearance.
here is my XML
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.atefhares.StartActivity"
android:clipToPadding="false">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:id="#+id/DetailsView"
android:layout_width="match_parent"
android:layout_height="100dp"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Details Should be shown here"
android:id="#+id/textView"
android:textSize="25sp"
android:padding="20dp" />
</LinearLayout>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.atefhares.Start_Activity" />
</LinearLayout>
<android.support.v4.widget.SlidingPaneLayout
android:id="#+id/bottom_sheet"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:behavior_peekHeight="70dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
android:background="#drawable/gradiant"
android:fillViewport="true"
android:elevation="50dp">
<include layout="#layout/bottom_sheet_layout"/>
</android.support.v4.widget.SlidingPaneLayout>
</android.support.design.widget.CoordinatorLayout>
Edit:
bottom_sheet_layout.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:orientation="vertical">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="70dp"
android:background="#color/colorPrimary"
android:padding="10dp"
android:id="#+id/inviteLL">
<ImageView
android:layout_width="40dp"
android:layout_height="40dp"
android:id="#+id/imageView"
android:background="#drawable/invite_icon"
android:layout_margin="5dp"
android:layout_gravity="center_vertical" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Invite Friends"
android:textSize="22sp"
android:textColor="#ffffff"
android:padding="10dp"
android:fontFamily="sans-serif-condensed"
android:gravity="center_vertical"
android:id="#+id/inviteTV"
android:layout_gravity="center_vertical"
android:layout_weight="1" />
<ImageView
android:layout_width="30dp"
android:layout_height="30dp"
android:id="#+id/arrowIV"
android:layout_gravity="center_vertical"
android:background="#drawable/arrow_up" />
</LinearLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:id="#+id/usersLV"
android:dividerHeight="1dp"
android:divider="#ffffff"
android:background="#ffffff" />
</LinearLayout>
So how can I make the elevation shows on top of the Bottom Sheet
Any one can help, please ?

Try this,
<android.support.v4.widget.SlidingPaneLayout
android:id="#+id/bottom_sheet"
xmlns:slide_panel="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:behavior_peekHeight="70dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
android:background="#drawable/gradiant"
android:fillViewport="true"
slide_panel:elevation="50dp">

According to the google guidelines with the android:elevation is not possible (Also you can read more about the keyligth).
Anyway on the most common cases when you scroll up the "BottomSheet" a semitransparent layer appears behind the "BottomSheet", this helps to keep the user focus on the "BottomSheet" actions, like these examples.
If anyway you want a top shadow you can set a drawable background with gradient like this (shadow_top.xml):
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:angle="90"
android:centerColor="#000000"
android:endColor="#android:color/transparent"
android:startColor="#000000"
android:type="linear" />
And your SlidingPanelLayout will be:
<android.support.v4.widget.SlidingPaneLayout
android:id="#+id/bottom_sheet"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:behavior_peekHeight="95dp"
android:paddingTop="25dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
android:background="#drawable/shadow_top"
android:fillViewport="true"
>
Best regards.

Do not forget that to draw shadow you must use hardwareAccelerated drawing
hardwareAccelerated = true
hardwareAccelerated = false
See Android Hardware Acceleration for details

The answer is: no, it is not possible (unless you create your own view custom with an elevation feature on top).
Elevetion is not meant to be visible in the top of a view, but in the bottom, on the right and on the left.
If you see closely on the official Material Design guidelines, you can see that the bottom bar simply don't have it (do not confuse with the gray space between the card and the bottom bar).
For example: import Card View sample from Android Studio and play with it with emulator or your device. You will see that if you increment the elevation value, the view will have his shadow everywhere except on top (see second image below).
Another example is given by importing Elevation Basic.
EDIT
Following code is taken from Card View sample. There is a layout containing a CardView with elevation. Whenever you change the elevation, you will always see shadow everywhere, but not on top (the code was tested with Lollipop and Marshmallow).
<LinearLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
>
<android.support.v7.widget.CardView
android:id="#+id/cardview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:elevation="100dp"
card_view:cardBackgroundColor="#color/cardview_initial_background"
card_view:cardCornerRadius="8dp"
android:layout_marginLeft="#dimen/margin_large"
android:layout_marginRight="#dimen/margin_large"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/margin_medium"
android:text="#string/cardview_contents"
/>
</android.support.v7.widget.CardView>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/margin_large"
android:orientation="horizontal"
>
<TextView
android:layout_width="#dimen/seekbar_label_length"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="#string/cardview_radius_seekbar_text"
/>
<SeekBar
android:id="#+id/cardview_radius_seekbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="#dimen/margin_medium"
/>
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="#dimen/seekbar_label_length"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="#string/cardview_elevation_seekbar_text"
/>
<SeekBar
android:id="#+id/cardview_elevation_seekbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="#dimen/margin_medium"
/>
</LinearLayout>
</LinearLayout>

Android: how to create a button with a centre line in it?

i want to create a button with green color background and a white line in center, like in the image.

If you want to use a 9 patch (name it btn_green.9.png - mind the extension!), put it in your /res/drawable-mdpi folder.
You can use this one:
This is how it is shown in the draw9patch tool:
This is how to add it:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ImageButton
android:layout_width="match_parent"
android:layout_height="96dp"
android:background="#drawable/btn_green"
/>
</RelativeLayout>
It only uses 1 View, so it's a superfast (the less Views, the better performances)!!

You can create an ImageButton with Background attribute, and then create a View for the line setting the margin attribute to move it the position you want.
This is a very fast xml, but you can start playing with it
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageButton
android:layout_width="fill_parent"
android:layout_height="100dp"
android:background="#009900" />
<View
android:layout_width="fill_parent"
android:layout_height="5dp"
android:layout_marginTop="50dp"
android:background="#FFFFFF" /> </RelativeLayout>

If you want to make the button like that, you can use FrameLayout.
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageButton
android:layout_width="fill_parent"
android:layout_height="100dp"
android:background="#009900" />
<View
android:layout_width="fill_parent"
android:layout_height="2dp"
android:layout_gravity="center_vertical"
android:background="#FFFFFF" />
</FrameLayout>
The reason why i'm using FrameLayout is to overlap Views. so try this code, i hope it works.

Problems with RelativeLayout Android

I am new to Java and Android and I am facing this problem:
I would like to add a photo to the top/left corner of a Rectangle. However, the ImageView of my photo gets always more space and so, it creates a blank space on top that I would not like to have. Here is a screenshot:
The code of my Layout is:
<?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"
android:padding="25dp">
<ImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:src="#drawable/profile_frame" />
<ImageView
android:id="#+id/imageView2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/imageView1"
android:layout_centerVertical="true"
android:src="#drawable/foto_facebook_juan_mejorada" />
</RelativeLayout>

Try this:
android:scaleType="fitStart"
android:adjustViewBounds="true"

It may be because of
size of the image. If the image not fit in the space given it will add blank space.

// try this way
<?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="match_parent"
android:gravity="center">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="30dp">
<ImageView
android:id="#+id/imageView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/profile_frame" />
<ImageView
android:id="#+id/imageView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitXY"
android:src="#drawable/foto_facebook_juan_mejorada" />
</FrameLayout>
</LinearLayout>

android background in xml: tranparency become black not white

I make a xml file for android interface. In this xml, there's an expendable items. I want to add background for this xml with tansparency (alpha) but when i add bacground in relative layout with alpha like this
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/background"
android:alpha="0.2"
tools:context=".ListGestureActivity" >
that will make background transparency become black not white. In other xml happened like that too.
But in other xml i tried to do this
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
tools:context=".HintGestureActivity" >
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:alpha="0.3"
android:background="#drawable/background"
/>
it worked. But in xml with expendable items didn't work.
Do you any suggestion?

U can do something like this
android:background="#00564678"
For Ex:
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:alpha="0.3"
android:background="#00564678"
/>

By default it takes black color as your background color and after that, if you apply transparency then you will not get desired output.Therefore, first you need to set some background color after that apply alpha on that. Try this :
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:alpha="0.2"
tools:context=".ListGestureActivity" >