Develop Reference

Add gradient to imageview

I want to add a gradient on the bottom of my image . Something like this :
I tried something like this but I only get the gradient no image..
<ImageView
android:id="#+id/trendingImageView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#drawable/trend_donald_sterling"
android:src="#drawable/trending_gradient_shape"
/>
trending_gradient_shape:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="90"
android:endColor="#android:color/darker_gray"
android:startColor="#android:color/darker_gray" />
<corners android:radius="0dp" />
</shape>

You need two layers: An ImageView, and a View on top of that with your gradient as android:background. Put these two Views in a FrameLayout:
<FrameLayout
... >
<ImageView
...
android:src="#drawable/trend_donald_sterling" />
<View
...
android:background="#drawable/trending_gradient_shape"/>
</FrameLayout>

Simply set the alpha value in your gardient.xml:
Your imageView:
android:background="#drawable/trend_donald_sterling"
android:src="#drawable/trending_gradient_shape"
Your gradient xml file:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="90"
android:endColor="#00ffffff"
android:startColor="#aa000000"
android:centerColor="#00ffffff" />
<corners android:radius="0dp" />
</shape>
In the color value, the first two places after # correspond to the alpha value, while the rest are the actual color value in R G B format, two for each.

try using the "foreground" attribute in your imageview
<ImageView
...
android:src="#drawable/trend_donald_sterling"
android:foreground="#drawable/trending_gradient_shape" />
it worked for me.

Use android:foreground="..." instead of android:background="..."
Now you won't need to put ImageView and View inside a FrameLayout!
So your final code will be:
ImageView
<ImageView
...
android:foreground="#drawable/trend_donald_sterling"/>
Drawable
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="90"
android:endColor="#00ffffff"
android:startColor="#aa000000"
android:centerColor="#00ffffff" />
<corners android:radius="0dp" />
</shape>

this is how im gonna do,
i used relative layout as my parent layout, use the following code
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="#drawable/img_sample"/>
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/gradiant"/>
<LinearLayout
android:layout_marginLeft="10dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="1">
<View
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.55"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="0.25"
android:text="Events"
android:gravity="bottom"
android:textStyle="bold"
android:textSize="18sp"
android:textColor="#ffffff"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="0.25"
android:text="Some description about the events goes here"
android:textSize="14sp"
android:textColor="#ffffff"/>
</LinearLayout>
</RelativeLayout>
hope you can figure out, here i attach my gradiant code below.use it inside the drawable folder....
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="90"
android:endColor="#00ffffff"
android:startColor="#aa000000"
android:centerColor="#00ffffff" />
<corners android:radius="0dp" />
</shape>

This is an easy way that creates a similar effect yet doesn't actually have the image disappear. Sometimes using the foreground attribute is not the best for the gradient, especially if using a motionlayout or you have nested scrollviews. Create an entirely new imageview and set the background to the gradient.
XML With Both Imageviews
<ImageView
android:id="#+id/main_imageView"
android:layout_width="0dp"
android:layout_height="0dp"
android:scaleType="centerCrop"
android:src="#drawable/peakpx__1_"
ads:layout_constraintHeight_percent=".55"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="#+id/main_imageView_gradient"
android:layout_width="0dp"
android:layout_height="0dp"
ads:layout_constraintHeight_percent=".55"
android:background="#drawable/gradient_theme_background"
app:layout_constraintEnd_toEndOf="#id/main_imageView"
app:layout_constraintBottom_toBottomOf="#id/main_imageView"
app:layout_constraintStart_toStartOf="#id/main_imageView" />
Then for the gradient, I use black #000000 for darker themes, and white #ffffff for lighter ones. A lot of answers I see on this are not adding the center color. This is important if you want to have the gradient start closer to the edge of the image.
gradient_background
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<gradient
android:angle="270"
android:type="linear"
android:endColor="#ff000000"
android:centerColor="#00000000"
android:startColor="#00000000"/>
</shape>

**1> Create file black_shadow.xml**
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<gradient
android:angle="270"
android:startColor="#00000000"
android:centerColor="#9c000000"
android:endColor="#000000"
android:type="linear" />
</shape>
</item>bla
</selector>
**2> Just add below line in Imageview.**
android:foreground="#drawable/black_shadow"

How can I show a label with text in the middle?

I am trying to get a TextView with white background and rounded corners and text in the middle.
Something that looks like this:
So far I have this but it is not giving me the above effect.
<TextView
android:textColor="#000000"
android:background="#FFFFFF"
android:text="0" />

First of all, I would create a custom drawable resource for easy implementation of rounded corners.
(place this in res/drawable)
my_bg.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid
android:color="ffffff" />
<corners
android:radius="15dp"/>
<stroke
android:width="1dp"
android:color="#android:color/black" />
</shape>
More info on xml drawable resources can be found right here if you want to get into more advanced drawables (gradients, layer-list, animation, etc...)
Then change your TextView in xml layout file to match this:
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="8dp"
android:textColor="#000000"
<!--refer to your custom drawable from earlier-->
android:background="#drawable/my_bg"
<!--center text within TextView-->
android:gravity="center"
android:text="0" />
I hope this helps, Happy Coding!

Set the gravity
android:gravity="center"
http://developer.android.com/reference/android/widget/TextView.html#attr_android:gravity
You are missing the width and height attribute for TextView.
For the rounded corners use a Shape Drawable
http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape
Under res/drawable
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle"
>
<solid android:color="#FFFFFF"/>
<corners android:radius="7dp" />
<stroke android:width="5px" />
</shape>
Then
<TextView
android:layout_width="100dp"
android:layout_height="50dp"
android:background="#drawable/background"
android:gravity="center"
android:text="0"
android:textColor="#000000" />
Snap

How to make a view transparent as a function of length in android

I have a frame layout (semi transparent black), on which I have written "Swiss Chalet - score a free side" and "Missisauga, ON". It is the same color/transparency from top to bottom, I want it to be more opaque towards the bottom and transparent towards the top, so that just above "Swiss Chalet" line it feels the the frame layout is merging with the background image. How do I implement that?
Right now my code is,
<FrameLayout
android:id="#+id/frameLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/frameLayout2"
android:layout_alignParentLeft="true"
android:background="#5A000000">
<TextView
android:id="#+id/campaignNameLabel"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:maxLines="2"
android:ellipsize="end"
android:text="Loading..."
android:layout_marginLeft="10dp"
android:textColor="#ffffff"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold" />
</FrameLayout>

You can use a GradientDrawable in your FrameLayout background to achieve what you want.
You can define a gradient in a xml file like this:
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
android:angle="270"
android:startColor="#5A000000"
android:endColor="#FF000000" />
</shape>
Or in your java code:
int[] colors = {0x5A000000, 0xFF000000};
GradientDrawable drawable = new GradientDrawable(GradientDrawable.Orientation.TOP_BOTTOM, colors);

You can do something like that using a gradient background for the FrameLayout as follows:
Step 1) Create a gradent_background_selector.xml as follows:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<gradient
android:angle="270"
android:startColor="#00000000"
android:centerColor="#44000000"
android:endColor="#5A000000"
android:type="linear" />
</shape>
</item>
</selector>
Step 2) Apply it to you FrameLayout as follows:
<FrameLayout
android:id="#+id/frameLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/frameLayout2"
android:layout_alignParentLeft="true"
android:background="#drawable/gradent_background_selector">
<TextView
android:id="#+id/campaignNameLabel"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:maxLines="2"
android:ellipsize="end"
android:text="Loading..."
android:layout_marginLeft="10dp"
android:textColor="#ffffff"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold" />
</FrameLayout>
Step 3) Play around with the values of startColor, centerColor and endColor to get the desired output.
Note: I used three color gradient because you mention "just above "Swiss Chalet" line it feels the the frame layout is merging with the background image". To get more precise results, you may want to read about multi-gradient shapes

Create your gradient selector in res/darawable like:
gradient_selector.xml
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<gradient
android:angle="90"
android:startColor="#5A000000"
android:endColor="#00000000"
android:type="linear" />
</shape>
</item>
</selector>
And use it as background of your layout:
<FrameLayout
android:id="#+id/frameLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/frameLayout2"
android:layout_alignParentLeft="true"
android:background="#drawable/gradient_selector">
</FrameLayout>

Android: Round Image inside ring shape

I want to create a button with image inside it as shown at the bottom of this pic https://trianglewiki.org/RGreenway_App/_files/android.jpg/_info/. I am trying using layer-list and shape drawables and able to create buttons very similar. My problem is that my image is not scaling inside the button as I would like. The ring shape is coming on the top of the image but image is not inside it.
I want the image to be completely inside the ring. I think there is something wrong with the parameters values I am giving. But it could be I am not doing it the proper way.
Can somebody check my xml files and see what is the problem or provide me with any information how to do it so that I get the same effect in the button as in the link above. Thanks
custom_button.xml (in res/drawable)
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:drawable="#drawable/map"/>
<item>
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadius="20dp"
android:innerRadiusRatio="1.75"
android:shape="ring"
android:thicknessRatio="25"
android:useLevel="false"
>
<gradient
android:angle="90"
android:endColor="#FFFFFF"
android:startColor="#FFFFFF" />
<size
android:width="50dp"
android:height="40dp" />
<solid android:color="#008000" />
</shape>
</item>
</layer-list>
custom_layout (in res/drawable for linearlayout's background)
<?xml version="1.0" encoding="utf-8"?>
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:angle="90"
android:startColor="#FF000000"
android:endColor="#FFFFFFFF"
android:type= "linear" />
<stroke
android:width="1dp"
android:color="#FF000000" />
<padding
android:left="5dp"
android:right="5dp"
/>
<size
android:height="50dp"
/>
<solid
android:color="#00FF00"
/>
</shape>
header.xml (in res/layout)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/buttonBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#drawable/custom_layout"
android:orientation="horizontal" >
<ImageButton
android:id="#+id/home"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:contentDescription="Button"
android:paddingLeft="2dip"
android:paddingRight="2dip"
android:background="#drawable/custom_button"
android:scaleType="fitXY"
android:color="#ff0000"
/>
<ImageButton
android:id="#+id/map"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:background="#drawable/custom_button"
android:contentDescription="Map"
android:paddingLeft="2dip"
android:paddingRight="2dip"
android:scaleType="fitXY"
/>
<ImageButton
android:id="#+id/weather"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:background="#drawable/custom_button"
android:contentDescription="Weather"
android:paddingLeft="2dip"
android:paddingRight="2dip"
android:scaleType="fitXY"
/>
<ImageButton
android:id="#+id/citilink"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:background="#drawable/custom_button"
android:contentDescription="CitiLink"
android:paddingLeft="2dip"
android:paddingRight="2dip"
android:scaleType="fitXY"
/>
</LinearLayout>

You are overcomplicating this is if I understand your question. Look to here for an answer. It's the trick I have used in the past.

Android shape background

Is it possible to draw a shape in xml, and use a png as the background to that shape? I already have the shape (it's a square with rounded corners), and i would like to put a background to that square.

Yes you can use any shape file as background for any view. This sample create rounded background with white color and black border around the shape.
Sample :
rounded_corner.xml
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<corners
android:bottomLeftRadius="10dp"
android:bottomRightRadius="10dp"
android:topLeftRadius="10dp"
android:topRightRadius="10dp" />
<stroke
android:width="0.5dp"
android:color="#color/color_grey" />
<solid android:color="#color/color_white" />
</shape>
u can use this as,
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center_horizontal"
android:background="#drawable/rounded_corner"
android:orientation="vertical" >

//try this way this will help you
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/rounded_corner"
android:padding="2dp"
android:orientation="vertical" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/yourdrawable />
</LinearLayout>