Develop Reference

How to set the background resource of a button from one custom drawable to another custom drawable in kotlin?

I have a set of buttons in Android which all use the same custom drawable as the background, When a button is pressed, I'd like the drawable that is used for the background to change to a different custom drawable. The code I used to do this is below:
selectedButton.setBackgroundResource(R.drawable.roundedbuttongreen)
// Change the background resource to the roundedbuttongreen drawable
the XML for the custom drawable called roundedbuttongreen.xml is:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" android:padding="10dp">
<solid android:color="#4CAD71"/> <!-- this one is ths color of the Rounded Button -->
<corners
android:bottomLeftRadius="50dp"
android:bottomRightRadius="50dp"
android:topLeftRadius="50dp"
android:topRightRadius="50dp"/>
</shape>
The problem that occurs is that the colour of the button is changed but not to the correct colour the colour it changes to instead is grey, it should be green. The screenshot is below:
image of the button after the background resource has been changed, it should be green
If anyone could let me know what I'm doing wrong that would be great

I suggest you to add checked status on custom shape like this then add this shape as a background for your buttons .
<selector
xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#drawable/button"
android:state_checked="false"/>
<item android:drawable="#drawable/roundedbuttongreen"
android:state_checked="true"/>
</selector>
I hope it will work with you .

I had a look through my xml code for my layout and in particular my buttons, The issue was that the buttons backgroundTint property had a value which was grey, as a result when I tried to change the background drawable, the colour of the button was always grey.
To fix the issue, I changed the value of the background tint to green and the issue was resolved

Android add border to button without losing material theme (using drawable)

I have a simple button
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/add"
android:backgroundTint="#color/add_bg"
android:textColor="#color/add_fg"
<!--android:borderColor?="#color/button_border"-->
android:text="#string/add"/>
I would like to have white background, blue text and blue border around. I am aware that I can achieve that through a drawable as shown here and in numerous other places. However I have observed that if you add a drawable to the button then it will lose all of its material properties (such as shadow and also upon clicking having the fancy ripple animation). So how would I add a border around the button without losing the material theme animations (shadow and tipple animation on click)?

Most of the items that android comes with are simply a pre-packaged set of attributes.
It would be almost impossible to expect the Android API developers to include a pre-packaged set of attributes for every possible color/border combination, but there is always a solution!
Unfortunately,as you mentioned, the solution does reside in creating your own custom XML file which can often be intimidating until you get the hang of it. Once you do, you too will marvel at the flexibility it allows.
Specifically for your situation, there are two options...
1) Create a custom XML border drawable.
2)under your buttons background property set your new custom border drawable
3)then also set the ripple effect under your buttons xml properties by adding:
android:foreground="?attr/selectableItemBackground"
android:clickable="true"
android:focusable="true"
----OR----
A more complex way is to make a drawable like the one below. This will add the "ripple" button effect as well as a custom shadow, button color, and border color!
"For anybody reading this later that may be less experienced)
1)In your project view go to res/drawable
2)right click the folder itself and select new/drawable resource file
3)Enter a file name my_ripple_button.xml(the root doesn't really matter because you wil replace it with the below code)
4)Click on the text tab if you aren't already there
5)select all text and basically replace with the following: (creating a custom color border is basically the same steps)
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
android:color="#color/colorPrimaryDark">
<item android:id="#android:id/ripple">
<shape android:shape="rectangle">
<solid android:color="#color/colorPrimaryDark" />
<corners android:radius="#dimen/button_radius_large" />
</shape>
</item>
<item android:id="#android:id/background">
<shape android:shape="rectangle">
<gradient
android:angle="90"
android:endColor="#color/colorPrimaryLight"
android:startColor="#color/colorPrimary"
android:type="linear" />
<corners android:radius="#dimen/button_radius_large" />
</shape>
</item>
</ripple>

How to change the background color of EditText without removing the standard bottom border

After the call of EditText.setBackgroundColor(Color.RED) I see only a red rectangle with text inside it, but I want to change only the text background and to keep the standard bottom border which is grey when the field has no focus and blue if it has focus. Can I do it programmatically?
I want to change the text background to red if the input is invalid and to transparent if it is valid.

I think the best way is to work with drawable/shape.xml as background and upon logic code situation call EditText.setBackground(some_other_shape.xml). Here is an example for shape file xml demonstrating how to use:
Border color ("stroke"): In this example some custom color from colors.xml
Fill color ("solid"): In this example Android default transparent color
Even image icon inside
<!--Example for custom shape file xml design-->
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#mipmap/icon_image" />
<item>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
<solid android:color="#android:color/transparent" />
<stroke android:width="1dp" android:color="#color/orange_primary" />
</shape>
</item>
</layer-list>
So just prepare several shapes for each situation you need. Another approach is to work with layout params etc. but I think this one is faster and gives more control for custom design in easy to understand code.

Android ImageButton background color

I have an ImageButton with a background image that has some transparency. By default, the button gets a grey background where the transparency pixels are - due to the Holo.Light theme. I tried setting the background color of the button to transparent via the setBackgroundColor(Color.TRANSPARENT) method. That works just fine and does what I need except now my button no longer has the light blue color when focused/pressed and looks rather flat (no borders around it, so it looks like an image).
I googled and saw that you can assign selectors as explained here but that would mean that I have to specify an image per button state and I don't want to do that. I want to inherit the focuses/pressed colors from the theme but overwrite the normal button background (when not pressed/focused) to transparent instead of grey. How can I achieve that?? Please provide a working example as I have tried many different combinations with no success.
Edit
Thank you all for helping. I figured out how to make this work without having to recreate the same image with the focused and pressed states for each button!
Here is my solution:
My button is defined as:
<ImageButton
android:id="#+id/ImageButton05"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="#drawable/button" />
And my background XML file (titled button.xml) is defined as follows:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true">
<layer-list>
<item android:drawable="#drawable/btn_default_pressed_holo_light"></item>
<item android:drawable="#drawable/network_wifi"></item>
</layer-list>
</item>
<item android:state_focused="true">
<layer-list>
<item android:drawable="#drawable/btn_default_focused_holo_light"></item>
<item android:drawable="#drawable/network_wifi"></item>
</layer-list>
</item>
<item android:state_hovered="true">
<layer-list>
<item android:drawable="#drawable/btn_default_focused_holo_light"></item>
<item android:drawable="#drawable/network_wifi"></item>
</layer-list>
</item>
<item>
<layer-list>
<item android:drawable="#drawable/btn_default_normal_holo_light"></item>
<item android:drawable="#drawable/network_wifi"></item>
</layer-list>
</item>
</selector>

You can put something into an xml file, for example, custom_button.xml and then set background="#drawable/custom_button" in the button view.
Please refer to this link as there is an xml example: Standard Android Button with a different color
I used it in my code and it worked just the way I wanted.
Reference:
Standard Android Button with a different color
Edited:
If you would rather use
Maybe you should try to set a border.
For example (Reference: Android - border for button ):
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient android:startColor="#FFFFFF"
android:endColor="#00FF00"
android:angle="270" />
<corners android:radius="3dp" />
<stroke android:width="5px" android:color="#000000" />
</shape>
OR,
You could try to set the style/theme for the button. (But it would be in a separate file)
The style/theme contains the color attributes for various states of button such as focused / enabled / disabled/ etc.
For setting background color/image and having click highlight effect,
Here is an example (Reference: How to programmatically setting style attribute in a view)
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_pressed="true"
android:drawable="#drawable/btn_pressed" />
<item
android:state_pressed="false"
android:drawable="#drawable/btn_normal" />
</selector>
You can then apply this selector to a Button by setting the property android:background="#drawable/my_button".

I want to inherit the focuses/pressed colors from the theme but overwrite the normal button background (when not pressed/focused) to transparent instead of grey. How can I achieve that??
AFAIK you can't because the focus/pressed colors are built in to the same image resources that contain the grey background.
If you want to keep the system focus/pressed but remove the background you'll have to grab a copy of the image resources (which can be found in your SDK at /sdkroot/platforms/[version]/data/res/drawable-hdpi replace [version] with whatever api level you are after. And if needbe replace hdpi with another density) and edit out the grey button from them with a photo editor. Then make a selector that references your modified images and set that as the background for your button.
EDIT:
Here are the default holo button images for focused and pressed

You can use ImageView instead of ImageButton to solve your problem. Please set the android:background property of the ImageView to the background color of the parent.

You can write this in your xml file:
android:background="#null"
It worked for me.

if u don't need the default gray background and u need your ImageButton seems like an icon without no backgrounds just use android:background attribute and set it to
#android:color/transparent**
<ImageButton
android:id="#+id/ImageButton05"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="#android:color/transparent"
android:background="#drawable/button" />
hope that help anybody

Why does assigning a color to the background of my ListView element not cover the entire ListView background, while assigning a drawable does?

I have a ListView that sits on the left side of a tablet-size screen. My goal was to give it a solid background with a border on the right, then apply an overlapping background on the list element to break that border so that it appears to be a part of the view on the right.
The ListView Background
I achieved the right border using a <layer-list> drawable as suggested by Emile in another question:
rightborder.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="rectangle">
<solid android:color="#color/black" />
</shape>
</item>
<item android:right="2dp">
<shape android:shape="rectangle">
<solid android:color="#color/white" />
</shape>
</item>
</layer-list>
...and here's the ListView definition for good measure:
<ListView
android:id="#+id/msglist"
android:layout_width="300dp"
android:layout_height="match_parent"
android:divider="#color/black"
android:dividerHeight="1dp"
android:background="#drawable/rightborder"
android:paddingRight="0dip">
</ListView>
<!-- I added the android:paddingRight after reading something
about shape drawables and padding, don't think it actually
did anything. -->
Attempting to override it with a color
In order to achieve the desired effect, I placed the following in the getView function of my adapter:
//If it's selected, highlight the background
if(position == mSelectedIndex)
convertView.setBackgroundColor(R.color.light_gray);
else
convertView.setBackgroundResource(0);
However, using this method, the black border of the ListView's drawable remained visible, and only the white part of the background was replaced by gray. Here's a screen capture:
Fixing it with a drawable
On a hunch, I replaced the color I was assigning with a shape drawable:
selectedmessage.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="rectangle"
xmlns:android="http://schemas.android.com/apk/res/android" >
<solid android:color="#color/light_gray" />
</shape>
getView snippet:
//If it's selected, highlight the background
if(position == mSelectedIndex)
convertView.setBackgroundResource(R.drawable.selectedmessage);
else
convertView.setBackgroundResource(0);
This achieves the desired result, as shown below:
The question:
Why does assigning a rectangle as the background for my ListView element cover the entire view, while assigning the color allows the black border to show through? I'm happy it's working, but I'd like to know why Android is rendering the view this way so I can learn more about how Android renders Views.
Other notes:
I'm running the project in the stock Android 3.2 emulator, if that makes any
difference.
One clue may be that the light_gray color background seems to render darker than the light_gray shape resource.
I doubt it makes a difference, but light_gray is:
<color name="light_gray">#FFCCCCCC</color>

You can't do this:
convertView.setBackgroundColor(R.color.light_gray);
setBackgroundColor does not take a resource id : http://developer.android.com/reference/android/view/View.html#setBackgroundColor(int)
So your getting some incidental behaviour that isn't doing what your expecting.
You would have to do:
convertView.setBackgroundColor(getResources().getColor(R.color.light_gray);
http://developer.android.com/reference/android/content/res/Resources.html#getColor(int)