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

How to create a gradient color background for splash screen in Flutter?

I'm working on the splash screen for my Flutter app, and in drawable folder I have to create a file called colors.xml in order to change background color for my splash screen. I'm finding it hard to make it a gradient color. My intention is to create a gradient background color that would start at the top left and end at bottom right, using two different colors. Does anyone have an example of how to do that in Flutter? Thanks!
P.S. An is there a difference in the process for android and ios?

1 In \android\app\src\main\res\drawable\launch_background.xml
change this :
<item android:drawable="#android:color/white" />
to :
<item android:drawable="#drawable/gradient_background" />
2 Create this file \android\app\src\main\res\values\colors.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="gradientstart">#3587d0</color>
<color name="gradientend">#36f1d3</color>
</resources>
3 Finally, create this file \android\app\src\main\res\drawable\gradient_background.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:startColor="#color/gradientstart"
android:endColor="#color/gradientend"
android:angle="90"/>
</shape>

For Android first define two color in your colors.xml:
<color name="gradientstart">#888888</color>
<color name="gradientend">#111111</color>
then in \android\app\src\main\res\drawable\launch_background.xml just replace this:
<item android:drawable="#color/background" />
to this:
<gradient android:startColor="#color/gradientstart" android:endColor="#color/gradientend" android:angle="315"/>
and for ios according to this question
If your gradient is a simple vertical or horizontal gradient, and
you’re really concerned about asset size, you can define a very narrow
image and then add an image view with “scale to fill” content mode.
But these images are so small anyway, the amount of space saved will
be negligible, so I’m not sure it’s worth worrying about.

I found use of flutter_native_splash much more easy and direct. Here's a link on the steps to creating one. First design your desired gradient as an image and instead of adding color, add a background_image on the pubspec.yaml file.
Something like:
flutter_native_splash:
image: ""
background_image: "assets/my_splash_background.png"

Android how to change the edittext cursor style

I want to customize the EditText slider style. See my screenshots below.
This is the default slider style:
This is what I want to see:
This may be a dumb question, but after a few hours Googling, I can only find ways to change the cursor color, but couldn't find an approach to change the slider style.
This is the code I am using for changing the cursor color (color_cursor.xml):
<?xml version="1.0" encoding="utf-8" ?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
<size android:width="2dp" />
<solid android:color="#008000" />
</shape>
And I applied the "android:textCursorDrawable="#drawable/color_cursor" to EditText.
Thanks.

android:textSelectHandle="#drawable/your_desired_drawable"
put this in your editText view. Set the drawable you prefer. Then change the color inside your drawable xml file.

An answer for myself (hope this will also help others):
After introducing the "Theme.material", the EditText will become the expected style. I will want to check out Material Design.

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.

Complex custom button states in Android

in my current project I'm building an App with API 10 which should look like an ICS App.
Since my GUI is not very complex I can build this all manually, but I have some problems with button states.
I googled a lot and found nothing that would work for me so I would appreciate any help ;)
I designed an action bar with google ICS stock icons. When for example someone touches the search-loupe-icon, which has an 8dp padding around it, it's background color should change to a defined highlight-color-value.
So now you would suggest probably a selector drawable. But my case is: I have an icon-drawable which has an background-color, which I want to change. I dont want to change the icon, so since I cant change the backgroundcolor from a selector-xml this doesn't work.
(I thought I can setup multiple drawable-xml with my icon static bg colors so that I could refer with one selector to those different colored icons, but since a shape-drawable-xml cannot have a source and an bitmap-drawable-xml cannot have a background color, this is no sollution.)
If I try to change the background color in my onclick-listener (also tried onTouch) with:
ImageButton searchIcon = (ImageButton) findViewById(R.id.upper_actionbar_icon_search);
searchIcon.setBackgroundColor(R.color.android_ics_blue_light);
The Icon gets a dark grey bg color. This is also true for any other color altough nothing lies on top of the ImageButton. I also tried an ImageView.
So could someone explain to my please how the hell I can define a highlighted bg color-image without any hacks (default-gone image that lies above the icon and is set visible onclick).
Thanks so much!!

Okay the solution is simple.
Write yourself a drawable selector which looks like this:
<?xml version="1.0" encoding="utf-8"?>
<item android:state_selected="true">
<shape android:shape="rectangle">
<solid android:color="#color/android_ics_blue_light"/>
</shape>
</item>
<item android:state_pressed="true">
<shape android:shape="rectangle">
<solid android:color="#color/android_ics_blue_light"/>
</shape>
</item>
<item>
<shape android:shape="rectangle">
<solid android:color="#color/light_grey"/>
</shape>
</item>
Within your ImageButton code define your icon as src and your new drawable as background, like this:
<ImageButton
<!-- ... -->
android:src="#drawable/icon_search"
android:background="#drawable/actionbar_ontouch"
/>
Works like a charm!