Develop Reference

Disabling a Button with an icon

I have a simple Button, which has a drawable set as icon:
<Button
android:id="#+id/bOk"
android:drawableStart="#drawable/icon_ok"
android:text="#string/ok"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
when I disable the button, either in XML layout file: android:enabled="false"
or programmaticaly: bOk.setEnabled(false);
The button gets disabled, it is 'grayed out', but the icon remains as it was ine the enabled state.
How can I get a look, that the icon is also 'grayed out'?

Create a new grayed icon and add both inside a selector.xml:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#drawable/icon_ok" android:state_enabled="true" />
<item android:drawable="#drawable/icon_ok_disabled" android:state_enabled="false" />
</selector>
Use inside button like: android:drawableStart="#drawable/selector"
For TextColor,
Create another selector inside res/color/mycustomtextcolor.xml:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:color="#666" android:state_enabled="false" />
<item android:color="#000" android:state_enabled="true"/>
</selector>
Inside your widget call using: android:textColor="#color/mycustomtextcolor"
Or
inside your style add another item using: <item name="android:textColor">#color/mycustomtextcolor</item>

Like a regular Button, a Button that has an image background is not grayed when disabled.
You have to use another image it appears grayed.
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_enabled="false"
android:drawable="#drawable/button_gray" /> ***button_gray is a Drawable image***
<item android:state_pressed="true"
android:drawable="#drawable/button_gray" />
<item android:drawable="#drawable/button_red" /> ***button_red is a Drawable image***
</selector>

You can tint your drawable on enabled and disabled state using a selector with bitmaps:
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_enabled="false">
<bitmap android:src="#drawable/icon_ok" android:tint="#color/disableColorWithAlpha" />
</item>
<item android:state_enabled="true">
<bitmap android:src="#drawable/icon_ok" android:tint="#color/colorAccent" />
</item>
</selector>

Effect for ImageButton in android

I want to create effects for ImageButton. For example, it will change color when clicked...How I do it? I want to do this in .xml file. Can you help me! Thank you!
I tried to create the state.xml file as follwing:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_pressed="true"
android:state_enabled="true"
android:drawable="#drawable/btn_0" />
<item
android:state_focused="true"
android:state_enabled="true"
android:drawable="#drawable/btn_ac" />
</selector>
However, I can't set background for ImageButton. The error like this:

All you have to do it to add the "android:background" attribut to your ImageButton and set a drawable.
Your layout
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/my_btn"
android:background="#drawable/btn_drawable"/>
btn_drawable.xml
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true"
android:drawable="#drawable/blue"
/>
<item android:state_focused="true"
android:drawable="#drawable/white"
/>
<item android:drawable="#drawable/green" />
</selector>
In that code above you set a different drawable when your ImageButton is pressed (state_pressed), focused (state_focus) or when is normal (not pressed and not focused).
Here you can find with more detail.

Create a drawable like below and name it as btn_drawable.
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_enabled="false"
android:drawable="#drawable/btn_disable" />
<item
android:state_pressed="true"
android:state_enabled="true"
android:drawable="#drawable/btn_click" />
</selector>
This is for an example,Like this you can add the <item/> according to your needs and state of the image button.
Then set the drawable as image button background.
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/btn_drawable"/>

ListView item color in XML file

I am using the Xamarin sample at the following link:
Part 3 - Customizing a ListView's Appearance
The sample code is from the following file: CustomRowView.zip
Here is a screenshot of my running code: Emulator screenshot
The background color of the ListView items are in yellow.
May I please have some help to change this color to be the default color, or to choose this color?
I am not sure where to find this in code. I have looked in the XML layout files, but cannot find the correct item.
In the RelativeLayout, there is a reference to the following:
android:background="#drawable/CustomSelector"
And this is the contents of the file:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="false"
android:state_selected="false"
android:drawable="#color/cellback" />
<item android:state_pressed="true" >
<shape>
<gradient
android:startColor="#E88A93"
android:endColor="#E88A93"
android:angle="270" />
</shape>
</item>
<item android:state_selected="true"
android:state_pressed="false"
android:drawable="#color/cellback" />
</selector>
Is this code relevant to the question?
Thanks in advance

The "yello background color" is the custom listview item's background color. In the toturial you referenced, you can find it in "/Resources/Layout/CustomView.axml" :
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#FFDAFF7F"
android:padding="8dp">
<LinearLayout android:id="#+id/Text"
android:orientation="vertical"
...
...
android:layout_height="48dp"
android:padding="5dp"
android:src="#drawable/icon"
android:layout_alignParentRight="true"
/>
</RelativeLayout >
the android:background="#FFDAFF7F" is what you want to modify.

Your ListView is using CustomView.axml for each row. in CustomView.axml parent element (RelativeLayout) is using CustomSelector.xml from Drawable folder in android:background attribute. In this file you can change colors of three states (pressed, pressed & selected, none) as you wish.

Create a color.xml in your values file and defines your color(which color you wnt to set to your listview ite) here
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="magenta">#FF00FF</color>
<color name="yellow">#FFFF00</color>
<color name="light_grey">#ffb9b8bb</color>
</resources>
and then use these colors in your custom selector
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#color/light_grey" android:state_pressed="false" android:state_selected="false"/>
<item android:state_pressed="true"><shape>
<gradient android:angle="270" android:endColor="#E88A93" android:startColor="#E88A93" />
</shape></item>
<item android:drawable="#color/light_grey" android:state_pressed="false" android:state_selected="true"/>
</selector>

I never get it yellow, which should come after pressing an item in the list.
(I changed your sample to yellow for state_pressed=true.
Tks
Seli
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#color/light_grey" android:state_pressed="false" android:state_selected="false"/>
<item android:state_pressed="true">
<shape>
<gradient android:angle="270" android:endColor="#E88A93" android:startColor="#E88A93" />
</shape>
</item>
<item android:drawable="#color/yellow" android:state_pressed="false" android:state_selected="true"/>
</selector>

Is it possible to create an xml subclass of a state list selector?

For example, say I have a color state list declared in XML, called example1.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:color="#color/red"
android:state_pressed="true" />
<item
android:color="#color/blue"
android:state_checked="true" />
<item
android:color="#color/green"
android:state_disabled="true" />
<item
android:color="#color/orange" />
</selector>
Then, I want to create example2.xml and I want it to be the exact same as example1.xml except I want the pressed color to be purple instead of red:
<item
android:color="#color/purple"
android:state_pressed="true" />
So example2.xml would end up acting like this:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:color="#color/purple" <-- note this value is different
android:state_pressed="true" />
<item
android:color="#color/blue"
android:state_checked="true" />
<item
android:color="#color/green"
android:state_disabled="true" />
<item
android:color="#color/orange" />
</selector>
but without all of the duplicate code. Also, if I want to change a color I can just change it in one place.
Is this possible?

I don't think you can do this on Android, You have to create multiple xml resources for different selector.

Can't use default ListView selector

I'm developing a ListView app for Android. I want to use the default ListView selector, for example the one in Market when you touch an item.
I don't get a highlight in my ListView, where's the way to correctly implement it? I've read about the "Touch mode" although I can't get it to work.
Thanks in advance!
<ListView
android:id="#id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>

You have to assign to each row layout a background composed by a selector that assign a different background for each state. Suppose that your item row layout is a RelativeLayout defined in a xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="2dip"
android:background="#drawable/transparent_selector"> ...
and transparent_selector is defined here: watch that carefully one drawable shape belongs to a single state.
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_selected="true" android:drawable="#drawable/shape_7"/>
<item android:state_pressed="true" android:drawable="#drawable/shape_7" />
<item android:state_pressed="false" android:drawable="#drawable/transparent_shape" />
</selector>
and a shape is defined here:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
android:startColor="#FF4FDBD5"
android:endColor="#FF1AA6A1"
android:type="linear"
android:angle="90"/>
</shape>
or in the other way when you construct the ListView items you can assign the selector to the 'convertView'
cheers

For your id attribute, change it to android:id="#android:id/list. This is the default ID for the ListView.

Try this selector. It works for me
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_window_focused="false" android:state_selected="true" android:drawable="#android:color/transparent" />
<item android:state_selected="true" android:drawable="#android:color/transparent" />
<item android:state_pressed="true" android:state_selected="false" android:drawable="#android:color/transparent" />
<item android:state_selected="false" android:drawable="#drawable/list_item_back" />
</selector>