How to create standard Borderless buttons (like in the design guideline mentioned)?

I was just checking the design guidelines and wondering about the borderless buttons. I goggled and tried to find in the source but can't bring it together by myself. Is this the normal Button widget but you add a custom (Android default) style? How to make these borderless buttons (of course you can set the background to empty, but then I don't have the divider)?

Here links to the design guidelines:

• http://developer.android.com/design/building-blocks/buttons.html
• http://developer.android.com/guide/topics/ui/controls/button.html#Borderless

To clear some confusion:

This is done in 2 steps: Setting the button background attribute to android:attr/selectableItemBackground creates you a button with feedback but no background.

android:background="?android:attr/selectableItemBackground"

The line to divide the borderless button from the rest of you layout is done by a view with the background android:attr/dividerVertical

android:background="?android:attr/dividerVertical"

For a better understanding here is a layout for a OK / Cancel borderless button combination at the bottom of your screen (like in the right picture above).

<RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="48dp"
	    android:layout_alignParentBottom="true">
        <View
        	android:layout_width="match_parent"
        	android:layout_height="1dip"
        	android:layout_marginLeft="4dip"
        	android:layout_marginRight="4dip"
        	android:background="?android:attr/dividerVertical"
        	android:layout_alignParentTop="true"/>
        <View
            android:id="@+id/ViewColorPickerHelper"
            android:layout_width="1dip"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="4dip"
            android:layout_marginTop="4dip"
            android:background="?android:attr/dividerVertical" 
            android:layout_centerHorizontal="true"/>
        <Button
            android:id="@+id/BtnColorPickerCancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:layout_toLeftOf="@id/ViewColorPickerHelper"
            android:background="?android:attr/selectableItemBackground"
            android:text="@android:string/cancel" 
            android:layout_alignParentBottom="true"/>
        <Button
            android:id="@+id/BtnColorPickerOk"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:background="?android:attr/selectableItemBackground"
            android:text="@android:string/ok" 
            android:layout_alignParentBottom="true" 
            android:layout_toRightOf="@id/ViewColorPickerHelper"/>
    </RelativeLayout>

Simply add the following style attribute in your Button tag:

    style="?android:attr/borderlessButtonStyle"

source: http://developer.android.com/guide/topics/ui/controls/button.html#Borderless

Then you can add dividers as in Karl's answer.

Late answer, but many views. As APIs < 11 ain't dead yet, for those interested here is a trick.

Let your container have the desired color (may be transparent). Then give your buttons a selector with default transparent color, and some color when pressed. That way you'll have a transparent button, but will change color when pressed (like holo's). You can also add some animation (like holo's). The selector should be something like this:

res/drawable/selector_transparent_button.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" 
          android:exitFadeDuration="@android:integer/config_shortAnimTime">
     <item android:state_pressed="true"
         android:drawable="@color/blue" />
       
   <item android:drawable="@color/transparent" />
</selector>

And the button should have android:background="@drawable/selector_transparent_button"

PS: let you container have the dividers (android:divider='@android:drawable/... for API < 11)

PS [Newbies]: you should define those colors in values/colors.xml

For the one who want borderless buttons but still animated when clicked. Add this in the button.

style="?android:attr/borderlessButtonStyle"

If you wanted a divider / line between them. Add this in the linear layout.

style="?android:buttonBarStyle"

Summary

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:orientation="horizontal"
   style="?android:buttonBarStyle">

	<Button
	    android:id="@+id/add"
	    android:layout_weight="1"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="@string/add_dialog" 
	    style="?android:attr/borderlessButtonStyle"
	 	/>

	<Button
	    android:id="@+id/cancel"
	    android:layout_weight="1"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="@string/cancel_dialog" 
	    style="?android:attr/borderlessButtonStyle"
	    />

</LinearLayout>

For material style add style="@style/Widget.AppCompat.Button.Borderless" when using the AppCompat library.

From the iosched app source I came up with this ButtonBar class:

/**
 * An extremely simple {@link LinearLayout} descendant that simply reverses the 
 * order of its child views on Android 4.0+. The reason for this is that on 
 * Android 4.0+, negative buttons should be shown to the left of positive buttons.
 */
public class ButtonBar extends LinearLayout {

    public ButtonBar(Context context) {
        super(context);
    }

    public ButtonBar(Context context, AttributeSet attributes) {
        super(context, attributes);
    }

    public ButtonBar(Context context, AttributeSet attributes, int def_style) {
        super(context, attributes, def_style);
    }

    @Override
    public View getChildAt(int index) {
        if (_has_ics)
            // Flip the buttons so that "OK | Cancel" becomes "Cancel | OK" on ICS
            return super.getChildAt(getChildCount() - 1 - index);

        return super.getChildAt(index);
    }

    private final static boolean _has_ics = Build.VERSION.SDK_INT >= 
                                        Build.VERSION_CODES.ICE_CREAM_SANDWICH;
}

This will be the LinearLayout that the "OK" and "Cancel" buttons go into, and will handle putting them in the appropriate order. Then put this in the layout you want the buttons in:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:divider="?android:attr/dividerHorizontal"
          android:orientation="vertical"
          android:showDividers="middle">
    <!--- A view, this approach only works with a single view here -->
    <your.package.ButtonBar style="?android:attr/buttonBarStyle"
        android:id="@+id/buttons"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="1.0">
        <Button style="?android:attr/buttonBarButtonStyle"
            android:id="@+id/ok_button"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:text="@string/ok_button" />
        <Button style="?android:attr/buttonBarButtonStyle"
            android:id="@+id/cancel_button"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:text="@string/cancel_button" />
    </your.package.ButtonBar>
</LinearLayout>

This gives you the look of the dialog with borderless buttons. You can find these attributes in the res in the framework. buttonBarStyle does the vertical divider and padding. buttonBarButtonStyle is set as borderlessButtonStyle for Holo theme, but I believe this should be the most robust way for displaying it as the framework wants to display it.

Look into the theme attributes buttonBarStyle, buttonBarButtonStyle, and borderlessButtonStyle.

You can make buttons borderless through code as well:

TypedValue value= new TypedValue();
getApplicationContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground, value, true);
 myButton.setBackgroundResource(value.resourceId);

For those who want to create borderless button programmatically for API's >= 8

ImageButton smsImgBtn = new ImageButton(this);
//Sets a drawable as the content of this button
smsImgBtn.setImageResource(R.drawable.message_icon);    
//Set to 0 to remove the background or for bordeless button
smsImgBtn.setBackgroundResource(0);

Another solution that should work on both older and newer android platform is to use

android:background="@android:color/transparent"

attribute for Button view. But after adding above line button will not provide touch feedback.

To provide touch feedback add the following code to Activity class

button.setOnTouchListener(new View.OnTouchListener() {			
	@Override
	public boolean onTouch(View view, MotionEvent event) {
		switch (event.getAction())
		{
			case MotionEvent.ACTION_DOWN:    
                ((Button)view).setBackgroundColor(Color.LTGRAY);
				break;
			case MotionEvent.ACTION_UP:
                ((Button)view).setBackgroundColor(Color.TRANSPARENT);
		}
		return false;
	}
});

Its working fine for me.

For anybody who's still searching:

inherit your own style for Holo buttonbars:

<style name="yourStyle" parent="@android:style/Holo.ButtonBar">
  ...
</style>

or Holo Light:

<style name="yourStyle" parent="@android:style/Holo.Light.ButtonBar">
  ...
</style>

and for borderless Holo buttons:

<style name="yourStyle" parent="@android:style/Widget.Holo.Button.Borderless.Small">
  ...
</style>

or Holo Light:

<style name="yourStyle" parent="@android:style/Widget.Holo.Light.Button.Borderless.Small">
  ...
</style>

This is how you create a borderless (flat) button programmatically without using XML

ContextThemeWrapper myContext = new ContextThemeWrapper(this.getActivity(), 
   R.style.Widget_AppCompat_Button_Borderless_Colored);

Button myButton = new Button(myContext, null, 
   R.style.Widget_AppCompat_Button_Borderless_Colored);

Use the below code in your xml file. Use android:background="#00000000" to have the transparent color.

<Button
   android:id="@+id/btnLocation"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:background="#00000000"
   android:text="@string/menu_location"
   android:paddingRight="7dp"
/>

You can use AppCompat Support Library for Borderless Button.

You can make a Borderless Button like this:

<Button
    style="@style/Widget.AppCompat.Button.Borderless"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="16dp" 
    android:text="@string/borderless_button"/>

You can make Borderless Colored Button like this:

<Button
    style="@style/Widget.AppCompat.Button.Borderless.Colored"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="16dp" 
    android:text="@string/borderless_colored_button"/>

If you want to achieve the same programmatically :

(this is C# but easily transatable to Java)

Button button = new Button(new ContextThemeWrapper(Context, Resource.Style.Widget_AppCompat_Button_Borderless_Colored), null, Resource.Style.Widget_AppCompat_Button_Borderless_Colored);

Match

    <Button
       style="@style/Widget.AppCompat.Button.Borderless.Colored"
    .../>

Try this code, to remove the background drawable (@drawable/bg) programmatically, just we need to provide null as a parameter.

Button btn= new Button(this);
btn.setText("HI");
btn.setBackground(null);

For some reason neither style="Widget.Holo.Button.Borderless" nor android:background="?android:attr/selectableItemBackground" worked for me. To be more precise Widget.Holo.Button.Borderless did the job on Android 4.0 but didn't work on Android 2.3.3. What did the trick for me on both versions was android:background="@drawable/transparent" and this XML in res/drawable/transparent.xml:

<shape xmlns:android="http://schemas.android.com/apk/res/android" 
    android:shape="rectangle" >
</shape>

Plain head through the wall approach.

A great slide show on how to achieve the desired effect from Googles Nick Butcher (start at slide 20). He uses the standard android @attr to style the button and divider.

Adding on to the top answer you can also use views with a dark gray background color in a Linear Layout like so.

<View
    android:layout_width="match_parent"
    android:layout_height="1dip"
    android:layout_marginBottom="4dip"
    android:layout_marginLeft="4dip"
    android:layout_marginRight="4dip"
    android:layout_marginTop="4dip"
    android:background="@android:color/darker_gray"/>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="4dip"
    android:orientation="horizontal"
    android:weightSum="1">

    <Button
        android:id="@+id/button_decline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_weight="0.50"
        android:background="?android:attr/selectableItemBackground"
        android:padding="10dip"
        android:text="@string/decline"/>

    <View
        android:layout_width="1dip"
        android:layout_height="match_parent"
        android:layout_marginLeft="4dip"
        android:layout_marginRight="4dip"
        android:background="@android:color/darker_gray"/>

    <Button
        android:id="@+id/button_accept"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="10dp"
        android:layout_weight="0.50"
        android:background="?android:attr/selectableItemBackground"
        android:padding="10dip"
        android:text="@string/accept"/>
</LinearLayout>

If your line is horizontal you'll want to set the height to 1dip and the width to match the parent and vice-versa if your line is vertical.