nomongo nomongo - 3 months ago 20
Android Question

How to set the padding for CardView widget in Android L

I'm using

android:paddingLeft
and
android:paddingTop
to set the padding for the new
CardView
widget but it doesn't work.

I can set the margin for all the controls inside the
CardView
as a workaround but that's a pain if there are too many controls.

How to set padding for the new cardview widget?

<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="200dp"
android:paddingLeft="20dp"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="20dp"
android:paddingBottom="@dimen/activity_vertical_margin"
card_view:cardCornerRadius="2dp">

<TextView
android:id="@+id/info_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello World!"/>
</android.support.v7.widget.CardView>

Answer

CardView prior to L-preview uses RoundRectDrawableWithShadow to draw its background, which overrides Drawable.getPadding() to add shadow padding. The view background gets set via code after inflation, which overrides any padding specified in XML.

You have two options:

  1. Set padding at run time using View.setPadding() and be careful to adjust for the shadows (but only prior to L-preview!).
  2. Place everything inside a layout that specifies padding.

The latter option is safest.

<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view"
    android:layout_gravity="center"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    card_view:cardCornerRadius="2dp">

    <FrameLayout
        android:paddingLeft="20dp"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="20dp"
        android:paddingBottom="@dimen/activity_vertical_margin">

        <TextView
            android:id="@+id/info_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Hello World!"/>
    </FrameLayout>
</android.support.v7.widget.CardView>