Cfrgtkky

I have this line in my account_particle.xml layout

            android:padding="?attrs/disc_padding"

this attrs.xml:

<resources>

  <declare-styleable name="AccountParticle">

    <attr name="apStyle" format="enum">

      <enum name="header" value="0"/>

      <enum name="list_item" value="1"/>

    </attr>



    <attr name="text_margin_start" format="reference"/>

    <attr name="text_margin_end" format="reference"/>

    <attr name="text_margin_right" format="reference"/>

    <attr name="text_margin_left" format="reference"/>

    <attr name="disc_padding" format="reference"/>

    <attr name="disc_imageViewSize" format="reference"/>





  </declare-styleable>

</resources>

and this styles.xml:

<style name="Theme.ap.header" parent="Theme.AppCompat">

    <item name="disc_padding">@dimen/account_menu_header_signed_in_avatar_margin_start</item>

  </style>



  <style name="Theme.ap.list_item" parent="Theme.AppCompat">

    <item name="disc_padding">@dimen/account_menu_account_list_item_avatar_margin_start</item>







      </style>

Why do i get this compilation error?

 error: Error: No resource found that matches the given name (at 'padding' with value '?attrs/disc_padding').

AccountParticle

The correct syntax for referring to a theme attribute value in a layout attribute is:

prefix:attribute="?attr/themeAttribute"

That is, attr instead of attrs.

Though you may have defined that attribute in a file named attrs.xml, the filename is actually irrelevant. When resources are being built, every file under the res/values*/ folder is processed, regardless of the filename.

This effectively means that you can name your files there whatever you want, and you can put any resources there in whichever file you want. They will all be processed according to their type, like <attr>, <color>, <string>, etc.

The issue is related to the attribute usages it should be ?attr/ instead of ?attrs/.

But you have another issue in your attrs.xml file. The problem is that you are declaring the following reference inside a declare-styleable:

<attr name="text_margin_start" format="reference"/>

<attr name="text_margin_end" format="reference"/>

<attr name="text_margin_right" format="reference"/>

<attr name="text_margin_left" format="reference"/>

<attr name="disc_padding" format="reference"/>

<attr name="disc_imageViewSize" format="reference"/>

This references should be moved outside the declare-styleable

Why

The declare-styleable is used to define a group of attrs that will be used in the context of a custom view. In your case, the disc_padding is used outside the context of an AccountParticle.

Documentation reference: https://developer.android.com/training/custom-views/create-view#customattr