Android: How to custom-declare XML namespace in styles.xml?

Question

I'm trying to put the custom XML namespace in the styles.xml and inherit it in the layout. I don't know how to declare the custom XML namespace in the styles.xml as I do in layout xml (eg xmlns:app="http://schemas.android.com/tools" ).

How do I use custom XML namespace in the styles.xml ?

What I have:

1. The font asset, ReallyCoolFont.ttf is saved in the asset/fonts .

2. my_layout.xml :

    <TextView <!-- more attributes here --> app:customFont="fonts/ReallyCoolFont.ttf" <!-- more attributes here --> </TextView> 

3. styles.xml :

    <style name="CoolTextView"> <!-- more items here --> <!-- more items here --> </style> 

What I'd like to have:

1. my_layout.xml :

    <TextView <!-- more attributes here --> style="@style/CoolTextView <!-- more attributes here --> </TextView> 

2. styles.xml :

    <style name="CoolTextView"> <!-- more items here --> <item name="app:customFont">ReallyCoolFont.ttf</item> <!-- more items here --> </style> 

Error I get:

Error:(1403, 21) No resource found that matches the given name: attr     'app:customFont'.

Answer 1

1) you need to define an attribute for your fonts in attr.xml file in res folder:

<attr name="myfonts" format="string"></attr>

2) you need to define custom style for your TextView and here we use our defined attribute(myfonts):

<declare-styleable name="MyCustomStyle">
    <attr name="myfonts" />
</declare-styleable>

3)

<style name="CoolTextView">
    <item name="myfonts">ReallyCoolFont.ttf</item>
</style>

summary of what you have so far:

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <attr name="myfonts" format="string">
    </attr>

    <declare-styleable name="MyCustomStyle">
        <attr name="myfonts" />
    </declare-styleable> 

    <style name="CoolTextView">
        <item name="myfonts">ReallyCoolFont.ttf</item>
    </style>

</resources> 

4)Now your layout would be:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <com.example.MyCustomTextView
        android:id="@+id/result"
        style="@style/CoolTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="HELLO WORLD!"
        android:textSize="24dp"
        android:gravity="center" >
    </com.example.MyCustomTextView>

</RelativeLayout>

5)and your MyCustomTextView is:

public class MyCustomTextView extends TextView {


    private static final String TAG = "TextView";

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

    public MyCustomTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        settingFont(context, attrs);
    }

    public MyCustomTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        settingFont(context, attrs);
    }


    private void settingFont(Context ctx, AttributeSet attrs) {
        TypedArray a = ctx.obtainStyledAttributes(attrs, R.styleable.MyCustomStyle);
        String customFont = a.getString(R.styleable.MyCustomStyle_myfonts);
        Typeface tf = null;
        try {
        tf = Typeface.createFromAsset(ctx.getAssets(), customFont);  
        } catch (Exception e) {
            Log.e(TAG,e.getMessage());
            a.recycle();
            return;
        }

        setTypeface(tf);  
        a.recycle();
    }


}

I assumed you put the font in asset not in asset/fonts directory.

also I highly recommend read this .

Answer 2

You don't need to add any prefix to reference your custom attributes in the style resource files. Doing it like this will work just fine:

<style name="CoolTextView">
    <item name="customFont">ReallyCoolFont.ttf</item>
</style>

Answer 3

You don't need any prefixes, it will work without them. This is code from one of my projects, which works just fine

<style name="defaultTriangle">
    <item name="triangleColor">#FF33B5E5</item>
    <item name="triangleStrokeColor">@android:color/black</item>
    <item name="triangleStrokeWidth">3dp</item>
</style>


<si.kseneman.views.Triangle
    style="@style/defaultTriangle"
    android:layout_width="match_parent"
    android:layout_height="0dip"
    android:layout_weight="1"
    android:padding="10dp"
    android:rotation="0"
    />

Answer 4

The answer is to NOT specify the namespace in the style.

<?xml version="1.0" encoding="utf-8" ?>
<resources xmlns:custom="http://schemas.android.com/apk/res/com.custom.project">
    <style name="CustomStyle">
        <item name="android:layout_width">wrap_content</item>
        <item name="android:layout_height">wrap_content</item>

        <item name="customAttr">value</item> <!-- tee hee -->
    </style>
</resources>

Answer 5

I've done next for custom font CustomTextView

public class KlavikaTextView extends TextView {

  private final static int KLAVIKA_BOLD = 0;
  private final static int KLAVIKA_BOLD_ITALIC = 1;
  private final static int KLAVIKA_LIGHT = 2;
  private final static int KLAVIKA_LIGHT_ITALIC = 3;
  private final static int KLAVIKA_MEDIUM = 4;
  private final static int KLAVIKA_MEDIUM_ITALIC = 5;
  private final static int KLAVIKA_REGULAR = 6;
  private final static int KLAVIKA_REGULAR_ITALIC = 7;

public KlavikaTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    parseAttributes(context, attrs);
}

public KlavikaTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    parseAttributes(context, attrs);
}

public KlavikaTextView(Context context) {
    super(context);

}

private void parseAttributes(Context context, AttributeSet attrs) {
    TypedArray values = context.obtainStyledAttributes(attrs, R.styleable.KlavikaTextView);

    // The value 0 is a default, but shouldn't ever be used since the attr is an enum
    int typeface = values.getInt(R.styleable.KlavikaTextView_typeface, KLAVIKA_REGULAR);

    // You can instantiate your typeface anywhere, I would suggest as a
    // singleton somewhere to avoid unnecessary copies
    switch (typeface) {
      case KLAVIKA_BOLD:
        setTypeface(App.klavikaBold);
        break;
      case KLAVIKA_BOLD_ITALIC:
        setTypeface(App.klavikaBoldItalic);
        break;
      case KLAVIKA_LIGHT:
        setTypeface(App.klavikaLight);
        break;
      case KLAVIKA_LIGHT_ITALIC:
        setTypeface(App.klavikaLightItalic);
        break;
      case KLAVIKA_MEDIUM:
        setTypeface(App.klavikaMedium);
        break;
      case KLAVIKA_MEDIUM_ITALIC:
        setTypeface(App.klavikaMediumItalic);
        break;
      case KLAVIKA_REGULAR_ITALIC:
        setTypeface(App.klavikaRegularItalic);
        break;
      case KLAVIKA_REGULAR:
      default:
        setTypeface(App.klavikaRegular);
        break;

    }
}}

Then in values I've created attr.xml

 <!-- Define the values for the attribute -->
<attr name="typeface" format="enum">
    <enum name="klavika_bold" value="0" />
    <enum name="klavika_bold_italic" value="1" />
    <enum name="klavika_light" value="2" />
    <enum name="klavika_light_italic" value="3" />
    <enum name="klavika_medium" value="4" />
    <enum name="klavika_medium_italic" value="5" />
    <enum name="klavika_regular" value="6" />
    <enum name="klavika_regular_italic" value="7" />
</attr>

<!--
     Tell Android that the class "KlavikaTextView" can be styled,
     and which attributes it supports-->
<declare-styleable name="KlavikaTextView">
    <attr name="typeface" />
</declare-styleable>

Next created the style

  <style name="TextView.Example">
    <item name="typeface">klavika_bold</item>
  </style>

This style you can use for your xml Layouts

style="@style/TextView.Example" 

Answer 6

<?xml version="1.0" encoding="utf-8"?>
<resources
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res/com.my.project">

    <style name="my_style"> <item name="custom:tag">some_value</item> </style>

</resources>

you are trying to apply XML namespacing to an attribute value, which won't work. In this case, you should specify the package name directly, like this:

 <style name="my_style"> <item name="com.my.project:tag">some_value</item> </style>

Answer 7

Fast solution via code!

 String pathFont = "fonts/ReallyCoolFont.ttf";
 TextView text = (TextView) findViewById(R.id.TextView1);
 Typeface fontFace = Typeface.createFromAsset( getAssets(), pathFont );
 text.setTypeface( fontFace );

Third-party libraries , solve the problem, in XML!

1 - https://github.com/leok7v/android-textview-custom-fonts

2 - https://github.com/ragunathjawahar/android-typeface-textview

My suggestion

You will have other needs, and for each component you will have to customize a class.

Another problem you have other layouts and N TextView components for maintenance you will have a lot of work .

I use this method in projects in the OnCreate of my activity if I need to change the font I have to do this only in the OnCreate method of each activity .

 private static final String FONT = "ReallyCoolFont.ttf";

public static void allTextView(final Context context, final View root) {
      String fontPath = FONT;
    try {
        if (root instanceof ViewGroup) {
            ViewGroup viewGroup = (ViewGroup) root;
            int childCount = viewGroup.getChildCount();
            for (int i = 0; i < childCount; i++)
                allTextView(context, viewGroup.getChildAt(i) );
        } else if (root instanceof TextView)
            ((TextView) root).setTypeface(Typeface.createFromAsset(context.getAssets(), fontPath));
    } catch (Exception e) { 
        e.printStackTrace();
    }
}

// call in OnCreate Activity    
allTextView(this, findViewById(R.layout.main) );

Answer 8

The custom attributes are defined using <declare-styleable> tags; usually the file is called attrs.xml. The namespace declaration will have your app's package name in it.

The whole process is described here: Creating a View Class | Android Developers