Complex Attributes in Android Custom View XML

Question

I've got a question on custom view XML-declarations.
I created my own View with the custom attributes as normal. Now I want to add more complex attributes like this: (This is non-working code)

<com.xxx.yyy.CustomTextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/customTextView1"
    android:layout_marginBottom="22dp"
    android:layout_toRightOf="@+id/buttonBlack"
    android:text="TextView" >
        <Animation
            animation:property1="123"
            animation:property2="456" />
        <Animation
            animation:property1="789"
            animation:property2="012" >
        </Animation>
</com.xxx.yyy.CustomTextView>

I didnt find a way to do this on my own but maybe someone has got an idea.

Thanks!

Edit:

I just solved the problem more or less nicely. I created a new .xml file in my /res/xml folder called animations.xml

<animations>
    <animation
        name="Animation name 1"
        float1="1.1"
        float2="1.2"
        integer1="11"
        integer2="12" />
    <animation
        name="Animation name 2"
        float1="2.1"
        float2="2.2"
        integer1="21"
        integer2="22" />
</animations>

My custom view in attrs.xml contains an attribute which is used to reference the animations.xml file from above:

<declare-styleable name="MyTextView">
    <attr name="animations" format="reference" />
</declare-styleable>

Now i parse the referenced .xml file in the constructor of the MyTextView as described here: http://thedevelopersinfo.com/2009/12/14/using-xml-file-resources-in-android/

Maybe this helps somebody at some time.

You should create custom XML attributes for this like described here: developer.android.com/training/custom-views/… — JimVanB
– JimVanB, Commented Apr 30, 2014 at 8:46

Karakuri · Accepted Answer · 2014-04-30 08:46:45Z

1

Unless CustomTextView extends ViewGroup (or has it in it's class hierarchy) and Animation is a custom view you've defined, this will not work. Only Views and ViewGroups are allowed in layout XML files (and some special tags defined by Android like include and merge), and only ViewGroup elements can have child elements.

answered Apr 30, 2014 at 8:46

Karakuri

38.6k12 gold badges91 silver badges106 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

p0wl90 Over a year ago

Okay thanks! That is exactly what i thought. I was just hoping that there is a way of doing this which i havent seen yet.

JimVanB · Accepted Answer · 2014-04-30 08:55:22Z

1

You can add custom XML attributes to your custom view like this:

<resources>

<declare-styleable name="YourCustomClass">
    <attr name="someCustomAnimationAttribute" format="reference" />
</declare-styleable>

<resources>

How you obtain it is described here:

http://developer.android.com/training/custom-views/create-view.html#applyattr

In your layout you have to declare a namespace:

xmlns:app="http://schemas.android.com/apk/res-auto"

and then use it like this:

<com.xxx.yyy.CustomTextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/customTextView1"
android:layout_marginBottom="22dp"
android:layout_toRightOf="@+id/buttonBlack"
android:text="TextView" 
app:someCustomAnimationAttribute="@drawable/someAnimation">

That way you can supply those animations via XML instead of adding them as as child elements which is not possible.

edited Apr 30, 2014 at 8:55

answered Apr 30, 2014 at 8:49

JimVanB

1,2251 gold badge13 silver badges29 bronze badges

3 Comments

waqaslam Over a year ago

i think the OP's main concern is how to retrieve a child xml tag in a custom view, i.e. <Animation />

JimVanB Over a year ago

As @Karakuri pointed out, if that custom view extends ViewGroup, one can add child views (custom child views with custom parameters for that matter). But supplying an animation that way won't work.

p0wl90 Over a year ago

Yes exactly. I already knew how to define simple attributes. The question was whether it is possible to define more complex attributes as XML child elements. But thanks anyway!

Collectives™ on Stack Overflow

Complex Attributes in Android Custom View XML

2 Answers 2

1 Comment

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related