CODEWITHSUNDEEP
androidandroid-custom-viewattr
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Reputation: 918

How to pass custom attributes to nested xml

I have structure like that:

preferences.xml:

...

<com.example.MyCustomPreference
    ...
    myCustomMessage="@string/abc"
    android:inputType="..."
    ... />

...

preference_my_custom.xml:

<LinearLayout ...>

    <com.example.MyCustomView
        ...
        app:myCustomMessage="?????"
        ... />

</LinearLayout>

view_my_custom.xml:

<GridView ...>
    ...EditTexts, TextViews, etc.
</GridView>

I would like to pass myCustomMessage's value (I omitted other attributes for simplification) from MyCustomPreference to MyCustomView using XML. MyCustomView reads custom attributes, so I would like to avoid reading attributes in MyCustomPreference programmatically, getting TextViews from MyCustomView and setting them values. However, I really don't know what to type in place of "?????".

How can i do this using XML? Is this possible?

Upvotes: 1

Views: 1189

Answers (2)

Harsh Mittal
Harsh Mittal

Reputation: 459

Create an attribute file for your customeView:

Add in attrs.xml

<declare-styleable name="CustomView">
    <attr name="width" format="dimension" />
</declare-styleable>

Used in your customView init: 

 public CustomView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);

    TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomView, defStyle, 0);
    mWidth = a.getDimensionPixelSize(R.styleable.CustomView_width,0);
    a.recycle();
}

Upvotes: 1

Marc Estrada
Marc Estrada

Reputation: 1667

You have to do it programmatically (unless you use data binding). For example, in your MyCustomPreference you catch de attribute myCustomMessage:

String myCustomMessage = null;
TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyCustomPreference, 0, 0);
try {
  myCustomMessage = a.getString(R.styleable.MyCustomPreference_myCustomMessage);
} finally {
  a.recycle();
}

Here you got the String value of your attribute. Then, I supose you have inflated your MyCustomView inside your MyCustomPreference. As an example:

View.inflate(getContext(), R.layout.preference_my_custom, this);
MyCustomView myCustomView = (MyCustomView) findViewById(R.id.you_custom_view_id);

So, here you can set programmatically your myCustomMessage in your MyCustomView.

myCustomView.setMyCustomMessage(myCustomMessage);

You should create this method to set correctly your text, and if necessary propagate this text to other child views of your MyCustomView.

Now, changing your String resId in your preferences.xml the interface should update as expected.

P.S: Since I don't know all your resource ids, please adapt them to your project.

Upvotes: 2

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