android: custom view layout wrapping

Question

I want to have two custom views like this:

class LoadingView extends RelativeLayout{
    //this view has a progressBar and can show and hide it.

    void setIsLoading(){
        // shows/hides progress bar
    }


    // some code ...
}

class OtherView extends LoadingView{
    //some code ...
}

LoadingView has a layout like this:

<RelativeLayout>
    <FrameLayout
        id="@+id/content">
        <!--this is where content goes-->
    </FrameLayout>

    <ProgressBar
        id="@+id/pb"/>
</RelativeLayout>

so that any custom view that inherits from it will be injected into FrameLayout

so if OtherView has it's own layout , it will be nested inside FrameLayout automatically and you will be able to call myOtherView.setIsLoading(true/false)

How would you suggest doing this ?

Answer 1

Keep a reference to the content FrameLayout when inflating the first view.

public class LoadingView extends RelativeLayout {

    private ProgressBar progressBar;
    private FrameLayout contentFrame;

    public LoadingView(Context context) {
        super(context);
        initialize();
    }

    public LoadingView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initialize();
    }

    public LoadingView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initialize();
    }

    private void initialize() {
        View root = inflate(getContext(), R.layout.loading_view, this);
        progressBar = (ProgressBar) root.findViewById(R.id.progress_bar);
        contentFrame = (FrameLayout) root.findViewById(R.id.content_frame);
    }

    public void setLoading(boolean loading) {
        progressBar.setVisibility(loading ? VISIBLE : GONE);
    }

    protected FrameLayout getContentFrame() {
        return contentFrame;
    }

}

Then use getContentFrame as the parent view when inflating the child view.

public class OtherView extends LoadingView {

    public OtherView(Context context) {
        super(context);
        initialize();
    }

    public OtherView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initialize();
    }

    public OtherView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initialize();
    }

    private void initialize() {
        View root = inflate(getContext(), R.layout.other_view, getContentFrame());
    }

}

loading_view.xml

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

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <ProgressBar
        android:id="@+id/progress_bar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</RelativeLayout>

other_view.xml

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

    <TextView
        android:text="Title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <TextView
        android:text="Subtitle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

And use it like this

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

    <com.example.client.ui.OtherView
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</FrameLayout>