Show loader on Spinner (Dropdown) when it is fetching data from web service

Question

In the image above, I have shown that when the user touches the drop-down spinner it will call the web api for getting data for the spinner. Then, that moment, I want to show the loader only on the spinner view on the left or right somewhere on the view itself like in the image, rather than on whole screen when it is getting data from the web service dynamically and hide that progress bar later when web service completely hit at the end (Ignore that search bar in image).

Answer 1

Just create an custom adapter for your spinner. Follow the instructions found here How to create Spinner-list using CustomAdapter in android . Put the loading view in the layout inflated in the getView method in the adapter, and manipulate it via a callback from your async task used for fetching the result.

Answer 2

In this i am showing loader on start button and hiding loader when stop button is pressed so you can use according to your need.So , for this i have made three class CustomSpinner,Spinner_Custom_adapter and Activity class for using it

In main layout file

 <LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:orientation="vertical">

    <www.your_packagename.com.spinnerwithloaderex.CustomSpinner
        android:id="@+id/custm_spnr"
        android:layout_width="120dp"
        android:layout_height="40dp"
        android:layout_centerInParent="true"
        android:layout_gravity="center"
        android:background="@drawable/dropdown_create_sales"
        android:paddingRight="15dp"
        android:text="Hello World!" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp">

        <Button
            android:id="@+id/start_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Start" />

        <Button
            android:id="@+id/stop_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Stop" />

    </LinearLayout>
</LinearLayout>

CustomSpinner class

public class CustomSpinner extends android.support.v7.widget.AppCompatSpinner {
private Spinner_Custom_adapter spinner_custom_adapter;

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

public CustomSpinner(Context context, int mode) {
    super(context, mode);
}

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

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

public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr, int mode) {
    super(context, attrs, defStyleAttr, mode);
}

public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr, int mode, Resources.Theme popupTheme) {
    super(context, attrs, defStyleAttr, mode, popupTheme);
}

public void setItems(Activity activity, ArrayList<String> spnr_Arr) {
    spinner_custom_adapter = new Spinner_Custom_adapter(activity, spnr_Arr);
    setAdapter(spinner_custom_adapter);
}

public Spinner_Custom_adapter getSpinner_custom_adapter() {
    return spinner_custom_adapter;
}

public void showLoader() {
    setEnabled(false);
    spinner_custom_adapter.showLoader(true, true);
}

public void dismissLoader() {
    setEnabled(true);
    spinner_custom_adapter.showLoader(false, true);
}

}

Custom_Adapter class

public class Spinner_Custom_adapter<T> extends ArrayAdapter<T> {

private LayoutInflater flater;
private ProgressBar spinner_progress;
private TextView txtTitle;
private Boolean showOrNot = false;

Spinner_Custom_adapter(Activity context, ArrayList<T> list) {
    super(context, R.layout.loader_spinner_lt, R.id.title, list);
    flater = context.getLayoutInflater();
}

@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        convertView = flater.inflate(R.layout.loader_spinner_lt, parent, false);
    }
    Object object = getItem(position);
    String rowItem = null;
    if (object instanceof String) {
        rowItem = (String) object;
    }

    TextView txtTitle = (TextView) convertView.findViewById(R.id.title);
    txtTitle.setText(rowItem);
    ProgressBar spinner_progress = (ProgressBar) convertView.findViewById(R.id.spinner_progress);
    this.txtTitle = txtTitle;
    this.spinner_progress = spinner_progress;
    showLoader(showOrNot, false);
    return convertView;
}

void showLoader(Boolean showOrNot, boolean notifyListOrNot) {
    if (txtTitle != null && spinner_progress != null) {
        this.showOrNot = showOrNot;

        spinner_progress.setVisibility(showOrNot ? View.VISIBLE : View.GONE);
        if (notifyListOrNot) {
            notifyDataSetChanged();
        }
    }
}

}

Spinner single view layout xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center_vertical"
    android:gravity="center_vertical"
    android:orientation="horizontal">

    <CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/title"
        style="?android:attr/spinnerDropDownItemStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toLeftOf="@+id/spinner_progress"
        android:ellipsize="end"
        android:singleLine="true"
        android:text="Strawberry"
        android:textColor="#CC0033"
        android:textSize="16dp" />

    <ProgressBar
        android:id="@+id/spinner_progress"
        style="?android:attr/progressBarStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:visibility="gone" />

</RelativeLayout>

and for using it

       custm_spnr = (CustomSpinner) findViewById(R.id.custm_spnr);
    ArrayList<String> items = new ArrayList<>();
    items.add("Abcdefg");
    items.add("hijklm");
    items.add("nopqr");
    items.add("stu");
    items.add("vwxyza1b1c1");
    items.add("d1e1f11g1h1");
    custm_spnr.setItems(MainActivity.this, items);

    findViewById(R.id.start_btn).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            custm_spnr.showLoader();
        }
    });

    findViewById(R.id.stop_btn).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            custm_spnr.dismissLoader();
        }
    });