Button click event for android widget

Question

I have an android widget that fetches data from a server every 10 minutes and display's it on the screen.
I'd like to add a "Refresh" button to that widget.
When the user clicks that button I'd like to run the method that fetches the information from the server.
Adding an event handler to a button in an application is very easy, however I couldn't find an example for a widget.
I'd like to get some help with adding a function to a button click in a widget.

Answer 1

Unlike the other answers here which use onReceive(), I found that it's actually a lot cleaner and simpler to do everything in onUpdate().

The official Android codelab Advanced Android 02.1: App widgets offers this solution. The example code there is in Java. Here I present the solution in Kotlin.

class MyAppWidgetProvider : AppWidgetProvider() {

    override fun onUpdate(
        context: Context?,
        appWidgetManager: AppWidgetManager?,
        appWidgetIds: IntArray?
    ) {
        appWidgetIds?.forEach { appWidgetId ->
            val views = RemoteViews(
                context?.packageName,
                R.layout.appwidget
            )
            // Coroutine to perform background IO task.
            GlobalScope.launch(Dispatchers.IO) {
                // Suspend function.
                val apiData = Api.retrofitService.getData()
                updateWidgetUI(views, apiData)
                context?.let {
                    views.setOnClickPendingIntent(
                        R.id.widget_button,
                        getUpdatePendingIntent(it, appWidgetId)
                    )
                }
                appWidgetManager?.updateAppWidget(appWidgetId, views)
            }
        }
    }

    private fun updateWidgetUI(views: RemoteViews, apiData: ApiData){
        views.apply {
            setTextViewText(R.id.widget_value_textview, apiData.value)
            setTextViewText(
                R.id.widget_last_updated_value_textview,
                DateFormat.getTimeInstance(DateFormat.MEDIUM).format(Date())
            )
        }
    }

    private fun getUpdatePendingIntent(context: Context, appWidgetId: Int): PendingIntent {
        val intent = Intent(context, MyAppWidgetProvider::class.java).also {
            it.action = AppWidgetManager.ACTION_APPWIDGET_UPDATE
            // It's very important to use intArrayOf instead of arrayOf,
            // as a primitive int array is expected.
            it.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, intArrayOf(appWidgetId))
        }
        // Set the immutability flag for Android 12.
        val flags = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
        } else {
            PendingIntent.FLAG_UPDATE_CURRENT
        }
        return PendingIntent.getBroadcast(
            context,
            appWidgetId,
            intent,
            flags
        )
    }
// No need for onReceive().
}

The key here is to use the built-int AppWidgetManager.ACTION_APPWIDGET_UPDATE action instead of a custom action.

Answer 2

In the pendingIntent, we can also put extra attribute appWidgetId to reuse it later in onReceive to update the widget clicked widget instance

class ExampleAppWidgetProvider : AppWidgetProvider() {

    override fun onUpdate(context: Context, appWidgetManager: AppWidgetManager, appWidgetIds: IntArray {

        appWidgetIds.forEach { appWidgetId ->
            Log.e("TAG", "onUpdate $appWidgetId")
            val pendingRefreshClickIntent: PendingIntent = Intent(context, javaClass).let {
                it.action = ACTION_REFRESH_CLICK
                it.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId)
                return@let PendingIntent.getBroadcast(
                    context,
                    appWidgetId, // click in all instances widget will work well (base on Alireza Mirian comment in the top answer)
                    it,
                    PendingIntent.FLAG_UPDATE_CURRENT
                )
            }

            val views = RemoteViews(
                context.packageName,
                R.layout.example_appwidget
            )
            views.setOnClickPendingIntent(R.id.button_refresh, pendingRefreshClickIntent)

            appWidgetManager.updateAppWidget(appWidgetId, views)
        }
    }

    override fun onReceive(context: Context?, intent: Intent?) {
        super.onReceive(context, intent)
        Log.i("TAG", "onReceive " + intent?.action)

        if (intent?.action == ACTION_REFRESH_CLICK) {
            val appWidgetId = intent.extras?.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID) ?: return
            Log.i("TAG", "onReceive appWidgetId $appWidgetId")

            val appWidgetManager = AppWidgetManager.getInstance(context)
            val views = RemoteViews(context!!.packageName, R.layout.example_appwidget)

            views.setTextViewText(R.id.text_data, "a " + (Math.random() * 9).roundToInt())
            appWidgetManager.updateAppWidget(appWidgetId, views)
        }
    }

    companion object {
        private const val ACTION_REFRESH_CLICK =  "com.example.androidwidgetbuttonclick.action.ACTION_REFRESH_CLICK"
    }
}

Widget initial layout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/text_data"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="AA"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button_refresh"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Refresh" />
</LinearLayout>

Answer 3

I tried the solution suggested by Sharon Haim Pour above, but my onReceive() method in AppWidgetProvider class has never been called on button press.

Intent intent = new Intent(WIDGET_BUTTON);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 
PendingIntent.FLAG_UPDATE_CURRENT);
views.setOnClickPendingIntent(R.id.MY_BUTTON_ID, pendingIntent );

After some research I could resolve the problem by updating the code as below:

Intent intent = new Intent(context, MY_APPWIDGETPROVIDER_CLASS.class);
intent.setAction(WIDGET_BUTTON);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 
PendingIntent.FLAG_UPDATE_CURRENT);
views.setOnClickPendingIntent(R.id.MY_BUTTON_ID, pendingIntent );

Do not forget to put below:

appWidgetManager.updateAppWidget(appWidgetId, views);

Answer 4

Here is another answer with the following benefits:

• It handles all App Widget instances (a user might have multiple instances of your widget in various configurations/sizes on your screen). Coding for all instances is what the official documentation prescribes. See Guide > App Widgets > Using the AppWidgetProvider Class , scroll down to the code example for "ExampleAppWidgetProvider".
• The workhorse code in onReceive in effect calls onUpdate (so you reduce code duplication).
• The code in onUpdate(Context context) is generalised so that it can be dropped into any AppWidgetProvider subclass.

The code:

public class MyWidget extends AppWidgetProvider {

    private static final String ACTION_UPDATE_CLICK = 
              "com.example.myapp.action.UPDATE_CLICK";

    private static int mCount = 0;

    private static String getMessage() {
        return String.valueOf(mCount++);
    }

    private PendingIntent getPendingSelfIntent(Context context, String action) {
        // An explicit intent directed at the current class (the "self").
        Intent intent = new Intent(context, getClass());
        intent.setAction(action);
        return PendingIntent.getBroadcast(context, 0, intent, 0);
    }

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager,
                         int[] appWidgetIds) {
        super.onUpdate(context, appWidgetManager, appWidgetIds);

        String message = getMessage();

        // Loop for every App Widget instance that belongs to this provider.
        // Noting, that is, a user might have multiple instances of the same
        // widget on
        // their home screen.
        for (int appWidgetID : appWidgetIds) {
            RemoteViews remoteViews = new RemoteViews(context.getPackageName(),
                                                      R.layout.my_widget);

            remoteViews.setTextViewText(R.id.textView_output, message);
            remoteViews.setOnClickPendingIntent(R.id.button_update,
                                                getPendingSelfIntent(context,
                                                           ACTION_UPDATE_CLICK)
            );

            appWidgetManager.updateAppWidget(appWidgetID, remoteViews);

        }
    }

    /**
     * A general technique for calling the onUpdate method,
     * requiring only the context parameter.
     *
     * @author John Bentley, based on Android-er code.
     * @see <a href="http://android-er.blogspot.com
     * .au/2010/10/update-widget-in-onreceive-method.html">
     * Android-er > 2010-10-19 > Update Widget in onReceive() method</a>
     */
    private void onUpdate(Context context) {
        AppWidgetManager appWidgetManager = AppWidgetManager.getInstance
                (context);

        // Uses getClass().getName() rather than MyWidget.class.getName() for
        // portability into any App Widget Provider Class
        ComponentName thisAppWidgetComponentName =
                new ComponentName(context.getPackageName(),getClass().getName()
        );
        int[] appWidgetIds = appWidgetManager.getAppWidgetIds(
                thisAppWidgetComponentName);
        onUpdate(context, appWidgetManager, appWidgetIds);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);

        if (ACTION_UPDATE_CLICK.equals(intent.getAction())) {
            onUpdate(context);
        }
    }

}

The widget looks like this

This builds on the getPendingSelfIntent work of @Kels, @SharonHaimPour and @Erti-ChrisEelmaa.

It also builds on Android-er > 2010-10-19 > Update Widget in onReceive() method (not me) where it is demonstrated how to call onUpdate from onReceive, on an App Widget instance basis. I make that code general and wrap it in callOnUpdate.

Answer 5

protected PendingIntent getPendingSelfIntent(Context context, String action) {
    Intent intent = new Intent(context, getClass());
    intent.setAction(action);
    return PendingIntent.getBroadcast(context, 0, intent, 0);
}

views.setOnClickPendingIntent(R.id.Timm, getPendingSelfIntent(context,
                              "ham"));

Also prefer URL :

How to correctly handle click events on Widget

If you solved it in a different way, please provide this as an answer

Answer 6

Here is one example more that should help:

package com.automatic.widget;

import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.widget.RemoteViews;

public class Widget extends AppWidgetProvider {

    private static final String SYNC_CLICKED    = "automaticWidgetSyncButtonClick";

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        RemoteViews remoteViews;
        ComponentName watchWidget;

        remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
        watchWidget = new ComponentName(context, Widget.class);

        remoteViews.setOnClickPendingIntent(R.id.sync_button, getPendingSelfIntent(context, SYNC_CLICKED));
        appWidgetManager.updateAppWidget(watchWidget, remoteViews);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        super.onReceive(context, intent);

        if (SYNC_CLICKED.equals(intent.getAction())) {

            AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);

            RemoteViews remoteViews;
            ComponentName watchWidget;

            remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
            watchWidget = new ComponentName(context, Widget.class);

            remoteViews.setTextViewText(R.id.sync_button, "TESTING");

            appWidgetManager.updateAppWidget(watchWidget, remoteViews);

        }
    }

    protected PendingIntent getPendingSelfIntent(Context context, String action) {
        Intent intent = new Intent(context, getClass());
        intent.setAction(action);
        return PendingIntent.getBroadcast(context, 0, intent, 0);
    }
}

Answer 7

I found out how to do that.
Add an action to the AndroidManifest.xml file in the > <receiver><intent-filter> tag:

<action android:name="MY_PACKAGE_NAME.WIDGET_BUTTON" />

In the provider add a constant that matches the action name:

public static String WIDGET_BUTTON = "MY_PACKAGE_NAME.WIDGET_BUTTON";

In the onUpdate() method add a pending intent that matches the action:

Intent intent = new Intent(WIDGET_BUTTON);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
views.setOnClickPendingIntent(R.id.MY_BUTTON_ID, pendingIntent );

Finally, in the onRecieve() method, check the action name:

 if (WIDGET_BUTTON.equals(intent.getAction())) {
//your code here

    }