Part 6 – Update Collection View

[embedyt] https://www.youtube.com/watch?v=0ehrgrKi9eE[/embedyt]

In part 6 of the app widget tutorial, we will learn how to update adapter-based collection widgets. For this we have to call notifyAppWidgetViewDataChanged on the AppWidgetManager, which then triggers the onDataSetChanged method in the RemoteViewsFactory class in the RemoteViewsService. In this method we can do long running operations like database and network calls synchronously, because we will just see a loading view while the data is being fetched.

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gradient.xmlexample_widget_item.xmlExampleWidgetService.javaactivity_example_app_widget_config.xmlExampleAppWidgetConfig.javaexample_widget.xmlExampleAppWidgetProvider.javaexample_appwidget_info.xmlAndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:angle="90"
        android:endColor="#044fab"
        android:startColor="#9cefee" />
</shape>

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/example_widget_item_text"
    android:layout_width="200dp"
    android:layout_height="200dp"
    android:background="@drawable/gradient"
    android:gravity="center"
    android:text="Item"
    android:textColor="@android:color/white"
    android:textSize="20sp"
    android:textStyle="bold" />

package com.codinginflow.widgetexample;

import android.appwidget.AppWidgetManager;
import android.content.Context;
import android.content.Intent;
import android.os.SystemClock;
import android.widget.RemoteViews;
import android.widget.RemoteViewsService;

import java.text.DateFormat;
import java.util.Date;


public class ExampleWidgetService extends RemoteViewsService {
    @Override
    public RemoteViewsFactory onGetViewFactory(Intent intent) {
        return new ExampleWidgetItemFactory(getApplicationContext(), intent);
    }

    class ExampleWidgetItemFactory implements RemoteViewsFactory {
        private Context context;
        private int appWidgetId;
        private String[] exampleData = {"one", "two", "three", "four",
                "five", "six", "seven", "eight", "nine", "ten"};

        ExampleWidgetItemFactory(Context context, Intent intent) {
            this.context = context;
            this.appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);
        }

        @Override
        public void onCreate() {
            //connect to data source
        }

        @Override
        public void onDataSetChanged() {
            //refresh data
            Date date = new Date();
            String timeFormatted = DateFormat.getTimeInstance(DateFormat.SHORT).format(date);
            exampleData = new String[]{"one\n" + timeFormatted, "two\n" + timeFormatted,
                    "three\n" + timeFormatted};
            SystemClock.sleep(3000);
        }

        @Override
        public void onDestroy() {
            //close data source
        }

        @Override
        public int getCount() {
            return exampleData.length;
        }

        @Override
        public RemoteViews getViewAt(int position) {
            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_widget_item);
            views.setTextViewText(R.id.example_widget_item_text, exampleData[position]);

            Intent fillIntent = new Intent();
            fillIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
            views.setOnClickFillInIntent(R.id.example_widget_item_text, fillIntent);

            SystemClock.sleep(500);
            return views;
        }

        @Override
        public RemoteViews getLoadingView() {
            return null;
        }

        @Override
        public int getViewTypeCount() {
            return 1;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public boolean hasStableIds() {
            return true;
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    tools:context="com.codinginflow.widgetexample.ExampleAppWidgetConfig">

    <EditText
        android:id="@+id/edit_text_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:hint="Button text" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="confirmConfiguration"
        android:text="Confirm" />

</LinearLayout>

package com.codinginflow.widgetexample;

import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.RemoteViews;

import static com.codinginflow.widgetexample.ExampleAppWidgetProvider.ACTION_REFRESH;

public class ExampleAppWidgetConfig extends AppCompatActivity {
    public static final String SHARED_PREFS = "prefs";
    public static final String KEY_BUTTON_TEXT = "keyButtonText";

    private int appWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
    private EditText editTextButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_example_app_widget_config);

        Intent configIntent = getIntent();
        Bundle extras = configIntent.getExtras();
        if (extras != null) {
            appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);
        }

        Intent resultValue = new Intent();
        resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        setResult(RESULT_CANCELED, resultValue);

        if (appWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {
            finish();
        }

        editTextButton = findViewById(R.id.edit_text_button);
    }

    public void confirmConfiguration(View v) {
        AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(this);

        Intent buttonIntent = new Intent(this, MainActivity.class);
        PendingIntent buttonPendingIntent = PendingIntent.getActivity(this,
                0, buttonIntent, 0);

        String buttonText = editTextButton.getText().toString();

        Intent serviceIntent = new Intent(this, ExampleWidgetService.class);
        serviceIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        serviceIntent.setData(Uri.parse(serviceIntent.toUri(Intent.URI_INTENT_SCHEME)));

        Intent clickIntent = new Intent(this, ExampleAppWidgetProvider.class);
        clickIntent.setAction(ACTION_REFRESH);
        PendingIntent clickPendingIntent = PendingIntent.getBroadcast(this,
                0, clickIntent, 0);

        RemoteViews views = new RemoteViews(this.getPackageName(), R.layout.example_widget);
        views.setOnClickPendingIntent(R.id.example_widget_button, buttonPendingIntent);
        views.setCharSequence(R.id.example_widget_button, "setText", buttonText);
        views.setRemoteAdapter(R.id.example_widget_stack_view, serviceIntent);
        views.setEmptyView(R.id.example_widget_stack_view, R.id.example_widget_empty_view);
        views.setPendingIntentTemplate(R.id.example_widget_stack_view, clickPendingIntent);

        appWidgetManager.updateAppWidget(appWidgetId, views);

        SharedPreferences prefs = getSharedPreferences(SHARED_PREFS, MODE_PRIVATE);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString(KEY_BUTTON_TEXT + appWidgetId, buttonText);
        editor.apply();

        Intent resultValue = new Intent();
        resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
        setResult(RESULT_OK, resultValue);
        finish();
    }
}

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

    <TextView
        android:id="@+id/example_widget_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#FFF"
        android:text="My Widget"
        android:textAppearance="@style/TextAppearance.AppCompat.Large" />

    <Button
        android:id="@+id/example_widget_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Press me" />

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <StackView
            android:id="@+id/example_widget_stack_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:loopViews="true" />

        <TextView
            android:id="@+id/example_widget_empty_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@android:color/darker_gray"
            android:gravity="center"
            android:text="Empty"
            android:textColor="@android:color/white"
            android:textSize="20sp"
            android:textStyle="bold" />

    </FrameLayout>

</LinearLayout>

package com.codinginflow.widgetexample;

import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.RemoteViews;
import android.widget.Toast;

import static com.codinginflow.widgetexample.ExampleAppWidgetConfig.KEY_BUTTON_TEXT;
import static com.codinginflow.widgetexample.ExampleAppWidgetConfig.SHARED_PREFS;


public class ExampleAppWidgetProvider extends AppWidgetProvider {
    public static final String ACTION_REFRESH = "actionRefresh";

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        for (int appWidgetId : appWidgetIds) {
            Intent buttonIntent = new Intent(context, MainActivity.class);
            PendingIntent buttonPendingIntent = PendingIntent.getActivity(context,
                    0, buttonIntent, 0);

            SharedPreferences prefs = context.getSharedPreferences(SHARED_PREFS, Context.MODE_PRIVATE);
            String buttonText = prefs.getString(KEY_BUTTON_TEXT + appWidgetId, "Press me");

            Intent serviceIntent = new Intent(context, ExampleWidgetService.class);
            serviceIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
            serviceIntent.setData(Uri.parse(serviceIntent.toUri(Intent.URI_INTENT_SCHEME)));

            Intent clickIntent = new Intent(context, ExampleAppWidgetProvider.class);
            clickIntent.setAction(ACTION_REFRESH);
            PendingIntent clickPendingIntent = PendingIntent.getBroadcast(context,
                    0, clickIntent, 0);

            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_widget);
            views.setOnClickPendingIntent(R.id.example_widget_button, buttonPendingIntent);
            views.setCharSequence(R.id.example_widget_button, "setText", buttonText);
            views.setRemoteAdapter(R.id.example_widget_stack_view, serviceIntent);
            views.setEmptyView(R.id.example_widget_stack_view, R.id.example_widget_empty_view);
            views.setPendingIntentTemplate(R.id.example_widget_stack_view, clickPendingIntent);

            Bundle appWidgetOptions = appWidgetManager.getAppWidgetOptions(appWidgetId);
            resizeWidget(appWidgetOptions, views);

            appWidgetManager.updateAppWidget(appWidgetId, views);
            appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetId, R.id.example_widget_stack_view);
        }
    }

    @Override
    public void onAppWidgetOptionsChanged(Context context, AppWidgetManager appWidgetManager, int appWidgetId, Bundle newOptions) {
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_widget);

        resizeWidget(newOptions, views);

        appWidgetManager.updateAppWidget(appWidgetId, views);
    }

    private void resizeWidget(Bundle appWidgetOptions, RemoteViews views) {
        int minWidth = appWidgetOptions.getInt(AppWidgetManager.OPTION_APPWIDGET_MIN_WIDTH);
        int maxWidth = appWidgetOptions.getInt(AppWidgetManager.OPTION_APPWIDGET_MAX_WIDTH);
        int minHeight = appWidgetOptions.getInt(AppWidgetManager.OPTION_APPWIDGET_MIN_HEIGHT);
        int maxHeight = appWidgetOptions.getInt(AppWidgetManager.OPTION_APPWIDGET_MAX_HEIGHT);

        if (maxHeight > 100) {
            views.setViewVisibility(R.id.example_widget_text, View.VISIBLE);
            views.setViewVisibility(R.id.example_widget_button, View.VISIBLE);
        } else {
            views.setViewVisibility(R.id.example_widget_text, View.GONE);
            views.setViewVisibility(R.id.example_widget_button, View.GONE);
        }
    }

    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        Toast.makeText(context, "onDeleted", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onEnabled(Context context) {
        Toast.makeText(context, "onEnabled", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onDisabled(Context context) {
        Toast.makeText(context, "onDisabled", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        if (ACTION_REFRESH.equals(intent.getAction())) {
            int appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);
            AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
            appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetId, R.id.example_widget_stack_view);
        }
        super.onReceive(context, intent);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:autoAdvanceViewId="@id/example_widget_stack_view"
    android:configure="com.codinginflow.widgetexample.ExampleAppWidgetConfig"
    android:initialLayout="@layout/example_widget"
    android:minHeight="110dp"
    android:minResizeHeight="40dp"
    android:minWidth="110dp"
    android:previewImage="@drawable/widget_preview"
    android:resizeMode="vertical|horizontal"
    android:updatePeriodMillis="3600000"
    android:widgetCategory="home_screen" />

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codinginflow.widgetexample">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".ExampleAppWidgetProvider">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/example_appwidget_info" />
        </receiver>

        <activity android:name=".ExampleAppWidgetConfig">
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
            </intent-filter>
        </activity>

        <service
            android:name=".ExampleWidgetService"
            android:permission="android.permission.BIND_REMOTEVIEWS" />
    </application>

</manifest>