Android Widgets

App Widgets is a small view of an application.We can embedded this widgets in other application.We can update this widgets periodically.App widget is a simple way to enhance your application by having a view on android Home Screen. Widgets is used to convey the update information of our application to the user.

RemoteViews

RemoteViews is used to describes a view hierarchy that can be displayed in another process. The hierarchy is inflated from a layout resource file, and this class provides some basic operations for modifying the content of the inflated hierarchy.

A RemoteViews object can support the following layout classes:

FrameLayout

LinearLayout

RelativeLayout

GridLayout

And the following widget classes:

AnalogClock

Button

Chronometer

ImageButton

ImageView

ProgressBar

TextView

ViewFlipper

ListView

GridView

StackView

AdapterViewFlipper

You can download source code here.

package com.etr.widgetsexample;

import java.util.Date;

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 DemoWidgetProvider extends AppWidgetProvider {

                @Override

                public void onUpdate(Context context, AppWidgetManager appWidgetManager,

                                                int[] appWidgetIds) {

                                RemoteViews remoteViews = new RemoteViews(context.getPackageName(),

                                                                R.layout.widget_layout);

                                remoteViews.setTextViewText(R.id.title, getTitle());

                                remoteViews.setTextViewText(R.id.desc, getDesc());

                                pushWidgetUpdate(context, remoteViews);

                                context.startService(new Intent(context, WidgetService.class));

                }

                private static CharSequence getDesc() {

                                return new Date().toString()

                                                                + " ::: Update \n\n http://androidtutorialspoint.blogspot.com ";

                }

                private static CharSequence getTitle() {

                                return "Every minute update";

                }

                public static void pushWidgetUpdate(Context context, RemoteViews remoteViews) {

                                ComponentName myWidget = new ComponentName(context,

                                                                DemoWidgetProvider.class);

                                AppWidgetManager manager = AppWidgetManager.getInstance(context);

                                manager.updateAppWidget(myWidget, remoteViews);

                }

}

AppWidgetProvider

onUpdate() is called to update the App Widget at intervals defined by the updatePeriodMillis attribute in the AppWidgetProviderInfo. 

onAppWidgetOptionsChanged() is called when the widget is first placed and any time the widget is resized.

onDeleted(Context, int[]) is called every time an App Widget is deleted from the App Widget host.

onEnabled(Context) is called when an instance the App Widget is created for the first time.

onDisabled(Context) is called when the last instance of your App Widget is deleted from the App Widget host.

onReceive(Context, Intent) is called for every broadcast and before each of the above callback methods.

package com.etr.widgetsexample;

import java.util.Date;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.widget.RemoteViews;

public class DemoWidgetIntentReceiver extends BroadcastReceiver {

@Override

public void onReceive(Context context, Intent intent) {

if (intent.getAction().equals(DemoWidgetUtils.WIDGET_UPDATE_ACTION)) {

updateWidgetPictureAndButtonListener(context);

}

}

private void updateWidgetPictureAndButtonListener(Context context) {

RemoteViews remoteViews = new RemoteViews(context.getPackageName(),

R.layout.widget_layout);

remoteViews.setTextViewText(R.id.title, getTitle());

remoteViews.setTextViewText(R.id.desc, getDesc(context));

DemoWidgetProvider.pushWidgetUpdate(context.getApplicationContext(),

remoteViews);

}

private String getDesc(Context context) {

return new Date().toString()

+ " ::: Update \n\n http://androidtutorialspoint.blogspot.com ";

}

private String getTitle() {

return "Every minute update";

}

}

AppWidgetManager

AppWidgetManager is used to Updates AppWidget state.

This is code for WidgetService.Every minutes it will update app widget content.

package com.etr.widgetsexample;

import java.util.Timer;
import java.util.TimerTask;

import android.app.PendingIntent;
import android.app.PendingIntent.CanceledException;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class WidgetService extends Service {
Timer updateWidgetsService;

@Override
public IBinder onBind(Intent arg0) {
return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
updateWidgetsService = new Timer();
updateWidgetsService.scheduleAtFixedRate(new TimerTask() {

@Override
public void run() {

Intent intent = new Intent();
intent.setAction(DemoWidgetUtils.WIDGET_UPDATE_ACTION);
PendingIntent pendingIntent = PendingIntent.getBroadcast(
getApplicationContext(), 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
try {
pendingIntent.send();
} catch (CanceledException e) {
e.printStackTrace();
}

}
}, 1000, 60000);
return START_STICKY;
}

@Override
public void onDestroy() {
}

}

This is code for appwidget-provider,It is placed inside of res/xml folder.

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:initialLayout="@layout/widget_layout"
    android:minHeight="146dp"
    android:minWidth="292dp"
    android:previewImage="@drawable/widget"
    android:updatePeriodMillis="10000" >

</appwidget-provider>

This is code widget_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/contentContainer"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:background="@drawable/appwidget_dark_bg"
    android:orientation="vertical"
    android:padding="8dp" >

    <TextView
        android:id="@+id/title"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:maxLines="2"
        android:paddingBottom="5dp"
        android:textColor="#fcfcfc"
        android:textSize="16sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/desc"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp"
        android:gravity="center"
        android:maxLines="5"
        android:textColor="#fcfcfc"
        android:textSize="13sp"
        android:textStyle="normal" />

</LinearLayout>

Output video