For a widget to work, below are some important items:
- AndroidManifest.xml must be altered
- Must create a layout file for widget provider
- Must create a layout for widget
- Main class source code
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sample.batterystatuswidget"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7" />
<application
android:icon="@drawable/widget_battery01"
android:label="@string/app_name" >
<receiver android:name=".BatteryStatusWidgetActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
</intent-filter>
<meta-data android:name="android.appwidget.provider"
android:resource="@xml/widget_main" />
</receiver>
</application>
</manifest>
Next, since in the AndroidManifest.xml above it refers to the @xml/widget_main, then widget_main.xml must exist:
<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:initialLayout="@layout/widget_layout"
android:minWidth="40dp"
android:minHeight="40dp"
android:updatePeriodMillis="30000">
</appwidget-provider>
Next, since in widget_main.xml above it refers to @layout/widget_layout, then widget_layout.xml must exist:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/relativeLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center" >
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:src="@drawable/widget_batt_frame01" />
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:layout_margin="10dip"
android:gravity="center_vertical"
android:orientation="vertical"
android:paddingTop="0dip" >
<TextView
android:id="@+id/widget_text"
style="@android:style/TextAppearance.Medium"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:gravity="center_horizontal|center_vertical"
android:text="@string/battery_level"
android:textSize="12dp"
android:textColor="#000000"/>
</LinearLayout>
</RelativeLayout>
Finally, the source code for the main class:
public class BatteryStatusWidgetActivity extends AppWidgetProvider {
/** Called when the activity is first created. */
private String batteryLevel = "init";
private int widgetImageFrame = R.drawable.widget_batt_frame01;
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
context.getApplicationContext().registerReceiver(this, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
updateView(context);
}
@Override
public void onReceive(Context context, Intent intent) {
int rawlevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
int level = -1;
level = (rawlevel * 100) / scale;
batteryLevel = Integer.toString(level);
widgetImageFrame = R.drawable.widget_batt_frame01;
updateView(context);
super.onReceive(context, intent);
}
public void updateView(Context context) {
RemoteViews thisViews = new RemoteViews(context.getApplicationContext().getPackageName(), R.layout.widget_layout);
thisViews.setTextViewText(R.id.widget_text, batteryLevel);
thisViews.setImageViewResource(R.id.imageView1, widgetImageFrame);
ComponentName thisWidget = new ComponentName(context, BatteryStatusWidgetActivity.class);
AppWidgetManager.getInstance(context).updateAppWidget(thisWidget, thisViews);
}
- updateView(context) function is needed to refresh the widget
- R.drawable.widget_batt_frame01 is referring to the image that registered to layout widgetImageFrame
Happy Coding Android!
That's all for now!
*I use http://codeformatter.blogspot.com/ to place codes in this post.
:: aerobrainTech ::
