Android example source code file (RadarActivity.java)

This example Android source code file (RadarActivity.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

activity, android, content, hardware, intent, location_update_interval_millis, locationmanager, menu_metric, menu_standard, mode_private, os, override, pref_metric, radaractivity, radarview, sensormanager, sharedpreferences, string, ui, view

The RadarActivity.java Android example source code

/*
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.radar;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.hardware.SensorManager;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.widget.TextView;

/**
 * Simple Activity wrapper that hosts a {@link RadarView}
 *
 */
public class RadarActivity extends Activity {

    private static final int LOCATION_UPDATE_INTERVAL_MILLIS = 1000;

    private static final int MENU_STANDARD = Menu.FIRST + 1;

    private static final int MENU_METRIC = Menu.FIRST + 2;

    private static final String RADAR = "radar";
    
    private static final String PREF_METRIC = "metric";

    private SensorManager mSensorManager;

    private RadarView mRadar;

    private LocationManager mLocationManager;

    private SharedPreferences mPrefs;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.radar);
        mRadar = (RadarView) findViewById(R.id.radar);
        mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
        mLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
     
        // Metric or standard units?
        mPrefs = getSharedPreferences(RADAR, MODE_PRIVATE);
        boolean useMetric = mPrefs.getBoolean(PREF_METRIC, false);
        mRadar.setUseMetric(useMetric);
        
        // Read the target from our intent
        Intent i = getIntent();
        int latE6 = (int)(i.getFloatExtra("latitude", 0) * GeoUtils.MILLION);
        int lonE6 = (int)(i.getFloatExtra("longitude", 0) * GeoUtils.MILLION);
        mRadar.setTarget(latE6, lonE6);
        mRadar.setDistanceView((TextView) findViewById(R.id.distance));
    }
    
    @Override
    protected void onResume()
    {
        super.onResume();
        mSensorManager.registerListener(mRadar, SensorManager.SENSOR_ORIENTATION,
                SensorManager.SENSOR_DELAY_GAME);
 
        // Start animating the radar screen
        mRadar.startSweep();
        
        // Register for location updates
        mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                LOCATION_UPDATE_INTERVAL_MILLIS, 1, mRadar);
        mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
                LOCATION_UPDATE_INTERVAL_MILLIS, 1, mRadar);
    }

    @Override
    protected void onPause()
    {
        mSensorManager.unregisterListener(mRadar);
        mLocationManager.removeUpdates(mRadar);
        
        // Stop animating the radar screen
        mRadar.stopSweep();
        super.onStop();
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        menu.add(0, MENU_STANDARD, 0, R.string.menu_standard)
                .setIcon(R.drawable.ic_menu_standard)
                .setAlphabeticShortcut('A');
        menu.add(0, MENU_METRIC, 0, R.string.menu_metric)
                .setIcon(R.drawable.ic_menu_metric)
                .setAlphabeticShortcut('C');
        return true;
    }
    
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case MENU_STANDARD: {
            setUseMetric(false);
            return true;
        }
        case MENU_METRIC: {
            setUseMetric(true);
            return true;
        }
        }

        return super.onOptionsItemSelected(item);
    }

    private void setUseMetric(boolean useMetric) {
        SharedPreferences.Editor e = mPrefs.edit();
        e.putBoolean(PREF_METRIC, useMetric);
        e.commit();
        mRadar.setUseMetric(useMetric);
    }
}