Android example source code file (UsbStorageActivity.java)

This example Android source code file (UsbStorageActivity.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

android, app, application, broadcastreceiver, button, content, dlg_error_sharing, failed, imageview, imountservice, os, override, progressbar, storagemanager, string, textview, ui, ums, usbstorageactivity, widget

The UsbStorageActivity.java Android example source code

/*
 * Copyright (C) 2007 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.android.server.status;

import com.android.internal.R;
import android.app.Activity;
import android.app.ActivityManager;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.DialogInterface.OnCancelListener;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder;
import android.os.storage.IMountService;
import android.os.storage.StorageManager;
import android.os.storage.StorageEventListener;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.widget.ImageView;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.view.View;
import android.view.Window;
import android.util.Log;

import java.util.List;

/**
 * This activity is shown to the user for him/her to enable USB mass storage
 * on-demand (that is, when the USB cable is connected). It uses the alert
 * dialog style. It will be launched from a notification.
 */
public class UsbStorageActivity extends Activity
        implements View.OnClickListener, OnCancelListener {
    private static final String TAG = "UsbStorageActivity";

    private Button mMountButton;
    private Button mUnmountButton;
    private ProgressBar mProgressBar;
    private TextView mBanner;
    private TextView mMessage;
    private ImageView mIcon;
    private StorageManager mStorageManager = null;
    private static final int DLG_CONFIRM_KILL_STORAGE_USERS = 1;
    private static final int DLG_ERROR_SHARING = 2;
    static final boolean localLOGV = false;

    /** Used to detect when the USB cable is unplugged, so we can call finish() */
    private BroadcastReceiver mBatteryReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction() == Intent.ACTION_BATTERY_CHANGED) {
                handleBatteryChanged(intent);
            }
        }
    };

    private StorageEventListener mStorageListener = new StorageEventListener() {
        @Override
        public void onStorageStateChanged(String path, String oldState, String newState) {
            final boolean on = newState.equals(Environment.MEDIA_SHARED);
            switchDisplay(on);
        }
    };
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (mStorageManager == null) {
            mStorageManager = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
            if (mStorageManager == null) {
                Log.w(TAG, "Failed to get StorageManager");
            }
        }

        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setProgressBarIndeterminateVisibility(true);

        setTitle(getString(com.android.internal.R.string.usb_storage_activity_title));

        setContentView(com.android.internal.R.layout.usb_storage_activity);

        mIcon = (ImageView) findViewById(com.android.internal.R.id.icon);
        mBanner = (TextView) findViewById(com.android.internal.R.id.banner);
        mMessage = (TextView) findViewById(com.android.internal.R.id.message);

        mMountButton = (Button) findViewById(com.android.internal.R.id.mount_button);
        mMountButton.setOnClickListener(this);
        mUnmountButton = (Button) findViewById(com.android.internal.R.id.unmount_button);
        mUnmountButton.setOnClickListener(this);
        mProgressBar = (ProgressBar) findViewById(com.android.internal.R.id.progress);
    }

    private void switchDisplay(boolean usbStorageInUse) {
        if (usbStorageInUse) {
            mProgressBar.setVisibility(View.GONE);
            mUnmountButton.setVisibility(View.VISIBLE);
            mMountButton.setVisibility(View.GONE);
            mIcon.setImageResource(com.android.internal.R.drawable.usb_android_connected);
            mBanner.setText(com.android.internal.R.string.usb_storage_stop_title);
            mMessage.setText(com.android.internal.R.string.usb_storage_stop_message);
        } else {
            mProgressBar.setVisibility(View.GONE);
            mUnmountButton.setVisibility(View.GONE);
            mMountButton.setVisibility(View.VISIBLE);
            mIcon.setImageResource(com.android.internal.R.drawable.usb_android);
            mBanner.setText(com.android.internal.R.string.usb_storage_title);
            mMessage.setText(com.android.internal.R.string.usb_storage_message);
        }
    }

    @Override
    protected void onResume() {
        super.onResume();

        mStorageManager.registerListener(mStorageListener);
        registerReceiver(mBatteryReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
        try {
            switchDisplay(mStorageManager.isUsbMassStorageEnabled());
        } catch (Exception ex) {
            Log.e(TAG, "Failed to read UMS enable state", ex);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        
        unregisterReceiver(mBatteryReceiver);
        if (mStorageManager == null && mStorageListener != null) {
            mStorageManager.unregisterListener(mStorageListener);
        }
    }

    private void handleBatteryChanged(Intent intent) {
        int pluggedType = intent.getIntExtra("plugged", 0);
        if (pluggedType == 0) {
            // It was disconnected from the plug, so finish
            finish();
        }
    }

    private IMountService getMountService() {
        IBinder service = ServiceManager.getService("mount");
        if (service != null) {
            return IMountService.Stub.asInterface(service);
        }
        return null;
    }

    @Override
    public Dialog onCreateDialog(int id, Bundle args) {
        switch (id) {
        case DLG_CONFIRM_KILL_STORAGE_USERS:
            return new AlertDialog.Builder(this)
                    .setTitle(R.string.dlg_confirm_kill_storage_users_title)
                    .setPositiveButton(R.string.dlg_ok, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            switchUsbMassStorageAsync(true);
                        }})
                    .setNegativeButton(R.string.cancel, null)
                    .setMessage(R.string.dlg_confirm_kill_storage_users_text)
                    .setOnCancelListener(this)
                    .create();
        case DLG_ERROR_SHARING:
            return new AlertDialog.Builder(this)
                    .setTitle(R.string.dlg_error_title)
                    .setNeutralButton(R.string.dlg_ok, null)
                    .setMessage(R.string.usb_storage_error_message)
                    .setOnCancelListener(this)
                    .create();
        }
        return null;
    }

    private void showDialogInner(int id) {
        removeDialog(id);
        showDialog(id);
    }

    private void switchUsbMassStorageAsync(boolean on) {
        mUnmountButton.setVisibility(View.GONE);
        mMountButton.setVisibility(View.GONE);

        mProgressBar.setVisibility(View.VISIBLE);
        // will be hidden once USB mass storage kicks in (or fails)
        
        final boolean _on = on;
        new Thread() {
            public void run() {
                if (_on) {
                    mStorageManager.enableUsbMassStorage();
                } else {
                    mStorageManager.disableUsbMassStorage();
                }
            }
        }.start();
    }

    private void checkStorageUsers() {
        IMountService ims = getMountService();
        if (ims == null) {
            // Display error dialog
            showDialogInner(DLG_ERROR_SHARING);
        }
        String extStoragePath = Environment.getExternalStorageDirectory().toString();
        boolean showDialog = false;
        try {
            int[] stUsers = ims.getStorageUsers(extStoragePath);
            if (stUsers != null && stUsers.length > 0) {
                showDialog = true;
            } else {
                // List of applications on sdcard.
                ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
                List<ApplicationInfo> infoList = am.getRunningExternalApplications();
                if (infoList != null && infoList.size() > 0) {
                    showDialog = true;
                }
            }
        } catch (RemoteException e) {
            // Display error dialog
            showDialogInner(DLG_ERROR_SHARING);
        }
        if (showDialog) {
            // Display dialog to user
            showDialogInner(DLG_CONFIRM_KILL_STORAGE_USERS);
        } else {
            if (localLOGV) Log.i(TAG, "Enabling UMS");
            switchUsbMassStorageAsync(true);
        }
    }

    public void onClick(View v) {
        if (v == mMountButton) {
           // Check for list of storage users and display dialog if needed.
            checkStorageUsers();
        } else if (v == mUnmountButton) {
            if (localLOGV) Log.i(TAG, "Disabling UMS");
            switchUsbMassStorageAsync(false);
        }
    }

    public void onCancel(DialogInterface dialog) {
        finish();
    }

}