Android example source code file (TranslateActivity.java)

This example Android source code file (TranslateActivity.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

about_dialog_id, android, button, content, edittext, handler, intent, language, language_dialog_id, object, onclicklistener, os, override, progressbar, sharedpreferences, string, translateactivity, ui, view, widget

The TranslateActivity.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.beust.android.translate;

import com.beust.android.translate.Languages.Language;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.provider.Contacts;
import android.text.TextUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.zip.GZIPInputStream;

/**
 * Main activity for the Translate application.
 *
 * @author Cedric Beust
 * @author Daniel Rall
 */
public class TranslateActivity extends Activity implements OnClickListener {
    static final String TAG = "Translate";
    private EditText mToEditText;
    private EditText mFromEditText;
    private Button mFromButton;
    private Button mToButton;
    private Button mTranslateButton;
    private Button mSwapButton;
    private Handler mHandler = new Handler();
    private ProgressBar mProgressBar;
    private TextView mStatusView;
    
    // true if changing a language should automatically trigger a translation
    private boolean mDoTranslate = true;

    // Dialog id's
    private static final int LANGUAGE_DIALOG_ID = 1;
    private static final int ABOUT_DIALOG_ID = 2;

    // Saved preferences
    private static final String FROM = "from";
    private static final String TO = "to";
    private static final String INPUT = "input";
    private static final String OUTPUT = "output";
    
    // Default language pair if no saved preferences are found
    private static final String DEFAULT_FROM = Language.ENGLISH.getShortName();
    private static final String DEFAULT_TO = Language.GERMAN.getShortName();

    private Button mLatestButton;

    private OnClickListener mClickListener = new OnClickListener() {
        public void onClick(View v) {
            mLatestButton = (Button) v;
            showDialog(LANGUAGE_DIALOG_ID);
        }
    };

    // Translation service handle.
    private ITranslate mTranslateService;

    // ServiceConnection implementation for translation.
    private ServiceConnection mTranslateConn = new ServiceConnection() {
        public void onServiceConnected(ComponentName name, IBinder service) {
            mTranslateService = ITranslate.Stub.asInterface(service);
            /* TODO(dlr): Register a callback to assure we don't lose our svc.
            try {
                mTranslateervice.registerCallback(mTranslateCallback);
            } catch (RemoteException e) {
                log("Failed to establish Translate service connection: " + e);
                return;
            }
            */
            if (mTranslateService != null) {
                mTranslateButton.setEnabled(true);
            } else {
                mTranslateButton.setEnabled(false);
                mStatusView.setText(getString(R.string.error));
                log("Unable to acquire TranslateService");
            }
        }

        public void onServiceDisconnected(ComponentName name) {
            mTranslateButton.setEnabled(false);
            mTranslateService = null;
        }
    };

    // Dictionary
    private static byte[] mWordBuffer;
    private static int mWordCount;
    private static ArrayList<Integer> mWordIndices;

    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        setContentView(R.layout.translate_activity);
        mFromEditText = (EditText) findViewById(R.id.input);
        mToEditText = (EditText) findViewById(R.id.translation);
        mFromButton = (Button) findViewById(R.id.from);
        mToButton = (Button) findViewById(R.id.to);
        mTranslateButton = (Button) findViewById(R.id.button_translate);
        mSwapButton = (Button) findViewById(R.id.button_swap);
        mProgressBar = (ProgressBar) findViewById(R.id.progress_bar);
        mStatusView = (TextView) findViewById(R.id.status);
        
        //
        // Install the language adapters on both the From and To spinners.
        //
        mFromButton.setOnClickListener(mClickListener);
        mToButton.setOnClickListener(mClickListener);

        mTranslateButton.setOnClickListener(this);
        mSwapButton.setOnClickListener(this);
        mFromEditText.selectAll();

        connectToTranslateService();
    }
    
    private void connectToTranslateService() {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        bindService(intent, mTranslateConn, Context.BIND_AUTO_CREATE);
    }

    @Override
    public void onResume() {
        super.onResume();
        SharedPreferences prefs = getPrefs(this);
        mDoTranslate = false;

        //
        // See if we have any saved preference for From
        //
        Language from = Language.findLanguageByShortName(prefs.getString(FROM, DEFAULT_FROM));
        updateButton(mFromButton, from, false /* don't translate */);

        //
        // See if we have any saved preference for To
        //
        //
        Language to = Language.findLanguageByShortName(prefs.getString(TO, DEFAULT_TO));
        updateButton(mToButton, to, true /* translate */);
        
        //
        // Restore input and output, if any
        //
        mFromEditText.setText(prefs.getString(INPUT, ""));
        setOutputText(prefs.getString(OUTPUT, ""));
        mDoTranslate = true;
    }
    
    private void setOutputText(String string) {
        log("Setting output to " + string);
        mToEditText.setText(new Entities().unescape(string));
    }

    private void updateButton(Button button, Language language, boolean translate) {
        language.configureButton(this, button);
        if (translate) maybeTranslate();
    }

    /**
     * Launch the translation if the input text field is not empty.
     */
    private void maybeTranslate() {
        if (mDoTranslate && !TextUtils.isEmpty(mFromEditText.getText().toString())) {
            doTranslate();
        }
    }
    
    @Override
    public void onPause() {
        super.onPause();

        //
        // Save the content of our views to the shared preferences
        //
        Editor edit = getPrefs(this).edit();
        String f = ((Language) mFromButton.getTag()).getShortName();
        String t = ((Language) mToButton.getTag()).getShortName();
        String input = mFromEditText.getText().toString();
        String output = mToEditText.getText().toString();
        savePreferences(edit, f, t, input, output);
    }
    
    static void savePreferences(Editor edit, String from, String to, String input, String output) {
        log("Saving preferences " + from + " " + to + " " + input + " " + output);
        edit.putString(FROM, from);
        edit.putString(TO, to);
        edit.putString(INPUT, input);
        edit.putString(OUTPUT, output);
        edit.commit();
    }
    
    static SharedPreferences getPrefs(Context context) {
        return context.getSharedPreferences(TAG, Context.MODE_PRIVATE);
    }
    
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(mTranslateConn);
    }

    public void onClick(View v) {
        if (v == mTranslateButton) {
            maybeTranslate();
        } else if (v == mSwapButton) {
            Object newFrom = mToButton.getTag();
            Object newTo = mFromButton.getTag();
            mFromEditText.setText(mToEditText.getText());
            mToEditText.setText("");
            setNewLanguage((Language) newFrom, true /* from */, false /* don't translate */);
            setNewLanguage((Language) newTo, false /* to */, true /* translate */);
            mFromEditText.requestFocus();
            mStatusView.setText(R.string.languages_swapped);
        }
    }
    
    private void doTranslate() {
        mStatusView.setText(R.string.retrieving_translation);
        mHandler.post(new Runnable() {
            public void run() {
                mProgressBar.setVisibility(View.VISIBLE);
                String result = "";
                try {
                    Language from = (Language) mFromButton.getTag();
                    Language to = (Language) mToButton.getTag();
                    String fromShortName = from.getShortName();
                    String toShortName = to.getShortName();
                    String input = mFromEditText.getText().toString();
                    log("Translating from " + fromShortName + " to " + toShortName);
                    result = mTranslateService.translate(input, fromShortName, toShortName);
                    if (result == null) {
                        throw new Exception(getString(R.string.translation_failed));
                    }
                    History.addHistoryRecord(TranslateActivity.this, from, to, input, result);
                    mStatusView.setText(R.string.found_translation);
                    setOutputText(result);
                    mProgressBar.setVisibility(View.INVISIBLE);
                    mFromEditText.selectAll();
                } catch (Exception e) {
                    mProgressBar.setVisibility(View.INVISIBLE);
                    mStatusView.setText("Error:" + e.getMessage());
                }
            }
        });
    }

    @Override
    protected void onPrepareDialog(int id, Dialog d) {
        if (id == LANGUAGE_DIALOG_ID) {
            boolean from = mLatestButton == mFromButton;
            ((LanguageDialog) d).setFrom(from);
        }
    }

    @Override
    protected Dialog onCreateDialog(int id) {
        if (id == LANGUAGE_DIALOG_ID) {
            return new LanguageDialog(this);
        } else if (id == ABOUT_DIALOG_ID) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle(R.string.about_title);
            builder.setMessage(getString(R.string.about_message));
            builder.setIcon(R.drawable.babelfish);
            builder.setPositiveButton(android.R.string.ok, null);
            builder.setNeutralButton(R.string.send_email,
                    new android.content.DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            Intent intent = new Intent(Intent.ACTION_SENDTO);
                            intent.setData(Uri.parse("mailto:cedric@beust.com"));
                            startActivity(intent);
                        }
                    });
            builder.setCancelable(true);
            return builder.create();
        }
        return null;
    }
    
    /**
     * Pick a random word and set it as the input word.
     */
    public void selectRandomWord() {
        BufferedReader fr = null;
        try {
            GZIPInputStream is =
                    new GZIPInputStream(getResources().openRawResource(R.raw.dictionary));
            if (mWordBuffer == null) {
                mWordBuffer = new byte[601000];
                int n = is.read(mWordBuffer, 0, mWordBuffer.length);
                int current = n;
                while (n != -1) {
                    n = is.read(mWordBuffer, current, mWordBuffer.length - current);
                    current += n;
                }
                is.close();
                mWordCount = 0;
                mWordIndices = Lists.newArrayList();
                for (int i = 0; i < mWordBuffer.length; i++) {
                    if (mWordBuffer[i] == '\n') {
                        mWordCount++;
                        mWordIndices.add(i);
                    }
                }
                log("Found " + mWordCount + " words");
            }

            int randomWordIndex = (int) (System.currentTimeMillis() % (mWordCount - 1));
            log("Random word index:" + randomWordIndex + " wordCount:" + mWordCount);
            int start = mWordIndices.get(randomWordIndex);
            int end = mWordIndices.get(randomWordIndex + 1);
            byte[] b = new byte[end - start - 2];
            System.arraycopy(mWordBuffer, start + 1, b, 0, (end - start - 2)); 
            String randomWord = new String(b);
            mFromEditText.setText(randomWord);
            updateButton(mFromButton,
                    Language.findLanguageByShortName(Language.ENGLISH.getShortName()),
                    true /* translate */);
        } catch (FileNotFoundException e) {
            Log.e(TAG, e.getMessage(), e);
        } catch (IOException e) {
            Log.e(TAG, e.getMessage(), e);
        }
        
    }

    public void setNewLanguage(Language language, boolean from, boolean translate) {
        updateButton(from ? mFromButton : mToButton, language, translate);
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.translate_activity_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch(item.getItemId()) {
        case R.id.about:
            showDialog(ABOUT_DIALOG_ID);
            break;

        case R.id.show_history:
            showHistory();
            break;

        case R.id.random_word:
            selectRandomWord();
            break;

        // We shouldn't need this menu item but because of a bug in 1.0, neither SMS nor Email
        // filter on the ACTION_SEND intent.  Since they won't be shown in the activity chooser,
        // I need to make an explicit menu for SMS
        case R.id.send_with_sms: {
            Intent i = new Intent(Intent.ACTION_PICK, Contacts.Phones.CONTENT_URI);
            Intent intent = new Intent(Intent.ACTION_PICK);
            intent.setType(Contacts.Phones.CONTENT_TYPE);
            startActivityForResult(intent, 42 /* not used */);
            break;
        }

        case R.id.send_with_email:
            Intent intent = new Intent(Intent.ACTION_SEND);
            intent.setType("text/plain");
            intent.putExtra(Intent.EXTRA_TEXT, mToEditText.getText());
            startActivity(Intent.createChooser(intent, null));
            break;
        }

        return true;
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent resultIntent) {
        if (resultIntent != null) {
            Uri contactURI = resultIntent.getData();
            
            Cursor cursor = getContentResolver().query(contactURI,
                    new String[] { Contacts.PhonesColumns.NUMBER }, 
                    null, null, null);
            if (cursor.moveToFirst()) {
                String phone = cursor.getString(0);
                Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.parse("smsto://" + phone));
                intent.putExtra("sms_body", mToEditText.getText().toString());
                startActivity(intent);
            }
        }
    }
    
    private void showHistory() {
        startActivity(new Intent(this, HistoryActivity.class));
    }
    
    private static void log(String s) {
        Log.d(TAG, "[TranslateActivity] " + s);
    }

}