Java tutorial
/* * ConnectBot: simple, powerful, open-source SSH client for Android * Copyright 2015 Kenny Root, Jeffrey Sharkey * * 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 org.connectbot; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import android.content.ComponentName; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.ServiceConnection; import android.content.res.TypedArray; import android.os.AsyncTask; import android.os.IBinder; import android.support.v4.app.FragmentManager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import org.connectbot.bean.HostBean; import org.connectbot.service.TerminalBridge; import org.connectbot.service.TerminalManager; import org.connectbot.util.HostDatabase; import org.connectbot.util.PubkeyDatabase; public class EditHostActivity extends AppCompatActivity implements HostEditorFragment.Listener { private static final String EXTRA_EXISTING_HOST_ID = "org.connectbot.existing_host_id"; private static final long NO_HOST_ID = -1; private static final int ENABLED_ALPHA = 255; private static final int DISABLED_ALPHA = 130; private HostDatabase mHostDb; private PubkeyDatabase mPubkeyDb; private ServiceConnection mTerminalConnection; private HostBean mHost; private TerminalBridge mBridge; private boolean mIsCreating; private MenuItem mSaveHostButton; public static Intent createIntentForExistingHost(Context context, long existingHostId) { Intent i = new Intent(context, EditHostActivity.class); i.putExtra(EXTRA_EXISTING_HOST_ID, existingHostId); return i; } public static Intent createIntentForNewHost(Context context) { return createIntentForExistingHost(context, NO_HOST_ID); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mHostDb = HostDatabase.get(this); mPubkeyDb = PubkeyDatabase.get(this); mTerminalConnection = new ServiceConnection() { public void onServiceConnected(ComponentName className, IBinder service) { TerminalManager bound = ((TerminalManager.TerminalBinder) service).getService(); mBridge = bound.getConnectedBridge(mHost); } public void onServiceDisconnected(ComponentName name) { mBridge = null; } }; long hostId = getIntent().getLongExtra(EXTRA_EXISTING_HOST_ID, NO_HOST_ID); mIsCreating = hostId == NO_HOST_ID; mHost = mIsCreating ? null : mHostDb.findHostById(hostId); // Note that the lists must be explicitly declared as ArrayLists because Bundle only accepts // ArrayLists of Strings. ArrayList<String> pubkeyNames = new ArrayList<>(); ArrayList<String> pubkeyValues = new ArrayList<>(); // First, add default pubkey names and values (e.g., "use any" and "don't use any"). TypedArray defaultPubkeyNames = getResources().obtainTypedArray(R.array.list_pubkeyids); for (int i = 0; i < defaultPubkeyNames.length(); i++) { pubkeyNames.add(defaultPubkeyNames.getString(i)); } TypedArray defaultPubkeyValues = getResources().obtainTypedArray(R.array.list_pubkeyids_value); for (int i = 0; i < defaultPubkeyValues.length(); i++) { pubkeyValues.add(defaultPubkeyValues.getString(i)); } // Now, add pubkeys which have been added by the user. for (CharSequence cs : mPubkeyDb.allValues(PubkeyDatabase.FIELD_PUBKEY_NICKNAME)) { pubkeyNames.add(cs.toString()); } for (CharSequence cs : mPubkeyDb.allValues("_id")) { pubkeyValues.add(cs.toString()); } setContentView(R.layout.activity_edit_host); FragmentManager fm = getSupportFragmentManager(); HostEditorFragment fragment = (HostEditorFragment) fm.findFragmentById(R.id.fragment_container); if (fragment == null) { fragment = HostEditorFragment.newInstance(mHost, pubkeyNames, pubkeyValues); getSupportFragmentManager().beginTransaction().add(R.id.fragment_container, fragment).commit(); } defaultPubkeyNames.recycle(); defaultPubkeyValues.recycle(); } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(mIsCreating ? R.menu.edit_host_activity_add_menu : R.menu.edit_host_activity_edit_menu, menu); mSaveHostButton = menu.getItem(0); // If the new host is being created, it can't be added until modifications have been made. setAddSaveButtonEnabled(!mIsCreating); return super.onCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.save: case android.R.id.home: attemptSaveAndExit(); return true; default: return super.onOptionsItemSelected(item); } } @Override public void onStart() { super.onStart(); bindService(new Intent(this, TerminalManager.class), mTerminalConnection, Context.BIND_AUTO_CREATE); final HostEditorFragment fragment = (HostEditorFragment) getSupportFragmentManager() .findFragmentById(R.id.fragment_container); if (CharsetHolder.isInitialized()) { fragment.setCharsetData(CharsetHolder.getCharsetData()); } else { // If CharsetHolder is uninitialized, initialize it in an AsyncTask. This is necessary // because Charset must touch the disk, which cannot be performed on the UI thread. AsyncTask<Void, Void, Void> charsetTask = new AsyncTask<Void, Void, Void>() { @Override protected Void doInBackground(Void... unused) { CharsetHolder.initialize(); return null; } @Override protected void onPostExecute(Void unused) { fragment.setCharsetData(CharsetHolder.getCharsetData()); } }; charsetTask.execute(); } } @Override public void onStop() { super.onStop(); unbindService(mTerminalConnection); } @Override public void onValidHostConfigured(HostBean host) { mHost = host; if (mSaveHostButton != null) setAddSaveButtonEnabled(true); } @Override public void onHostInvalidated() { mHost = null; if (mSaveHostButton != null) setAddSaveButtonEnabled(false); } @Override public void onBackPressed() { attemptSaveAndExit(); } /** * If the host represents a valid URI, save it and exit; otherwise, pop up a dialog asking * the user if he/she wants to discard the changes. */ private void attemptSaveAndExit() { if (mHost == null) { showDiscardDialog(); return; } mHostDb.saveHost(mHost); if (mBridge != null) { // If the console is already open, apply the new encoding now. If the console // was not yet opened, this will be applied automatically when it is opened. mBridge.setCharset(mHost.getEncoding()); } finish(); } private void showDiscardDialog() { android.support.v7.app.AlertDialog.Builder builder = new android.support.v7.app.AlertDialog.Builder(this, R.style.AlertDialogTheme); builder.setMessage(R.string.discard_host_changes_message) .setPositiveButton(R.string.discard_host_button, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // Do not save to the database - just exit. finish(); } }).setNegativeButton(R.string.discard_host_cancel_button, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // Do nothing. } }); builder.show(); } private void setAddSaveButtonEnabled(boolean enabled) { mSaveHostButton.setEnabled(enabled); mSaveHostButton.getIcon().setAlpha(enabled ? ENABLED_ALPHA : DISABLED_ALPHA); } // Private static class used to generate a list of available Charsets. Note that this class // must not be initialized by the UI thread because it blocks on disk access. private static class CharsetHolder { private static boolean mInitialized = false; // Map from Charset display name to Charset value (i.e., unique ID). private static Map<String, String> mData; public static Map<String, String> getCharsetData() { if (mData == null) initialize(); return mData; } private synchronized static void initialize() { if (mInitialized) return; mData = new HashMap<>(); for (Map.Entry<String, Charset> entry : Charset.availableCharsets().entrySet()) { Charset c = entry.getValue(); if (c.canEncode() && c.isRegistered()) { String key = entry.getKey(); if (key.startsWith("cp")) { // Custom CP437 charset changes. mData.put("CP437", "CP437"); } mData.put(c.displayName(), entry.getKey()); } } mInitialized = true; } public static boolean isInitialized() { return mInitialized; } } }