diff src/com/five_ten_sg/connectbot/service/TerminalBridge.java @ 0:0ce5cc452d02

initial version
author Carl Byington <carl@five-ten-sg.com>
date Thu, 22 May 2014 10:41:19 -0700
parents
children 1588e359a972 017eeed8332c
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/five_ten_sg/connectbot/service/TerminalBridge.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,1509 @@
+/*
+ * ConnectBot: simple, powerful, open-source SSH client for Android
+ * Copyright 2007 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 com.five_ten_sg.connectbot.service;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.five_ten_sg.connectbot.R;
+import com.five_ten_sg.connectbot.TerminalView;
+import com.five_ten_sg.connectbot.bean.HostBean;
+import com.five_ten_sg.connectbot.bean.PortForwardBean;
+import com.five_ten_sg.connectbot.bean.SelectionArea;
+import com.five_ten_sg.connectbot.transport.AbsTransport;
+import com.five_ten_sg.connectbot.transport.TransportFactory;
+import com.five_ten_sg.connectbot.util.HostDatabase;
+import com.five_ten_sg.connectbot.util.PreferenceConstants;
+import android.app.AlertDialog;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.FontMetrics;
+import android.graphics.Typeface;
+import android.os.Binder;
+import android.os.Environment;
+import android.text.ClipboardManager;
+import android.text.Editable;
+import android.text.method.CharacterPickerDialog;
+import android.util.FloatMath;
+import android.util.Log;
+import android.view.KeyEvent;
+import android.view.View;
+import android.widget.AdapterView;
+import android.widget.Button;
+import de.mud.terminal.VDUBuffer;
+import de.mud.terminal.VDUDisplay;
+import de.mud.terminal.vt320;
+
+
+/**
+ * Provides a bridge between a MUD terminal buffer and a possible TerminalView.
+ * This separation allows us to keep the TerminalBridge running in a background
+ * service. A TerminalView shares down a bitmap that we can use for rendering
+ * when available.
+ *
+ * This class also provides SSH hostkey verification prompting, and password
+ * prompting.
+ */
+@SuppressWarnings("deprecation")  // for ClipboardManager
+public class TerminalBridge implements VDUDisplay {
+    public final static String TAG = "ConnectBot.TerminalBridge";
+
+    public  final static int    DEFAULT_FONT_SIZE = 10;
+    private final static int    FONT_SIZE_STEP    = 2;
+
+    public Integer[] color;
+
+    public int defaultFg = HostDatabase.DEFAULT_FG_COLOR;
+    public int defaultBg = HostDatabase.DEFAULT_BG_COLOR;
+
+    protected final TerminalManager manager;
+
+    public HostBean host;
+
+    AbsTransport transport;
+
+    final Paint defaultPaint;
+
+    private Relay relay;
+
+    private final String emulation;
+    private final int scrollback;
+
+    public Bitmap bitmap = null;
+    public vt320  buffer = null;
+
+    private TerminalView parent = null;
+    private final Canvas canvas = new Canvas();
+
+    private boolean disconnected = false;
+    private boolean awaitingClose = false;
+
+    private boolean forcedSize = false;
+    private int columns;
+    private int rows;
+
+    public  TerminalMonitor     monitor = null;
+    private TerminalKeyListener keyListener = null;
+
+    private boolean selectingForCopy = false;
+    private final SelectionArea selectionArea;
+
+    // TODO add support for the new clipboard API
+    private ClipboardManager clipboard;
+
+    public int charWidth = -1;
+    public int charHeight = -1;
+    private int charTop = -1;
+
+    private float fontSize = -1;
+
+    private final List<FontSizeChangedListener> fontSizeChangedListeners;
+
+    private final List<String> localOutput;
+
+    /**
+     * Flag indicating if we should perform a full-screen redraw during our next
+     * rendering pass.
+     */
+    private boolean fullRedraw = false;
+
+    public PromptHelper promptHelper;
+
+    protected BridgeDisconnectedListener disconnectListener = null;
+
+    /**
+     * Create a new terminal bridge suitable for unit testing.
+     */
+    public TerminalBridge() {
+        buffer = new vt320() {
+            @Override
+            public void write(byte[] b) {}
+            @Override
+            public void write(int b) {}
+            @Override
+            public void sendTelnetCommand(byte cmd) {}
+            @Override
+            public void setWindowSize(int c, int r) {}
+            @Override
+            public void debug(String s) {}
+        };
+        emulation = null;
+        manager = null;
+        defaultPaint = new Paint();
+        selectionArea = new SelectionArea();
+        scrollback = 1;
+        localOutput = new LinkedList<String>();
+        fontSizeChangedListeners = new LinkedList<FontSizeChangedListener>();
+        transport   = null;
+        keyListener = new TerminalKeyListener(manager, this, buffer, null);
+        monitor     = null;
+    }
+
+    /**
+     * Create new terminal bridge with following parameters. We will immediately
+     * launch thread to start SSH connection and handle any hostkey verification
+     * and password authentication.
+     */
+    public TerminalBridge(final TerminalManager manager, final HostBean host) throws IOException {
+        float hostFontSize;
+        this.manager = manager;
+        this.host = host;
+        emulation = manager.getEmulation();
+        scrollback = manager.getScrollback();
+        // create prompt helper to relay password and hostkey requests up to gui
+        promptHelper = new PromptHelper(this);
+        // create our default paint
+        defaultPaint = new Paint();
+        defaultPaint.setAntiAlias(true);
+        defaultPaint.setTypeface(Typeface.MONOSPACE);
+        defaultPaint.setFakeBoldText(true);  // more readable?
+        localOutput = new LinkedList<String>();
+        fontSizeChangedListeners = new LinkedList<FontSizeChangedListener>();
+        Integer defaultFontSize = Integer.parseInt(manager.prefs.getString(PreferenceConstants.DEFAULT_FONT_SIZE, "-1"));
+        Log.i(TAG, "fontSize: " + this.fontSize + ", defaultFontSize: " + defaultFontSize);
+
+        if (this.fontSize == -1) {
+            if (defaultFontSize > 0 && host.getFontSize() == -1)
+                hostFontSize = defaultFontSize;
+            else
+                hostFontSize = host.getFontSize();
+        }
+        else
+            hostFontSize = this.fontSize;
+
+        if (hostFontSize <= 0)
+            hostFontSize = DEFAULT_FONT_SIZE;
+
+        setFontSize(hostFontSize);
+        // create terminal buffer and handle outgoing data
+        // this is probably status reply information
+        buffer = new vt320() {
+            @Override
+            public void debug(String s) {
+                Log.d(TAG, s);
+            }
+            @Override
+            public void write(byte[] b) {
+                try {
+                    if (b != null && transport != null)
+                        if (monitor != null) monitor.hostData(b);
+
+                    transport.write(b);
+                }
+                catch (IOException e) {
+                    Log.e(TAG, "Problem writing outgoing data in vt320() thread", e);
+                }
+            }
+            @Override
+            public void write(int b) {
+                try {
+                    if (transport != null)
+                        if (monitor != null) monitor.hostData(b);
+
+                    transport.write(b);
+                }
+                catch (IOException e) {
+                    Log.e(TAG, "Problem writing outgoing data in vt320() thread", e);
+                }
+            }
+            // We don't use telnet sequences.
+            @Override
+            public void sendTelnetCommand(byte cmd) {
+            }
+            // We don't want remote to resize our window.
+            @Override
+            public void setWindowSize(int c, int r) {
+            }
+            // test for changed screen contents
+            @Override
+            public void testChanged() {
+                if (monitor != null) monitor.testChanged();
+            }
+            // play beep noise
+            @Override
+            public void beep() {
+                if (parent.isShown())
+                    manager.playBeep();
+                else
+                    manager.sendActivityNotification(host);
+            }
+            // monitor placement of new characters
+            @Override
+            public void putChar(int c, int l, char ch, int attributes) {
+                if (monitor != null) monitor.screenChanged(l, c);
+
+                super.putChar(c, l, ch, attributes);
+            }
+            @Override
+            public void insertChar(int c, int l, char ch, int attributes) {
+                if (monitor != null) monitor.screenChanged(l, l, c, width - 1);
+
+                super.insertChar(c, l, ch, attributes);
+            }
+            @Override
+            public void insertLine(int l, int n, boolean scrollDown) {
+                if (monitor != null) {
+                    if (scrollDown) monitor.screenChanged(l, height - 1, 0, width - 1);
+                    else            monitor.screenChanged(0, l, 0, width - 1);
+                }
+
+                super.insertLine(l, n, scrollDown);
+            }
+            @Override
+            public void deleteLine(int l) {
+                if (monitor != null) monitor.screenChanged(l, height - 1, 0, width - 1);
+
+                super.deleteLine(l);
+            }
+            @Override
+            public void deleteChar(int c, int l) {
+                if (monitor != null) monitor.screenChanged(l, l, c, width - 1);
+
+                super.deleteChar(c, l);
+            }
+            @Override
+            public void setCursorPosition(int c, int l) {
+                if (monitor != null) monitor.cursorMove(l, c);
+
+                super.setCursorPosition(c, l);
+            }
+        };
+
+        // Don't keep any scrollback if a session is not being opened.
+        if (host.getWantSession())
+            buffer.setBufferSize(scrollback);
+        else
+            buffer.setBufferSize(0);
+
+        resetColors();
+        buffer.setDisplay(this);
+        selectionArea = new SelectionArea();
+        keyListener   = new TerminalKeyListener(manager, this, buffer, host.getEncoding());
+
+        String monitor_init = host.getMonitor();
+        if ((monitor_init != null) && (monitor_init.length() > 0)) {
+            monitor = new TerminalMonitor(manager, buffer, keyListener, parent, monitor_init);
+        }
+    }
+
+    public PromptHelper getPromptHelper() {
+        return promptHelper;
+    }
+
+    /**
+     * Spawn thread to open connection and start login process.
+     */
+    protected void startConnection() {
+        transport = TransportFactory.getTransport(host.getProtocol());
+        transport.setBridge(this);
+        transport.setManager(manager);
+        transport.setHost(host);
+        // TODO make this more abstract so we don't litter on AbsTransport
+        transport.setCompression(host.getCompression());
+        transport.setHttpproxy(host.getHttpproxy());
+        transport.setUseAuthAgent(host.getUseAuthAgent());
+        transport.setEmulation(emulation);
+
+        if (transport.canForwardPorts()) {
+            for (PortForwardBean portForward : manager.hostdb.getPortForwardsForHost(host))
+                transport.addPortForward(portForward);
+        }
+
+        outputLine(manager.res.getString(R.string.terminal_connecting, host.getHostname(), host.getPort(), host.getProtocol()));
+        Thread connectionThread = new Thread(new Runnable() {
+            public void run() {
+                transport.connect();
+            }
+        });
+        connectionThread.setName("Connection");
+        connectionThread.setDaemon(true);
+        connectionThread.start();
+    }
+
+    /**
+     * Handle challenges from keyboard-interactive authentication mode.
+     */
+    public String[] replyToChallenge(String name, String instruction, int numPrompts, String[] prompt, boolean[] echo) {
+        String[] responses = new String[numPrompts];
+
+        for (int i = 0; i < numPrompts; i++) {
+            // request response from user for each prompt
+            responses[i] = promptHelper.requestPasswordPrompt(instruction, prompt[i]);
+        }
+
+        return responses;
+    }
+
+    /**
+     * @return charset in use by bridge
+     */
+    public Charset getCharset() {
+        return relay.getCharset();
+    }
+
+    /**
+     * Sets the encoding used by the terminal. If the connection is live,
+     * then the character set is changed for the next read.
+     * @param encoding the canonical name of the character encoding
+     */
+    public void setCharset(String encoding) {
+        if (relay != null)
+            relay.setCharset(encoding);
+
+        keyListener.setCharset(encoding);
+    }
+
+    /**
+     * Convenience method for writing a line into the underlying MUD buffer.
+     * Should never be called once the session is established.
+     */
+    public final void outputLine(String line) {
+        if (transport != null && transport.isSessionOpen())
+            Log.e(TAG, "Session established, cannot use outputLine!", new IOException("outputLine call traceback"));
+
+        synchronized (localOutput) {
+            final String s = line + "\r\n";
+            localOutput.add(s);
+            buffer.putString(s);
+            // For accessibility
+            final char[] charArray = s.toCharArray();
+            propagateConsoleText(charArray, charArray.length);
+        }
+    }
+
+    /**
+     * Inject a specific string into this terminal. Used for post-login strings
+     * and pasting clipboard.
+     */
+    public void injectString(final String string) {
+        if (string == null || string.length() == 0)
+            return;
+
+        Thread injectStringThread = new Thread(new Runnable() {
+            public void run() {
+                try {
+                    transport.write(string.getBytes(host.getEncoding()));
+                }
+                catch (Exception e) {
+                    Log.e(TAG, "Couldn't inject string to remote host: ", e);
+                }
+            }
+        });
+        injectStringThread.setName("InjectString");
+        injectStringThread.start();
+    }
+
+    /**
+     * Internal method to request actual PTY terminal once we've finished
+     * authentication. If called before authenticated, it will just fail.
+     */
+    public void onConnected() {
+        disconnected = false;
+        buffer.reset();
+        // We no longer need our local output.
+        localOutput.clear();
+        // previously tried vt100 and xterm for emulation modes
+        // "screen" works the best for color and escape codes
+        buffer.setAnswerBack(emulation);
+
+        if (HostDatabase.DELKEY_BACKSPACE.equals(host.getDelKey()))
+            buffer.setBackspace(vt320.DELETE_IS_BACKSPACE);
+        else
+            buffer.setBackspace(vt320.DELETE_IS_DEL);
+
+        // create thread to relay incoming connection data to buffer
+        relay = new Relay(this, transport, buffer, host.getEncoding());
+        Thread relayThread = new Thread(relay);
+        relayThread.setDaemon(true);
+        relayThread.setName("Relay");
+        relayThread.start();
+        // force font-size to make sure we resizePTY as needed
+        setFontSize(fontSize);
+        // finally send any post-login string, if requested
+        injectString(host.getPostLogin());
+    }
+
+    /**
+     * @return whether a session is open or not
+     */
+    public boolean isSessionOpen() {
+        if (transport != null) return transport.isSessionOpen();
+
+        return false;
+    }
+
+    public void setOnDisconnectedListener(BridgeDisconnectedListener disconnectListener) {
+        this.disconnectListener = disconnectListener;
+    }
+
+    /**
+     * Force disconnection of this terminal bridge.
+     */
+    public void dispatchDisconnect(boolean immediate) {
+        // We don't need to do this multiple times.
+        synchronized (this) {
+            if (disconnected && !immediate) return;
+
+            disconnected = true;
+        }
+
+        // Cancel any pending prompts.
+        promptHelper.cancelPrompt();
+        // disconnection request hangs if we havent really connected to a host yet
+        // temporary fix is to just spawn disconnection into a thread
+        Thread disconnectThread = new Thread(new Runnable() {
+            public void run() {
+                if (transport != null && transport.isConnected())
+                    transport.close();
+            }
+        });
+        disconnectThread.setName("Disconnect");
+        disconnectThread.start();
+
+        if (immediate) {
+            awaitingClose = true;
+
+            if (disconnectListener != null)
+                disconnectListener.onDisconnected(TerminalBridge.this);
+        }
+        else {
+            final String line = manager.res.getString(R.string.alert_disconnect_msg);
+            buffer.putString("\r\n" + line + "\r\n");
+
+            if (host.getStayConnected()) {
+                manager.requestReconnect(this);
+                return;
+            }
+
+            Thread disconnectPromptThread = new Thread(new Runnable() {
+                public void run() {
+                    Boolean result = promptHelper.requestBooleanPrompt(null,
+                                     manager.res.getString(R.string.prompt_host_disconnected));
+
+                    if (result == null || result.booleanValue()) {
+                        awaitingClose = true;
+
+                        // Tell the TerminalManager that we can be destroyed now.
+                        if (disconnectListener != null)
+                            disconnectListener.onDisconnected(TerminalBridge.this);
+                    }
+                }
+            });
+            disconnectPromptThread.setName("DisconnectPrompt");
+            disconnectPromptThread.setDaemon(true);
+            disconnectPromptThread.start();
+        }
+
+        // close the monitor
+        if (monitor != null) monitor.Disconnect();
+        monitor = null;
+    }
+
+    public void setSelectingForCopy(boolean selectingForCopy) {
+        this.selectingForCopy = selectingForCopy;
+    }
+
+    public boolean isSelectingForCopy() {
+        return selectingForCopy;
+    }
+
+    public SelectionArea getSelectionArea() {
+        return selectionArea;
+    }
+
+    public synchronized void tryKeyVibrate() {
+        manager.tryKeyVibrate();
+    }
+
+    /**
+     * Request a different font size. Will make call to parentChanged() to make
+     * sure we resize PTY if needed.
+     */
+    /* package */ final void setFontSize(float size) {
+        if (size <= 0.0)
+            return;
+
+        defaultPaint.setTextSize(size);
+        fontSize = size;
+        // read new metrics to get exact pixel dimensions
+        FontMetrics fm = defaultPaint.getFontMetrics();
+        charTop = (int)FloatMath.ceil(fm.top);
+        float[] widths = new float[1];
+        defaultPaint.getTextWidths("X", widths);
+        charWidth = (int)FloatMath.ceil(widths[0]);
+        charHeight = (int)FloatMath.ceil(fm.descent - fm.top);
+
+        // refresh any bitmap with new font size
+        if (parent != null)
+            parentChanged(parent);
+
+        for (FontSizeChangedListener ofscl : fontSizeChangedListeners)
+            ofscl.onFontSizeChanged(size);
+
+        host.setFontSize((int) fontSize);
+        manager.hostdb.updateFontSize(host);
+    }
+
+    /**
+     * Add an {@link FontSizeChangedListener} to the list of listeners for this
+     * bridge.
+     *
+     * @param listener
+     *            listener to add
+     */
+    public void addFontSizeChangedListener(FontSizeChangedListener listener) {
+        fontSizeChangedListeners.add(listener);
+    }
+
+    /**
+     * Remove an {@link FontSizeChangedListener} from the list of listeners for
+     * this bridge.
+     *
+     * @param listener
+     */
+    public void removeFontSizeChangedListener(FontSizeChangedListener listener) {
+        fontSizeChangedListeners.remove(listener);
+    }
+
+    /**
+     * Something changed in our parent {@link TerminalView}, maybe it's a new
+     * parent, or maybe it's an updated font size. We should recalculate
+     * terminal size information and request a PTY resize.
+     */
+
+    public final synchronized void parentChanged(TerminalView parent) {
+        if (manager != null && !manager.isResizeAllowed()) {
+            Log.d(TAG, "Resize is not allowed now");
+            return;
+        }
+
+        this.parent = parent;
+        final int width = parent.getWidth();
+        final int height = parent.getHeight();
+
+        // Something has gone wrong with our layout; we're 0 width or height!
+        if (width <= 0 || height <= 0)
+            return;
+
+        clipboard = (ClipboardManager) parent.getContext().getSystemService(Context.CLIPBOARD_SERVICE);
+        keyListener.setClipboardManager(clipboard);
+
+        if (!forcedSize) {
+            // recalculate buffer size
+            int newColumns, newRows;
+            newColumns = width / charWidth;
+            newRows = height / charHeight;
+
+            // If nothing has changed in the terminal dimensions and not an intial
+            // draw then don't blow away scroll regions and such.
+            if (newColumns == columns && newRows == rows)
+                return;
+
+            columns = newColumns;
+            rows = newRows;
+        }
+
+        // reallocate new bitmap if needed
+        boolean newBitmap = (bitmap == null);
+
+        if (bitmap != null)
+            newBitmap = (bitmap.getWidth() != width || bitmap.getHeight() != height);
+
+        if (newBitmap) {
+            discardBitmap();
+            bitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
+            canvas.setBitmap(bitmap);
+        }
+
+        // clear out any old buffer information
+        defaultPaint.setColor(Color.BLACK);
+        canvas.drawPaint(defaultPaint);
+
+        // Stroke the border of the terminal if the size is being forced;
+        if (forcedSize) {
+            int borderX = (columns * charWidth) + 1;
+            int borderY = (rows * charHeight) + 1;
+            defaultPaint.setColor(Color.GRAY);
+            defaultPaint.setStrokeWidth(0.0f);
+
+            if (width >= borderX)
+                canvas.drawLine(borderX, 0, borderX, borderY + 1, defaultPaint);
+
+            if (height >= borderY)
+                canvas.drawLine(0, borderY, borderX + 1, borderY, defaultPaint);
+        }
+
+        try {
+            // request a terminal pty resize
+            synchronized (buffer) {
+                buffer.setScreenSize(columns, rows, true);
+            }
+
+            if (transport != null)
+                transport.setDimensions(columns, rows, width, height);
+        }
+        catch (Exception e) {
+            Log.e(TAG, "Problem while trying to resize screen or PTY", e);
+        }
+
+        // redraw local output if we don't have a sesson to receive our resize request
+        if (transport == null) {
+            synchronized (localOutput) {
+                buffer.reset();
+
+                for (String line : localOutput)
+                    buffer.putString(line);
+            }
+        }
+
+        // force full redraw with new buffer size
+        fullRedraw = true;
+        redraw();
+        parent.notifyUser(String.format("%d x %d", columns, rows));
+        Log.i(TAG, String.format("parentChanged() now width=%d, height=%d", columns, rows));
+    }
+
+    /**
+     * Somehow our parent {@link TerminalView} was destroyed. Now we don't need
+     * to redraw anywhere, and we can recycle our internal bitmap.
+     */
+
+    public synchronized void parentDestroyed() {
+        parent = null;
+        discardBitmap();
+    }
+
+    private void discardBitmap() {
+        if (bitmap != null)
+            bitmap.recycle();
+
+        bitmap = null;
+    }
+
+    public void propagateConsoleText(char[] rawText, int length) {
+        if (parent != null) {
+            parent.propagateConsoleText(rawText, length);
+        }
+    }
+
+    public void onDraw() {
+        int fg, bg;
+
+        synchronized (buffer) {
+            boolean entireDirty = buffer.update[0] || fullRedraw;
+            boolean isWideCharacter = false;
+
+            // walk through all lines in the buffer
+            for (int l = 0; l < buffer.height; l++) {
+                // check if this line is dirty and needs to be repainted
+                // also check for entire-buffer dirty flags
+                if (!entireDirty && !buffer.update[l + 1]) continue;
+
+                // reset dirty flag for this line
+                buffer.update[l + 1] = false;
+
+                // walk through all characters in this line
+                for (int c = 0; c < buffer.width; c++) {
+                    int addr = 0;
+                    int currAttr = buffer.charAttributes[buffer.windowBase + l][c];
+                    {
+                        int fgcolor = defaultFg;
+
+                        // check if foreground color attribute is set
+                        if ((currAttr & VDUBuffer.COLOR_FG) != 0)
+                            fgcolor = ((currAttr & VDUBuffer.COLOR_FG) >> VDUBuffer.COLOR_FG_SHIFT) - 1;
+
+                        if (fgcolor < 8 && (currAttr & VDUBuffer.BOLD) != 0)
+                            fg = color[fgcolor + 8];
+                        else
+                            fg = color[fgcolor];
+                    }
+
+                    // check if background color attribute is set
+                    if ((currAttr & VDUBuffer.COLOR_BG) != 0)
+                        bg = color[((currAttr & VDUBuffer.COLOR_BG) >> VDUBuffer.COLOR_BG_SHIFT) - 1];
+                    else
+                        bg = color[defaultBg];
+
+                    // support character inversion by swapping background and foreground color
+                    if ((currAttr & VDUBuffer.INVERT) != 0) {
+                        int swapc = bg;
+                        bg = fg;
+                        fg = swapc;
+                    }
+
+                    // set underlined attributes if requested
+                    defaultPaint.setUnderlineText((currAttr & VDUBuffer.UNDERLINE) != 0);
+                    isWideCharacter = (currAttr & VDUBuffer.FULLWIDTH) != 0;
+
+                    if (isWideCharacter)
+                        addr++;
+                    else {
+                        // determine the amount of continuous characters with the same settings and print them all at once
+                        while (c + addr < buffer.width
+                                && buffer.charAttributes[buffer.windowBase + l][c + addr] == currAttr) {
+                            addr++;
+                        }
+                    }
+
+                    // Save the current clip region
+                    canvas.save(Canvas.CLIP_SAVE_FLAG);
+                    // clear this dirty area with background color
+                    defaultPaint.setColor(bg);
+
+                    if (isWideCharacter) {
+                        canvas.clipRect(c * charWidth,
+                                        l * charHeight,
+                                        (c + 2) * charWidth,
+                                        (l + 1) * charHeight);
+                    }
+                    else {
+                        canvas.clipRect(c * charWidth,
+                                        l * charHeight,
+                                        (c + addr) * charWidth,
+                                        (l + 1) * charHeight);
+                    }
+
+                    canvas.drawPaint(defaultPaint);
+                    // write the text string starting at 'c' for 'addr' number of characters
+                    defaultPaint.setColor(fg);
+
+                    if ((currAttr & VDUBuffer.INVISIBLE) == 0)
+                        canvas.drawText(buffer.charArray[buffer.windowBase + l], c,
+                                        addr, c * charWidth, (l * charHeight) - charTop,
+                                        defaultPaint);
+
+                    // Restore the previous clip region
+                    canvas.restore();
+                    // advance to the next text block with different characteristics
+                    c += addr - 1;
+
+                    if (isWideCharacter)
+                        c++;
+                }
+            }
+
+            // reset entire-buffer flags
+            buffer.update[0] = false;
+        }
+
+        fullRedraw = false;
+    }
+
+    public void redraw() {
+        if (parent != null)
+            parent.postInvalidate();
+    }
+
+    // We don't have a scroll bar.
+    public void updateScrollBar() {
+    }
+
+    /**
+     * Resize terminal to fit [rows]x[cols] in screen of size [width]x[height]
+     * @param rows
+     * @param cols
+     * @param width
+     * @param height
+     */
+
+    public synchronized void resizeComputed(int cols, int rows, int width, int height) {
+        float size = 8.0f;
+        float step = 8.0f;
+        float limit = 0.125f;
+        int direction;
+
+        while ((direction = fontSizeCompare(size, cols, rows, width, height)) < 0)
+            size += step;
+
+        if (direction == 0) {
+            Log.d("fontsize", String.format("Found match at %f", size));
+            return;
+        }
+
+        step /= 2.0f;
+        size -= step;
+
+        while ((direction = fontSizeCompare(size, cols, rows, width, height)) != 0
+                && step >= limit) {
+            step /= 2.0f;
+
+            if (direction > 0) {
+                size -= step;
+            }
+            else {
+                size += step;
+            }
+        }
+
+        if (direction > 0)
+            size -= step;
+
+        this.columns = cols;
+        this.rows = rows;
+        forcedSize = true;
+        setFontSize(size);
+    }
+
+    private int fontSizeCompare(float size, int cols, int rows, int width, int height) {
+        // read new metrics to get exact pixel dimensions
+        defaultPaint.setTextSize(size);
+        FontMetrics fm = defaultPaint.getFontMetrics();
+        float[] widths = new float[1];
+        defaultPaint.getTextWidths("X", widths);
+        int termWidth = (int)widths[0] * cols;
+        int termHeight = (int)FloatMath.ceil(fm.descent - fm.top) * rows;
+        Log.d("fontsize", String.format("font size %f resulted in %d x %d", size, termWidth, termHeight));
+
+        // Check to see if it fits in resolution specified.
+        if (termWidth > width || termHeight > height)
+            return 1;
+
+        if (termWidth == width || termHeight == height)
+            return 0;
+
+        return -1;
+    }
+
+    /**
+     * @return whether underlying transport can forward ports
+     */
+    public boolean canFowardPorts() {
+        return transport.canForwardPorts();
+    }
+
+    /**
+     * Adds the {@link PortForwardBean} to the list.
+     * @param portForward the port forward bean to add
+     * @return true on successful addition
+     */
+    public boolean addPortForward(PortForwardBean portForward) {
+        return transport.addPortForward(portForward);
+    }
+
+    /**
+     * Removes the {@link PortForwardBean} from the list.
+     * @param portForward the port forward bean to remove
+     * @return true on successful removal
+     */
+    public boolean removePortForward(PortForwardBean portForward) {
+        return transport.removePortForward(portForward);
+    }
+
+    /**
+     * @return the list of port forwards
+     */
+    public List<PortForwardBean> getPortForwards() {
+        return transport.getPortForwards();
+    }
+
+    /**
+     * Enables a port forward member. After calling this method, the port forward should
+     * be operational.
+     * @param portForward member of our current port forwards list to enable
+     * @return true on successful port forward setup
+     */
+    public boolean enablePortForward(PortForwardBean portForward) {
+        if (!transport.isConnected()) {
+            Log.i(TAG, "Attempt to enable port forward while not connected");
+            return false;
+        }
+
+        return transport.enablePortForward(portForward);
+    }
+
+    /**
+     * Disables a port forward member. After calling this method, the port forward should
+     * be non-functioning.
+     * @param portForward member of our current port forwards list to enable
+     * @return true on successful port forward tear-down
+     */
+    public boolean disablePortForward(PortForwardBean portForward) {
+        if (!transport.isConnected()) {
+            Log.i(TAG, "Attempt to disable port forward while not connected");
+            return false;
+        }
+
+        return transport.disablePortForward(portForward);
+    }
+
+    /**
+     * @return whether underlying transport can transfer files
+     */
+    public boolean canTransferFiles() {
+        return transport.canTransferFiles();
+    }
+
+    /**
+     * Downloads the specified remote file to the local connectbot folder.
+     * @return true on success, false on failure
+     */
+    public boolean downloadFile(String remoteFile, String localFolder) {
+        return transport.downloadFile(remoteFile, localFolder);
+    }
+
+    /**
+     * Uploads the specified local file to the remote host's default directory.
+     * @return true on success, false on failure
+     */
+    public boolean uploadFile(String localFile, String remoteFolder, String remoteFile, String mode) {
+        if (mode == null)
+            mode = "0600";
+
+        return transport.uploadFile(localFile, remoteFolder, remoteFile, mode);
+    }
+
+    /**
+     * @return whether the TerminalBridge should close
+     */
+    public boolean isAwaitingClose() {
+        return awaitingClose;
+    }
+
+    /**
+     * @return whether this connection had started and subsequently disconnected
+     */
+    public boolean isDisconnected() {
+        return disconnected;
+    }
+
+    /* (non-Javadoc)
+     * @see de.mud.terminal.VDUDisplay#setColor(byte, byte, byte, byte)
+     */
+    public void setColor(int index, int red, int green, int blue) {
+        // Don't allow the system colors to be overwritten for now. May violate specs.
+        if (index < color.length && index >= 16)
+            color[index] = 0xff000000 | red << 16 | green << 8 | blue;
+    }
+
+    public final void resetColors() {
+        int[] defaults = manager.hostdb.getDefaultColorsForScheme(HostDatabase.DEFAULT_COLOR_SCHEME);
+        defaultFg = defaults[0];
+        defaultBg = defaults[1];
+        color = manager.hostdb.getColorsForScheme(HostDatabase.DEFAULT_COLOR_SCHEME);
+    }
+
+    private static Pattern urlPattern = null;
+
+    /**
+     * @return
+     */
+    public List<String> scanForURLs() {
+        Set<String> urls = new LinkedHashSet<String>();
+
+        if (urlPattern == null) {
+            // based on http://www.ietf.org/rfc/rfc2396.txt
+            String scheme = "[A-Za-z][-+.0-9A-Za-z]*";
+            String unreserved = "[-._~0-9A-Za-z]";
+            String pctEncoded = "%[0-9A-Fa-f]{2}";
+            String subDelims = "[!$&'()*+,;:=]";
+            String userinfo = "(?:" + unreserved + "|" + pctEncoded + "|" + subDelims + "|:)*";
+            String h16 = "[0-9A-Fa-f]{1,4}";
+            String decOctet = "(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])";
+            String ipv4address = decOctet + "\\." + decOctet + "\\." + decOctet + "\\." + decOctet;
+            String ls32 = "(?:" + h16 + ":" + h16 + "|" + ipv4address + ")";
+            String ipv6address = "(?:(?:" + h16 + "){6}" + ls32 + ")";
+            String ipvfuture = "v[0-9A-Fa-f]+.(?:" + unreserved + "|" + subDelims + "|:)+";
+            String ipLiteral = "\\[(?:" + ipv6address + "|" + ipvfuture + ")\\]";
+            String regName = "(?:" + unreserved + "|" + pctEncoded + "|" + subDelims + ")*";
+            String host = "(?:" + ipLiteral + "|" + ipv4address + "|" + regName + ")";
+            String port = "[0-9]*";
+            String authority = "(?:" + userinfo + "@)?" + host + "(?::" + port + ")?";
+            String pchar = "(?:" + unreserved + "|" + pctEncoded + "|" + subDelims + "|@)";
+            String segment = pchar + "*";
+            String pathAbempty = "(?:/" + segment + ")*";
+            String segmentNz = pchar + "+";
+            String pathAbsolute = "/(?:" + segmentNz + "(?:/" + segment + ")*)?";
+            String pathRootless = segmentNz + "(?:/" + segment + ")*";
+            String hierPart = "(?://" + authority + pathAbempty + "|" + pathAbsolute + "|" + pathRootless + ")";
+            String query = "(?:" + pchar + "|/|\\?)*";
+            String fragment = "(?:" + pchar + "|/|\\?)*";
+            String uriRegex = scheme + ":" + hierPart + "(?:" + query + ")?(?:#" + fragment + ")?";
+            urlPattern = Pattern.compile(uriRegex);
+        }
+
+        char[] visibleBuffer = new char[buffer.height * buffer.width];
+
+        for (int l = 0; l < buffer.height; l++)
+            System.arraycopy(buffer.charArray[buffer.windowBase + l], 0,
+                             visibleBuffer, l * buffer.width, buffer.width);
+
+        Matcher urlMatcher = urlPattern.matcher(new String(visibleBuffer));
+
+        while (urlMatcher.find())
+            urls.add(urlMatcher.group());
+
+        return (new LinkedList<String> (urls));
+    }
+
+    /**
+     * @return
+     */
+    public boolean isUsingNetwork() {
+        return transport.usesNetwork();
+    }
+
+    /**
+     * @return
+     */
+    public TerminalKeyListener getKeyHandler() {
+        return keyListener;
+    }
+
+    /**
+     *
+     */
+    public void resetScrollPosition() {
+        // if we're in scrollback, scroll to bottom of window on input
+        if (buffer.windowBase != buffer.screenBase)
+            buffer.setWindowBase(buffer.screenBase);
+    }
+
+    /**
+     *
+     */
+    public void increaseFontSize() {
+        setFontSize(fontSize + FONT_SIZE_STEP);
+    }
+
+    /**
+     *
+     */
+    public void decreaseFontSize() {
+        setFontSize(fontSize - FONT_SIZE_STEP);
+    }
+
+    /**
+     * Auto-size window back to default
+     */
+    public void resetSize(TerminalView parent) {
+        this.forcedSize = false;
+        Integer defaultFontSize = Integer.parseInt(manager.prefs.getString(PreferenceConstants.DEFAULT_FONT_SIZE, "-1"));
+
+        if (this.fontSize != -1 && defaultFontSize > 0)
+            setFontSize(defaultFontSize);
+        else
+            setFontSize(DEFAULT_FONT_SIZE);
+    }
+
+    /**
+     * Create a screenshot of the current view
+     */
+    public void captureScreen() {
+        String msg;
+        File dir, path;
+        boolean success = true;
+        Bitmap screenshot = this.bitmap;
+
+        if (manager == null || parent == null || screenshot == null)
+            return;
+
+        SimpleDateFormat s = new SimpleDateFormat("yyyyMMdd_HHmmss");
+        String date = s.format(new Date());
+        String pref_path = manager.prefs.getString(PreferenceConstants.SCREEN_CAPTURE_FOLDER, "");
+        File default_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
+
+        if (pref_path.equals(""))
+            dir = default_path;
+        else
+            dir = new File(pref_path);
+
+        path = new File(dir, "vx-" + date + ".png");
+
+        try {
+            dir.mkdirs();
+            FileOutputStream out = new FileOutputStream(path);
+            screenshot.compress(Bitmap.CompressFormat.PNG, 90, out);
+            out.close();
+        }
+        catch (Exception e) {
+            e.printStackTrace();
+            success = false;
+        }
+
+        if (success) {
+            msg = manager.getResources().getString(R.string.screenshot_saved_as) + " " + path;
+
+            if (manager.prefs.getBoolean(PreferenceConstants.SCREEN_CAPTURE_POPUP, true)) {
+                new AlertDialog.Builder(parent.getContext())
+                .setTitle(R.string.screenshot_success_title)
+                .setMessage(msg)
+                .setPositiveButton(R.string.button_close, null)
+                .show();
+            }
+        }
+        else {
+            msg = manager.getResources().getString(R.string.screenshot_not_saved_as) + " " + path;
+            new AlertDialog.Builder(parent.getContext())
+            .setTitle(R.string.screenshot_error_title)
+            .setMessage(msg)
+            .setNegativeButton(R.string.button_close, null)
+            .show();
+        }
+
+        return;
+    }
+
+    /**
+     * Show change font size dialog
+     */
+    public boolean showFontSizeDialog() {
+        final String pickerString = "+-";
+        CharSequence str = "";
+        Editable content = Editable.Factory.getInstance().newEditable(str);
+
+        if (parent == null)
+            return false;
+
+        CharacterPickerDialog cpd = new CharacterPickerDialog(parent.getContext(),
+        parent, content, pickerString, true) {
+            private void changeFontSize(CharSequence result) {
+                if (result.equals("+"))
+                    increaseFontSize();
+                else if (result.equals("-"))
+                    decreaseFontSize();
+            }
+            @Override
+            public void onItemClick(AdapterView p, View v, int pos, long id) {
+                final String result = String.valueOf(pickerString.charAt(pos));
+                changeFontSize(result);
+            }
+            @Override
+            public void onClick(View v) {
+                if (v instanceof Button) {
+                    final CharSequence result = ((Button) v).getText();
+
+                    if (result.equals(""))
+                        dismiss();
+                    else
+                        changeFontSize(result);
+                }
+            }
+            @Override
+            public boolean dispatchKeyEvent(KeyEvent event) {
+                if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
+                        dismiss();
+
+                    return keyListener.onKey(parent, event.getKeyCode(), event);
+                }
+
+                return true;
+            }
+        };
+        cpd.show();
+        return true;
+    }
+
+    /**
+     * Show arrows dialog
+     */
+    public boolean showArrowsDialog() {
+        final String pickerString = "←→↑↓TIDE";
+        CharSequence str = "";
+        Editable content = Editable.Factory.getInstance().newEditable(str);
+
+        if (parent == null)
+            return false;
+
+        CharacterPickerDialog cpd = new CharacterPickerDialog(parent.getContext(),
+        parent, content, pickerString, true) {
+            private void buttonPressed(CharSequence result) {
+                if (result.equals("←"))
+                    buffer.keyPressed(vt320.KEY_LEFT, ' ', 0);
+                else if (result.equals("→"))
+                    buffer.keyPressed(vt320.KEY_RIGHT, ' ', 0);
+                else if (result.equals("↑"))
+                    buffer.keyPressed(vt320.KEY_UP, ' ', 0);
+                else if (result.equals("↓"))
+                    buffer.keyPressed(vt320.KEY_DOWN, ' ', 0);
+                else if (result.equals("I"))
+                    buffer.keyPressed(vt320.KEY_INSERT, ' ', 0);
+                else if (result.equals("D"))
+                    buffer.keyPressed(vt320.KEY_DELETE, ' ', 0);
+                else if (result.equals("E"))
+                    buffer.keyTyped(vt320.KEY_ENTER, ' ', 0);
+                else if (result.equals("T")) {
+                    try {
+                        transport.write(0x09);
+                    }
+                    catch (IOException e) {
+                        Log.e(TAG, "Problem with the arrowsDialog", e);
+                    }
+                }
+            }
+            @Override
+            public void onItemClick(AdapterView p, View v, int pos, long id) {
+                final String result = String.valueOf(pickerString.charAt(pos));
+                buttonPressed(result);
+            }
+            @Override
+            public void onClick(View v) {
+                if (v instanceof Button) {
+                    final CharSequence result = ((Button) v).getText();
+
+                    if (result.equals(""))
+                        dismiss();
+                    else
+                        buttonPressed(result);
+                }
+            }
+            @Override
+            public boolean dispatchKeyEvent(KeyEvent event) {
+                if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
+                        dismiss();
+
+                    return keyListener.onKey(parent, event.getKeyCode(), event);
+                }
+
+                return true;
+            }
+        };
+        cpd.show();
+        return true;
+    }
+
+
+    /**
+     * CTRL dialog
+     */
+    private String getCtrlString() {
+        final String defaultSet = "ABCDEKLOQRWSTUXZ";
+        String set = manager.prefs.getString(PreferenceConstants.CTRL_STRING, defaultSet);
+
+        if (set == null || set.equals("")) {
+            set = defaultSet;
+        }
+
+        return set;
+    }
+
+    public boolean showCtrlDialog() {
+        CharSequence str = "";
+        Editable content = Editable.Factory.getInstance().newEditable(str);
+
+        if (parent == null)
+            return false;
+
+        CharacterPickerDialog cpd = new CharacterPickerDialog(parent.getContext(),
+        parent, content, getCtrlString(), true) {
+            private void buttonPressed(CharSequence result) {
+                int code = result.toString().toUpperCase().charAt(0) - 64;
+
+                if (code > 0 && code < 80) {
+                    try {
+                        transport.write(code);
+                    }
+                    catch (IOException e) {
+                        Log.d(TAG, "Error writing CTRL+" + result.toString().toUpperCase().charAt(0));
+                    }
+                }
+
+                dismiss();
+            }
+            @Override
+            public void onItemClick(AdapterView p, View v, int pos, long id) {
+                final String result = String.valueOf(getCtrlString().charAt(pos));
+                buttonPressed(result);
+            }
+            @Override
+            public void onClick(View v) {
+                if (v instanceof Button) {
+                    final CharSequence result = ((Button) v).getText();
+
+                    if (result.equals(""))
+                        dismiss();
+                    else
+                        buttonPressed(result);
+                }
+            }
+            @Override
+            public boolean dispatchKeyEvent(KeyEvent event) {
+                if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
+                        dismiss();
+
+                    return keyListener.onKey(parent, event.getKeyCode(), event);
+                }
+
+                return true;
+            }
+        };
+        cpd.show();
+        return true;
+    }
+
+    /**
+     * Function keys dialog
+     */
+    public boolean showFKeysDialog() {
+        final String pickerString = "1234567890";
+        CharSequence str = "";
+        Editable content = Editable.Factory.getInstance().newEditable(str);
+
+        if (parent == null)
+            return false;
+
+        CharacterPickerDialog cpd = new CharacterPickerDialog(parent.getContext(),
+        parent, content, pickerString, true) {
+            private void buttonPressed(CharSequence result) {
+                int key = 0;
+
+                if (result.equals("1"))
+                    key = vt320.KEY_F1;
+                else if (result.equals("2"))
+                    key = vt320.KEY_F2;
+                else if (result.equals("3"))
+                    key = vt320.KEY_F3;
+                else if (result.equals("4"))
+                    key = vt320.KEY_F4;
+                else if (result.equals("5"))
+                    key = vt320.KEY_F5;
+                else if (result.equals("6"))
+                    key = vt320.KEY_F6;
+                else if (result.equals("7"))
+                    key = vt320.KEY_F7;
+                else if (result.equals("8"))
+                    key = vt320.KEY_F8;
+                else if (result.equals("9"))
+                    key = vt320.KEY_F9;
+                else if (result.equals("0"))
+                    key = vt320.KEY_F10;
+
+                if (key != 0)
+                    buffer.keyPressed(key, ' ', 0);
+
+                dismiss();
+            }
+            @Override
+            public void onItemClick(AdapterView p, View v, int pos, long id) {
+                final String result = String.valueOf(pickerString.charAt(pos));
+                buttonPressed(result);
+            }
+            @Override
+            public void onClick(View v) {
+                if (v instanceof Button) {
+                    final CharSequence result = ((Button) v).getText();
+
+                    if (result.equals(""))
+                        dismiss();
+                    else
+                        buttonPressed(result);
+                }
+            }
+            @Override
+            public boolean dispatchKeyEvent(KeyEvent event) {
+                if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK)
+                        dismiss();
+
+                    return keyListener.onKey(parent, event.getKeyCode(), event);
+                }
+
+                return true;
+            }
+        };
+        cpd.show();
+        return true;
+    }
+
+    private String getPickerString() {
+        final String defaultSet = "~\\^()[]{}<>|/:_;,.!@#$%&*?\"'-+=";
+        String set = manager.prefs.getString(PreferenceConstants.PICKER_STRING, defaultSet);
+
+        if (set == null || set.equals("")) {
+            set = defaultSet;
+        }
+
+        return set;
+    }
+
+    public boolean showCharPickerDialog() {
+        CharSequence str = "";
+        Editable content = Editable.Factory.getInstance().newEditable(str);
+
+        if (parent == null || !transport.isAuthenticated())
+            return false;
+
+        CharacterPickerDialog cpd = new CharacterPickerDialog(parent.getContext(),
+        parent, content, getPickerString(), true) {
+            private void writeChar(CharSequence result) {
+                try {
+                    if (transport.isAuthenticated())
+                        transport.write(result.toString().getBytes(getCharset().name()));
+                }
+                catch (IOException e) {
+                    Log.e(TAG, "Problem with the CharacterPickerDialog", e);
+                }
+
+                if (!manager.prefs.getBoolean(PreferenceConstants.PICKER_KEEP_OPEN, false))
+                    dismiss();
+            }
+            @Override
+            public void onItemClick(AdapterView p, View v, int pos, long id) {
+                String result = String.valueOf(getPickerString().charAt(pos));
+                writeChar(result);
+            }
+            @Override
+            public void onClick(View v) {
+                if (v instanceof Button) {
+                    CharSequence result = ((Button) v).getText();
+
+                    if (result.equals(""))
+                        dismiss();
+                    else
+                        writeChar(result);
+                }
+            }
+            @Override
+            public boolean dispatchKeyEvent(KeyEvent event) {
+                int keyCode = event.getKeyCode();
+
+                if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                    // close window if SYM or BACK keys are pressed
+                    if (keyListener.isSymKey(keyCode) ||
+                            keyCode == KeyEvent.KEYCODE_BACK) {
+                        dismiss();
+                        return true;
+                    }
+
+//                  return keyListener.onKey(parent, event.getKeyCode(), event);
+                }
+
+                return super.dispatchKeyEvent(event);
+            }
+        };
+        cpd.show();
+        return true;
+    }
+}