--- /dev/null
+//
+// getline.cs: A command line editor
+//
+// Authors:
+// Miguel de Icaza (miguel@novell.com)
+//
+// Copyright 2008 Novell, Inc.
+//
+// Dual-licensed under the terms of the MIT X11 license or the
+// Apache License 2.0
+//
+// USE -define:DEMO to build this as a standalone file and test it
+//
+// TODO:
+// Enter an error (a = 1); Notice how the prompt is in the wrong line
+// This is caused by Stderr not being tracked by System.Console.
+// Completion support
+// Why is Thread.Interrupt not working? Currently I resort to Abort which is too much.
+//
+// Limitations in System.Console:
+// Console needs SIGWINCH support of some sort
+// Console needs a way of updating its position after things have been written
+// behind its back (P/Invoke puts for example).
+// System.Console needs to get the DELETE character, and report accordingly.
+//
+
+using System;
+using System.Text;
+using System.IO;
+using System.Threading;
+using System.Reflection;
+
+namespace Mono.Terminal {
+
+ public class LineEditor {
+
+ public class Completion {
+ public string [] Result;
+ public string Prefix;
+
+ public Completion (string prefix, string [] result)
+ {
+ Prefix = prefix;
+ Result = result;
+ }
+ }
+
+ public delegate Completion AutoCompleteHandler (string text, int pos);
+
+ //static StreamWriter log;
+
+ // The text being edited.
+ StringBuilder text;
+
+ // The text as it is rendered (replaces (char)1 with ^A on display for example).
+ StringBuilder rendered_text;
+
+ // The prompt specified, and the prompt shown to the user.
+ string prompt;
+ string shown_prompt;
+
+ // The current cursor position, indexes into "text", for an index
+ // into rendered_text, use TextToRenderPos
+ int cursor;
+
+ // The row where we started displaying data.
+ int home_row;
+
+ // The maximum length that has been displayed on the screen
+ int max_rendered;
+
+ // If we are done editing, this breaks the interactive loop
+ bool done = false;
+
+ // The thread where the Editing started taking place
+ Thread edit_thread;
+
+ // Our object that tracks history
+ History history;
+
+ // The contents of the kill buffer (cut/paste in Emacs parlance)
+ string kill_buffer = "";
+
+ // The string being searched for
+ string search;
+ string last_search;
+
+ // whether we are searching (-1= reverse; 0 = no; 1 = forward)
+ int searching;
+
+ // The position where we found the match.
+ int match_at;
+
+ // Used to implement the Kill semantics (multiple Alt-Ds accumulate)
+ KeyHandler last_handler;
+
+ delegate void KeyHandler ();
+
+ struct Handler {
+ public ConsoleKeyInfo CKI;
+ public KeyHandler KeyHandler;
+
+ public Handler (ConsoleKey key, KeyHandler h)
+ {
+ CKI = new ConsoleKeyInfo ((char) 0, key, false, false, false);
+ KeyHandler = h;
+ }
+
+ public Handler (char c, KeyHandler h)
+ {
+ KeyHandler = h;
+ // Use the "Zoom" as a flag that we only have a character.
+ CKI = new ConsoleKeyInfo (c, ConsoleKey.Zoom, false, false, false);
+ }
+
+ public Handler (ConsoleKeyInfo cki, KeyHandler h)
+ {
+ CKI = cki;
+ KeyHandler = h;
+ }
+
+ public static Handler Control (char c, KeyHandler h)
+ {
+ return new Handler ((char) (c - 'A' + 1), h);
+ }
+
+ public static Handler Alt (char c, ConsoleKey k, KeyHandler h)
+ {
+ ConsoleKeyInfo cki = new ConsoleKeyInfo ((char) c, k, false, true, false);
+ return new Handler (cki, h);
+ }
+ }
+
+ /// <summary>
+ /// Invoked when the user requests auto-completion using the tab character
+ /// </summary>
+ /// <remarks>
+ /// The result is null for no values found, an array with a single
+ /// string, in that case the string should be the text to be inserted
+ /// for example if the word at pos is "T", the result for a completion
+ /// of "ToString" should be "oString", not "ToString".
+ ///
+ /// When there are multiple results, the result should be the full
+ /// text
+ /// </remarks>
+ public AutoCompleteHandler AutoCompleteEvent;
+
+ static Handler [] handlers;
+
+ public LineEditor (string name) : this (name, 10) { }
+
+ public LineEditor (string name, int histsize)
+ {
+ handlers = new Handler [] {
+ new Handler (ConsoleKey.Home, CmdHome),
+ new Handler (ConsoleKey.End, CmdEnd),
+ new Handler (ConsoleKey.LeftArrow, CmdLeft),
+ new Handler (ConsoleKey.RightArrow, CmdRight),
+ new Handler (ConsoleKey.UpArrow, CmdHistoryPrev),
+ new Handler (ConsoleKey.DownArrow, CmdHistoryNext),
+ new Handler (ConsoleKey.Enter, CmdDone),
+ new Handler (ConsoleKey.Backspace, CmdBackspace),
+ new Handler (ConsoleKey.Delete, CmdDeleteChar),
+ new Handler (ConsoleKey.Tab, CmdTabOrComplete),
+
+ // Emacs keys
+ Handler.Control ('A', CmdHome),
+ Handler.Control ('E', CmdEnd),
+ Handler.Control ('B', CmdLeft),
+ Handler.Control ('F', CmdRight),
+ Handler.Control ('P', CmdHistoryPrev),
+ Handler.Control ('N', CmdHistoryNext),
+ Handler.Control ('K', CmdKillToEOF),
+ Handler.Control ('Y', CmdYank),
+ Handler.Control ('D', CmdDeleteChar),
+ Handler.Control ('L', CmdRefresh),
+ Handler.Control ('R', CmdReverseSearch),
+ Handler.Control ('G', delegate {} ),
+ Handler.Alt ('B', ConsoleKey.B, CmdBackwardWord),
+ Handler.Alt ('F', ConsoleKey.F, CmdForwardWord),
+
+ Handler.Alt ('D', ConsoleKey.D, CmdDeleteWord),
+ Handler.Alt ((char) 8, ConsoleKey.Backspace, CmdDeleteBackword),
+
+ // DEBUG
+ //Handler.Control ('T', CmdDebug),
+
+ // quote
+ Handler.Control ('Q', delegate { HandleChar (Console.ReadKey (true).KeyChar); })
+ };
+
+ rendered_text = new StringBuilder ();
+ text = new StringBuilder ();
+
+ history = new History (name, histsize);
+
+ //if (File.Exists ("log"))File.Delete ("log");
+ //log = File.CreateText ("log");
+ }
+
+ void CmdDebug ()
+ {
+ history.Dump ();
+ Console.WriteLine ();
+ Render ();
+ }
+
+ void Render ()
+ {
+ Console.Write (shown_prompt);
+ Console.Write (rendered_text);
+
+ int max = System.Math.Max (rendered_text.Length + shown_prompt.Length, max_rendered);
+
+ for (int i = rendered_text.Length + shown_prompt.Length; i < max_rendered; i++)
+ Console.Write (' ');
+ max_rendered = shown_prompt.Length + rendered_text.Length;
+
+ // Write one more to ensure that we always wrap around properly if we are at the
+ // end of a line.
+ Console.Write (' ');
+
+ UpdateHomeRow (max);
+ }
+
+ void UpdateHomeRow (int screenpos)
+ {
+ int lines = 1 + (screenpos / Console.WindowWidth);
+
+ home_row = Console.CursorTop - (lines - 1);
+ if (home_row < 0)
+ home_row = 0;
+ }
+
+
+ void RenderFrom (int pos)
+ {
+ int rpos = TextToRenderPos (pos);
+ int i;
+
+ for (i = rpos; i < rendered_text.Length; i++)
+ Console.Write (rendered_text [i]);
+
+ if ((shown_prompt.Length + rendered_text.Length) > max_rendered)
+ max_rendered = shown_prompt.Length + rendered_text.Length;
+ else {
+ int max_extra = max_rendered - shown_prompt.Length;
+ for (; i < max_extra; i++)
+ Console.Write (' ');
+ }
+ }
+
+ void ComputeRendered ()
+ {
+ rendered_text.Length = 0;
+
+ for (int i = 0; i < text.Length; i++){
+ int c = (int) text [i];
+ if (c < 26){
+ if (c == '\t')
+ rendered_text.Append (" ");
+ else {
+ rendered_text.Append ('^');
+ rendered_text.Append ((char) (c + (int) 'A' - 1));
+ }
+ } else
+ rendered_text.Append ((char)c);
+ }
+ }
+
+ int TextToRenderPos (int pos)
+ {
+ int p = 0;
+
+ for (int i = 0; i < pos; i++){
+ int c;
+
+ c = (int) text [i];
+
+ if (c < 26){
+ if (c == 9)
+ p += 4;
+ else
+ p += 2;
+ } else
+ p++;
+ }
+
+ return p;
+ }
+
+ int TextToScreenPos (int pos)
+ {
+ return shown_prompt.Length + TextToRenderPos (pos);
+ }
+
+ string Prompt {
+ get { return prompt; }
+ set { prompt = value; }
+ }
+
+ int LineCount {
+ get {
+ return (shown_prompt.Length + rendered_text.Length)/Console.WindowWidth;
+ }
+ }
+
+ void ForceCursor (int newpos)
+ {
+ cursor = newpos;
+
+ int actual_pos = shown_prompt.Length + TextToRenderPos (cursor);
+ int row = home_row + (actual_pos/Console.WindowWidth);
+ int col = actual_pos % Console.WindowWidth;
+
+ if (row >= Console.BufferHeight)
+ row = Console.BufferHeight-1;
+ Console.SetCursorPosition (col, row);
+
+ //log.WriteLine ("Going to cursor={0} row={1} col={2} actual={3} prompt={4} ttr={5} old={6}", newpos, row, col, actual_pos, prompt.Length, TextToRenderPos (cursor), cursor);
+ //log.Flush ();
+ }
+
+ void UpdateCursor (int newpos)
+ {
+ if (cursor == newpos)
+ return;
+
+ ForceCursor (newpos);
+ }
+
+ void InsertChar (char c)
+ {
+ int prev_lines = LineCount;
+ text = text.Insert (cursor, c);
+ ComputeRendered ();
+ if (prev_lines != LineCount){
+
+ Console.SetCursorPosition (0, home_row);
+ Render ();
+ ForceCursor (++cursor);
+ } else {
+ RenderFrom (cursor);
+ ForceCursor (++cursor);
+ UpdateHomeRow (TextToScreenPos (cursor));
+ }
+ }
+
+ //
+ // Commands
+ //
+ void CmdDone ()
+ {
+ done = true;
+ }
+
+ void CmdTabOrComplete ()
+ {
+ bool complete = false;
+
+ if (AutoCompleteEvent != null){
+ if (TabAtStartCompletes)
+ complete = true;
+ else {
+ for (int i = 0; i < cursor; i++){
+ if (!Char.IsWhiteSpace (text [i])){
+ complete = true;
+ break;
+ }
+ }
+ }
+
+ if (complete){
+ Completion completion = AutoCompleteEvent (text.ToString (), cursor);
+ string [] completions = completion.Result;
+ if (completions == null)
+ return;
+
+ int ncompletions = completions.Length;
+ if (ncompletions == 0)
+ return;
+
+ if (completions.Length == 1){
+ InsertTextAtCursor (completions [0]);
+ } else {
+ int last = -1;
+
+ for (int p = 0; p < completions [0].Length; p++){
+ char c = completions [0][p];
+
+
+ for (int i = 1; i < ncompletions; i++){
+ if (completions [i].Length < p)
+ goto mismatch;
+
+ if (completions [i][p] != c){
+ goto mismatch;
+ }
+ }
+ last = p;
+ }
+ mismatch:
+ if (last != -1){
+ InsertTextAtCursor (completions [0].Substring (0, last+1));
+ }
+ Console.WriteLine ();
+ foreach (string s in completions){
+ Console.Write (completion.Prefix);
+ Console.Write (s);
+ Console.Write (' ');
+ }
+ Console.WriteLine ();
+ Render ();
+ ForceCursor (cursor);
+ }
+ } else
+ HandleChar ('\t');
+ } else
+ HandleChar ('t');
+ }
+
+ void CmdHome ()
+ {
+ UpdateCursor (0);
+ }
+
+ void CmdEnd ()
+ {
+ UpdateCursor (text.Length);
+ }
+
+ void CmdLeft ()
+ {
+ if (cursor == 0)
+ return;
+
+ UpdateCursor (cursor-1);
+ }
+
+ void CmdBackwardWord ()
+ {
+ int p = WordBackward (cursor);
+ if (p == -1)
+ return;
+ UpdateCursor (p);
+ }
+
+ void CmdForwardWord ()
+ {
+ int p = WordForward (cursor);
+ if (p == -1)
+ return;
+ UpdateCursor (p);
+ }
+
+ void CmdRight ()
+ {
+ if (cursor == text.Length)
+ return;
+
+ UpdateCursor (cursor+1);
+ }
+
+ void RenderAfter (int p)
+ {
+ ForceCursor (p);
+ RenderFrom (p);
+ ForceCursor (cursor);
+ }
+
+ void CmdBackspace ()
+ {
+ if (cursor == 0)
+ return;
+
+ text.Remove (--cursor, 1);
+ ComputeRendered ();
+ RenderAfter (cursor);
+ }
+
+ void CmdDeleteChar ()
+ {
+ // If there is no input, this behaves like EOF
+ if (text.Length == 0){
+ done = true;
+ text = null;
+ Console.WriteLine ();
+ return;
+ }
+
+ if (cursor == text.Length)
+ return;
+ text.Remove (cursor, 1);
+ ComputeRendered ();
+ RenderAfter (cursor);
+ }
+
+ int WordForward (int p)
+ {
+ if (p >= text.Length)
+ return -1;
+
+ int i = p;
+ if (Char.IsPunctuation (text [p]) || Char.IsSymbol (text [p]) || Char.IsWhiteSpace (text[p])){
+ for (; i < text.Length; i++){
+ if (Char.IsLetterOrDigit (text [i]))
+ break;
+ }
+ for (; i < text.Length; i++){
+ if (!Char.IsLetterOrDigit (text [i]))
+ break;
+ }
+ } else {
+ for (; i < text.Length; i++){
+ if (!Char.IsLetterOrDigit (text [i]))
+ break;
+ }
+ }
+ if (i != p)
+ return i;
+ return -1;
+ }
+
+ int WordBackward (int p)
+ {
+ if (p == 0)
+ return -1;
+
+ int i = p-1;
+ if (i == 0)
+ return 0;
+
+ if (Char.IsPunctuation (text [i]) || Char.IsSymbol (text [i]) || Char.IsWhiteSpace (text[i])){
+ for (; i >= 0; i--){
+ if (Char.IsLetterOrDigit (text [i]))
+ break;
+ }
+ for (; i >= 0; i--){
+ if (!Char.IsLetterOrDigit (text[i]))
+ break;
+ }
+ } else {
+ for (; i >= 0; i--){
+ if (!Char.IsLetterOrDigit (text [i]))
+ break;
+ }
+ }
+ i++;
+
+ if (i != p)
+ return i;
+
+ return -1;
+ }
+
+ void CmdDeleteWord ()
+ {
+ int pos = WordForward (cursor);
+
+ if (pos == -1)
+ return;
+
+ string k = text.ToString (cursor, pos-cursor);
+
+ if (last_handler == CmdDeleteWord)
+ kill_buffer = kill_buffer + k;
+ else
+ kill_buffer = k;
+
+ text.Remove (cursor, pos-cursor);
+ ComputeRendered ();
+ RenderAfter (cursor);
+ }
+
+ void CmdDeleteBackword ()
+ {
+ int pos = WordBackward (cursor);
+ if (pos == -1)
+ return;
+
+ string k = text.ToString (pos, cursor-pos);
+
+ if (last_handler == CmdDeleteBackword)
+ kill_buffer = k + kill_buffer;
+ else
+ kill_buffer = k;
+
+ text.Remove (pos, cursor-pos);
+ ComputeRendered ();
+ RenderAfter (pos);
+ }
+
+ //
+ // Adds the current line to the history if needed
+ //
+ void HistoryUpdateLine ()
+ {
+ history.Update (text.ToString ());
+ }
+
+ void CmdHistoryPrev ()
+ {
+ if (!history.PreviousAvailable ())
+ return;
+
+ HistoryUpdateLine ();
+
+ SetText (history.Previous ());
+ }
+
+ void CmdHistoryNext ()
+ {
+ if (!history.NextAvailable())
+ return;
+
+ history.Update (text.ToString ());
+ SetText (history.Next ());
+
+ }
+
+ void CmdKillToEOF ()
+ {
+ kill_buffer = text.ToString (cursor, text.Length-cursor);
+ text.Length = cursor;
+ ComputeRendered ();
+ RenderAfter (cursor);
+ }
+
+ void CmdYank ()
+ {
+ InsertTextAtCursor (kill_buffer);
+ }
+
+ void InsertTextAtCursor (string str)
+ {
+ int prev_lines = LineCount;
+ text.Insert (cursor, str);
+ ComputeRendered ();
+ if (prev_lines != LineCount){
+ Console.SetCursorPosition (0, home_row);
+ Render ();
+ cursor += str.Length;
+ ForceCursor (cursor);
+ } else {
+ RenderFrom (cursor);
+ cursor += str.Length;
+ ForceCursor (cursor);
+ UpdateHomeRow (TextToScreenPos (cursor));
+ }
+ }
+
+ void SetSearchPrompt (string s)
+ {
+ SetPrompt ("(reverse-i-search)`" + s + "': ");
+ }
+
+ void ReverseSearch ()
+ {
+ int p;
+
+ if (cursor == text.Length){
+ // The cursor is at the end of the string
+
+ p = text.ToString ().LastIndexOf (search);
+ if (p != -1){
+ match_at = p;
+ cursor = p;
+ ForceCursor (cursor);
+ return;
+ }
+ } else {
+ // The cursor is somewhere in the middle of the string
+ int start = (cursor == match_at) ? cursor - 1 : cursor;
+ if (start != -1){
+ p = text.ToString ().LastIndexOf (search, start);
+ if (p != -1){
+ match_at = p;
+ cursor = p;
+ ForceCursor (cursor);
+ return;
+ }
+ }
+ }
+
+ // Need to search backwards in history
+ HistoryUpdateLine ();
+ string s = history.SearchBackward (search);
+ if (s != null){
+ match_at = -1;
+ SetText (s);
+ ReverseSearch ();
+ }
+ }
+
+ void CmdReverseSearch ()
+ {
+ if (searching == 0){
+ match_at = -1;
+ last_search = search;
+ searching = -1;
+ search = "";
+ SetSearchPrompt ("");
+ } else {
+ if (search == ""){
+ if (last_search != "" && last_search != null){
+ search = last_search;
+ SetSearchPrompt (search);
+
+ ReverseSearch ();
+ }
+ return;
+ }
+ ReverseSearch ();
+ }
+ }
+
+ void SearchAppend (char c)
+ {
+ search = search + c;
+ SetSearchPrompt (search);
+
+ //
+ // If the new typed data still matches the current text, stay here
+ //
+ if (cursor < text.Length){
+ string r = text.ToString (cursor, text.Length - cursor);
+ if (r.StartsWith (search))
+ return;
+ }
+
+ ReverseSearch ();
+ }
+
+ void CmdRefresh ()
+ {
+ Console.Clear ();
+ max_rendered = 0;
+ Render ();
+ ForceCursor (cursor);
+ }
+
+ void InterruptEdit (object sender, ConsoleCancelEventArgs a)
+ {
+ // Do not abort our program:
+ a.Cancel = true;
+
+ // Interrupt the editor
+ edit_thread.Abort();
+ }
+
+ void HandleChar (char c)
+ {
+ if (searching != 0)
+ SearchAppend (c);
+ else
+ InsertChar (c);
+ }
+
+ void EditLoop ()
+ {
+ ConsoleKeyInfo cki;
+
+ while (!done){
+ ConsoleModifiers mod;
+
+ cki = Console.ReadKey (true);
+ if (cki.Key == ConsoleKey.Escape){
+ cki = Console.ReadKey (true);
+
+ mod = ConsoleModifiers.Alt;
+ } else
+ mod = cki.Modifiers;
+
+ bool handled = false;
+
+ foreach (Handler handler in handlers){
+ ConsoleKeyInfo t = handler.CKI;
+
+ if (t.Key == cki.Key && t.Modifiers == mod){
+ handled = true;
+ handler.KeyHandler ();
+ last_handler = handler.KeyHandler;
+ break;
+ } else if (t.KeyChar == cki.KeyChar && t.Key == ConsoleKey.Zoom){
+ handled = true;
+ handler.KeyHandler ();
+ last_handler = handler.KeyHandler;
+ break;
+ }
+ }
+ if (handled){
+ if (searching != 0){
+ if (last_handler != CmdReverseSearch){
+ searching = 0;
+ SetPrompt (prompt);
+ }
+ }
+ continue;
+ }
+
+ if (cki.KeyChar != (char) 0)
+ HandleChar (cki.KeyChar);
+ }
+ }
+
+ void InitText (string initial)
+ {
+ text = new StringBuilder (initial);
+ ComputeRendered ();
+ cursor = text.Length;
+ Render ();
+ ForceCursor (cursor);
+ }
+
+ void SetText (string newtext)
+ {
+ Console.SetCursorPosition (0, home_row);
+ InitText (newtext);
+ }
+
+ void SetPrompt (string newprompt)
+ {
+ shown_prompt = newprompt;
+ Console.SetCursorPosition (0, home_row);
+ Render ();
+ ForceCursor (cursor);
+ }
+
+ public string Edit (string prompt, string initial)
+ {
+ edit_thread = Thread.CurrentThread;
+ searching = 0;
+ Console.CancelKeyPress += InterruptEdit;
+
+ done = false;
+ history.CursorToEnd ();
+ max_rendered = 0;
+
+ Prompt = prompt;
+ shown_prompt = prompt;
+ InitText (initial);
+ history.Append (initial);
+
+ do {
+ try {
+ EditLoop ();
+ } catch (ThreadAbortException){
+ searching = 0;
+ Thread.ResetAbort ();
+ Console.WriteLine ();
+ SetPrompt (prompt);
+ SetText ("");
+ }
+ } while (!done);
+ Console.WriteLine ();
+
+ Console.CancelKeyPress -= InterruptEdit;
+
+ if (text == null){
+ history.Close ();
+ return null;
+ }
+
+ string result = text.ToString ();
+ if (result != "")
+ history.Accept (result);
+ else
+ history.RemoveLast ();
+
+ return result;
+ }
+
+ public void SaveHistory ()
+ {
+ if (history != null) {
+ history.Close ();
+ }
+ }
+
+ public bool TabAtStartCompletes { get; set; }
+
+ //
+ // Emulates the bash-like behavior, where edits done to the
+ // history are recorded
+ //
+ class History {
+ string [] history;
+ int head, tail;
+ int cursor, count;
+ string histfile;
+
+ public History (string app, int size)
+ {
+ if (size < 1)
+ throw new ArgumentException ("size");
+
+ if (app != null){
+ string dir = Environment.GetFolderPath (Environment.SpecialFolder.ApplicationData);
+ //Console.WriteLine (dir);
+ if (!Directory.Exists (dir)){
+ try {
+ Directory.CreateDirectory (dir);
+ } catch {
+ app = null;
+ }
+ }
+ if (app != null)
+ histfile = Path.Combine (dir, app) + ".history";
+ }
+
+ history = new string [size];
+ head = tail = cursor = 0;
+
+ if (File.Exists (histfile)){
+ using (StreamReader sr = File.OpenText (histfile)){
+ string line;
+
+ while ((line = sr.ReadLine ()) != null){
+ if (line != "")
+ Append (line);
+ }
+ }
+ }
+ }
+
+ public void Close ()
+ {
+ if (histfile == null)
+ return;
+
+ try {
+ using (StreamWriter sw = File.CreateText (histfile)){
+ int start = (count == history.Length) ? head : tail;
+ for (int i = start; i < start+count; i++){
+ int p = i % history.Length;
+ sw.WriteLine (history [p]);
+ }
+ }
+ } catch {
+ // ignore
+ }
+ }
+
+ //
+ // Appends a value to the history
+ //
+ public void Append (string s)
+ {
+ //Console.WriteLine ("APPENDING {0} head={1} tail={2}", s, head, tail);
+ history [head] = s;
+ head = (head+1) % history.Length;
+ if (head == tail)
+ tail = (tail+1 % history.Length);
+ if (count != history.Length)
+ count++;
+ //Console.WriteLine ("DONE: head={1} tail={2}", s, head, tail);
+ }
+
+ //
+ // Updates the current cursor location with the string,
+ // to support editing of history items. For the current
+ // line to participate, an Append must be done before.
+ //
+ public void Update (string s)
+ {
+ history [cursor] = s;
+ }
+
+ public void RemoveLast ()
+ {
+ head = head-1;
+ if (head < 0)
+ head = history.Length-1;
+ }
+
+ public void Accept (string s)
+ {
+ int t = head-1;
+ if (t < 0)
+ t = history.Length-1;
+
+ history [t] = s;
+ }
+
+ public bool PreviousAvailable ()
+ {
+ //Console.WriteLine ("h={0} t={1} cursor={2}", head, tail, cursor);
+ if (count == 0)
+ return false;
+ int next = cursor-1;
+ if (next < 0)
+ next = count-1;
+
+ if (next == head)
+ return false;
+
+ return true;
+ }
+
+ public bool NextAvailable ()
+ {
+ if (count == 0)
+ return false;
+ int next = (cursor + 1) % history.Length;
+ if (next == head)
+ return false;
+ return true;
+ }
+
+
+ //
+ // Returns: a string with the previous line contents, or
+ // nul if there is no data in the history to move to.
+ //
+ public string Previous ()
+ {
+ if (!PreviousAvailable ())
+ return null;
+
+ cursor--;
+ if (cursor < 0)
+ cursor = history.Length - 1;
+
+ return history [cursor];
+ }
+
+ public string Next ()
+ {
+ if (!NextAvailable ())
+ return null;
+
+ cursor = (cursor + 1) % history.Length;
+ return history [cursor];
+ }
+
+ public void CursorToEnd ()
+ {
+ if (head == tail)
+ return;
+
+ cursor = head;
+ }
+
+ public void Dump ()
+ {
+ Console.WriteLine ("Head={0} Tail={1} Cursor={2} count={3}", head, tail, cursor, count);
+ for (int i = 0; i < history.Length;i++){
+ Console.WriteLine (" {0} {1}: {2}", i == cursor ? "==>" : " ", i, history[i]);
+ }
+ //log.Flush ();
+ }
+
+ public string SearchBackward (string term)
+ {
+ for (int i = 0; i < count; i++){
+ int slot = cursor-i-1;
+ if (slot < 0)
+ slot = history.Length+slot;
+ if (slot >= history.Length)
+ slot = 0;
+ if (history [slot] != null && history [slot].IndexOf (term) != -1){
+ cursor = slot;
+ return history [slot];
+ }
+ }
+
+ return null;
+ }
+
+ }
+ }
+
+#if DEMO
+ class Demo {
+ static void Main ()
+ {
+ LineEditor le = new LineEditor ("foo");
+ string s;
+
+ while ((s = le.Edit ("shell> ", "")) != null){
+ Console.WriteLine ("----> [{0}]", s);
+ }
+ }
+ }
+#endif
+}
HCoop / jackhill / mal.git / commitdiff