/// <summary>
/// Get the newest copy of the screen buffer once, for use in all calculations for a while.
/// This was added when telnet clients were added. The execution cost of obtaining a buffer snapshot
/// from the ScreenBuffer class is non-trivial, and therefore shouldn't be done over and over
/// for each telnet client that needs it within the span of a short time. This gets it
/// once for all of them to borrow. All calls will re-use this copy for a while,
/// until the next terminal refresh (1/20th of a second, at the moment).
/// </summary>
void GetNewestBuffer()
{
DateTime newTime = DateTime.Now;
// Throttle it back so the faster Update() rates don't cause pointlessly repeated work:
// Needs to be no faster than the fastest theoretical typist or script might change the view.
if (newTime > lastBufferGet + TimeSpan.FromMilliseconds(50)) // = 1/20th second.
{
mostRecentScreen = new ScreenSnapShot(shared.Screen);
lastBufferGet = newTime;
}
}
//Printing
public void GetNewestBuffer()
{
DateTime newTime = DateTime.Now;
// Throttle it back so the faster Update() rates don't cause pointlessly repeated work:
// Needs to be no faster than the fastest theoretical typist or script might change the view.
if (newTime > lastBufferGet + TimeSpan.FromMilliseconds(50)) // = 1/20th second.
{
mostRecentScreen = new ScreenSnapShot(processor_shares[current_processor_id].Screen);
lastBufferGet = newTime;
}
}
void GetNewestBuffer()
{
mostRecentScreen = new ScreenSnapShot(processor_shares[current_processor_id].Screen);
}
/// <summary>
/// Get a list of the operations that would make a terminal window look like this snapshot
/// if you assume that beforehand it looked like the older snapshot you pass in.
/// </summary>
/// <param name="older">the older snapshot of a screen to diff from</param>
/// <returns>the string that if output in order, will give you the desired changes</returns>
public string DiffFrom(IScreenSnapShot older)
{
StringBuilder output = new StringBuilder();
int verticalScroll = TopRow - older.TopRow;
int trackCursorColumn = older.CursorColumn; // track the movements that will occur as the outputs happen.
int trackCursorRow = older.CursorRow; // track the movements that will occur as the outputs happen.
// First, output the command to make the terminal scroll to match:
if (verticalScroll > 0) // scrolling text up (eyeballs panning down)
output.Append(new String((char)UnicodeCommand.SCROLLSCREENUPONE, verticalScroll)); // A run of scrollup chars
else if (verticalScroll < 0) // scrolling text down (eyeballs panning up)
output.Append(new String((char)UnicodeCommand.SCROLLSCREENDOWNONE, -verticalScroll)); // A run of scrolldown chars
// Check each row:
for (int newRowNum = 0 ; newRowNum < RowCount ; ++newRowNum)
{
// Account for the diff due to the scrolling:
int oldRowNum = newRowNum + verticalScroll;
IScreenBufferLine newRow = Buffer[newRowNum];
bool oldRowExists = (oldRowNum >= 0 && oldRowNum < older.Buffer.Count);
IScreenBufferLine olderRow = oldRowExists ? older.Buffer[oldRowNum] : new ScreenBufferLine(0);
// if new row is an empty dummy, then pad it out so it gets properly diffed against the old row:
if (newRow.Length == 0)
newRow = new ScreenBufferLine(olderRow.Length);
// If the old row is a dummy pad or if the new row is newer than the old row, then it needs checking for diffs:
if (olderRow.Length == 0 || newRow.LastChangeTick > olderRow.LastChangeTick)
{
List<DiffChunk> diffs = new List<DiffChunk>();
for (int newCol = 0 ; newCol < newRow.Length ; ++newCol)
{
// Check if they differ, but in a way that treats ' ' and 0x00 as identical, and treats a shorter
// old row as if it has been padded with spaces:
bool oldRowTooShort = newCol >= olderRow.Length;
char newChar = (newRow[newCol] == '\0' ? ' ' : newRow[newCol]);
char oldChar = (oldRowTooShort ? ' ' : (olderRow[newCol] == '\0' ? ' ' : olderRow[newCol]));
if (newChar != oldChar)
{
// Start a new diff chunk if there isn't one yet, or the diff is a long enough distance from the existing one:
if (diffs.Count == 0 || diffs[diffs.Count-1].EndCol < newCol - JOIN_DIFF_DIST)
{
DiffChunk newChunk = new DiffChunk
{
StartCol = newCol,
EndCol = newCol
};
diffs.Add(newChunk);
}
else // stretch the existing diff chunk to here.
{
diffs[diffs.Count-1].EndCol = newCol;
}
}
}
string newRowText = newRow.ToString();
foreach (DiffChunk diff in diffs)
{
/* comment-out -----------------
// If we're lucky enough that the current cursor happens to be right where we need it to
// be, some of these are more efficient. Else it does TELEPORTCURSOR's:
// Just one char removed to the left of current cursor pos - do a backspace instead of the ugly work:
if (trackCursorRow == newRowNum && (diff.EndCol == trackCursorColumn - 1 && diff.StartCol == diff.EndCol))
{
output.Append(String.Format("{0}{1}{2}", (char)0x08, newRowText.Substring(diff.StartCol,1), (char)0x08));
trackCursorColumn = diff.EndCol;
trackCursorRow = newRowNum;
}
else
{
--------------------------- */
// If the change starts right where the cursor happens to be (i.e. when typing, one char
// at current cursor position will typically be the only diff from one update to the next),
// then don't bother moving the cursor first, else move it to the new pos:
string moveString;
if (trackCursorRow == newRowNum && diff.StartCol == trackCursorColumn)
moveString = "";
else
moveString = String.Format("{0}{1}{2}",
(char)UnicodeCommand.TELEPORTCURSOR,
(char)diff.StartCol,
(char)newRowNum);
// content = the bit of string to print at this location, with nulls made into spaces so the
// telnet terminal will print correctly.
string content = newRowText.Substring(diff.StartCol, diff.EndCol - diff.StartCol + 1).Replace('\0',' ');
output.Append(String.Format("{0}{1}", moveString, content));
trackCursorColumn = diff.EndCol+1;
trackCursorRow = newRowNum;
/* comment-out -----------------
}
--------------------------- */
}
}
}
// Now set the cursor back to the right spot one more time, unless it's already there:
if (trackCursorRow != CursorRow || trackCursorColumn != CursorColumn)
{
output.Append(String.Format("{0}{1}{2}",
(char)UnicodeCommand.TELEPORTCURSOR,
(char)CursorColumn,
(char)CursorRow));
}
return output.ToString();
}
/// <summary>
/// Get a list of the operations that would make a terminal window look like this snapshot
/// if you assume that beforehand it looked like the older snapshot you pass in.
/// </summary>
/// <param name="older">the older snapshot of a screen to diff from</param>
/// <returns>the string that if output in order, will give you the desired changes</returns>
public string DiffFrom(IScreenSnapShot older)
{
StringBuilder output = new StringBuilder();
int verticalScroll = TopRow - older.TopRow;
int trackCursorColumn = older.CursorColumn; // track the movements that will occur as the outputs happen.
int trackCursorRow = older.CursorRow; // track the movements that will occur as the outputs happen.
// First, output the command to make the terminal scroll to match:
if (verticalScroll > 0) // scrolling text up (eyeballs panning down)
{
output.Append(new String((char)UnicodeCommand.SCROLLSCREENUPONE, verticalScroll)); // A run of scrollup chars
}
else if (verticalScroll < 0) // scrolling text down (eyeballs panning up)
{
output.Append(new String((char)UnicodeCommand.SCROLLSCREENDOWNONE, -verticalScroll)); // A run of scrolldown chars
}
// Check each row:
for (int newRowNum = 0; newRowNum < RowCount; ++newRowNum)
{
// Account for the diff due to the scrolling:
int oldRowNum = newRowNum + verticalScroll;
IScreenBufferLine newRow = Buffer[newRowNum];
bool oldRowExists = (oldRowNum >= 0 && oldRowNum < older.Buffer.Count);
IScreenBufferLine olderRow = oldRowExists ? older.Buffer[oldRowNum] : new ScreenBufferLine(0);
// if new row is an empty dummy, then pad it out so it gets properly diffed against the old row:
if (newRow.Length == 0)
{
newRow = new ScreenBufferLine(olderRow.Length);
}
// If the old row is a dummy pad or if the new row is newer than the old row, then it needs checking for diffs:
if (olderRow.Length == 0 || newRow.LastChangeTick > olderRow.LastChangeTick)
{
List <DiffChunk> diffs = new List <DiffChunk>();
for (int newCol = 0; newCol < newRow.Length; ++newCol)
{
// Check if they differ, but in a way that treats ' ' and 0x00 as identical, and treats a shorter
// old row as if it has been padded with spaces:
bool oldRowTooShort = newCol >= olderRow.Length;
char newChar = (newRow[newCol] == '\0' ? ' ' : newRow[newCol]);
char oldChar = (oldRowTooShort ? ' ' : (olderRow[newCol] == '\0' ? ' ' : olderRow[newCol]));
if (newChar != oldChar)
{
// Start a new diff chunk if there isn't one yet, or the diff is a long enough distance from the existing one:
if (diffs.Count == 0 || diffs[diffs.Count - 1].EndCol < newCol - JOIN_DIFF_DIST)
{
DiffChunk newChunk = new DiffChunk
{
StartCol = newCol,
EndCol = newCol
};
diffs.Add(newChunk);
}
else // stretch the existing diff chunk to here.
{
diffs[diffs.Count - 1].EndCol = newCol;
}
}
}
string newRowText = newRow.ToString();
foreach (DiffChunk diff in diffs)
{
/* comment-out -----------------
* // If we're lucky enough that the current cursor happens to be right where we need it to
* // be, some of these are more efficient. Else it does TELEPORTCURSOR's:
*
* // Just one char removed to the left of current cursor pos - do a backspace instead of the ugly work:
* if (trackCursorRow == newRowNum && (diff.EndCol == trackCursorColumn - 1 && diff.StartCol == diff.EndCol))
* {
* output.Append(String.Format("{0}{1}{2}", (char)0x08, newRowText.Substring(diff.StartCol,1), (char)0x08));
* trackCursorColumn = diff.EndCol;
* trackCursorRow = newRowNum;
* }
* else
* {
* --------------------------- */
// If the change starts right where the cursor happens to be (i.e. when typing, one char
// at current cursor position will typically be the only diff from one update to the next),
// then don't bother moving the cursor first, else move it to the new pos:
string moveString;
if (trackCursorRow == newRowNum && diff.StartCol == trackCursorColumn)
{
moveString = "";
}
else
{
moveString = String.Format("{0}{1}{2}",
(char)UnicodeCommand.TELEPORTCURSOR,
(char)diff.StartCol,
(char)newRowNum);
}
// content = the bit of string to print at this location, with nulls made into spaces so the
// telnet terminal will print correctly.
string content = newRowText.Substring(diff.StartCol, diff.EndCol - diff.StartCol + 1).Replace('\0', ' ');
output.Append(String.Format("{0}{1}", moveString, content));
trackCursorColumn = diff.EndCol + 1;
trackCursorRow = newRowNum;
/* comment-out -----------------
* }
* --------------------------- */
}
}
}
// Now set the cursor back to the right spot one more time, unless it's already there:
if (trackCursorRow != CursorRow || trackCursorColumn != CursorColumn)
{
output.Append(String.Format("{0}{1}{2}",
(char)UnicodeCommand.TELEPORTCURSOR,
(char)CursorColumn,
(char)CursorRow));
}
return(output.ToString());
}
