private void flushOutputBuffer()
{
// save the line currently pointed to by cursor,
// remove it from Console and write it back after the output buffer flush.
// this is done in order to avoid deletion of user input from console,
// in case user was in the middle of typing.
// it is assumed that user input spans at most one line in console.
bool restoreInputToConsoleFlag = false;
// cursor doesn't point to beginning of line, user might be in the middle of typing
if (!ConsoleIOUtils.IsCursorPointingToBeginningOfLine())
{
// clear the current console line (holding user input)
ConsoleGraphicsHandler.ClearConsoleInputLine();
// restore user input after flush
restoreInputToConsoleFlag = true;
}
// write all entries in output buffer to Console
// in insert order.
while (outputBuffer.Count > 0)
{
string outPutEntry = outputBuffer.Dequeue();
WriteOutput(outPutEntry);
}
// restore input
if (restoreInputToConsoleFlag)
{
writeInputToConsole();
}
}
/// <summary>
/// handles browsing key encapsulated by <paramref name="consoleKeyInfo"/>,
/// as defined by the browsing mechanism:
/// <see cref="ConsoleKey.UpArrow"/> displays less recent entries;
/// <see cref="ConsoleKey.DownArrow"/> displays more recent entries.
/// </summary>
/// <param name="consoleKeyInfo"></param>
private void handleBrowsingKey(ConsoleKeyInfo consoleKeyInfo)
{
// amount to increment / decrement index of currently selected input entry
int selectedEntryIndexIncrementAmount = 0;
if (consoleKeyInfo.Key == ConsoleKey.UpArrow)
{
selectedEntryIndexIncrementAmount = 1;
// start of browsing procedure
if (!browsingActive)
{
// push current user input to stack so it can be retrieved later
string userInput = consoleIOHandler.GetInputBufferContent();
recentInputEntries.Push(userInput);
// set browsing procedure state to active
browsingActive = true;
}
}
else // consoleKeyInfo.Key == ConsoleKey.DownArrow
{
selectedEntryIndexIncrementAmount = -1;
// top of recent input entry stack reached (back to original user input)
if (browsingActive && selectedEntryIndex == 0)
{
// pop original user input from stack
string originalUserInput = recentInputEntries.Pop();
// set browsing procedure state to inactive
browsingActive = false;
}
}
// still within stack bounds, top or bottom not yet reached
if (recentInputEntries.HasElementAt(
selectedEntryIndex + selectedEntryIndexIncrementAmount))
{
// increment selected input entry index
selectedEntryIndex += selectedEntryIndexIncrementAmount;
// get selected entry from stack
string selectedInputEntry =
recentInputEntries.ElementAt(selectedEntryIndex);
// overwrite current console input line
ConsoleGraphicsHandler.OverwriteInputLine(selectedInputEntry);
// overwrite input buffer
consoleIOHandler.FlushInputBuffer();
consoleIOHandler.appendToInputBuffer(selectedInputEntry);
}
}
private void readKeyIfAvailable()
{
ConsoleKeyInfo consoleKeyInfo = ConsoleIOUtils.ReadKey(out bool keyAvailable);
// key available in console input buffer
if (keyAvailable)
{
if (registerInput)
{
handleInputConsoleKey(consoleKeyInfo);
ConsoleGraphicsHandler.HandleInputKey(consoleKeyInfo);
}
else
{
// discard Console input
ConsoleIOUtils.ClearConsoleInputBuffer();
}
}
}
/// <summary>
/// writes output string <paramref name="str"/> to Console.
/// </summary>
/// <remarks>
/// default implementation writes <paramref name="output"/> string as-is to Console.
/// </remarks>
/// <seealso cref="System.Console.Write(string)"/>
/// <param name="output"></param>
protected virtual void WriteOutput(string output)
{
ConsoleGraphicsHandler.HandleOutput(output);
}
