/// <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);
}
}
