Unify pane splitting and new tab creation

[DHowett]

In my eyes, spawning a new tab is a special case of splitting a nonexistent window into one pane.

Right now, we have a lot of divergence between opening a tab (1) and opening a pane (2); in both cases we spawn a new control, but the way it gets propagated into the tree is vastly different. The same applies for duplicating an active pane; the code in pane splitting suggests that duplicating a pane keeps the working directory but a tab does not (!) (see 3) EDIT: No, we accounted for it. Double the code, double the places to look 😉

1

terminal/src/cascadia/TerminalApp/TabManagement.cpp

Lines 242 to 272 in 10992b7

	auto connection = existingConnection ? existingConnection : _CreateConnectionFromSettings(profile, settings.DefaultSettings());
	// If we had an `existingConnection`, then this is an inbound handoff from somewhere else.
	// We need to tell it about our size information so it can match the dimensions of what
	// we are about to present.
	if (existingConnection)
	{
	connection.Resize(settings.DefaultSettings().InitialRows(), settings.DefaultSettings().InitialCols());
	}
	TerminalConnection::ITerminalConnection debugConnection{ nullptr };
	if (_settings.GlobalSettings().DebugFeaturesEnabled())
	{
	const CoreWindow window = CoreWindow::GetForCurrentThread();
	const auto rAltState = window.GetKeyState(VirtualKey::RightMenu);
	const auto lAltState = window.GetKeyState(VirtualKey::LeftMenu);
	const bool bothAltsPressed = WI_IsFlagSet(lAltState, CoreVirtualKeyStates::Down) &&
	WI_IsFlagSet(rAltState, CoreVirtualKeyStates::Down);
	if (bothAltsPressed)
	{
	std::tie(connection, debugConnection) = OpenDebugTapConnection(connection);
	}
	}
	// Give term control a child of the settings so that any overrides go in the child
	// This way, when we do a settings reload we just update the parent and the overrides remain
	auto term = _InitControl(settings, connection);
	auto newTabImpl = winrt::make_self<TerminalTab>(profile, term);
	_RegisterTerminalEvents(term);
	_InitializeTab(newTabImpl);

2

terminal/src/cascadia/TerminalApp/TerminalPage.cpp

Lines 1391 to 1416 in 10992b7

	const auto controlConnection = _CreateConnectionFromSettings(profile, controlSettings.DefaultSettings());
	const float contentWidth = ::base::saturated_cast<float>(_tabContent.ActualWidth());
	const float contentHeight = ::base::saturated_cast<float>(_tabContent.ActualHeight());
	const winrt::Windows::Foundation::Size availableSpace{ contentWidth, contentHeight };
	auto realSplitType = splitType;
	if (realSplitType == SplitState::Automatic)
	{
	realSplitType = tab.PreCalculateAutoSplit(availableSpace);
	}
	const auto canSplit = tab.PreCalculateCanSplit(realSplitType, splitSize, availableSpace);
	if (!canSplit)
	{
	return;
	}
	auto newControl = _InitControl(controlSettings, controlConnection);
	// Hookup our event handlers to the new terminal
	_RegisterTerminalEvents(newControl);
	_UnZoomIfNeeded();
	tab.SplitPane(realSplitType, splitSize, profile, newControl);

Collapsed note 3

3

terminal/src/cascadia/TerminalApp/TerminalPage.cpp

Lines 1359 to 1370 in 10992b7

	if (splitMode == SplitType::Duplicate)
	{
	profile = tab.GetFocusedProfile();
	if (profile)
	{
	controlSettings = TerminalSettings::CreateWithProfile(_settings, profile, *_bindings);
	const auto workingDirectory = tab.GetActiveTerminalControl().WorkingDirectory();
	const auto validWorkingDirectory = !workingDirectory.empty();
	if (validWorkingDirectory)
	{
	controlSettings.DefaultSettings().StartingDirectory(workingDirectory);
	}

[DHowett]

/cc @PankajBhojwani you did some of the work here to make control initialization uniform, but this is the "farther step" i was talking about. You don't need to do this; it's just an FYI. 😄

[PankajBhojwani]

Ah I like this

[zadjii-msft]

I've meant to do this for so long. The TabManagement.cpp PR really highlighted how bad this one is

[Rosefield]

The CreateNewTabFromPane function that I added as part of move pane to tab could probably be used for this. If you look at _SplitPane, you create the profile/control, then in one branch you do the PreCalculate* and then tab.SplitPane and on the other you just CreateNewTabFromPane. That should get you most of the way there, I think. Internally Pane::Split is effectively just auto pane = std::make_shared<Pane>; _Split(pane) so that could just be modified to take a pane directly instead of passing the control/profile down.