Is there a way to get caret position?

[maraf]

I'm building an application that opens a small window next to caret, and so I need to find a position of the caret.

In some applications, using IAccessible.accLocation provides good results.
In other ones, using IUIAutomationTextPattern or IUIAutomationTextPattern2 provides good results.
Sometimes Win32 GetCaretPos works great.

None of these seem to be working for Terminal.
Is there a way to get caret position?

[maraf]

I have a progress. I'm able to get a IUIAutomationTextPattern, but still can't get the caret position.

(the code assumes that terminal has focus)

var automation = new CUIAutomation();
var element = automation.GetFocusedElement();
var pattern = (IUIAutomationTextPattern)element.GetCurrentPattern(10014);
if (pattern != null)
{
    var selectons = pattern.GetSelection();
    if (selectons.Length > 0)
    {
        var selection = selectons.GetElement(0);
        var bounds = selection.GetBoundingRectangles();
        // bounds is an empty array 👈
    }
}

Is this a good path? Should it work? Or am I missing something?

[j4james]

I haven't played with the UIAutomation functionality myself, but just based on what I've seen of the implementation in the Windows Terminal source, I think you're on the right track. As far as I can see, IUIAutomationTextPattern2 is not supported, so GetCaretRange isn't an option, but GetSelection should return the cursor position when nothing else is selected. See here:

terminal/src/types/ScreenInfoUiaProviderBase.cpp

Lines 237 to 243 in 4d9a266

	WRL::ComPtr<UiaTextRangeBase> range;
	if (!_pData->IsSelectionActive())
	{
	// return a degenerate range at the cursor position
	const auto& cursor = _getTextBuffer().GetCursor();
	hr = CreateTextRange(this, cursor, _wordDelimiters, &range);
	}

I think your problem is that the returned selection is then going to be zero width, so that would explain why there are no bounding rectangles. And this is a wild guess, but you could try using ExpandToEnclosingUnit to normalize the range to one character unit, and then see what GetBoundingRectangles returns.

Otherwise, I've also seen some people saying you can use CompareEndpoints to compare the range against something like the document range, and that'll give you an offset into the document. However, I don't think that's guaranteed to work, and you've still then got to figure out the 2D coordinates from that somehow.

[maraf]

👏 Thank you! The ExpandToEnclosingUnit made the trick. Now bounds contain cursor position.
If post it as a separate answer, I can mark as THE answer to get you kudos 🙂

[j4james]

To summarise what we've established in the other threads:

1. Windows Terminal doesn't support IUIAutomationTextPattern2, but the GetSelection method from IUIAutomationTextPattern should return the caret position when nothing else is selected.
2. However, that returned selection will have a zero width, so you'll then need to call ExpandToEnclosingUnit to normalize the range to one character unit.
3. Once the range has a non-zero width, you can call GetBoundingRectangles to obtain the boundaries, and that should give you the position you're looking for.