[IME] The CandidateWindow seems placed not correctly in Windows

[realybin]

Describe the bug

The CandidateWindow's top is not aligned to the caret pos

To Reproduce

<TextBox/>

Use Chinese Pinyin Input Method and type in it

Expected behavior

Could be same as most of major UI frameworks

Avalonia version

11.x

OS

Windows

Additional context

-- ptCurrentPos = new POINT {X = x2, Y = y2}
++ ptCurrentPos = new POINT {X = x2, Y = (int)((rect.Top + rect.Bottom)/2 * s) }

The Y might be incorrect, I tried to adjust(see the image), it's looks good but I think that's may not the solution. (Scale changed to 250% for test it's accuracy)

Avalonia/src/Windows/Avalonia.Win32/Input/Imm32InputMethod.cs

Line 229 in 73d7579

ptCurrentPos = new POINT {X = x2, Y = y2}

[Gillibald]

ptCurrentPos = new POINT {X = x2, Y = Math.Max(0, y2 - y1) / 2} seems to be the correct fix

[realybin]

ptCurrentPos = new POINT {X = x2, Y = Math.Max(0, y2 - y1) / 2} seems to be the correct fix

250% Scaling

Seems not aligned

[Gillibald]

I have no idea why the scaling is breaking the candidate window position. This is only happening with PinYin IME

[realybin]

1. sougousrfa 搜狗输入法
2. Microsoft Pinyin 微软拼音
3. Microsoft Pinyin 微软拼音 (Legacy version for compatibility)
4. WeType 微信输入法

I have read many documents and finally bring a possible solution with out hacks and looks good in all scaling and most of popular Chinese IMEs

I only changed the loginc in the part of PinYin IME and make it works

[realybin]

https://github.com/chromium/chromium/blame/0fff454fdc718cb0253e04e7cb1d74ff939f3bc7/ui/base/win/ime_input.cc#L190

I think the original source code might outdated (committed 17 years ago).

We might need to re-inspect what the Pinyin IME can be now.

[Gillibald]

If your changes make things work please provide a PR

[realybin]

If your changes make things work please provide a PR

Thank you, I am trying to test it on Windows 7 with Classic IMEs and other version of Windows