Input Events on Win32 Child Windows

[softworkz]

Hi,

this is a follow-up to our discussion in my proposal here microsoft/microsoft-ui-xaml#10050 (comment). I'm replying here to avoid it getting side-tracked too much ;-)

Thanks at lot for pointing me at this sample. I had seen it before and didn't expect it to be working and it actually does work on Win11 and even with pointer input messages getting properly directed to the control.
I've been MS MVP for Windows API from 2003-2011 and thought I had tried everything. So, especially the outcome of further analysis has turned out to be quite surprising: It's all and only about the WS_EX_LAYERED window style.
(not about ATL, not about the AtlAxWin window class, not about the subclassing of the child window, etc.)

The underlying behavior is as follows

• Inside a XAML island window layering is generally ignored. Input events (keyboard, mouse, pointer) are being captured directly (without those messages going through any of the child windows' message loops)
• Except when there is a window (inside the XAML island), which has the WS_EX_LAYERED style and is above the DesktopChildSiteBridge window: For the area which is covered by this window, the internal input handling is disabled and and works like normal on Windows
• The WS_EX_LAYERED window itself doesn't play any other role:
  • The windows which you want to receive input do not need to be children of the WS_EX_LAYERED window
  • They can even be above it

Example:

The "Static" window has style WS_EX_LAYERED (and no content). It's sole existence causes the (hWnd-based) WebView2 to receive input events in the area it covers.

While I'm glad to have found a solution workaround eventually, there's one question remaining: "WTF Microsoft???" WS_EX_LAYERED has nothing to do with input handling (and really shouldn't).

[softworkz]

Thanks for having tested on Windows 11, because I only have Windows 10 (22H2) to do my tests, and everytime I ask people to test some code on other OS, they give up the thread 😕
(btw, I was also MVP SDK at same period,

❤️

but now I'm not even "P" anymore 😏 (I'm disabled : impossible to find a job in my country (France))

From looking at the things you are doing in these repos, you seem very "abled" to me 🚀!
Maybe rather look for remote jobs outside your country where personal presence is not a relevant matter anyway?

[castorix]

Maybe rather look for remote jobs outside your country where personal presence is not a relevant matter anyway?

But I'm not fluent in english, I can read/write but when I try to understand American/English people speaking, I have difficulty...

[softworkz]

But I'm not fluent in english, I can read/write but when I try to understand American/English people speaking, I have difficulty...

You should not overestimate or be afraid of voice communication. Companies who are hiring developers internationally don't want you for talking. That's very different from France or Germany (where I am from), especially at an advanced level where questions are rarely easy and immediately answerable. Of course it depends on the company, but as long as you're good in writing, it's usually fine. I had jobs where we never even spoke and in other cases there was just a single kind of introduction call.
At earlier times I had similar issues and sometimes still have, I always used to say it right away that I'm not great in talking, and it's never been a problem at all.