tauri-plugin-desktop-underlay 0.2.1

Tauri plugin for attaching a window to desktop, below icons and above wallpaper.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

use anyhow::{Result, bail};
use windows::Win32::Foundation::{HWND, LPARAM, WPARAM};
use windows::Win32::UI::WindowsAndMessaging::{
    EnumWindows, FindWindowA, FindWindowExA, SMTO_NORMAL, SendMessageTimeoutA, SetParent,
};
use windows::core::{BOOL, s};

/// Helper function to find the WorkerW window.
unsafe extern "system" fn enum_window(window: HWND, ref_worker_w: LPARAM) -> BOOL {
    unsafe {
        let shell_dll_def_view =
            FindWindowExA(Some(window), None, s!("SHELLDLL_DefView"), None).unwrap_or_default();
        if HWND::is_invalid(&shell_dll_def_view) {
            return true.into();
        }

        let worker_w = FindWindowExA(None, Some(window), s!("WorkerW"), None).unwrap_or_default();
        if HWND::is_invalid(&worker_w) {
            return true.into();
        }

        *(ref_worker_w.0 as *mut HWND) = worker_w;
        true.into()
    }
}

/// Set the window as a desktop underlay.
pub(super) unsafe fn set_underlay(hwnd: HWND) -> Result<()> {
    unsafe {
        let progman = FindWindowA(s!("Progman"), None)?;
        SendMessageTimeoutA(
            progman,
            0x052C,
            WPARAM(0x0000000D),
            LPARAM(0x00000001),
            SMTO_NORMAL,
            1000,
            None,
        );

        let mut worker_w = HWND::default();
        EnumWindows(Some(enum_window), LPARAM(&mut worker_w as *mut HWND as _))?;
        if HWND::is_invalid(&worker_w) {
            worker_w = FindWindowExA(Some(progman), None, s!("WorkerW"), None)?;
            if HWND::is_invalid(&worker_w) {
                bail!("Failed to find WorkerW");
            }
        }

        SetParent(hwnd, Some(worker_w))?;
        Ok(())
    }
}

/// Unset the window from being a desktop underlay.
pub(super) unsafe fn unset_underlay(hwnd: HWND) -> Result<()> {
    unsafe {
        SetParent(hwnd, None)?;
        Ok(())
    }
}