76 lines
2.3 KiB
Go
76 lines
2.3 KiB
Go
//go:build windows
|
|
|
|
package winapi
|
|
|
|
import (
|
|
"unsafe"
|
|
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
var (
|
|
user32 = windows.NewLazySystemDLL("user32.dll")
|
|
procGetWindowTextW = user32.NewProc("GetWindowTextW")
|
|
procShowWindow = user32.NewProc("ShowWindow")
|
|
)
|
|
|
|
// ForegroundWindow returns the current foreground window's handle (as a uintptr
|
|
// so platform-neutral callers need not import windows), its title, and its
|
|
// on-task class (process exe base name; see ClassFromImagePath). ok is false
|
|
// when GetForegroundWindow returns null, which happens transiently during focus
|
|
// changes and some secure-desktop transitions (UAC / lock screen).
|
|
func ForegroundWindow() (hwnd uintptr, title, class string, ok bool) {
|
|
h := windows.GetForegroundWindow()
|
|
if h == 0 {
|
|
return 0, "", "", false
|
|
}
|
|
return uintptr(h), windowTitle(h), windowClass(h), true
|
|
}
|
|
|
|
func windowTitle(h windows.HWND) string {
|
|
// 512 uint16s; titles over 511 chars are truncated — acceptable for a sensor tag.
|
|
const max = 512
|
|
buf := make([]uint16, max)
|
|
n, _, _ := procGetWindowTextW.Call(
|
|
uintptr(h),
|
|
uintptr(unsafe.Pointer(&buf[0])),
|
|
uintptr(max),
|
|
)
|
|
// n==0 covers both call failure and a genuinely empty title; both are fine here.
|
|
return windows.UTF16ToString(buf[:n])
|
|
}
|
|
|
|
func windowClass(h windows.HWND) string {
|
|
var pid uint32
|
|
if _, err := windows.GetWindowThreadProcessId(h, &pid); err != nil || pid == 0 {
|
|
return ""
|
|
}
|
|
proc, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, pid)
|
|
if err != nil {
|
|
return ""
|
|
}
|
|
defer windows.CloseHandle(proc)
|
|
|
|
buf := make([]uint16, windows.MAX_PATH)
|
|
size := uint32(len(buf))
|
|
// MAX_PATH suffices for almost all paths; an over-long path fails here and
|
|
// degrades windowClass to "" (window left unclassified), never a crash.
|
|
if err := windows.QueryFullProcessImageName(proc, 0, &buf[0], &size); err != nil {
|
|
return ""
|
|
}
|
|
return ClassFromImagePath(windows.UTF16ToString(buf[:size]))
|
|
}
|
|
|
|
// MinimizeForeground minimizes the current foreground window. It returns nil
|
|
// when nothing is focused. ShowWindow's BOOL return reports prior visibility,
|
|
// not success, so there is nothing to error-check; minimize is best-effort by
|
|
// the Guard contract.
|
|
func MinimizeForeground() error {
|
|
h := windows.GetForegroundWindow()
|
|
if h == 0 {
|
|
return nil
|
|
}
|
|
procShowWindow.Call(uintptr(h), uintptr(windows.SW_MINIMIZE))
|
|
return nil
|
|
}
|