119 lines
3.8 KiB
C#
119 lines
3.8 KiB
C#
using System.Windows.Threading;
|
|
using CursorLang.Interop;
|
|
using CursorLang.Models;
|
|
|
|
namespace CursorLang.Services;
|
|
|
|
/// <summary>
|
|
/// The settings of layout tracking.
|
|
/// </summary>
|
|
public sealed class KeyboardLayoutOptions
|
|
{
|
|
/// <summary>How often to check the layout of the active window.</summary>
|
|
public TimeSpan PollInterval { get; init; } = TimeSpan.FromMilliseconds(150);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Polls the active window on a timer.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// Polling was chosen not for simplicity: there is no event-based way to learn about
|
|
/// a layout change in another process from managed code. HSHELL_LANGUAGE from
|
|
/// RegisterShellHookWindow does not arrive on Windows 10/11, and TSF notifications
|
|
/// (ITfLanguageProfileNotifySink) report only language changes inside our own process
|
|
/// — both options were tried and did not work. One tick is three Win32 calls reading
|
|
/// data from kernel memory.
|
|
/// </remarks>
|
|
public sealed class KeyboardLayoutService : IKeyboardLayoutService, IDisposable
|
|
{
|
|
private readonly DispatcherTimer _pollTimer;
|
|
private readonly Func<IntPtr> _getForegroundWindow;
|
|
private readonly Func<int> _getActiveLocaleId;
|
|
private readonly Action _requestNextLayout;
|
|
|
|
private int _lastLocaleId = -1;
|
|
private IntPtr _lastForegroundWindow;
|
|
|
|
public KeyboardLayoutService(KeyboardLayoutOptions options)
|
|
: this(
|
|
options,
|
|
KeyboardLayoutNative.GetForegroundWindow,
|
|
KeyboardLayoutNative.GetActiveLocaleId,
|
|
KeyboardLayoutNative.RequestNextLayout)
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// Takes the sources of system information explicitly: in tests the layout and the
|
|
/// active window are not provided by Windows.
|
|
/// </summary>
|
|
internal KeyboardLayoutService(
|
|
KeyboardLayoutOptions options,
|
|
Func<IntPtr> getForegroundWindow,
|
|
Func<int> getActiveLocaleId,
|
|
Action requestNextLayout)
|
|
{
|
|
_getForegroundWindow = getForegroundWindow;
|
|
_getActiveLocaleId = getActiveLocaleId;
|
|
_requestNextLayout = requestNextLayout;
|
|
|
|
_pollTimer = new DispatcherTimer { Interval = options.PollInterval };
|
|
_pollTimer.Tick += OnTick;
|
|
}
|
|
|
|
public event EventHandler<LayoutChangedEventArgs>? LayoutChanged;
|
|
|
|
public KeyboardLayout Current => KeyboardLayout.FromLocaleId(_getActiveLocaleId());
|
|
|
|
public void Start()
|
|
{
|
|
_lastForegroundWindow = _getForegroundWindow();
|
|
_lastLocaleId = _getActiveLocaleId();
|
|
_pollTimer.Start();
|
|
}
|
|
|
|
public void Stop() => _pollTimer.Stop();
|
|
|
|
public void SwitchToNext() => _requestNextLayout();
|
|
|
|
public void Dispose()
|
|
{
|
|
_pollTimer.Stop();
|
|
_pollTimer.Tick -= OnTick;
|
|
}
|
|
|
|
private void OnTick(object? sender, EventArgs e) => Poll();
|
|
|
|
// A single poll step. Called by the timer, and in tests — directly:
|
|
// there is no point waiting for a tick to check how the reason for a layout
|
|
// change is decided
|
|
internal void Poll()
|
|
{
|
|
IntPtr foreground = _getForegroundWindow();
|
|
if (foreground == IntPtr.Zero)
|
|
{
|
|
return;
|
|
}
|
|
|
|
bool appSwitched = foreground != _lastForegroundWindow;
|
|
_lastForegroundWindow = foreground;
|
|
|
|
int localeId = _getActiveLocaleId();
|
|
if (localeId == _lastLocaleId)
|
|
{
|
|
return;
|
|
}
|
|
|
|
_lastLocaleId = localeId;
|
|
|
|
// Moving to another application with a layout of its own is not the same as
|
|
// the user switching the layout, and the subscribers are free to react to
|
|
// these cases differently
|
|
LayoutChangeReason reason = appSwitched
|
|
? LayoutChangeReason.ApplicationSwitched
|
|
: LayoutChangeReason.UserSwitched;
|
|
|
|
LayoutChanged?.Invoke(this, new LayoutChangedEventArgs(KeyboardLayout.FromLocaleId(localeId), reason));
|
|
}
|
|
}
|