SEBPatch/SafeExamBrowser.Monitoring/Keyboard/KeyboardInterceptor.cs

63 lines
1.8 KiB
C#

/*
* Copyright (c) 2024 ETH Zürich, IT Services
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
using System;
using System.Linq;
using System.Windows.Input;
using SafeExamBrowser.Logging.Contracts;
using SafeExamBrowser.Monitoring.Contracts.Keyboard;
using SafeExamBrowser.Settings.Monitoring;
using SafeExamBrowser.WindowsApi.Contracts;
using SafeExamBrowser.WindowsApi.Contracts.Events;
namespace SafeExamBrowser.Monitoring.Keyboard
{
public class KeyboardInterceptor : IKeyboardInterceptor
{
private Guid? hookId;
private readonly ILogger logger;
private readonly INativeMethods nativeMethods;
private readonly KeyboardSettings settings;
public KeyboardInterceptor(ILogger logger, INativeMethods nativeMethods, KeyboardSettings settings)
{
this.logger = logger;
this.nativeMethods = nativeMethods;
this.settings = settings;
}
public void Start()
{
hookId = nativeMethods.RegisterKeyboardHook(KeyboardHookCallback);
}
public void Stop()
{
if (hookId.HasValue)
{
nativeMethods.DeregisterKeyboardHook(hookId.Value);
}
}
private bool KeyboardHookCallback(int keyCode, KeyModifier modifier, KeyState state)
{
var block = false;
return block;
}
private void Log(Key key, int keyCode, KeyModifier modifier, KeyState state)
{
var modifierFlags = Enum.GetValues(typeof(KeyModifier)).OfType<KeyModifier>().Where(m => m != KeyModifier.None && modifier.HasFlag(m));
var modifiers = modifierFlags.Any() ? String.Join(" + ", modifierFlags) + " + " : string.Empty;
logger.Info($"Blocked '{modifiers}{key}' ({key} = {keyCode}) when {state.ToString().ToLower()}.");
}
}
}