/// <summary>
/// Removes the specified hot key.
/// </summary>
/// <param name="state">The hot key to remove.</param>
/// <returns>true if the hot key was removed successfully; otherwise false.</returns>
/// <exception cref="ArgumentNullException">state is null</exception>
/// <exception cref="ArgumentException">state was created by a different HotKeyComponent instance</exception>
/// <exception cref="ArgumentException">state is invalid type</exception>
public bool Remove(HotKeyState state)
{
if (state == null)
{
throw new ArgumentNullException("state");
}
if (state.Owner != this)
{
throw new ArgumentException("The specified state was created by a different HotKeyComponent instance.", "state");
}
InternalHotKeyState hotkey = state as InternalHotKeyState; //cast state
if (hotkey == null) //validate state
{
throw new ArgumentException("The specified state is an invalid type.", "state");
}
if (localHotKeys.Remove(hotkey.ID)) //attempt to remove the hotkey
{
UnregisterHotKey(hotkey); //unregister the hotkey
return(true);
}
else
{
return(false);
}
}
private bool RegisterHotKey(InternalHotKeyState hotkey)
{
KeyModifiers modifiers = hotkey.HotKey.NativeModifier;
if (!hotkey.AllowRepeat)
{
modifiers |= KeyModifiers.MOD_NOREPEAT; //not supported on Windows Vista and Windows XP/2000
}
return(NativeMethods.RegisterHotKey(window.Handle, hotkey.ID, modifiers, hotkey.HotKey.Key));
}
/// <summary>
/// Sets up the hot key sink and initializes synchronization control.
/// </summary>
private void Init()
{
//calculate the key repeat rate and repeat delay
int repeatRate = (int)Math.Ceiling(1000M / (27.5M * (GetKeyboardSpeed() / 31) + 2.5M));
int repeatDelay = (int)Math.Ceiling(750M * (GetKeyboardRepeatDelay() / 3M) + 250M);
//account for lag:
repeatRate += 100;
repeatDelay += 100;
//use the larger of the delays, unfortunately, there is no hot key released event
int minimumInterval = Math.Max(repeatRate, repeatDelay);
//handles hot key notifications
window.HotKeyPressed += (sender, e) =>
{
InternalHotKeyState hotkey = null;
if (localHotKeys.TryGetValue(e.HotKeyID, out hotkey))
{
//utc timestamps for better performance
bool invoke = hotkey.AllowRepeat || DateTime.UtcNow.Subtract(hotkey.TimeStamp).TotalMilliseconds > minimumInterval;
hotkey.TimeStamp = DateTime.UtcNow; //update timestamp
if (invoke)
{
HotKeyActivatedEventArgs args = new HotKeyActivatedEventArgs(hotkey);
if (HotKeyActivated != null)
{
HotKeyActivated(this, args);
}
if (hotkey.Callback != null)
{
hotkey.Callback(this, args);
}
}
}
};
}
/// <summary>
/// Attempts to create a new system-wide hot key with repeat options, user state and a callback.
/// </summary>
/// <param name="hotkey">The hot key to register.</param>
/// <param name="allow_repeat">true to allow repeating key events; otherwise, false.</param>
/// <param name="state">An optional user state.</param>
/// <param name="callback">A callback to invoke when the hot key is pressed.</param>
/// <param name="result">When this method returns, contains an instance of a new state representing the hot key registration or null if the registration failed.</param>
/// <returns>true if a new system-wide hot key was registered; otherwise, false.</returns>
public bool TryAdd(HotKey hotkey, bool allow_repeat, object state, EventHandler <HotKeyActivatedEventArgs> callback, out HotKeyState result)
{
int id = ++HotKeyID; //get next hotkey id
if (id > MAXIMUM_REGISTERHOTKEY_ID) //max value id can be
{
throw new NotImplementedException($"HotKeyComponent cannot support identification numbers greater-than {MAXIMUM_REGISTERHOTKEY_ID}; previously unregistered hotkey ids should be reused.");
}
//create internal state for timestamps, state and callback
InternalHotKeyState key_state = new InternalHotKeyState(this, id, hotkey, allow_repeat, state, callback);
if (RegisterHotKey(key_state)) //register hot key with system
{
localHotKeys.Add(id, key_state); //add to collection
result = key_state; //set state
return(true);
}
result = null;
return(false);
}
private bool UnregisterHotKey(InternalHotKeyState hotkey)
{
return(NativeMethods.UnregisterHotKey(window.Handle, hotkey.ID));
}