[SOLVED] Laptop lid close
lazarus / 21-General

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pcurtis · 2021-01-31 00:30

Hi All,

how can I detect when the lid of my laptop closes?

I know I have to use the RegisterPowerSettingNotification API, but
how?

Windows 10.

Thanks in advance.

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jamie · 2021-01-31 00:33

I believe that is a device change message or Power message..
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i           
 IntPtr handle = new
WindowInteropHelper(Application.Current.Windows[0]).Handle;          
IntPtr hLIDSWITCHSTATECHANGE =
RegisterPowerSettingNotification(handle,                 ref
GUID_LIDSWITCH_STATE_CHANGE,               
 DEVICE_NOTIFY_WINDOW_HANDLE);  
Something like that ….
then you need to process the WM_POWERBROADCAST message in the form

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pcurtis · 2021-01-31 01:01

Hi there - It's all 'C' to me   I don't understand.

I've found this :-

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
Controls, Graphics, Dialogs, StdCtrls, Windows, Messages; type   {
TForm1 }   TForm1 = class(TForm)    Memo1: TMemo;    procedure
FormCreate(Sender: TObject);  private     FHPOWERNOTIFY: THandle; 
 protected     procedure WM_POWERBROADCAST(var Msg: TMessage); message
WM_POWERBROADCAST;   public   end;   function
RegisterPowerSettingNotification(hRecipient: THandle;   
PowerSettingGuid: PGUID; Flags: DWORD): THandle; stdcall;  external
'user32.dll';  function UnregisterPowerSettingNotification(Handle:
THandle): BOOL; stdcall;  external 'user32.dll'; var  Form1:
TForm1; const  GUID_MONITOR_POWER_ON: TGUID =    
'{02731015-4510-4526-99E6-E5A17EBD1AEA}'; implementation {$R
*.lfm} procedure TForm1.FormCreate(Sender: TObject);begin 
FHPOWERNOTIFY := RegisterPowerSettingNotification(Handle,   
@GUID_MONITOR_POWER_ON, DEVICE_NOTIFY_WINDOW_HANDLE);end; procedure
TForm1.WM_POWERBROADCAST(var Msg: TMessage);begin  if
PPOWERBROADCAST_SETTING(Msg.LParam)^.Data[0] = 0 then   
Memo1.Lines.Add('Off')  else    Memo1.Lines.Add('ON')end; end. 
but it won't compile.

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jamie · 2021-01-31 01:19

What part isn't compiling ?

Btw, you shouldn't use the procedure name the same as the message name

WMPOWERBROADCAST would be good, take the - out of it.

btw, a list of the GUID strings you need to use … Take your pick

https://docs.microsoft.com/en-us/windows/win32/power/power-setting-
guids

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jamie · 2021-01-31 02:01

I wanted to mention that although you may get that to compile it may
not notify you..

I am not so sure if the LCL is allowing that message to be processed
through the form's message handler.

you may need to hook the Window Procedure

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pcurtis · 2021-01-31 07:50

Your right, I use MsgHook that allows me to do that.
The final program is :-

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
{Controls, Graphics, Dialogs, StdCtrls,} Windows, Messages,
msghook; type  PPowerbroadcastSetting = ^TPowerbroadcastSetting; 
TPowerBroadcastSetting = record   PowerSetting: TGUID;   DataLength:
DWORD;   Data: array[0..0] of UCHAR;  end;  { TForm1 }   TForm1 =
class(TForm)    procedure FormCreate(Sender: TObject);  private   
 FHPOWERNOTIFY: THandle;   protected  public    procedure
WMPOWERBROADCAST(var Msg: TMessage); message WM_POWERBROADCAST; 
end;   function RegisterPowerSettingNotification(hRecipient: THandle; 
  PowerSettingGuid: PGUID; Flags: DWORD): THandle; stdcall;  external
'user32.dll';  function UnregisterPowerSettingNotification(Handle:
THandle): BOOL; stdcall;  external 'user32.dll';  function
LockWorkStation: boolean; stdcall; external 'user32.dll' name
'LockWorkStation';var  Form1: TForm1;  bOpen : boolean = false; const 
GUID_LIDSWITCH_STATE_CHANGE: TGUID  =
'{BA3E0F4D-B817-4094-A2D1-D56379E6A0F3}'; 
DEVICE_NOTIFY_WINDOW_HANDLE: DWORD  = 0;  PBT_POWERSETTINGCHANGE     
       = $8013; implementation {$R *.lfm} procedure
TForm1.FormCreate(Sender: TObject);begin  AddMsg(self,
WM_POWERBROADCAST);  FHPOWERNOTIFY :=
RegisterPowerSettingNotification(Handle, @GUID_LIDSWITCH_STATE_CHANGE,
DEVICE_NOTIFY_WINDOW_HANDLE);end; procedure
TForm1.WMPOWERBROADCAST(var Msg: TMessage);var  PB_SETTING :
TPowerBroadcastSetting;  Buf : dword;begin  if Msg.wParam =
PBT_POWERSETTINGCHANGE then    begin      Buf := 0;     
Move(PB_SETTING.Data, Buf, SizeOf(dword));      if Buf = 0 then bOpen
:= not bOpen;       if not bOpen then LockWorkStation;  end;end; end.