How-totrap-mouse-events-outside-of-my-application


            Title: How totrap mouse events outside of my application
unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
 Dialogs, AppEvnts, StdCtrls;
type
 TForm1 = class(TForm)
 ApplicationEvents1: TApplicationEvents;
 Button_StartJour: TButton;
 Button_StopJour: TButton;
 ListBox1: TListBox;
 procedure ApplicationEvents1Message(var Msg: tagMSG;
 var Handled: Boolean);
 procedure Button_StartJourClick(Sender: TObject);
 procedure Button_StopJourClick(Sender: TObject);
 procedure FormClose(Sender: TObject; var Action: TCloseAction);
 private
 { Private declarations }
 FHookStarted : Boolean;
 public
 { Public declarations }
 end;
var
 Form1: TForm1;
implementation
{$R *.dfm}
var
 JHook: THandle;
// The JournalRecordProc hook procedure is an application-defined or library-defined callback
// function used with the SetWindowsHookEx function.
// The function records messages the system removes from the system message queue.
// A JournalRecordProc hook procedure does not need to live in a dynamic-link library.
// A JournalRecordProc hook procedure can live in the application itself.
// WH_JOURNALPLAYBACK Hook Function
//Syntax
// JournalPlaybackProc(
// nCode: Integer; {a hook code}
// wParam: WPARAM; {this parameter is not used}
// lParam: LPARAM {a pointer to a TEventMsg structure}
// ): LRESULT; {returns a wait time in clock ticks}
function JournalProc(Code, wParam: Integer; var EventStrut: TEventMsg): Integer; stdcall;
var
 Char1: PChar;
 s: string;
begin
 {this is the JournalRecordProc}
 Result := CallNextHookEx(JHook, Code, wParam, Longint(@EventStrut));
 {the CallNextHookEX is not really needed for journal hook since it it not
 really in a hook chain, but it's standard for a Hook}
 if Code 0 then Exit;
 {you should cancel operation if you get HC_SYSMODALON}
 if Code = HC_SYSMODALON then Exit;
 if Code = HC_ACTION then
 begin
 {
 The lParam parameter contains a pointer to a TEventMsg
 structure containing information on
 the message removed from the system message queue.
 }
 s := '';
 if EventStrut.message = WM_LBUTTONUP then
 s := 'Left Mouse UP at X pos ' +
 IntToStr(EventStrut.paramL) + ' and Y pos ' + IntToStr(EventStrut.paramH);
 if EventStrut.message = WM_LBUTTONDOWN then
 s := 'Left Mouse Down at X pos ' +
 IntToStr(EventStrut.paramL) + ' and Y pos ' + IntToStr(EventStrut.paramH);
 if EventStrut.message = WM_RBUTTONDOWN then
 s := 'Right Mouse Down at X pos ' +
 IntToStr(EventStrut.paramL) + ' and Y pos ' + IntToStr(EventStrut.paramH);
 if (EventStrut.message = WM_RBUTTONUP) then
 s := 'Right Mouse Up at X pos ' +
 IntToStr(EventStrut.paramL) + ' and Y pos ' + IntToStr(EventStrut.paramH);
 if (EventStrut.message = WM_MOUSEWHEEL) then
 s := 'Mouse Wheel at X pos ' +
 IntToStr(EventStrut.paramL) + ' and Y pos ' + IntToStr(EventStrut.paramH);
 if (EventStrut.message = WM_MOUSEMOVE) then
 s := 'Mouse Position at X:' +
 IntToStr(EventStrut.paramL) + ' and Y: ' + IntToStr(EventStrut.paramH);
 if s '' then
 Form1.ListBox1.ItemIndex := Form1.ListBox1.Items.Add(s);
 end;
end;
procedure TForm1.Button_StartJourClick(Sender: TObject);
begin
 if FHookStarted then
 begin
 ShowMessage('Mouse is already being Journaled, can not restart');
 Exit;
 end;
 JHook := SetWindowsHookEx(WH_JOURNALRECORD, @JournalProc, hInstance, 0);
 {SetWindowsHookEx starts the Hook}
 if JHook 0 then
 begin
 FHookStarted := True;
 end
 else
 ShowMessage('No Journal Hook availible');
end;
procedure TForm1.Button_StopJourClick(Sender: TObject);
begin
 FHookStarted := False;
 UnhookWindowsHookEx(JHook);
 JHook := 0;
end;
procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
 var Handled: Boolean);
begin
 {the journal hook is automaticly camceled if the Task manager
 (Ctrl-Alt-Del) or the Ctrl-Esc keys are pressed, you restart it
 when the WM_CANCELJOURNAL is sent to the parent window, Application}
 Handled := False;
 if (Msg.message = WM_CANCELJOURNAL) and FHookStarted then
 JHook := SetWindowsHookEx(WH_JOURNALRECORD, @JournalProc, 0, 0);
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
 {make sure you unhook it if the app closes}
 if FHookStarted then
 UnhookWindowsHookEx(JHook);
end;
end.
Hardware Delphi
