diff options
Diffstat (limited to 'VideoPreview/src/lib/other')
| -rw-r--r-- | VideoPreview/src/lib/other/DirWatch.pas | 345 | ||||
| -rw-r--r-- | VideoPreview/src/lib/other/WinAllocation.pas | 101 |
2 files changed, 446 insertions, 0 deletions
diff --git a/VideoPreview/src/lib/other/DirWatch.pas b/VideoPreview/src/lib/other/DirWatch.pas new file mode 100644 index 00000000..1e00ec5d --- /dev/null +++ b/VideoPreview/src/lib/other/DirWatch.pas @@ -0,0 +1,345 @@ +unit DirWatch; + +// ----------------------------------------------------------------------------- +// Component Name: TDirectoryWatch . +// Module: DirWatch . +// Description: Implements watching for file changes in a designated . +// directory (or directories). . +// Version: 1.4 . +// Date: 10-MAR-2003 . +// Target: Win32, Delphi 3 - Delphi 7 . +// Author: Angus Johnson, angusj-AT-myrealbox-DOT-com . +// A portion of code has been copied from the Drag & Drop . +// Component Suite which I co-authored with Anders Melander. . +// Copyright: © 2003 Angus Johnson . +// . +// Usage: 1. Add a TDirectoryWatch component to your form. . +// 2. Set its Directory property . +// 3. If you wish to watch its subdirectories too then set . +// the WatchSubDir property to true . +// 4. Assign the OnChange event . +// 5. Set Active to true . +// ----------------------------------------------------------------------------- + +interface + +{$IFDEF FPC} + {$MODE Delphi} + {$H+} // use long strings +{$ENDIF} + +uses + Windows, + Messages, + Classes, + {$IFDEF FPC} + WinAllocation, + {$ENDIF} + SysUtils; + +type + TNotifyFilters = set of (nfFilename, nfDirname, nfAttrib, + nfSize, nfLastWrite, nfSecurity); + + TWatchThread = class; //forward declaration + + TDirectoryWatch = class(TComponent) + private + fWindowHandle: THandle; + fWatchThread: TWatchThread; + fWatchSubDirs: boolean; + fDirectory: string; + fActive: boolean; + fNotifyFilters: TNotifyFilters; //see FindFirstChangeNotification in winAPI + fOnChangeEvent: TNotifyEvent; + procedure SetActive(aActive: boolean); + procedure SetDirectory(aDir: string); + procedure SetWatchSubDirs(aWatchSubDirs: boolean); + procedure SetNotifyFilters(aNotifyFilters: TNotifyFilters); + procedure WndProc(var aMsg: TMessage); + public + constructor Create(aOwner: TComponent); override; + destructor Destroy; override; + published + property Directory: string read fDirectory write SetDirectory; + property NotifyFilters: TNotifyFilters + read fNotifyFilters write SetNotifyFilters; + property WatchSubDirs: boolean read fWatchSubDirs write SetWatchSubDirs; + property Active: boolean read fActive write SetActive; + property OnChange: TNotifyEvent read fOnChangeEvent write fOnChangeEvent; + end; + + TWatchThread = class(TThread) + private + fOwnerHdl: Thandle; + fChangeNotify : THandle; //Signals whenever Windows detects a change in . + //the watched directory . + fBreakEvent: THandle; //Signals when either the Directory property . + //changes or when the thread terminates . + fDirectory: string; + fWatchSubDirs: longbool; + fNotifyFilters: dword; + fFinished: boolean; + protected + procedure SetDirectory(const Value: string); + procedure ProcessFilenameChanges; + procedure Execute; override; + public + constructor Create( OwnerHdl: THandle; + const InitialDir: string; WatchSubDirs: boolean; NotifyFilters: dword); + destructor Destroy; override; + procedure Terminate; + property Directory: string write SetDirectory; + end; + +procedure Register; + +implementation + +const + NOTIFYCHANGE_MESSAGE = WM_USER + 1; + +resourcestring + sInvalidDir = 'Invalid Directory: '; + +//---------------------------------------------------------------------------- +// Miscellaneous functions ... +//---------------------------------------------------------------------------- + +procedure Register; +begin + RegisterComponents('Samples', [TDirectoryWatch]); +end; +//---------------------------------------------------------------------------- + +function DirectoryExists(const Name: string): Boolean; +var + Code: Integer; +begin + Code := GetFileAttributes(PChar(Name)); + Result := (Code <> -1) and (FILE_ATTRIBUTE_DIRECTORY and Code <> 0); +end; + +//---------------------------------------------------------------------------- +// TDirectoryWatch methods ... +//---------------------------------------------------------------------------- + +constructor TDirectoryWatch.Create(aOwner: TComponent); +begin + inherited Create(aOwner); + //default Notify values - notify if either a file name or a directory name + //changes or if a file is modified ... + fNotifyFilters := [nfFilename, nfDirname, nfLastWrite]; + fDirectory := 'C:\'; + //this non-visual control needs to handle messages, so ... + if not (csDesigning in ComponentState) then + fWindowHandle := AllocateHWnd(WndProc); +end; +//---------------------------------------------------------------------------- + +destructor TDirectoryWatch.Destroy; +begin + Active := false; + if not (csDesigning in ComponentState) then + DeallocateHWnd(fWindowHandle); + inherited Destroy; +end; +//---------------------------------------------------------------------------- + +procedure TDirectoryWatch.WndProc(var aMsg: TMessage); +begin + with aMsg do + if Msg = NOTIFYCHANGE_MESSAGE then + begin + if assigned(OnChange) then OnChange(self); + end else + Result := DefWindowProc(FWindowHandle, Msg, wParam, lParam); +end; +//------------------------------------------------------------------------------ + +procedure TDirectoryWatch.SetNotifyFilters(aNotifyFilters: TNotifyFilters); +begin + if aNotifyFilters = fNotifyFilters then exit; + fNotifyFilters := aNotifyFilters; + if assigned(fWatchThread) then + begin + Active := false; + Active := true; + end; +end; +//------------------------------------------------------------------------------ + +procedure TDirectoryWatch.SetWatchSubDirs(aWatchSubDirs: boolean); +begin + if aWatchSubDirs = fWatchSubDirs then exit; + fWatchSubDirs := aWatchSubDirs; + if assigned(fWatchThread) then + begin + Active := false; + Active := true; + end; +end; +//------------------------------------------------------------------------------ + +procedure TDirectoryWatch.SetDirectory(aDir: string); +begin + if aDir = '' then + begin + Active := false; + fDirectory := ''; + exit; + end; + if (aDir[length(aDir)] <> '\') then aDir := aDir + '\'; + if aDir = fDirectory then exit; + if not (csDesigning in ComponentState) and not DirectoryExists(aDir) then + raise Exception.Create( sInvalidDir + aDir); + fDirectory := aDir; + if assigned(fWatchThread) then + fWatchThread.Directory := fDirectory; +end; +//------------------------------------------------------------------------------ + +procedure TDirectoryWatch.SetActive(aActive: boolean); +var + nf: dword; +begin + if aActive = fActive then exit; + fActive := aActive; + if csDesigning in ComponentState then exit; + if fActive then + begin + if not DirectoryExists(fDirectory) then + begin + fActive := false; + raise Exception.Create(sInvalidDir + fDirectory); + end; + nf := 0; + if nfFilename in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_FILE_NAME; + if nfDirname in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_DIR_NAME; + if nfAttrib in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_ATTRIBUTES; + if nfSize in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_SIZE; + if nfLastWrite in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_LAST_WRITE; + if nfSecurity in fNotifyFilters then + nf := nf or FILE_NOTIFY_CHANGE_SECURITY; + fWatchThread := TWatchThread.Create( + fWindowHandle, fDirectory, fWatchSubDirs, nf); + end else + begin + fWatchThread.Terminate; + fWatchThread := nil; + end; +end; + +//---------------------------------------------------------------------------- +// TWatchThread methods ... +//---------------------------------------------------------------------------- + +constructor TWatchThread.Create(OwnerHdl: THandle; + const InitialDir: string; WatchSubDirs: boolean; NotifyFilters: dword); +begin + inherited Create(True); + fOwnerHdl := OwnerHdl; + if WatchSubDirs then + cardinal(fWatchSubDirs) := 1 //workaround a Win9x OS issue + else + fWatchSubDirs := false; + FreeOnTerminate := true; + Priority := tpLowest; + fDirectory := InitialDir; + fNotifyFilters := NotifyFilters; + fBreakEvent := windows.CreateEvent(nil, False, False, nil); + Resume; +end; +//------------------------------------------------------------------------------ + +destructor TWatchThread.Destroy; +begin + CloseHandle(fBreakEvent); + inherited Destroy; +end; +//------------------------------------------------------------------------------ + +procedure TWatchThread.SetDirectory(const Value: string); +begin + if (Value = FDirectory) then exit; + FDirectory := Value; + SetEvent(fBreakEvent); +end; +//------------------------------------------------------------------------------ + +procedure TWatchThread.Terminate; +begin + inherited Terminate; + SetEvent(fBreakEvent); + while not fFinished do sleep(10); //avoids a reported resource leak + //if called while closing the application. +end; +//------------------------------------------------------------------------------ + +procedure TWatchThread.Execute; +begin + //OUTER LOOP - manages Directory property reassignments + while (not Terminated) do + begin + fChangeNotify := FindFirstChangeNotification(pchar(fDirectory), + fWatchSubDirs, fNotifyFilters); + if (fChangeNotify = INVALID_HANDLE_VALUE) then + //Can't monitor the specified directory so we'll just wait for + //a new Directory assignment or the thread terminating ... + WaitForSingleObject(fBreakEvent, INFINITE) + else + try + //Now do the INNER loop... + ProcessFilenameChanges; + finally + FindCloseChangeNotification(fChangeNotify); + end; + end; + fFinished := true; +end; +//------------------------------------------------------------------------------ + +procedure TWatchThread.ProcessFilenameChanges; +var + WaitResult : DWORD; + HandleArray : array[0..1] of THandle; +const + TEN_MSECS = 10; + HUNDRED_MSECS = 100; +begin + HandleArray[0] := fBreakEvent; + HandleArray[1] := fChangeNotify; + //INNER LOOP - exits only when fBreakEvent signaled + while (not Terminated) do + begin + //waits for either fChangeNotify or fBreakEvent ... + WaitResult := WaitForMultipleObjects(2, @HandleArray, False, INFINITE); + if (WaitResult = WAIT_OBJECT_0 + 1) then //fChangeNotify + begin + repeat //ie: if a number of files are changing in a block + //just post the one notification message ... + FindNextChangeNotification(fChangeNotify); + until Terminated or + (WaitForSingleObject(fChangeNotify, TEN_MSECS) <> WAIT_OBJECT_0); + if Terminated then break; + //OK, now notify the main thread (before restarting inner loop)... + PostMessage(fOwnerHdl, NOTIFYCHANGE_MESSAGE, 0, 0); + end else //fBreakEvent ... + begin + //If the Directory property is undergoing multiple rapid reassignments + //wait 'til this stops before restarting monitoring of a new directory ... + while (not Terminated) and + (WaitForSingleObject(fBreakEvent, HUNDRED_MSECS) = WAIT_OBJECT_0) do; + break; //EXIT LOOP HERE + end; + end; +end; +//------------------------------------------------------------------------------ +//------------------------------------------------------------------------------ + +end.
\ No newline at end of file diff --git a/VideoPreview/src/lib/other/WinAllocation.pas b/VideoPreview/src/lib/other/WinAllocation.pas new file mode 100644 index 00000000..ba1b0919 --- /dev/null +++ b/VideoPreview/src/lib/other/WinAllocation.pas @@ -0,0 +1,101 @@ +unit WinAllocation; + +// FPC misses AllocateHWnd and DeallocateHWnd which is used by several +// libraries such as Midi... or DirWatch. +// Since FPC 2.2.2 there are dummies in Classes that just raise RunTime exceptions. +// To avoid those exceptions, include this unit AFTER Classes. +// Maybe the dummies will be replaced by functional routines in the future.WinAllocation +// +// THESE FUNCTIONS ARE ONLY FOR COMPATIBILITY WITH SOME EXTERNAL WIN32 LIBS. +// DO NOT USE THEM IN USDX CODE. +// + +interface + +{$IFDEF FPC} + {$MODE Delphi} +{$ENDIF} + +uses + Classes, + Windows; + +function AllocateHWnd(Method: TWndMethod): HWND; +procedure DeallocateHWnd(hWnd: HWND); + +implementation + +function AllocateHWndCallback(hWnd: HWND; uMsg: UINT; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall; +var + Msg: TMessage; + MethodPtr: ^TWndMethod; +begin + FillChar(Msg, SizeOf(Msg), 0); + Msg.msg := uMsg; + Msg.wParam := wParam; + Msg.lParam := lParam; + + MethodPtr := Pointer(GetWindowLongPtr(hwnd, GWL_USERDATA)); + if Assigned(MethodPtr) then + MethodPtr^(Msg); + + Result := DefWindowProc(hwnd, uMsg, wParam, lParam); +end; + +function AllocateHWnd(Method: TWndMethod): HWND; +var + ClassExists: Boolean; + WndClass, OldClass: TWndClass; + MethodPtr: ^TMethod; +begin + Result := 0; + + // setup class-info + FillChar(WndClass, SizeOf(TWndClass), 0); + WndClass.hInstance := HInstance; + // Important: do not enable AllocateHWndCallback before the msg-handler method is assigned, + // otherwise race-conditions might occur + WndClass.lpfnWndProc := @DefWindowProc; + WndClass.lpszClassName:= 'USDXUtilWindowClass'; + + // check if class is already registered + ClassExists := GetClassInfo(HInstance, WndClass.lpszClassName, OldClass); + // create window-class shared by all windows created by AllocateHWnd() + if (not ClassExists) or (@OldClass.lpfnWndProc <> @DefWindowProc) then + begin + if ClassExists then + UnregisterClass(WndClass.lpszClassName, HInstance); + if (RegisterClass(WndClass) = 0) then + Exit; + end; + // create window + Result := CreateWindowEx(WS_EX_TOOLWINDOW, WndClass.lpszClassName, '', + DWORD(WS_POPUP), 0, 0, 0, 0, 0, 0, HInstance, nil); + if (Result = 0) then + Exit; + // assign individual callback procedure to the window + if Assigned(Method) then + begin + // TMethod contains two pointers but we can pass just one as USERDATA + GetMem(MethodPtr, SizeOf(TMethod)); + MethodPtr^ := TMethod(Method); + SetWindowLongPtr(Result, GWL_USERDATA, LONG_PTR(MethodPtr)); + end; + // now enable AllocateHWndCallback for this window + SetWindowLongPtr(Result, GWL_WNDPROC, LONG_PTR(@AllocateHWndCallback)); +end; + +procedure DeallocateHWnd(hWnd: HWND); +var + MethodPtr: ^TMethod; +begin + if (hWnd <> 0) then + begin + MethodPtr := Pointer(GetWindowLongPtr(hWnd, GWL_USERDATA)); + DestroyWindow(hWnd); + if Assigned(MethodPtr) then + FreeMem(MethodPtr); + end; +end; + +end. |