aboutsummaryrefslogtreecommitdiffstats
path: root/src/classes0/UHooks.pas
diff options
context:
space:
mode:
Diffstat (limited to 'src/classes0/UHooks.pas')
-rw-r--r--src/classes0/UHooks.pas434
1 files changed, 434 insertions, 0 deletions
diff --git a/src/classes0/UHooks.pas b/src/classes0/UHooks.pas
new file mode 100644
index 00000000..f0ba3276
--- /dev/null
+++ b/src/classes0/UHooks.pas
@@ -0,0 +1,434 @@
+unit UHooks;
+
+{*********************
+ THookManager
+ Class for saving, managing and calling of Hooks.
+ Saves all hookable events and their subscribers
+*********************}
+interface
+
+{$IFDEF FPC}
+ {$MODE Delphi}
+{$ENDIF}
+
+{$I switches.inc}
+
+uses uPluginDefs,
+ SysUtils;
+
+type
+ //Record that saves info from Subscriber
+ PSubscriberInfo = ^TSubscriberInfo;
+ TSubscriberInfo = record
+ Self: THandle; //ID of this Subscription (First Word: ID of Subscription; 2nd Word: ID of Hook)
+ Next: PSubscriberInfo; //Pointer to next Item in HookChain
+
+ Owner: Integer; //For Error Handling and Plugin Unloading.
+
+ //Here is s/t tricky
+ //To avoid writing of Wrapping Functions to Hook an Event with a Class
+ //We save a Normal Proc or a Method of a Class
+ Case isClass: boolean of
+ False: (Proc: TUS_Hook); //Proc that will be called on Event
+ True: (ProcOfClass: TUS_Hook_of_Object);
+ end;
+
+ TEventInfo = record
+ Name: String[60]; //Name of Event
+ FirstSubscriber: PSubscriberInfo; //First subscriber in chain
+ LastSubscriber: PSubscriberInfo; //Last " (for easier subscriber adding
+ end;
+
+ THookManager = class
+ private
+ Events: array of TEventInfo;
+ SpaceinEvents: Word; //Number of empty Items in Events Array. (e.g. Deleted Items)
+
+ Procedure FreeSubscriber(const EventIndex: Word; const Last, Cur: PSubscriberInfo);
+ public
+ constructor Create(const SpacetoAllocate: Word);
+
+ Function AddEvent (const EventName: PChar): THandle;
+ Function DelEvent (hEvent: THandle): Integer;
+
+ Function AddSubscriber (const EventName: PChar; const Proc: TUS_Hook = nil; const ProcOfClass: TUS_Hook_of_Object = nil): THandle;
+ Function DelSubscriber (const hSubscriber: THandle): Integer;
+
+ Function CallEventChain (const hEvent: THandle; const wParam: TwParam; lParam: TlParam): Integer;
+ Function EventExists (const EventName: PChar): Integer;
+
+ Procedure DelbyOwner(const Owner: Integer);
+ end;
+
+function HookTest(wParam: TwParam; lParam: TlParam): integer; stdcall;
+
+var
+ HookManager: THookManager;
+
+implementation
+uses
+ ULog,
+ UCore;
+
+//------------
+// Create - Creates Class and Set Standard Values
+//------------
+constructor THookManager.Create(const SpacetoAllocate: Word);
+var I: Integer;
+begin
+ inherited Create();
+
+ //Get the Space and "Zero" it
+ SetLength (Events, SpacetoAllocate);
+ For I := 0 to SpacetoAllocate-1 do
+ Events[I].Name[1] := chr(0);
+
+ SpaceinEvents := SpacetoAllocate;
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Succesful Created.');
+ {$ENDIF}
+end;
+
+//------------
+// AddEvent - Adds an Event and return the Events Handle or 0 on Failure
+//------------
+Function THookManager.AddEvent (const EventName: PChar): THandle;
+var I: Integer;
+begin
+ Result := 0;
+
+ if (EventExists(EventName) = 0) then
+ begin
+ If (SpaceinEvents > 0) then
+ begin
+ //There is already Space available
+ //Go Search it!
+ For I := 0 to High(Events) do
+ If (Events[I].Name[1] = chr(0)) then
+ begin //Found Space
+ Result := I;
+ Dec(SpaceinEvents);
+ Break;
+ end;
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Found Space for Event at Handle: ''' + InttoStr(Result+1) + '');
+ {$ENDIF}
+ end
+ else
+ begin //There is no Space => Go make some!
+ Result := Length(Events);
+ SetLength(Events, Result + 1);
+ end;
+
+ //Set Events Data
+ Events[Result].Name := EventName;
+ Events[Result].FirstSubscriber := nil;
+ Events[Result].LastSubscriber := nil;
+
+ //Handle is Index + 1
+ Inc(Result);
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Add Event succesful: ''' + EventName + '');
+ {$ENDIF}
+ end
+ {$IFDEF DEBUG}
+ else
+ debugWriteLn('HookManager: Trying to ReAdd Event: ''' + EventName + '');
+ {$ENDIF}
+end;
+
+//------------
+// DelEvent - Deletes an Event by Handle Returns False on Failure
+//------------
+Function THookManager.DelEvent (hEvent: THandle): Integer;
+var
+ Cur, Last: PSubscriberInfo;
+begin
+ hEvent := hEvent - 1; //Arrayindex is Handle - 1
+ Result := -1;
+
+
+ If (Length(Events) > hEvent) AND (Events[hEvent].Name[1] <> chr(0)) then
+ begin //Event exists
+ //Free the Space for all Subscribers
+ Cur := Events[hEvent].FirstSubscriber;
+
+ While (Cur <> nil) do
+ begin
+ Last := Cur;
+ Cur := Cur.Next;
+ FreeMem(Last, SizeOf(TSubscriberInfo));
+ end;
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Removed Event succesful: ''' + Events[hEvent].Name + '');
+ {$ENDIF}
+
+ //Free the Event
+ Events[hEvent].Name[1] := chr(0);
+ Inc(SpaceinEvents); //There is one more space for new events
+ end
+
+ {$IFDEF DEBUG}
+ else
+ debugWriteLn('HookManager: Try to Remove not Existing Event. Handle: ''' + InttoStr(hEvent) + '');
+ {$ENDIF}
+end;
+
+//------------
+// AddSubscriber - Adds an Subscriber to the Event by Name
+// Returns Handle of the Subscribtion or 0 on Failure
+//------------
+Function THookManager.AddSubscriber (const EventName: PChar; const Proc: TUS_Hook; const ProcOfClass: TUS_Hook_of_Object): THandle;
+var
+ EventHandle: THandle;
+ EventIndex: Cardinal;
+ Cur: PSubscriberInfo;
+begin
+ Result := 0;
+
+ If (@Proc <> nil) or (@ProcOfClass <> nil) then
+ begin
+ EventHandle := EventExists(EventName);
+
+ If (EventHandle <> 0) then
+ begin
+ EventIndex := EventHandle - 1;
+
+ //Get Memory
+ GetMem(Cur, SizeOf(TSubscriberInfo));
+
+ //Fill it with Data
+ Cur.Next := nil;
+
+ //Add Owner
+ Cur.Owner := Core.CurExecuted;
+
+ If (@Proc = nil) then
+ begin //Use the ProcofClass Method
+ Cur.isClass := True;
+ Cur.ProcOfClass := ProcofClass;
+ end
+ else //Use the normal Proc
+ begin
+ Cur.isClass := False;
+ Cur.Proc := Proc;
+ end;
+
+ //Create Handle (1st Word: Handle of Event; 2nd Word: unique ID
+ If (Events[EventIndex].LastSubscriber = nil) then
+ begin
+ If (Events[EventIndex].FirstSubscriber = nil) then
+ begin
+ Result := (EventHandle SHL 16);
+ Events[EventIndex].FirstSubscriber := Cur;
+ end
+ Else
+ begin
+ Result := Events[EventIndex].FirstSubscriber.Self + 1;
+ end;
+ end
+ Else
+ begin
+ Result := Events[EventIndex].LastSubscriber.Self + 1;
+ Events[EventIndex].LastSubscriber.Next := Cur;
+ end;
+
+ Cur.Self := Result;
+
+ //Add to Chain
+ Events[EventIndex].LastSubscriber := Cur;
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Add Subscriber to Event ''' + Events[EventIndex].Name + ''' succesful. Handle: ''' + InttoStr(Result) + ''' Owner: ' + InttoStr(Cur.Owner));
+ {$ENDIF}
+ end;
+ end;
+end;
+
+//------------
+// FreeSubscriber - Helper for DelSubscriber. Prevents Loss of Chain Items. Frees Memory.
+//------------
+Procedure THookManager.FreeSubscriber(const EventIndex: Word; const Last, Cur: PSubscriberInfo);
+begin
+ //Delete from Chain
+ If (Last <> nil) then
+ begin
+ Last.Next := Cur.Next;
+ end
+ else //Was first Popup
+ begin
+ Events[EventIndex].FirstSubscriber := Cur.Next;
+ end;
+
+ //Was this Last subscription ?
+ If (Cur = Events[EventIndex].LastSubscriber) then
+ begin //Change Last Subscriber
+ Events[EventIndex].LastSubscriber := Last;
+ end;
+
+ //Free Space:
+ FreeMem(Cur, SizeOf(TSubscriberInfo));
+end;
+
+//------------
+// DelSubscriber - Deletes a Subscribtion by Handle, return non Zero on Failure
+//------------
+Function THookManager.DelSubscriber (const hSubscriber: THandle): Integer;
+var
+ EventIndex: Cardinal;
+ Cur, Last: PSubscriberInfo;
+begin
+ Result := -1;
+ EventIndex := ((hSubscriber AND (High(THandle) xor High(Word))) SHR 16) - 1;
+
+ //Existing Event ?
+ If (EventIndex < Length(Events)) AND (Events[EventIndex].Name[1] <> chr(0)) then
+ begin
+ Result := -2; //Return -1 on not existing Event, -2 on not existing Subscription
+
+ //Search for Subscription
+ Cur := Events[EventIndex].FirstSubscriber;
+ Last := nil;
+
+ //go through the chain ...
+ While (Cur <> nil) do
+ begin
+ If (Cur.Self = hSubscriber) then
+ begin //Found Subscription we searched for
+ FreeSubscriber(EventIndex, Last, Cur);
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Del Subscriber from Event ''' + Events[EventIndex].Name + ''' succesful. Handle: ''' + InttoStr(hSubscriber) + '');
+ {$ENDIF}
+
+ //Set Result and Break the Loop
+ Result := 0;
+ Break;
+ end;
+
+ Last := Cur;
+ Cur := Cur.Next;
+ end;
+
+ end;
+end;
+
+
+//------------
+// CallEventChain - Calls the Chain of a specified EventHandle
+// Returns: -1: Handle doesn't Exist, 0 Chain is called until the End
+//------------
+Function THookManager.CallEventChain (const hEvent: THandle; const wParam: TwParam; lParam: TlParam): Integer;
+var
+ EventIndex: Cardinal;
+ Cur: PSubscriberInfo;
+ CurExecutedBackup: Integer; //backup of Core.CurExecuted Attribute
+begin
+ Result := -1;
+ EventIndex := hEvent - 1;
+
+ If ((EventIndex <= High(Events)) AND (Events[EventIndex].Name[1] <> chr(0))) then
+ begin //Existing Event
+ //Backup CurExecuted
+ CurExecutedBackup := Core.CurExecuted;
+
+ //Start calling the Chain !!!11
+ Cur := Events[EventIndex].FirstSubscriber;
+ Result := 0;
+ //Call Hooks until the Chain is at the End or breaked
+ While ((Cur <> nil) AND (Result = 0)) do
+ begin
+ //Set CurExecuted
+ Core.CurExecuted := Cur.Owner;
+ if (Cur.isClass) then
+ Result := Cur.ProcOfClass(wParam, lParam)
+ else
+ Result := Cur.Proc(wParam, lParam);
+
+ Cur := Cur.Next;
+ end;
+
+ //Restore CurExecuted
+ Core.CurExecuted := CurExecutedBackup;
+ end;
+
+ {$IFDEF DEBUG}
+ debugWriteLn('HookManager: Called Chain from Event ''' + Events[EventIndex].Name + ''' succesful. Result: ''' + InttoStr(Result) + '');
+ {$ENDIF}
+end;
+
+//------------
+// EventExists - Returns non Zero if an Event with the given Name exists
+//------------
+Function THookManager.EventExists (const EventName: PChar): Integer;
+var
+ I: Integer;
+ Name: String[60];
+begin
+ Result := 0;
+ //If (Length(EventName) <
+ Name := String(EventName);
+
+ //Sure not to search for empty space
+ If (Name[1] <> chr(0)) then
+ begin
+ //Search for Event
+ For I := 0 to High(Events) do
+ If (Events[I].Name = Name) then
+ begin //Event found
+ Result := I + 1;
+ Break;
+ end;
+ end;
+end;
+
+//------------
+// DelbyOwner - Dels all Subscriptions by a specific Owner. (For Clean Plugin/Module unloading)
+//------------
+Procedure THookManager.DelbyOwner(const Owner: Integer);
+var
+ I: Integer;
+ Cur, Last: PSubscriberInfo;
+begin
+ //Search for Owner in all Hooks Chains
+ For I := 0 to High(Events) do
+ begin
+ If (Events[I].Name[1] <> chr(0)) then
+ begin
+
+ Last := nil;
+ Cur := Events[I].FirstSubscriber;
+ //Went Through Chain
+ While (Cur <> nil) do
+ begin
+ If (Cur.Owner = Owner) then
+ begin //Found Subscription by Owner -> Delete
+ FreeSubscriber(I, Last, Cur);
+ If (Last <> nil) then
+ Cur := Last.Next
+ else
+ Cur := Events[I].FirstSubscriber;
+ end
+ Else
+ begin
+ //Next Item:
+ Last := Cur;
+ Cur := Cur.Next;
+ end;
+ end;
+ end;
+ end;
+end;
+
+
+function HookTest(wParam: TwParam; lParam: TlParam): integer; stdcall;
+begin
+ Result := 0; //Don't break the chain
+ Core.ShowMessage(CORE_SM_INFO, PChar(String(PChar(Pointer(lParam))) + ': ' + String(PChar(Pointer(wParam)))));
+end;
+
+end.