First commit 19/07/1998

CDopping/CoolForm/TrMemo.pas

@@ -0,0 +1,100 @@
+unit TrMemo;
+{$R-}
+interface
+uses Messages, Controls, StdCtrls,classes;
+const TMWM__SpecialInvalidate=WM_USER+1111;
+type
+  TTransparentMemo = class(TMemo)
+  private
+    procedure SpecialInvalidate(var Message:TMessage); message
+TMWM__SpecialInvalidate;
+    procedure WMHScroll(var Message: TWMHScroll); message WM_HSCROLL;
+    procedure WMVScroll(var Message: TWMVScroll); message WM_VSCROLL;
+    procedure WMSetText(var Message:TWMSetText); message WM_SETTEXT;
+    procedure CNCTLCOLOREDIT(var Message:TWMCTLCOLOREDIT); message
+CN_CTLCOLOREDIT;
+    procedure WMKeyDown(var Message: TWMKeyDown); message WM_KEYDOWN;
+    procedure WMEraseBkgnd(var Message: TWMEraseBkgnd); message WM_ERASEBKGND;
+  protected
+    procedure CreateParams(var Params: TCreateParams); override;
+  public
+constructor Create(AOwner: TComponent); override;
+  end;
+procedure Register;
+implementation
+uses Windows;
+{ TTransparentMemo }
+procedure TTransparentMemo.WMHScroll(var Message: TWMHScroll);
+begin
+  inherited;
+  PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
+end;
+procedure TTransparentMemo.WMVScroll(var Message: TWMVScroll);
+begin
+  SendMessage(Handle,TMWM__SpecialInvalidate,0,0);
+  inherited;
+  PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
+end;
+procedure TTransparentMemo.CNCTLCOLOREDIT(var Message:TWMCTLCOLOREDIT);
+begin
+  with Message do
+    begin
+      SetBkMode(ChildDC,TRANSPARENT);
+      Result:=GetStockObject(HOLLOW_BRUSH)
+    end
+end;
+procedure TTransparentMemo.WMSetText(var Message:TWMSetText);
+begin
+  inherited;
+  if not (csDesigning in ComponentState) then
+    PostMessage(Handle,TMWM__SpecialInvalidate,0,0)
+end;
+procedure TTransparentMemo.SpecialInvalidate(var Message:TMessage);
+var r:TRect;
+begin
+  if Parent<>nil then
+    begin
+      r:=ClientRect;
+      r.TopLeft:=Parent.ScreenToClient(ClientToScreen(r.TopLeft));
+      r.BottomRight:=Parent.ScreenToClient(ClientToScreen(r.BottomRight));
+      InvalidateRect(Parent.Handle,@r,true);
+      RedrawWindow(Handle,nil,0,RDW_FRAME+RDW_INVALIDATE)
+    end;
+end;
+procedure TTransparentMemo.WMKeyDown(var Message: TWMKeyDown);
+begin
+  SendMessage(Handle,TMWM__SpecialInvalidate,0,0);
+  inherited;
+  PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
+end;
+procedure TTransparentMemo.WMEraseBkgnd(var Message: TWMEraseBkgnd);
+begin
+  Message.Result:=1
+end;
+
+constructor TTransparentMemo.Create(AOwner: TComponent);
+begin
+inherited;
+ControlStyle:=[csCaptureMouse, csDesignInteractive,
+csClickEvents,  csSetCaption, csOpaque, csDoubleClicks,
+  csReplicatable, csNoStdEvents];
+end;
+
+procedure TTransparentMemo.CreateParams(var Params: TCreateParams);
+begin
+  inherited CreateParams(Params);
+  with Params do
+  begin
+  	ExStyle:=ExStyle or WS_EX_TRANSPARENT and not WS_EX_WINDOWEDGE
+     		and not WS_EX_STATICEDGE and not WS_EX_DLGMODALFRAME and not
+           WS_EX_CLIENTEDGE;
+  end;
+end;
+procedure Register;
+begin
+  RegisterComponents('cool!', [tTransparentMemo]);
+end;
+end.
+
+
+