carbon: allow to set grayed status for checkboxes. #21136

git-svn-id: trunk@34915 -

lcl/interfaces/carbon/carbonbuttons.pp

@@ -37,13 +37,17 @@ uses
   LCLMessageGlue, LCLType, Graphics;
 
 type
+  TUpdateValueEvent = procedure (Sender: TObject; CurrentValue: Integer; var AValue: Integer) of object;
 
   { TCarbonCustomCheckBox }
 
   TCarbonCustomCheckBox = class(TCarbonControl)
   private
     fSupressNotify : Boolean;
+    LastState: Integer;
+    isSetState: Boolean;
   public
+    UpdateValue: TUpdateValueEvent;
     class function GetValidEvents: TCarbonControlEvents; override;
     procedure Hit(AControlPart: ControlPartCode); override;
     procedure ValueChanged; override;
@@ -146,7 +150,17 @@ end;
   Value changed event handler
  ------------------------------------------------------------------------------}
 procedure TCarbonCustomCheckBox.ValueChanged;
+var
+  NewState: Integer;
+  RS: Integer;
 begin
+  if not isSetState and Assigned(UpdateValue) then begin
+    RS:=RetrieveState;
+    NewState:=RS;
+    UpdateValue(Self, LastState, NewState);
+    if NewState<>RS then SetValue(NewState);
+  end;
+  LastState:=RetrieveState;
   if not fSupressNotify then
     LCLSendChangedMsg(LCLObject)
   else
@@ -171,8 +185,11 @@ end;
 procedure TCarbonCustomCheckBox.SetState(AState: Integer; NotifyChangeState: Boolean);
 begin
   if RetrieveState=AState then Exit;
+  isSetState:=True;
   fSupressNotify := not NotifyChangeState;
   SetControl32BitValue(ControlRef(Widget), AState);
+  LastState:=AState;
+  isSetState:=False;
 end;
 
 { TCarbonCheckBox }

lcl/interfaces/carbon/carbonwsstdctrls.pp

@@ -197,6 +197,8 @@ type
   { TCarbonWSCustomCheckBox }
 
   TCarbonWSCustomCheckBox = class(TWSCustomCheckBox)
+  public
+    class procedure UpdateValue(Sender: TObject; OldValue: Integer; var ANewValue: Integer);
   published
     class function  CreateHandle(const AWinControl: TWinControl; const AParams: TCreateParams): TLCLIntfHandle; override;
     class function  RetrieveState(const ACustomCheckBox: TCustomCheckBox): TCheckBoxState; override;
@@ -1060,6 +1062,28 @@ end;
 
 { TCarbonWSCustomCheckBox }
 
+{------------------------------------------------------------------------------
+  Method:  TCarbonWSCustomCheckBox.CreateHandle
+  Params:  Sender   - CarbonCheckBox
+           OldValue - the previous value of the checkbox
+           NewValue - the value of the check box, about to be set
+
+  Updates the value, to be Mixed state, if AllowGray is on the TCustomCheckBox
+  The method is called, only if the it's being updated by User, rather than
+  explicit SetState method
+ ------------------------------------------------------------------------------}
+class procedure TCarbonWSCustomCheckBox.UpdateValue(Sender: TObject; OldValue: Integer; var ANewValue: Integer);
+var
+  cb: TCarbonCheckBox;
+begin
+  cb:=TCarbonCheckBox(Sender);
+  if (TCustomCheckBox(cb.LCLObject).AllowGrayed) and (OldValue=kControlCheckBoxUncheckedValue)
+    and (ANewValue=kControlCheckBoxCheckedValue) then
+  begin
+    ANewValue:=kControlCheckBoxMixedValue;
+  end;
+end;
+
 {------------------------------------------------------------------------------
   Method:  TCarbonWSCustomCheckBox.CreateHandle
   Params:  AWinControl - LCL control
@@ -1070,8 +1094,12 @@ end;
  ------------------------------------------------------------------------------}
 class function TCarbonWSCustomCheckBox.CreateHandle(const AWinControl: TWinControl;
   const AParams: TCreateParams): TLCLIntfHandle;
+var
+  cb : TCarbonCheckBox;
 begin
-  Result := TLCLIntfHandle(TCarbonCheckBox.Create(AWinControl, AParams));
+  cb:=TCarbonCheckBox.Create(AWinControl, AParams);
+  cb.UpdateValue:=@UpdateValue;
+  Result := TLCLIntfHandle(cb);
 end;
 
 {------------------------------------------------------------------------------