Difference between UnPin and Close UnPinned

When the user clicks 'x' on a Pinned Form OnClose is called.

When the user clicks 'x' on an Unpinned Form OnHide is called

When the user clicks 'UnPin' on a Pinned Form OnHide is called.

I'm trying to synchronise the visible forms with a menu system but I don't know how to determine the difference in the OnHide event between when the user clicks 'x' and when the user clicks 'UnPin'. I want to intercept the 'x' and call Close instead.

Each child is a descendant of TManagerPanel which in turn is a descendant of TForm with the border style set to bsSizeToolWin, Drag Kind set to dkDock and Drag Mode is dmAutomatic.

type
    TPanelManager = class(TForm)
    ...
    private
    ...        
        Panels: TManagerPanelList;
        Settings: TSettings; //User Settings
    ...
end;
...

function TPanelManager.InitChild(ChildClass: TManagerPanelClass): TManagerPanel;
var
    Child: TManagerPanel;
begin
    Child := ChildClass.Create(Self);
    Child.Connection := MSConnectio开发者_运维知识库n1;
    Child.Settings := Settings;
    Child.Styles := Styles;
    ...
    Child.OnPanelClosed := PanelClosed;
    Child.OnPercentChanged := PercentChanged;
    ...
    Child.OnPanelHide := PanelHide;
    Child.Font := Font;
    Child.Initialise;
    Child.ManualDock(DockTarget);
    Panels.AddPanel(Child);
    Result := Child;
end;

procedure TPanelManager.PanelClosed(Sender: TObject; var Action: TCloseAction);
var
    MenuItem: TMenuItem;
    Child: TManagerPanel;
begin
    if Sender is TManagerPanel then
    begin
        Child := TManagerPanel(Sender);
        Action := caFree;
        MenuItem := MenuItemFromChild(Child);
        MenuItem.Checked := False;
        Settings[RemoveAmpersand(MenuItem.Caption)] := MenuItem.Checked;
        Panels.Remove(Child);
    end;
end;

EDIT: What I mean by a "Pinned" Form: A docked form with the pin set such that it always visible.

What I mean by a "UnPinned" Form: A docked form with the pin released such that a tab appears in a dock tab set and the form appears when the tab is selected.

Delphi Version is 2007

it seems that pinning and unpinning a docked form changes it's parent between a TTabDockPanel and the TPanel I'm docking it to.

Adding an OnHide method to the Demo Dock Form...

procedure TfrmDock.FormHide(Sender: TObject);
begin
  if Assigned(Self.Parent) then
      ShowMessage(Self.Parent.ClassName)
  else 
      ShowMessage('No Parent');
end;

I can now distinguish between "Floating", "Docked,Pinned" and "Docked, Unpinned" when the form gets hidden.

EDIT I've found a better way of doing this

procedure TfrmDock.FormHide(Sender: TObject);
begin
    if Assigned(Parent) then
    begin
        if Not (csDocking in ControlState) then //This was the original test above
        begin
            if Parent is TTabDockPanel then // This is now a safety check
            begin
                if TTabDockPanel(Parent).AnimateSpeed = 1 then //Additional Test
                    //form is closing
                else
                    //form is hiding (Unpinned focused changed)
            end;
        end
        else 
            //form is being unpinned.
    end;
end;

In DockCaptionMouseUp the Animation Speed is set to 1 so that the panel appears to close (Hides really fast). The same happens for "Unpinning" but control state changes.