// DEPRECATED. Enables (valid) use of 'IN' operator (this
      // is a hack for speed. It will be replaced by the use of the widgetset
      // classes.
      // So, don't use it anymore.        

Performs checks that there is already a valid host control to which the present control is to be docked, removes old controls from the list of docked controls and adds the new control to the list, then calls DoDock to perform the actual docking process

Docks this control to DropControl or on NewDockSite.

If DropControl is not nil, ControlSide defines on which side of DropControl this control is docked. (alNone,alClient for stacked in pages). DropControl will become part of a TDockManager.

If DropControl is nil, then DropControl becomes a normal child of NewDockSite and ControlSide is ignored.

{------------------------------------------------------------------------------
  function TControl.ManualFloat(TheScreenRect: TRect;
    KeepDockSiteSize: Boolean = true): Boolean;

  Undock and float.
  Float means here: create the floating dock site and dock this control into it.
  Exception: Forms do not need float dock sites and float on their own.
------------------------------------------------------------------------------}

{------------------------------------------------------------------------------
  TControl.AdjustSize

  Calls DoAutoSize smart.
  During loading and handle creation the calls are delayed.

  This method does the same as TWinControl.DoAutoSize at the beginning.
  But since DoAutoSize is commonly overriden by existing Delphi components,
  they do not all tests, which can result in too much overhead. To reduce this
  the LCL calls AdjustSize instead.
------------------------------------------------------------------------------}

{------------------------------------------------------------------------------
  procedure TControl.AnchorToNeighbour(Side: TAnchorKind; Space: integer;
    Sibling: TControl);

  Setup AnchorSide to anchor one side to the side of a neighbour sibling.
  For example Right side to Left side, or Top side to Bottom.
 ------------------------------------------------------------------------------}

{------------------------------------------------------------------------------
  procedure TControl.GetPreferredSize(
    var PreferredWidth, PreferredHeight: integer; Raw: boolean;
    WithThemeSpace: Boolean);
    
  Returns the default/preferred width and height for a control, which is used
  by the LCL autosizing algorithms as default size. Only positive values are
  valid. Negative or 0 are treated as undefined and the LCL uses other sizes
  instead.

  Raw: If not Raw then the values will be adjusted by the constraints and
  undefined values will be replaced by the current width and height.

  WithThemeSpace: If true, adds space for stacking. For example: TRadioButton
  has a minimum size. But for stacking multiple TRadioButtons there should be
  some space around. This space is theme dependent, so it passed parameter to
  the widgetset.

  TWinControl overrides this and asks the interface for theme dependent values.
  See TWinControl.GetPreferredSize for more information.
 ------------------------------------------------------------------------------}

TControl.EditingDone
  
  Called when user has finished editing. This procedure can be used by data
  links to commit the changes.
  For example:
  - When focus switches to another control (default)
  - When user selected another item
  It's totally up to the control, what events will commit.

{------------------------------------------------------------------------------
  Method: TControl.BeginDrag
  Params: Immediate: Drag behaviour
          Threshold: distance to move before dragging starts
                     -1 uses the default value of Mouse.DragThreshold
  Returns: Nothing

  Starts the dragging of a control. If the Immediate flag is set, dragging
  starts immediately.
 ------------------------------------------------------------------------------}

* The VCL implementation relies on the virtual Get/SetTextBuf to 
 * exchange text between widgets and VCL. This means a lot of 
 * (unnecesary) text copies.
 * The LCL uses strings for exchanging text (more efficient).
 * To maintain VCL compatibility, the virtual RealGet/SetText is
 * introduced. These functions interface with the LCLInterface. The
 * default Get/SetTextbuf implementation calls the RealGet/SetText.
 * As long as the Get/SetTextBuf isn't overridden Get/SetText 
 * calls RealGet/SetText to avoid PChar copying.
 * To keep things optimal, LCL implementations should always 
 * override RealGet/SetText. Get/SetTextBuf is only kept for
 * compatibility.

* The VCL implementation relies on the virtual Get/SetTextBuf to 
 * exchange text between widgets and VCL. This means a lot of 
 * (unnecesary) text copies.
 * The LCL uses strings for exchanging text (more efficient).
 * To maintain VCL compatibility, the virtual RealGet/SetText is
 * introduced. These functions interface with the LCLInterface. The
 * default Get/SetTextbuf implementation calls the RealGet/SetText.
 * As long as the Get/SetTextBuf isn't overridden Get/SetText 
 * calls RealGet/SetText to avoid PChar copying.
 * To keep things optimal, LCL implementations should always 
 * override RealGet/SetText. Get/SetTextBuf is only kept for
 * compatibility.

By default, the Caption appears the same as the control Name in the Object Inspector, and the developer needs to set it explicitly to some new text.

Gets caption as a text-string (GetText), or stores the new caption (SetText). Shows flag if caption is stored (IsCaptionStored).

The VCL implementation relies on the virtual Get/SetTextBuf to exchange text between widgets and VCL. This means a lot of (unnecesary) text copies. The LCL uses strings for exchanging text (more efficient). To maintain VCL compatibility, the virtual RealGet/SetText is introduced. These functions interface with the LCLInterface. The default Get/SetTextbuf implementation calls the RealGet/SetText. As long as the Get/SetTextBuf isn't overridden Get/SetText calls RealGet/SetText to avoid PChar copying. To keep things optimal, LCL implementations should always override RealGet/SetText. Get/SetTextBuf is only kept for compatibility.

The Visible property represents the ability to see a visual control. 
          If Visible is True the control is shown, otherwise it is hidden.
          Setting Visible to True is equivalent to calling Show method.
          Setting Visible to False is equivalent to calling Hide method.

TGraphicControl supports simple lightweight controls that do not 
need the ability to accept keyboard input or contain other controls.  Since 
lightweight controls do not wrap GUI screen objects, they are faster and use 
fewer resources than controls based on TWinControl.
          TGraphicControl provides a Canvas property for access to the 
control's drawing surface and a virtual Paint method called in response to 
paint requests received by the parent control.

The TGraphicsControl.Canvas is a clipping window to the parent canvas.

If you ask for the Canvas.Width or Canvas.Height, you are actually getting the parent control's Canvas dimensions. To get the dimensions of the TGraphicControl, you must query the ClientRect.