align(3U)						    InterViews Reference Manual 						 align(3U)

NAME

       AlignCmd, AlignToGridCmd - commands for aligning interactors to each other and to a grid

SYNOPSIS

       #include <Unidraw/Commands/align.h>

DESCRIPTION

       AlignCmd  is a purely interpretive command for aligning selected components with respect to one another. For example, it can align the left
       sides of selected components so that they coincide.  AlignToGridCmd is interpreted by selected GraphicView objects to align  themselves	to
       the  grid  (if  any)  associated with the viewer in which they appear.  Each component can thus define what it means to align itself to the
       grid.

ALIGNCMD PUBLIC OPERATIONS

       AlignCmd(
	   ControlInfo*,
	   Alignment reference = Left, Alignment affected = Left
       )

       AlignCmd(Editor* = nil, Alignment = Left, Alignment = Left)
	      The constructor takes optional arguments for specifying the alignment desired. The reference parameter specifies a point on a  fixed
	      reference  component.  The affected parameter specifies a point on components that will move to realize the alignment.  The defaults
	      for these parameters specify that all affected components should align their left sides to reference's left side.

       void GetAlignment(Alignment&, Alignment&)
	      Return the alignment parameters specified in the constructor.

       GraphicComp* GetReference(GraphicComp* affected)
	      Return the reference component given a potentially affected component.  If affected appears in the AlignCmd's clipboard, then GetRe-
	      ference  returns the GraphicComp preceding it in the clipboard.  If affected is the first component in the clipboard or if it is not
	      on the clipboard, then GetReference returns the first component on the clipboard.

ALIGNTOGRIDCMD PUBLIC OPERATIONS

       AlignToGridCmd(ControlInfo*)
       AlignToGridCmd(Editor* = nil)
	      Construct an AlignToGridCmd.

       virtual void Execute()
       virtual void Unexecute()
	      AlignToGridCmd redefines Execute to let the selected GraphicView objects interpret the command the first time.  This lets the compo-
	      nents  determine	the  proper  grid with which to align themselves and the amount of movement required.  Execute assumes that Graph-
	      icView objects will use the Align operation (described below) to compute the amount of movement, store it in a MoveData object,  and
	      finally  issue  a MoveCmd to the subject for interpretation.  Unexecute simply calls Unmove (described below) to reverse the Align's
	      effects.

       virtual void Align(GraphicView*, float, float)
       virtual void Unalign(GraphicView*)
	      GraphicView objects interpreting the AlignToGridCmd should use the Align operation to specify a point to	align  to  the	grid  that
	      affects  them.   Align will effectively move the component so that the given point falls on the grid.  It will also store the amount
	      of movement in this by calling Store with a MoveData object.  Finally, Align calls Move (described below) to actually move the  com-
	      ponent  that  amount.  Unalign provides a public interface to reversing the effects of Align by simply calling Unmove with its argu-
	      ment's subject.

ALIGNTOGRIDCMD PROTECTED OPERATIONS

       void Move(GraphicComp*)
       void Unmove(GraphicComp*)
	      Move produces a MoveCmd based on the MoveData stored for the given GraphicComp and tells the GraphicComp to interpret  the  MoveCmd.
	      Conversely, Unmove produces a MoveCmd based on the the same information and tells the GraphicComp to uninterpret it.

SEE ALSO

       Command(3U), GraphicComp(3U), GraphicView(3U), Grid(3U), Viewer(3U), datas(3U), transforms(3U)

Unidraw 							  23 January 1991							 align(3U)