perspective(3i) [centos man page]

Perspective(3I)                                             InterViews Reference Manual                                            Perspective(3I)

NAME

       Perspective - visible portion of an interactor

SYNOPSIS

       #include <InterViews/perspective.h>

DESCRIPTION

       A  perspective  object  describes  which part of an interactor's total display area is visible in the interactor's canvas.  The main use of
       perspectives is for scrolling, panning, and zooming interactors.  The member variables (x0, y0) define the origin of the interactor's  dis-
       play  area;  width  and  height define the total height of the area.  The member variables (curx, cury) define the lower-left corner of the
       interactor's canvas relative to the total area; curwidth and curheight define how much of the total area is displayed in the canvas.

       The member variables sx, sy, lx, and ly specify small and large increments in each dimension.  These increments are used by a  scroller  to
       implement line and page scrolling.

PUBLIC OPERATIONS

       Perspective()
              Define a new perspective with all member variables initialized to zero.

       void Attach(Interactor*)
              Add to the list of interactors that are interested in updates to the perspective.  These interactors reflect the perspective visual-
              ly; examples include scrollers and sliders.

       void Detach(Interactor*)
              Remove an interactor from the list of those interested in updates.  This operation should be called from the  interactor's  destruc-
              tor.

       void Init(Coord x0, Coord y0, Coord width, Coord height)
              Initialize the perspective display area.

       void Update()
              Notify all the interactors interested in the perspective that it has changed.  The perspective's interactor should call Update after
              modifying its perspective.

SEE ALSO

       Adjuster(3I), Interactor(3I), Panner(3I), Scroller(3I)

InterViews                                                         15 June 1987                                                    Perspective(3I)

Panner(3I)						    InterViews Reference Manual 						Panner(3I)

NAME

       Panner - two-dimensional scrolling and zooming

SYNOPSIS

       #include <InterViews/panner.h>

DESCRIPTION

       A  panner is an interactor that manipulates the perspective of another interactor to provide two-dimensional scrolling and zooming.  A pan-
       ner is composed of a slider and several adjusters, including two zoomers and four movers. The slider's position and size reflect  the  cur-
       rent  origin,  size, and aspect ratio in the interactor's perspective.  Dragging the slider around with the mouse changes the perspective's
       curx and cury members.

PUBLIC OPERATIONS

       Panner(Interactor*, int size = 0)
	      Create a panner for the given interactor, optionally with the given width.  If the size is 0, a reasonable  default  size  is  used.
	      The panner's aspect ratio reflects that of the perspective.

       Slider(Interactor*)
       Slider::Handle(Event&)
       Slider::Reshape(Shape&)
       Slider::Update()
	      A  slider  reflects  and	lets the user specify the visible portion of the view.	A rectangle represents the visible area, while the
	      area surrounding it represents the total area.  Clicking and holding down any mouse button on the rectangle allows you to drag it to
	      a different position within the total area.  The perspective's current origin is shifted to reflect the new position when the button
	      is released.  Holding down the shift key while dragging the rectangle constrains its motion horizontally	or  vertically.   Clicking
	      outside  the  rectangle  moves  it in the corresponding one of eight directions; for example, clicking to the right of the rectangle
	      moves it to the right.  If the left mouse button is used, the movement increment equals the perspective's sx or sy member variables.
	      The  middle  mouse  button  increments by lx or ly, and the right mouse button centers the rectangle around the cursor.  The Reshape
	      call sets the width of the slider to that of the passed Shape and calls Change on the  parent  interactor.   Update  redisplays  the
	      slider to reflect a change in the interactor's perspective.

X DEFAULTS

       The  ``syncScroll''  resource  specifies  whether  the slider should work in real-time or not.  When synchronized scrolling is employed the
       interactor scrolls synchronously as the slider is dragged; otherwise the slider's outline follows the mouse during dragging, and the inter-
       actor  is scrolled only after the user stops dragging the slider.  Sliders will scroll synchronously if their syncScroll resource is set to
       ``on'' or ``true.''

SEE ALSO

       Adjuster(3I), Interactor(3I), Perspective(3I)

InterViews							  15 January 1988							Panner(3I)