Adjuster(3I) InterViews Reference Manual Adjuster(3I)
Adjuster - button-like interactors for incremental scrolling and zooming
Adjuster objects manipulate a perspective using a pushbutton-like interface. Adjusters also provide an auto-repeat capability. Depressing
and holding down any mouse button on an adjuster for a specified time causes it to repeatedly perform its operation. The auto-repeat ter-
minates when the button is released.
Predefined subclasses of Adjuster include Zoomer and Mover. Zoomers adjust the perspective's curwidth and curheight members to suggest
magnification. The user clicks on a zoomer to magnify or reduce the contents of the interactor through its perspective. The Enlarger
zoomer subclass halves the perspective values while the Reducer class doubles them. Movers provide an incremental movement of the perspec-
tive in one of four directions; left, right, down, or up. The user clicks on a mover to move the perspective.
Adjuster(Interactor*, int = NO_AUTOREPEAT)
Adjuster constructors take a pointer to the interactor whose perspective will be adjusted and a delay (in tenths of a second) after
which auto-repeat will begin once the adjuster is ``pressed''.
virtual void Highlight()
virtual void UnHighlight()
These functions define how the adjuster draws itself when it is pressed. The adjuster is highlighted when it is pressed with any
mouse button and unhighlighted when the button is released. The default is to invert the adjuster when highlighted.
virtual void AdjustView(Event&)
This function defines how the adjuster adjusts the interactor's perspective. It is called after the adjuster is pressed and
released, or repeatedly during auto-repeat. Derived classes should redefine this function to implement the desired behavior.
Enlargers and reducers adjust an interactor's perspective to enlarge and reduce the visible area by factors of one half and two,
respectively. This suggests to an interactor to enlarge or reduce its contents. Auto-repeat is disabled on these adjusters.
LeftMover(Interactor*, int delay = NO_AUTOREPEAT)
RightMover(Interactor*, int delay = NO_AUTOREPEAT)
DownMover(Interactor*, int delay = NO_AUTOREPEAT)
UpMover(Interactor*, int delay = NO_AUTOREPEAT)
These subclasses of Mover adjust the current origin of the interactor's perspective by an amount in the corresponding direction. If
the shift key is down while the mover is pressed, the amount corresponds to the perspective's lx or ly member variables; otherwise,
the sx or sy values are used.
InterViews 15 January 1988 Adjuster(3I)