xmScrollBar

An xmScrollBar may be horizontal or vertical (depending its -orientation resource). An xmScrollBar is composed of two arrows, a long rectangle called the scroll region, and a smaller rectangle called the slider. The data is scrolled by clicking either arrow, clicking inside the scroll region, or by dragging the slider. When the mouse is held down in the scroll region or in either arrow, the data continues to move at a constant speed.

The following example uses two scrollbars to move a target button:

#! /usr/sgitcl/bin/moat 
xtAppInitialize
xmBulletinBoard .top managed
xmScrollBar .top.h managed \
    -orientation horizontal -width 150 \
    -y 160 -minimum 10 -maximum 140
xmScrollBar .top.v managed \
    -orientation vertical -height 150 \
    -x 160 -minimum 10 -maximum 140
xmPushButton .top.target managed -labelString "X"
proc track_it {} {
    .top.h getValues -value x
    .top.v getValues -value y
    .top.target setValues -x [expr 8+$x] -y [expr 8+$y]
}
.top.h dragCallback track_it
.top.v dragCallback track_it
.top.h valueChangedCallback track_it
.top.v valueChangedCallback track_it
track_it
. realizeWidget
. mainLoop

xmScrollBar Resources

Resource Name	Default Value	Type or Legal Values
-increment	1	Integer
-initialDelay	250 ms	Integer
-maximum	100	Integer
-minimum	0	Integer
-orientation	vertical	horizontal vertical
-pageIncrement	10	Integer
-processingDirection	computed	max_on_bottom max_on_left max_on_right max_on_top
-repeatDelay	50 ms	Integer
-showArrows	True	Boolean
-sliderSize	computed	Integer
-troughColor	computed	Color
-value	0	Integer

The -value resource specifies the current position of the scrollbar slider, between the minimum and maximum -sliderSize. The slider moves between -minimum and -maximum by -increment steps (clipped at the ends). Clicking either scrollbar arrow moves the slider by -pageIncrement. The -sliderSize reflects the portion of the widget currently in view.

The -troughColor specifies the scrollbar slider fill color. Constant speed movement can be parameterized with -repeatDelay and -initialDelay. If -showArrows is set to False, the scroll bar will not have arrows at either end.

xmScrollBar Methods

Method Name	Why
decrementCallback	Value was decremented.
dragCallback	The slider is being dragged.
incrementCallback	Value was incremented.
pageDecrementCallback	Value was decremented by pageIncrement.
pageIncrementCallback	Value was incremented by pageIncrement.
toTopCallback	Value was reset to minimum.
toBottomCallback	Value was reset to maximum.
valueChangedCallback	The value had changed.

In the callbacks above, the %value substitution returns the current scroll bar position.