void SetDirection(long set)
long GetDirection(void)
Set/Return the direction of the scroll-bar.
Acceptable values are
WDS_SCROLLBAR_HORIZONTAL or WDS_SCROLLBAR_VERTICAL.
void SetOffset(float set)
float GetOffset(void)
Set/Get the offset of the piston within the shaft, relative to unity.
For example, an offset of 0.2 will display a bar that is offset
one fifth into the length of the shaft.
Values are automatically bounded to the ends of the shaft.
This value can also be interactively changed by the user by
operating the scroll-bar, assuming the scroll-bar is configured to do so.
void SetFraction(float set)
float GetFraction(void)
Set/Get the fraction that the piston represents, relative to unity.
For example, a fraction of 0.25 will display a piston that is one quarter the size of the length of the shaft.
Values are automatically bounded to the ends of the shaft.
void SetStepSize(float set)
float GetStepSize(void)
Set/Get the fraction that the piston moves after an arrow button press.
Movement is automatically bounded to the ends of the shaft.
void Increment(void)
void Decrement(void)
Move the piston one step size as though an arrow button was pressed.
void AddField(float start,float size)
void ClearFields(void)
Add one or clear all scroll fields. These appear as
off-colored ranges in the scroll shaft background.
If a scroll-bar has any fields, it will presumably
switch to an alternate "hollow" style piston
for increased visibility of the underlying shaft. The
start and size
are like the offset and fraction described above.
For WDS_ScrollRegion's,
these member functions should not be called directly,
but through WDS_ScrollRegion's member functions.
| WDS_STATE_0 | Piston moved |
| WDS_STATE_1 | Piston grabbed for moving |