.TH wxScrollBar 3erl "wx 2.2.1" "wxWidgets team." "Erlang Module Definition"
.SH NAME
wxScrollBar \- Functions for wxScrollBar class
.SH DESCRIPTION
.LP
A \fIwxScrollBar\fR\& is a control that represents a horizontal or vertical scrollbar\&.
.LP
It is distinct from the two scrollbars that some windows provide automatically, but the two types of scrollbar share the way events are received\&.
.LP
Remark: A scrollbar has the following main attributes: range, thumb size, page size, and position\&. The range is the total number of units associated with the view represented by the scrollbar\&. For a table with 15 columns, the range would be 15\&. The thumb size is the number of units that are currently visible\&. For the table example, the window might be sized so that only 5 columns are currently visible, in which case the application would set the thumb size to 5\&. When the thumb size becomes the same as or greater than the range, the scrollbar will be automatically hidden on most platforms\&. The page size is the number of units that the scrollbar should scroll by, when \&'paging\&' through the data\&. This value is normally the same as the thumb size length, because it is natural to assume that the visible window size defines a page\&. The scrollbar position is the current thumb position\&. Most applications will find it convenient to provide a function called AdjustScrollbars() which can be called initially, from an OnSize event handler, and whenever the application data changes in size\&. It will adjust the view, object and page size according to the size of the window and the size of the data\&.
.LP
Styles
.LP
This class supports the following styles:
.LP
The difference between EVT_SCROLL_THUMBRELEASE and EVT_SCROLL_CHANGED
.LP
The EVT_SCROLL_THUMBRELEASE event is only emitted when actually dragging the thumb using the mouse and releasing it (This EVT_SCROLL_THUMBRELEASE event is also followed by an EVT_SCROLL_CHANGED event)\&.
.LP
The EVT_SCROLL_CHANGED event also occurs when using the keyboard to change the thumb position, and when clicking next to the thumb (In all these cases the EVT_SCROLL_THUMBRELEASE event does not happen)\&.
.LP
In short, the EVT_SCROLL_CHANGED event is triggered when scrolling/moving has finished independently of the way it had started\&. Please see the page_samples_widgets ("Slider" page) to see the difference between EVT_SCROLL_THUMBRELEASE and EVT_SCROLL_CHANGED in action\&.
.LP
See: Overview scrolling, Overview events, \fIwxScrolled\fR\& (not implemented in wx)
.LP
This class is derived (and can use functions) from: \fIwxControl\fR\& \fIwxWindow\fR\& \fIwxEvtHandler\fR\&
.LP
wxWidgets docs: wxScrollBar
.SH "EVENTS"

.LP
Event types emitted from this class: \fIscroll_top\fR\&, \fIscroll_bottom\fR\&, \fIscroll_lineup\fR\&, \fIscroll_linedown\fR\&, \fIscroll_pageup\fR\&, \fIscroll_pagedown\fR\&, \fIscroll_thumbtrack\fR\&, \fIscroll_thumbrelease\fR\&, \fIscroll_changed\fR\&, \fIscroll_top\fR\&, \fIscroll_bottom\fR\&, \fIscroll_lineup\fR\&, \fIscroll_linedown\fR\&, \fIscroll_pageup\fR\&, \fIscroll_pagedown\fR\&, \fIscroll_thumbtrack\fR\&, \fIscroll_thumbrelease\fR\&, \fIscroll_changed\fR\&
.SH DATA TYPES
.nf

\fBwxScrollBar()\fR\& = wx:wx_object()
.br
.fi
.SH EXPORTS
.LP
.nf

.B
new() -> wxScrollBar()
.br
.fi
.br
.RS
.LP
Default constructor\&.
.RE

.LP
.nf

.B
new(Parent, Id) -> wxScrollBar()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Parent = wxWindow:wxWindow()
.br
Id = integer()
.br
.RE
.RE
.LP
.nf

.B
new(Parent, Id, Options :: [Option]) -> wxScrollBar()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Parent = wxWindow:wxWindow()
.br
Id = integer()
.br
Option = 
.br
    {pos, {X :: integer(), Y :: integer()}} |
.br
    {size, {W :: integer(), H :: integer()}} |
.br
    {style, integer()} |
.br
    {validator, wx:wx_object()}
.br
.RE
.RE
.RS
.LP
Constructor, creating and showing a scrollbar\&.
.LP
See: \fIcreate/4\fR\&, \fIwxValidator\fR\& (not implemented in wx)
.RE

.LP
.nf

.B
destroy(This :: wxScrollBar()) -> ok
.br
.fi
.br
.RS
.LP
Destructor, destroying the scrollbar\&.
.RE

.LP
.nf

.B
create(This, Parent, Id) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
Parent = wxWindow:wxWindow()
.br
Id = integer()
.br
.RE
.RE
.LP
.nf

.B
create(This, Parent, Id, Options :: [Option]) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
Parent = wxWindow:wxWindow()
.br
Id = integer()
.br
Option = 
.br
    {pos, {X :: integer(), Y :: integer()}} |
.br
    {size, {W :: integer(), H :: integer()}} |
.br
    {style, integer()} |
.br
    {validator, wx:wx_object()}
.br
.RE
.RE
.RS
.LP
Scrollbar creation function called by the scrollbar constructor\&.
.LP
See \fInew/3\fR\& for details\&.
.RE

.LP
.nf

.B
getRange(This) -> integer()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
.RE
.RE
.RS
.LP
Returns the length of the scrollbar\&.
.LP
See: \fIsetScrollbar/6\fR\& 
.RE

.LP
.nf

.B
getPageSize(This) -> integer()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
.RE
.RE
.RS
.LP
Returns the page size of the scrollbar\&.
.LP
This is the number of scroll units that will be scrolled when the user pages up or down\&. Often it is the same as the thumb size\&.
.LP
See: \fIsetScrollbar/6\fR\& 
.RE

.LP
.nf

.B
getThumbPosition(This) -> integer()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
.RE
.RE
.RS
.LP
Returns the current position of the scrollbar thumb\&.
.LP
See: \fIsetThumbPosition/2\fR\& 
.RE

.LP
.nf

.B
getThumbSize(This) -> integer()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
.RE
.RE
.RS
.LP
Returns the thumb or \&'view\&' size\&.
.LP
See: \fIsetScrollbar/6\fR\& 
.RE

.LP
.nf

.B
setThumbPosition(This, ViewStart) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
ViewStart = integer()
.br
.RE
.RE
.RS
.LP
Sets the position of the scrollbar\&.
.LP
See: \fIgetThumbPosition/1\fR\& 
.RE

.LP
.nf

.B
setScrollbar(This, Position, ThumbSize, Range, PageSize) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
Position = ThumbSize = Range = PageSize = integer()
.br
.RE
.RE
.LP
.nf

.B
setScrollbar(This, Position, ThumbSize, Range, PageSize,
.B
             Options :: [Option]) ->
.B
                ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxScrollBar()
.br
Position = ThumbSize = Range = PageSize = integer()
.br
Option = {refresh, boolean()}
.br
.RE
.RE
.RS
.LP
Sets the scrollbar properties\&.
.LP
Remark: Let\&'s say you wish to display 50 lines of text, using the same font\&. The window is sized so that you can only see 16 lines at a time\&. You would use: The page size is 1 less than the thumb size so that the last line of the previous page will be visible on the next page, to help orient the user\&. Note that with the window at this size, the thumb position can never go above 50 minus 16, or 34\&. You can determine how many lines are currently visible by dividing the current view size by the character height in pixels\&. When defining your own scrollbar behaviour, you will always need to recalculate the scrollbar settings when the window size changes\&. You could therefore put your scrollbar calculations and \fIsetScrollbar/6\fR\& call into a function named AdjustScrollbars, which can be called initially and also from a \fIwxSizeEvent\fR\& event handler function\&.
.RE