// Purpose: interface of wxScrollBar
// Author: wxWidgets team
// RCS-ID: $Id$
-// Licence: wxWindows license
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
/**
@class wxScrollBar
- A wxScrollBar is a control that represents a horizontal or
- vertical scrollbar. It is distinct from the two scrollbars that some windows
- provide automatically, but the two types of scrollbar share the way
- events are received.
+ A wxScrollBar is a control that represents a horizontal or vertical scrollbar.
+
+ It is distinct from the two scrollbars that some windows provide automatically,
+ but the two types of scrollbar share the way events are received.
+
+ @remarks
+ 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.
@beginStyleTable
@style{wxSB_HORIZONTAL}
Specifies a vertical scrollbar.
@endStyleTable
+ @beginEventEmissionTable{wxScrollEvent}
+ You can use EVT_COMMAND_SCROLL... macros with window IDs for when intercepting
+ scroll events from controls, or EVT_SCROLL... macros without window IDs for
+ intercepting scroll events from the receiving window -- except for this,
+ the macros behave exactly the same.
+ @event{EVT_SCROLL(func)}
+ Process all scroll events.
+ @event{EVT_SCROLL_TOP(func)}
+ Process @c wxEVT_SCROLL_TOP scroll-to-top events (minimum position).
+ @event{EVT_SCROLL_BOTTOM(func)}
+ Process @c wxEVT_SCROLL_BOTTOM scroll-to-bottom events (maximum position).
+ @event{EVT_SCROLL_LINEUP(func)}
+ Process @c wxEVT_SCROLL_LINEUP line up events.
+ @event{EVT_SCROLL_LINEDOWN(func)}
+ Process @c wxEVT_SCROLL_LINEDOWN line down events.
+ @event{EVT_SCROLL_PAGEUP(func)}
+ Process @c wxEVT_SCROLL_PAGEUP page up events.
+ @event{EVT_SCROLL_PAGEDOWN(func)}
+ Process @c wxEVT_SCROLL_PAGEDOWN page down events.
+ @event{EVT_SCROLL_THUMBTRACK(func)}
+ Process @c wxEVT_SCROLL_THUMBTRACK thumbtrack events
+ (frequent events sent as the user drags the thumbtrack).
+ @event{EVT_SCROLL_THUMBRELEASE(func)}
+ Process @c wxEVT_SCROLL_THUMBRELEASE thumb release events.
+ @event{EVT_SCROLL_CHANGED(func)}
+ Process @c wxEVT_SCROLL_CHANGED end of scrolling events (MSW only).
+ @event{EVT_COMMAND_SCROLL(id, func)}
+ Process all scroll events.
+ @event{EVT_COMMAND_SCROLL_TOP(id, func)}
+ Process @c wxEVT_SCROLL_TOP scroll-to-top events (minimum position).
+ @event{EVT_COMMAND_SCROLL_BOTTOM(id, func)}
+ Process @c wxEVT_SCROLL_BOTTOM scroll-to-bottom events (maximum position).
+ @event{EVT_COMMAND_SCROLL_LINEUP(id, func)}
+ Process @c wxEVT_SCROLL_LINEUP line up events.
+ @event{EVT_COMMAND_SCROLL_LINEDOWN(id, func)}
+ Process @c wxEVT_SCROLL_LINEDOWN line down events.
+ @event{EVT_COMMAND_SCROLL_PAGEUP(id, func)}
+ Process @c wxEVT_SCROLL_PAGEUP page up events.
+ @event{EVT_COMMAND_SCROLL_PAGEDOWN(id, func)}
+ Process @c wxEVT_SCROLL_PAGEDOWN page down events.
+ @event{EVT_COMMAND_SCROLL_THUMBTRACK(id, func)}
+ Process @c wxEVT_SCROLL_THUMBTRACK thumbtrack events
+ (frequent events sent as the user drags the thumbtrack).
+ @event{EVT_COMMAND_SCROLL_THUMBRELEASE(func)}
+ Process @c wxEVT_SCROLL_THUMBRELEASE thumb release events.
+ @event{EVT_COMMAND_SCROLL_CHANGED(func)}
+ Process @c wxEVT_SCROLL_CHANGED end of scrolling events (MSW only).
+ @endEventTable
+
+ @section scrollbar_diff The difference between EVT_SCROLL_THUMBRELEASE and EVT_SCROLL_CHANGED
+
+ 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).
+
+ 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).
+
+ In short, the EVT_SCROLL_CHANGED event is triggered when scrolling/moving has
+ finished independently of the way it had started. Please see the widgets sample
+ ("Slider" page) to see the difference between EVT_SCROLL_THUMBRELEASE and
+ EVT_SCROLL_CHANGED in action.
+
@library{wxcore}
@category{ctrl}
- <!-- @appearance{scrollbar.png} -->
+ @appearance{scrollbar.png}
- @see @ref overview_scrolling, @ref overview_eventhandling, wxScrolled
+ @see @ref overview_scrolling, @ref overview_events, wxScrolled
*/
class wxScrollBar : public wxControl
{
Default constructor
*/
wxScrollBar();
-
+
/**
Constructor, creating and showing a scrollbar.
@param id
Window identifier. The value wxID_ANY indicates a default value.
@param pos
- Window position. If wxDefaultPosition is specified then a default
- position is chosen.
+ Window position.
+ If ::wxDefaultPosition is specified then a default position is chosen.
@param size
- Window size. If wxDefaultSize is specified then a default size
- is chosen.
+ Window size.
+ If ::wxDefaultSize is specified then a default size is chosen.
@param style
Window style. See wxScrollBar.
@param validator
const wxSize& size = wxDefaultSize,
long style = wxSB_HORIZONTAL,
const wxValidator& validator = wxDefaultValidator,
- const wxString& name = "scrollBar");
+ const wxString& name = wxScrollBarNameStr);
/**
Destructor, destroying the scrollbar.
*/
- ~wxScrollBar();
+ virtual ~wxScrollBar();
/**
Scrollbar creation function called by the scrollbar constructor.
*/
bool Create(wxWindow* parent, wxWindowID id,
const wxPoint& pos = wxDefaultPosition,
- const wxSize& size = wxDefaultSize,
- long style = wxSB_HORIZONTAL,
+ const wxSize& size = wxDefaultSize, long style = wxSB_HORIZONTAL,
const wxValidator& validator = wxDefaultValidator,
- const wxString& name = "scrollBar");
+ const wxString& name = wxScrollBarNameStr);
/**
- Returns the page size of the scrollbar. 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.
+ Returns the page size of the scrollbar.
+
+ 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.
@see SetScrollbar()
*/
- int GetPageSize() const;
+ virtual int GetPageSize() const;
/**
Returns the length of the scrollbar.
@see SetScrollbar()
*/
- int GetRange() const;
+ virtual int GetRange() const;
/**
Returns the current position of the scrollbar thumb.
@see SetThumbPosition()
*/
- int GetThumbPosition() const;
+ virtual int GetThumbPosition() const;
/**
Returns the thumb or 'view' size.
@see SetScrollbar()
*/
- int GetThumbSize() const;
+ virtual int GetThumbSize() const;
/**
Sets the scrollbar properties.
The maximum position of the scrollbar.
@param pageSize
The size of the page size in scroll units. This is the number of units
- the scrollbar will scroll when it is paged up or down. Often it is the same
- as
- the thumb size.
+ the scrollbar will scroll when it is paged up or down.
+ Often it is the same as the thumb size.
@param refresh
@true to redraw the scrollbar, @false otherwise.
- @remarks 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.
+ @remarks
+ 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:
+ @code
+ scrollbar->SetScrollbar(0, 16, 50, 15);
+ @endcode
+ 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 SetScrollbar()
+ call into a function named AdjustScrollbars, which can be called
+ initially and also from a wxSizeEvent event handler function.
*/
virtual void SetScrollbar(int position, int thumbSize, int range,
int pageSize,
@see GetThumbPosition()
*/
- void SetThumbPosition(int viewStart);
+ virtual void SetThumbPosition(int viewStart);
};
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