************ wx.ScrollBar ************ Inheritance diagram for `wx.ScrollBar`: | .. inheritance-diagram:: wx.ScrollBar | Description =========== A `wx.ScrollBar` 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. .. seealso:: `wx.ScrolledWindow `_ Derived From ^^^^^^^^^^^^^ * `wx.Control `_ * `wx.Window `_ * `wx.EvtHandler `_ * `wx.Object `_ Window Styles ^^^^^^^^^^^^^ ================================================== ================================================== Window Style Description ================================================== ================================================== ``wx.SB_HORIZONTAL`` Specifies a horizontal scrollbar. ``wx.SB_VERTICAL`` Specifies a vertical scrollbar. ================================================== ================================================== Event Handling ^^^^^^^^^^^^^^ To process a scroll event, use these event handler macros to direct input to member functions that take a `wx.ScrollEvent <../Events/wx.ScrollEvent.html>`_ argument. 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 Name Description ================================================== ================================================== wx.EVT_SCROLL(func) Process all scroll events. wx.EVT_SCROLL_TOP(func) Process ``wx.wxEVT_SCROLL_TOP`` scroll-to-top events (minimum position). wx.EVT_SCROLL_BOTTOM(func) Process ``wx.wxEVT_SCROLL_BOTTOM`` scroll-to-bottom events (maximum position). wx.EVT_SCROLL_LINEUP(func) Process ``wx.wxEVT_SCROLL_LINEUP`` line up events. wx.EVT_SCROLL_LINEDOWN(func) Process ``wx.wxEVT_SCROLL_LINEDOWN`` line down events. wx.EVT_SCROLL_PAGEUP(func) Process ``wx.wxEVT_SCROLL_PAGEUP`` page up events. wx.EVT_SCROLL_PAGEDOWN(func) Process ``wx.wxEVT_SCROLL_PAGEDOWN`` page down events. wx.EVT_SCROLL_THUMBTRACK(func) Process ``wx.wxEVT_SCROLL_THUMBTRACK`` thumbtrack events (frequent events sent as the user drags the thumbtrack). wx.EVT_SCROLL_THUMBRELEASE(func) Process ``wx.wxEVT_SCROLL_THUMBRELEASE`` thumb release events. wx.EVT_SCROLL_CHANGED(func) Process ``wx.wxEVT_SCROLL_CHANGED`` end of scrolling events (MSW only). wx.EVT_COMMAND_SCROLL(id, func) Process all scroll events. wx.EVT_COMMAND_SCROLL_TOP(id, func) Process ``wx.wxEVT_SCROLL_TOP`` scroll-to-top events (minimum position). wx.EVT_COMMAND_SCROLL_BOTTOM(id, func) Process ``wx.wxEVT_SCROLL_BOTTOM`` scroll-to-bottom events (maximum position). wx.EVT_COMMAND_SCROLL_LINEUP(id, func) Process ``wx.wxEVT_SCROLL_LINEUP`` line up events. wx.EVT_COMMAND_SCROLL_LINEDOWN(id, func) Process ``wx.wxEVT_SCROLL_LINEDOWN`` line down events. wx.EVT_COMMAND_SCROLL_PAGEUP(id, func) Process ``wx.wxEVT_SCROLL_PAGEUP`` page up events. wx.EVT_COMMAND_SCROLL_PAGEDOWN(id, func) Process ``wx.wxEVT_SCROLL_PAGEDOWN`` page down events. wx.EVT_COMMAND_SCROLL_THUMBTRACK(id, func) Process ``wx.wxEVT_SCROLL_THUMBTRACK`` thumbtrack events (frequent events sent as the user drags the thumbtrack). wx.EVT_COMMAND_SCROLL_THUMBRELEASE(func) Process ``wx.wxEVT_SCROLL_THUMBRELEASE`` thumb release events. wx.EVT_COMMAND_SCROLL_CHANGED(func) Process ``wx.wxEVT_SCROLL_CHANGED`` end of scrolling events (MSW only). ================================================== ================================================== 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. | Control Appearance ^^^^^^^^^^^^^^^^^^ | .. figure:: ../images/wxWidgets/wxmsw/scrollbar.png :alt: wxMSW :figclass: floatleft **wxMSW** .. figure:: ../images/wxWidgets/wxmac/scrollbar.png :alt: wxMAC :figclass: floatright **wxMAC** .. figure:: ../images/wxWidgets/wxgtk/scrollbar.png :alt: wxGTK :figclass: floatcenter **wxGTK** | Methods Summary ^^^^^^^^^^^^^^^ * `__init__ <#__init__>`_ * `GetPageSize <#GetPageSize>`_ * `GetRange <#GetRange>`_ * `GetThumbPosition <#GetThumbPosition>`_ * `GetThumbSize <#GetThumbSize>`_ * `IsVertical <#IsVertical>`_ * `SetScrollbar <#SetScrollbar>`_ * `SetThumbPosition <#SetThumbPosition>`_ Properties Summary ^^^^^^^^^^^^^^^^^^ * `PageSize <#PageSize>`_ * `Range <#Range>`_ * `ThumbPosition <#ThumbPosition>`_ * `ThumbSize <#ThumbSize>`_ Class API ========= Methods ^^^^^^^ .. method:: __init__(parent, id=-1, pos=wx.DefaultPosition, size=wx.DefaultSize, style=wx.SB_HORIZONTAL, validator=wx.DefaultValidator, name=wx.ScrollBarNameStr) Constructor, creating and showing a scrollbar. **Parameters:** * `parent` (`wx.Window `_) * `id` (int) * `pos` (`wx.Point `_) * `size` (`wx.Size `_) * `style` (long) * `validator` (`wx.Validator `_) * `name` (string) | **Returns:** `wx.ScrollBar `_ -------- .. method:: GetPageSize() 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:** `int` .. seealso:: `SetScrollbar <#SetScrollbar>`_ -------- .. method:: GetRange() Returns the length of the scrollbar. | **Returns:** `int` .. seealso:: `SetScrollbar <#SetScrollbar>`_ -------- .. method:: GetThumbPosition() Returns the current position of the scrollbar thumb. | **Returns:** `int` .. seealso:: `SetThumbPosition <#SetThumbPosition>`_ -------- .. method:: GetThumbSize() Returns the thumb or 'view' size. | **Returns:** `int` .. seealso:: `SetScrollbar <#SetScrollbar>`_ -------- .. method:: IsVertical() `No docstrings available for this method.` -------- .. method:: SetScrollbar(position, thumbSize, range, pageSize, refresh=True) Sets the scrollbar properties. 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:: scrollbar.SetScrollbar(0, 16, 50, 15) 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:: Note that with the window at this size, the thumb position can never go above 50 minus 16, or 34. **Parameters:** * `position` (int): The position of the scrollbar in scroll units. * `thumbSize` (int): The size of the thumb, or visible portion of the scrollbar, in scroll units. * `range` (int): The maximum position of the scrollbar. * `pageSize` (int): 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. * `refresh` (bool): ``True`` to redraw the scrollbar, ``False`` otherwise. .. note:: You can determine how many lines are currently visible by dividing the current view size by the character height in pixels. .. note:: 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 `wx.SizeEvent <../Events/wx.SizeEvent.html>`_ event handler function. .. seealso:: `wx.Window.SetScrollbar `_, `wx.ScrolledWindow `_ -------- .. method:: SetThumbPosition(viewStart) Sets the position of the scrollbar. **Parameters:** * `viewStart` (int): The position of the scrollbar thumb. .. seealso:: `GetThumbPosition <#GetThumbPosition>`_ -------- Properties ^^^^^^^^^^ .. attribute:: PageSize See `GetPageSize <#GetPageSize>`_ .. attribute:: Range See `GetRange <#GetRange>`_ .. attribute:: ThumbPosition See `GetThumbPosition <#GetThumbPosition>`_ and `SetThumbPosition <#SetThumbPosition>`_ .. attribute:: ThumbSize See `GetThumbSize <#GetThumbSize>`_