wxVarHScrollHelper Class Reference

#include <wx/vscroll.h>

Inheritance diagram for wxVarHScrollHelper:

Detailed Description

This class provides functions wrapping the wxVarScrollHelperBase class, targeted for horizontal-specific scrolling.

Like wxVarScrollHelperBase, this class is mostly only useful to those classes built into wxWidgets deriving from here, and this documentation is mostly only provided for referencing the functions provided by this class. You will likely want to derive your window from wxHScrolledWindow rather than from here directly.

Library:  wxCore

Category:  Miscellaneous Windows

See Also

wxHScrolledWindow, wxHVScrolledWindow, wxVScrolledWindow

Public Member Functions
	wxVarHScrollHelper (wxWindow *winToScroll)
	Constructor taking the target window to be scrolled by this helper class.
size_t	GetColumnCount () const
	Returns the number of columns the target window contains.
size_t	GetVisibleColumnsBegin () const
	Returns the index of the first visible column based on the scroll position.
size_t	GetVisibleColumnsEnd () const
	Returns the index of the last visible column based on the scroll position.
bool	IsColumnVisible (size_t column) const
	Returns true if the given column is currently visible (even if only partially visible) or false otherwise.
virtual void	RefreshColumn (size_t column)
	Triggers a refresh for just the given column's area of the window if it's visible.
virtual void	RefreshColumns (size_t from, size_t to)
	Triggers a refresh for the area between the specified range of columns given (inclusively).
virtual bool	ScrollColumnPages (int pages)
	Scroll by the specified number of pages which may be positive (to scroll right) or negative (to scroll left).
virtual bool	ScrollColumns (int columns)
	Scroll by the specified number of columns which may be positive (to scroll right) or negative (to scroll left).
bool	ScrollToColumn (size_t column)
	Scroll to the specified column.
void	SetColumnCount (size_t columnCount)
	Set the number of columns the window contains.
Public Member Functions inherited from wxVarScrollHelperBase
	wxVarScrollHelperBase (wxWindow *winToScroll)
	Constructor taking the target window to be scrolled by this helper class.
virtual	~wxVarScrollHelperBase ()
	Virtual destructor for detaching scroll event handlers attached with this helper class.
int	CalcScrolledPosition (int coord) const
	Translates the logical coordinate given to the current device coordinate.
int	CalcUnscrolledPosition (int coord) const
	Translates the device coordinate given to the corresponding logical coordinate.
void	EnablePhysicalScrolling (bool scrolling=true)
	With physical scrolling on (when this is true), the device origin is changed properly when a wxPaintDC is prepared, children are actually moved and laid out properly, and the contents of the window (pixels) are actually moved.
virtual int	GetNonOrientationTargetSize () const =0
	This function needs to be overridden in the in the derived class to return the window size with respect to the opposing orientation.
virtual wxOrientation	GetOrientation () const =0
	This function need to be overridden to return the orientation that this helper is working with, either wxHORIZONTAL or wxVERTICAL.
virtual int	GetOrientationTargetSize () const =0
	This function needs to be overridden in the in the derived class to return the window size with respect to the orientation this helper is working with.
virtual wxWindow *	GetTargetWindow () const
	This function will return the target window this helper class is currently scrolling.
size_t	GetVisibleBegin () const
	Returns the index of the first visible unit based on the scroll position.
size_t	GetVisibleEnd () const
	Returns the index of the last visible unit based on the scroll position.
bool	IsVisible (size_t unit) const
	Returns true if the given scroll unit is currently visible (even if only partially visible) or false otherwise.
virtual void	RefreshAll ()
	Recalculate all parameters and repaint all units.
virtual void	SetTargetWindow (wxWindow *target)
	Normally the window will scroll itself, but in some rare occasions you might want it to scroll (part of) another window (e.g.
virtual void	UpdateScrollbar ()
	Update the thumb size shown by the scrollbar.
int	VirtualHitTest (wxCoord coord) const
	Returns the virtual scroll unit under the device unit given accounting for scroll position or wxNOT_FOUND if none (i.e.

Protected Member Functions
virtual wxCoord	EstimateTotalWidth () const
	This class forwards calls from EstimateTotalSize() to this function so derived classes can override either just the height or the width estimation, or just estimate both differently if desired in any wxHVScrolledWindow derived class.
virtual void	OnGetColumnsWidthHint (size_t columnMin, size_t columnMax) const
	This function doesn't have to be overridden but it may be useful to do so if calculating the columns' sizes is a relatively expensive operation as it gives your code a chance to calculate several of them at once and cache the result if necessary.
virtual wxCoord	OnGetColumnWidth (size_t column) const =0
	This function must be overridden in the derived class, and should return the width of the given column in pixels.
Protected Member Functions inherited from wxVarScrollHelperBase
virtual void	OnGetUnitsSizeHint (size_t unitMin, size_t unitMax) const
	This function doesn't have to be overridden but it may be useful to do so if calculating the units' sizes is a relatively expensive operation as it gives your code a chance to calculate several of them at once and cache the result if necessary.
virtual wxCoord	EstimateTotalSize () const
	When the number of scroll units change, we try to estimate the total size of all units when the full window size is needed (i.e.
virtual wxCoord	OnGetUnitSize (size_t unit) const =0
	This function must be overridden in the derived class, and should return the size of the given unit in pixels.

Constructor & Destructor Documentation

wxVarHScrollHelper::wxVarHScrollHelper

(

wxWindow *

winToScroll

)

Constructor taking the target window to be scrolled by this helper class.

This will attach scroll event handlers to the target window to catch and handle scroll events appropriately.

Member Function Documentation

virtual wxCoord wxVarHScrollHelper::EstimateTotalWidth ( ) const

protectedvirtual

This class forwards calls from EstimateTotalSize() to this function so derived classes can override either just the height or the width estimation, or just estimate both differently if desired in any wxHVScrolledWindow derived class.

Note

This function will not be called if EstimateTotalSize() is overridden in your derived class.

size_t wxVarHScrollHelper::GetColumnCount

(

)

const

Returns the number of columns the target window contains.

See Also

SetColumnCount()

size_t wxVarHScrollHelper::GetVisibleColumnsBegin

(

)

const

Returns the index of the first visible column based on the scroll position.

size_t wxVarHScrollHelper::GetVisibleColumnsEnd

(

)

const

Returns the index of the last visible column based on the scroll position.

This includes the last column even if it is only partially visible.

bool wxVarHScrollHelper::IsColumnVisible

(

size_t

column

)

const

Returns true if the given column is currently visible (even if only partially visible) or false otherwise.

virtual void wxVarHScrollHelper::OnGetColumnsWidthHint ( size_t  columnMin, size_t  columnMax  ) const

protectedvirtual

This function doesn't have to be overridden but it may be useful to do so if calculating the columns' sizes is a relatively expensive operation as it gives your code a chance to calculate several of them at once and cache the result if necessary.

OnGetColumnsWidthHint() is normally called just before OnGetColumnWidth() but you shouldn't rely on the latter being called for all columns in the interval specified here. It is also possible that OnGetColumnWidth() will be called for units outside of this interval, so this is really just a hint, not a promise.

Finally, note that columnMin is inclusive, while columnMax is exclusive.

virtual wxCoord wxVarHScrollHelper::OnGetColumnWidth ( size_t  column ) const

protectedpure virtual

This function must be overridden in the derived class, and should return the width of the given column in pixels.

virtual void wxVarHScrollHelper::RefreshColumn ( size_t  column )

virtual

Triggers a refresh for just the given column's area of the window if it's visible.

virtual void wxVarHScrollHelper::RefreshColumns ( size_t  from, size_t  to  )

virtual

Triggers a refresh for the area between the specified range of columns given (inclusively).

virtual bool wxVarHScrollHelper::ScrollColumnPages ( int  pages )

virtual

Scroll by the specified number of pages which may be positive (to scroll right) or negative (to scroll left).

virtual bool wxVarHScrollHelper::ScrollColumns ( int  columns )

virtual

Scroll by the specified number of columns which may be positive (to scroll right) or negative (to scroll left).

Returns

true if the window was scrolled, false otherwise (for example, if we're trying to scroll right but we are already showing the last column).

bool wxVarHScrollHelper::ScrollToColumn

(

size_t

column

)

Scroll to the specified column.

It will become the first visible column in the window.

Returns

true if we scrolled the window, false if nothing was done.

void wxVarHScrollHelper::SetColumnCount

(

size_t

columnCount

)

Set the number of columns the window contains.

The derived class must provide the widths for all columns with indices up to the one given here in it's OnGetColumnWidth() implementation.

See Also

GetColumnCount()