X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/8795498cd9ec480873e88fccbb63b94be3eddb92..6a121452ee63c7cfce8d2907e6209397dc9bcecb:/docs/latex/wx/vscroll.tex diff --git a/docs/latex/wx/vscroll.tex b/docs/latex/wx/vscroll.tex index 7ed7688716..d75c477519 100644 --- a/docs/latex/wx/vscroll.tex +++ b/docs/latex/wx/vscroll.tex @@ -18,20 +18,20 @@ are shown on the screen need to be measured; or, even, "vertical" because this class only supports scrolling in one direction currently (this could and probably will change in the future however). -In any case, this is a generalization of the +In any case, this is a generalization of the \helpref{wxScrolledWindow}{wxscrolledwindow} class which can be only used when all lines have the same height. It lacks some other wxScrolledWindow features however, notably there is currently no support for horizontal scrolling; it can't scroll another window nor only a rectangle of the window and not its entire client area. - -To use this class, you need to derive from it and implement + +To use this class, you need to derive from it and implement \helpref{OnGetLineHeight()}{wxvscrolledwindowongetlineheight} pure virtual -method. You also must call \helpref{SetLineCount}{wxvscrolledwindowsetlinecount} +method. You also must call \helpref{SetLineCount}{wxvscrolledwindowsetlinecount} to let the base class know how many lines it should display but from that moment on the scrolling is handled entirely by wxVScrolledWindow, you only need to draw the visible part of contents in your {\tt OnPaint()} method as -usual. You should use \helpref{GetFirstVisibleLine()}{wxvscrolledwindowgetfirstvisibleline} +usual. You should use \helpref{GetFirstVisibleLine()}{wxvscrolledwindowgetfirstvisibleline} and \helpref{GetLastVisibleLine()}{wxvscrolledwindowgetlastvisibleline} to select the lines to display. Note that the device context origin is not shifted so the first visible line always appears at the point $(0, 0)$ in physical as @@ -39,7 +39,10 @@ well as logical coordinates. \wxheading{Derived from} -\helpref{wxPanel}{wxpanel} +\helpref{wxPanel}{wxpanel}\\ +\helpref{wxWindow}{wxwindow}\\ +\helpref{wxEvtHandler}{wxevthandler}\\ +\helpref{wxObject}{wxobject} \wxheading{Include files} @@ -60,7 +63,7 @@ no need to specify it explicitly. \func{}{wxVScrolledWindow}{\void} -Default constructor, you must call \helpref{Create()}{wxvscrolledwindowcreate} +Default constructor, you must call \helpref{Create()}{wxvscrolledwindowcreate} later. \wxheading{Parameters} @@ -95,7 +98,7 @@ need to specify it explicitly. \constfunc{virtual wxCoord}{EstimateTotalHeight}{\void} This protected function is used internally by wxVScrolledWindow to estimate the -total height of the window when \helpref{SetLineCount}{wxvscrolledwindowsetlinecount} +total height of the window when \helpref{SetLineCount}{wxvscrolledwindowsetlinecount} is called. The default implementation uses the brute force approach if the number of the items in the control is small enough. Otherwise, it tries to find the average line height using some lines in the beginning, middle and the end. @@ -115,22 +118,57 @@ try to make the best guess possible. Returns the index of the first currently visible line. +This is same as \helpref{GetVisibleBegin}{wxvscrolledwindowgetvisiblebegin} and +exists only for symmetry with \helpref{GetLastVisibleLine}{wxvscrolledwindowgetlastvisibleline}. + \membersection{wxVScrolledWindow::GetLastVisibleLine}\label{wxvscrolledwindowgetlastvisibleline} \constfunc{size\_t}{GetLastVisibleLine}{\void} -Returns the index of the last currently visible line. +Returns the index of the last currently visible line. Note that this method +returns \texttt{(size\_t)-1} (i.e. a huge positive number) if the control is +empty so if this is possible you should use \helpref{GetVisibleEnd}{wxvscrolledwindowgetvisibleend} +instead. + +\wxheading{See also} + +\helpref{GetFirstVisibleLine}{wxvscrolledwindowgetfirstvisibleline} \membersection{wxVScrolledWindow::GetLineCount}\label{wxvscrolledwindowgetlinecount} \constfunc{size\_t}{GetLineCount}{\void} -Get the number of lines this window contains (previously set by +Get the number of lines this window contains (previously set by \helpref{SetLineCount()}{wxvscrolledwindowsetlinecount}) +\membersection{wxVScrolledWindow::GetVisibleBegin}\label{wxvscrolledwindowgetvisiblebegin} + +\constfunc{size\_t}{GetVisibleBegin}{\void} + +Returns the index of the first currently visible line. + +\wxheading{See also} + +\helpref{GetVisibleEnd}{wxvscrolledwindowgetvisibleend} + + +\membersection{wxVScrolledWindow::GetVisibleEnd}\label{wxvscrolledwindowgetvisibleend} + +\constfunc{size\_t}{GetVisibleEnd}{\void} + +Returns the index of the first line after the currently visible one. If the +return value is $0$ it means that no lines are currently shown (which only +happens if the control is empty). Note that the index returned by this method +is not always a valid index as it may be equal to \helpref{GetLineCount}{wxvscrolledwindowgetlinecount}. + +\wxheading{See also} + +\helpref{GetVisibleBegin}{wxvscrolledwindowgetvisiblebegin} + + \membersection{wxVScrolledWindow::HitTest}\label{wxvscrolledwindowhittest} \constfunc{int}{HitTest}{\param{wxCoord }{x}, \param{wxCoord }{y}} @@ -145,13 +183,13 @@ Return the item at the specified (in physical coordinates) position or \constfunc{bool}{IsVisible}{\param{size\_t }{line}} -Returns {\tt true} if the given line is (at least partially) visible or +Returns {\tt true} if the given line is (at least partially) visible or {\tt false} otherwise. \membersection{wxVScrolledWindow::OnGetLineHeight}\label{wxvscrolledwindowongetlineheight} -\constfunc{wxCoord}{OnGetLineHeight}{\param{size\_t }{n}} +\constfunc{virtual wxCoord}{OnGetLineHeight}{\param{size\_t }{n}} This protected virtual function must be overridden in the derived class and it should return the height of the given line in pixels. @@ -163,14 +201,14 @@ should return the height of the given line in pixels. \membersection{wxVScrolledWindow::OnGetLinesHint}\label{wxvscrolledwindowongetlineshint} -\constfunc{void}{OnGetLinesHint}{\param{size\_t }{lineMin}, \param{size\_t }{lineMax}} +\constfunc{virtual void}{OnGetLinesHint}{\param{size\_t }{lineMin}, \param{size\_t }{lineMax}} This function doesn't have to be overridden but it may be useful to do it if calculating the lines heights is a relatively expensive operation as it gives the user code a possibility to calculate several of them at once. -{\tt OnGetLinesHint()} is normally called just before +{\tt OnGetLinesHint()} is normally called just before \helpref{OnGetLineHeight()}{wxvscrolledwindowongetlineheight} but you shouldn't rely on the latter being called for all lines in the interval specified here. It is also possible that OnGetLineHeight() will be @@ -262,4 +300,3 @@ Set the number of lines the window contains: the derived class must provide the heights for all lines with indices up to the one given here in its \helpref{OnGetLineHeight()}{wxvscrolledwindowongetlineheight}. -