1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2 %% Name: varvscrollhelper.tex
3 %% Purpose: wxVarVScrollHelper Documentation
8 %% Copyright: (c) 2007 wxWidgets Team
9 %% License: wxWindows Licence
10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
12 \section{\class{wxVarVScrollHelper
}}\label{wxvarvscrollhelper
}
14 This class provides functions wrapping the
15 \helpref{wxVarScrollHelperBase
}{wxvarscrollhelperbase
} class, targeted for
16 vertical-specific scrolling using
\helpref{wxVScrolledWindow
}{wxvscrolledwindow
}.
18 Like wxVarScrollHelperBase, this class is mostly only useful to those classes
19 built into wxWidgets deriving from here, and this documentation is mostly
20 only provided for referencing those functions provided. You will likely want
21 to derive your window from wxVScrolledWindow rather than from here directly.
23 \wxheading{Derived from
}
25 \helpref{wxVarScrollHelperBase
}{wxvarscrollhelperbase
}
27 \wxheading{Include files
}
33 \helpref{wxHScrolledWindow
}{wxhscrolledwindow
},
34 \rtfsp\helpref{wxHVScrolledWindow
}{wxhvscrolledwindow
},
35 \rtfsp\helpref{wxVScrolledWindow
}{wxvscrolledwindow
}
37 \latexignore{\rtfignore{\wxheading{Members
}}}
40 \membersection{wxVarVScrollHelper::wxVarVScrollHelper
}\label{wxvarvscrollhelperwxvarvscrollhelper
}
42 \func{}{wxVarVScrollHelper
}{\param{wxWindow*
}{winToScroll
}}
44 Constructor taking the target window to be scrolled by this helper class.
45 This will attach scroll event handlers to the target window to catch and
46 handle scroll events appropriately.
49 \membersection{wxVarVScrollHelper::EstimateTotalHeight
}\label{wxvarvscrollhelperestimatetotalheight
}
51 \constfunc{virtual wxCoord
}{EstimateTotalHeight
}{\void}
53 This class forwards calls from
54 \helpref{wxVarScrollHelperBase::EstimateTotalSize
}{wxvarscrollhelperbaseestimatetotalsize
}
55 to this function so derived classes can override either just the height or
56 the width estimation, or just estimate both differently if desired in any
57 \helpref{wxHVScrolledWindow
}{wxhvscrolledwindow
} derived class.
59 Please note that this function will not be called if
{\tt EstimateTotalSize()
}
60 is overridden in your derived class.
63 \membersection{wxVarVScrollHelper::GetRowCount
}\label{wxvarvscrollhelpergetrowcount
}
65 \constfunc{size
\_t}{GetRowCount
}{\void}
67 Returns the number of rows the target window contains.
71 \helpref{SetRowCount()
}{wxvarvscrollhelpersetrowcount
}
74 \membersection{wxVarVScrollHelper::GetVisibleRowsBegin
}\label{wxvarvscrollhelpergetvisiblerowsbegin
}
76 \constfunc{size
\_t}{GetVisibleRowsBegin
}{\void}
78 Returns the index of the first visible row based on the scroll position.
81 \membersection{wxVarVScrollHelper::GetVisibleRowsEnd
}\label{wxvarvscrollhelpergetvisiblerowsend
}
83 \constfunc{size
\_t}{GetVisibleRowsEnd
}{\void}
85 Returns the index of the last visible row based on the scroll position. This
86 includes the last row even if it is only partially visible.
89 \membersection{wxVarVScrollHelper::IsRowVisible
}\label{wxvarvscrollhelperisrowvisible
}
91 \constfunc{bool
}{IsRowVisible
}{\param{size
\_t }{row
}}
93 Returns
{\tt true
} if the given row is currently visible (even if only
94 partially visible) or
{\tt false
} otherwise.
97 \membersection{wxVarVScrollHelper::OnGetRowHeight
}\label{wxvarvscrollhelperongetrowheight
}
99 \constfunc{virtual wxCoord
}{OnGetRowHeight
}{\param{size
\_t }{row
}}
101 This function must be overridden in the derived class, and should return the
102 height of the given row in pixels.
105 \membersection{wxVarVScrollHelper::OnGetRowsHeightHint
}\label{wxvarvscrollhelperongetrowsheighthint
}
107 \constfunc{virtual void
}{OnGetRowsHeightHint
}{\param{size
\_t }{rowMin
},
\param{size
\_t }{rowMax
}}
109 This function doesn't have to be overridden but it may be useful to do so if
110 calculating the rows' sizes is a relatively expensive operation as it gives
111 your code a chance to calculate several of them at once and cache the result
114 {\tt OnGetRowsHeightHint()
} is normally called just before
115 \helpref{OnGetRowHeight()
}{wxvarvscrollhelperongetrowheight
} but you
116 shouldn't rely on the latter being called for all rows in the interval
117 specified here. It is also possible that OnGetRowHeight() will be called for
118 units outside of this interval, so this is really just a hint, not a promise.
120 Finally, note that rowMin is inclusive, while rowMax is exclusive.
123 \membersection{wxVarVScrollHelper::RefreshRow
}\label{wxvarvscrollhelperrefreshrow
}
125 \func{virtual void
}{RefreshRow
}{\param{size
\_t }{row
}}
127 Triggers a refresh for just the given row's area of the window if it's visible.
130 \membersection{wxVarVScrollHelper::RefreshRows
}\label{wxvarvscrollhelperrefreshrows
}
132 \func{virtual void
}{RefreshRows
}{\param{size
\_t }{from
},
\param{size
\_t }{to
}}
134 Triggers a refresh for the area between the specified range of rows given
138 \membersection{wxVarVScrollHelper::ScrollRowPages
}\label{wxvarvscrollhelperscrollrowpages
}
140 \func{virtual bool
}{ScrollRowPages
}{\param{int
}{pages
}}
142 Scroll by the specified number of pages which may be positive (to scroll down)
143 or negative (to scroll up).
146 \membersection{wxVarVScrollHelper::ScrollRows
}\label{wxvarvscrollhelperscrollrows
}
148 \func{virtual bool
}{ScrollRows
}{\param{int
}{rows
}}
150 Scroll by the specified number of rows which may be positive (to scroll down)
151 or negative (to scroll up).
153 Returns
{\tt true
} if the window was scrolled,
{\tt false
} otherwise (for
154 example, if we're trying to scroll down but we are already showing the last
158 \membersection{wxVarVScrollHelper::ScrollToRow
}\label{wxvarvscrollhelperscrolltorow
}
160 \func{bool
}{ScrollToRow
}{\param{size
\_t }{row
}}
162 Scroll to the specified row. It will become the first visible row in the window.
164 Returns
{\tt true
} if we scrolled the window,
{\tt false
} if nothing was done.
167 \membersection{wxVarVScrollHelper::SetRowCount
}\label{wxvarvscrollhelpersetrowcount
}
169 \func{void
}{SetRowCount
}{\param{size
\_t }{rowCount
}}
171 Set the number of rows the window contains. The derived class must provide the
172 heights for all rows with indices up to the one given here in it's
173 \helpref{OnGetRowHeight()
}{wxvarvscrollhelperongetrowheight
} implementation.
177 \helpref{GetRowCount()
}{wxvarvscrollhelpergetrowcount
}