documented DoPrepareDC()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@28321 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
2004-07-20 10:04:25 +00:00
parent a2cffa18c9
commit 9f9895a8d9

View File

@@ -47,10 +47,11 @@ As with all windows, an application can draw onto a wxScrolledWindow using
a \helpref{device context}{dcoverview}. a \helpref{device context}{dcoverview}.
You have the option of handling the OnPaint handler You have the option of handling the OnPaint handler
or overriding the \helpref{OnDraw}{wxscrolledwindowondraw} function, which is passed or overriding the \helpref{OnDraw}{wxscrolledwindowondraw} function, which is
a pre-scrolled device context (prepared by \helpref{PrepareDC}{wxscrolledwindowpreparedc}). passed a pre-scrolled device context (prepared by
\helpref{DoPrepareDC}{wxscrolledwindowdopreparedc}).
If you don't wish to calculate your own scrolling, you must call PrepareDC when not drawing from If you don't wish to calculate your own scrolling, you must call DoPrepareDC when not drawing from
within OnDraw, to set the device origin for the device context according to the current within OnDraw, to set the device origin for the device context according to the current
scroll position. scroll position.
@@ -102,6 +103,7 @@ to build your own scroll behaviour.
\latexignore{\rtfignore{\wxheading{Members}}} \latexignore{\rtfignore{\wxheading{Members}}}
\membersection{wxScrolledWindow::wxScrolledWindow}\label{wxscrolledwindowconstr} \membersection{wxScrolledWindow::wxScrolledWindow}\label{wxscrolledwindowconstr}
\func{}{wxScrolledWindow}{\void} \func{}{wxScrolledWindow}{\void}
@@ -136,12 +138,14 @@ The window is initially created without visible scrollbars.
Call \helpref{wxScrolledWindow::SetScrollbars}{wxscrolledwindowsetscrollbars} to Call \helpref{wxScrolledWindow::SetScrollbars}{wxscrolledwindowsetscrollbars} to
specify how big the virtual window size should be. specify how big the virtual window size should be.
\membersection{wxScrolledWindow::\destruct{wxScrolledWindow}} \membersection{wxScrolledWindow::\destruct{wxScrolledWindow}}
\func{}{\destruct{wxScrolledWindow}}{\void} \func{}{\destruct{wxScrolledWindow}}{\void}
Destructor. Destructor.
\membersection{wxScrolledWindow::CalcScrolledPosition}\label{wxscrolledwindowcalcscrolledposition} \membersection{wxScrolledWindow::CalcScrolledPosition}\label{wxscrolledwindowcalcscrolledposition}
\constfunc{void}{CalcScrolledPosition}{ \constfunc{void}{CalcScrolledPosition}{
@@ -165,6 +169,7 @@ parameters and returns xx and yy as a tuple of values.}
\perlnote{In wxPerl this method takes two parameters and returns a \perlnote{In wxPerl this method takes two parameters and returns a
2-element list {\tt ( xx, yy )}.} 2-element list {\tt ( xx, yy )}.}
\membersection{wxScrolledWindow::CalcUnscrolledPosition}\label{wxscrolledwindowcalcunscrolledposition} \membersection{wxScrolledWindow::CalcUnscrolledPosition}\label{wxscrolledwindowcalcunscrolledposition}
\constfunc{void}{CalcUnscrolledPosition}{ \constfunc{void}{CalcUnscrolledPosition}{
@@ -188,6 +193,7 @@ parameters and returns xx and yy as a tuple of values.}
\perlnote{In wxPerl this method takes two parameters and returns a \perlnote{In wxPerl this method takes two parameters and returns a
2-element list {\tt ( xx, yy )}.} 2-element list {\tt ( xx, yy )}.}
\membersection{wxScrolledWindow::Create}\label{wxscrolledwindowcreate} \membersection{wxScrolledWindow::Create}\label{wxscrolledwindowcreate}
\func{bool}{Create}{\param{wxWindow*}{ parent}, \param{wxWindowID }{id = -1},\rtfsp \func{bool}{Create}{\param{wxWindow*}{ parent}, \param{wxWindowID }{id = -1},\rtfsp
@@ -198,6 +204,7 @@ Creates the window for two-step construction. Derived classes
should call or replace this function. See \helpref{wxScrolledWindow::wxScrolledWindow}{wxscrolledwindowconstr}\rtfsp should call or replace this function. See \helpref{wxScrolledWindow::wxScrolledWindow}{wxscrolledwindowconstr}\rtfsp
for details. for details.
\membersection{wxScrolledWindow::EnableScrolling}\label{wxscrolledwindowenablescrolling} \membersection{wxScrolledWindow::EnableScrolling}\label{wxscrolledwindowenablescrolling}
\func{void}{EnableScrolling}{\param{const bool}{ xScrolling}, \param{const bool}{ yScrolling}} \func{void}{EnableScrolling}{\param{const bool}{ xScrolling}, \param{const bool}{ yScrolling}}
@@ -221,6 +228,7 @@ is disabled.
Physical scrolling may not be available on all platforms. Where it is available, it is enabled Physical scrolling may not be available on all platforms. Where it is available, it is enabled
by default. by default.
\membersection{wxScrolledWindow::GetScrollPixelsPerUnit}\label{wxscrolledwindowgetscrollpixelsperunit} \membersection{wxScrolledWindow::GetScrollPixelsPerUnit}\label{wxscrolledwindowgetscrollpixelsperunit}
\constfunc{void}{GetScrollPixelsPerUnit}{\param{int* }{xUnit}, \param{int* }{yUnit}} \constfunc{void}{GetScrollPixelsPerUnit}{\param{int* }{xUnit}, \param{int* }{yUnit}}
@@ -246,6 +254,7 @@ parameters and returns a tuple of values for xUnit and yUnit.}
\perlnote{In wxPerl this method takes no parameters and returns a \perlnote{In wxPerl this method takes no parameters and returns a
2-element list {\tt ( xUnit, yUnit )}.} 2-element list {\tt ( xUnit, yUnit )}.}
\membersection{wxScrolledWindow::GetViewStart}\label{wxscrolledwindowgetviewstart} \membersection{wxScrolledWindow::GetViewStart}\label{wxscrolledwindowgetviewstart}
\constfunc{void}{GetViewStart}{\param{int* }{x}, \param{int* }{ y}} \constfunc{void}{GetViewStart}{\param{int* }{x}, \param{int* }{ y}}
@@ -277,6 +286,7 @@ parameters and returns a tuple of values for x and y.}
\perlnote{In wxPerl this method takes no parameters and returns a \perlnote{In wxPerl this method takes no parameters and returns a
2-element list {\tt ( x, y )}.} 2-element list {\tt ( x, y )}.}
\membersection{wxScrolledWindow::GetVirtualSize}\label{wxscrolledwindowgetvirtualsize} \membersection{wxScrolledWindow::GetVirtualSize}\label{wxscrolledwindowgetvirtualsize}
\constfunc{void}{GetVirtualSize}{\param{int* }{x}, \param{int* }{y}} \constfunc{void}{GetVirtualSize}{\param{int* }{x}, \param{int* }{y}}
@@ -307,20 +317,22 @@ parameters and returns a tuple of values for x and y.}
\perlnote{In wxPerl this method takes no parameters and returns a \perlnote{In wxPerl this method takes no parameters and returns a
2-element list {\tt ( x, y )}.} 2-element list {\tt ( x, y )}.}
\membersection{wxScrolledWindow::IsRetained}\label{wxscrolledwindowisretained} \membersection{wxScrolledWindow::IsRetained}\label{wxscrolledwindowisretained}
\constfunc{bool}{IsRetained}{\void} \constfunc{bool}{IsRetained}{\void}
Motif only: true if the window has a backing bitmap. Motif only: true if the window has a backing bitmap.
\membersection{wxScrolledWindow::PrepareDC}\label{wxscrolledwindowpreparedc}
\func{void}{PrepareDC}{\param{wxDC\& }{dc}} \membersection{wxScrolledWindow::DoPrepareDC}\label{wxscrolledwindowdopreparedc}
\func{void}{DoPrepareDC}{\param{wxDC\& }{dc}}
Call this function to prepare the device context for drawing a scrolled image. It Call this function to prepare the device context for drawing a scrolled image. It
sets the device origin according to the current scroll position. sets the device origin according to the current scroll position.
PrepareDC is called automatically within the default wxScrolledWindow::OnPaint event DoPrepareDC is called automatically within the default wxScrolledWindow::OnPaint event
handler, so your \helpref{wxScrolledWindow::OnDraw}{wxscrolledwindowondraw} override handler, so your \helpref{wxScrolledWindow::OnDraw}{wxscrolledwindowondraw} override
will be passed a 'pre-scrolled' device context. However, if you wish to draw from will be passed a 'pre-scrolled' device context. However, if you wish to draw from
outside of OnDraw (via OnPaint), or you wish to implement OnPaint yourself, you must outside of OnDraw (via OnPaint), or you wish to implement OnPaint yourself, you must
@@ -330,7 +342,7 @@ call this function yourself. For example:
void MyWindow::OnEvent(wxMouseEvent& event) void MyWindow::OnEvent(wxMouseEvent& event)
{ {
wxClientDC dc(this); wxClientDC dc(this);
PrepareDC(dc); DoPrepareDC(dc);
dc.SetPen(*wxBLACK_PEN); dc.SetPen(*wxBLACK_PEN);
float x, y; float x, y;
@@ -344,18 +356,30 @@ void MyWindow::OnEvent(wxMouseEvent& event)
} }
\end{verbatim} \end{verbatim}
\membersection{wxScrolledWindow::OnDraw}\label{wxscrolledwindowondraw} \membersection{wxScrolledWindow::OnDraw}\label{wxscrolledwindowondraw}
\func{virtual void}{OnDraw}{\param{wxDC\& }{dc}} \func{virtual void}{OnDraw}{\param{wxDC\& }{dc}}
Called by the default paint event handler to allow the application to define Called by the default paint event handler to allow the application to define
painting behaviour without having to worry about calling painting behaviour without having to worry about calling
\helpref{wxScrolledWindow::PrepareDC}{wxscrolledwindowpreparedc}. \helpref{wxScrolledWindow::DoPrepareDC}{wxscrolledwindowdopreparedc}.
Instead of overriding this function you may also just process the paint event Instead of overriding this function you may also just process the paint event
in the derived class as usual, but then you will have to call PrepareDC() in the derived class as usual, but then you will have to call DoPrepareDC()
yourself. yourself.
\membersection{wxScrolledWindow::PrepareDC}\label{wxscrolledwindowpreparedc}
\func{void}{DoPrepareDC}{\param{wxDC\& }{dc}}
This function is for backwards compatibility only and simply calls
\helpref{DoPrepareDC}{wxscrolledwindowdopreparedc} now. Notice that it is
\emph{not} called by the default paint event handle (DoPrepareDC() is), so
overriding this method in your derived class is useless.
\membersection{wxScrolledWindow::Scroll}\label{wxscrolledwindowscroll} \membersection{wxScrolledWindow::Scroll}\label{wxscrolledwindowscroll}
\func{void}{Scroll}{\param{int}{ x}, \param{int}{ y}} \func{void}{Scroll}{\param{int}{ x}, \param{int}{ y}}
@@ -380,6 +404,7 @@ that direction).
\helpref{wxScrolledWindow::SetScrollbars}{wxscrolledwindowsetscrollbars},\rtfsp \helpref{wxScrolledWindow::SetScrollbars}{wxscrolledwindowsetscrollbars},\rtfsp
\helpref{wxScrolledWindow::GetScrollPixelsPerUnit}{wxscrolledwindowgetscrollpixelsperunit} \helpref{wxScrolledWindow::GetScrollPixelsPerUnit}{wxscrolledwindowgetscrollpixelsperunit}
\membersection{wxScrolledWindow::SetScrollbars}\label{wxscrolledwindowsetscrollbars} \membersection{wxScrolledWindow::SetScrollbars}\label{wxscrolledwindowsetscrollbars}
\func{void}{SetScrollbars}{\param{int}{ pixelsPerUnitX}, \param{int}{ pixelsPerUnitY},\rtfsp \func{void}{SetScrollbars}{\param{int}{ pixelsPerUnitX}, \param{int}{ pixelsPerUnitY},\rtfsp
@@ -434,6 +459,7 @@ adjusting the scrollbars appropriately.
\helpref{wxWindow::SetVirtualSize}{wxwindowsetvirtualsize} \helpref{wxWindow::SetVirtualSize}{wxwindowsetvirtualsize}
\membersection{wxScrolledWindow::SetScrollRate}\label{wxscrolledwindowsetscrollrate} \membersection{wxScrolledWindow::SetScrollRate}\label{wxscrolledwindowsetscrollrate}
\func{void}{SetScrollRate}{\param{int}{ xstep}, \param{int}{ ystep}} \func{void}{SetScrollRate}{\param{int}{ xstep}, \param{int}{ ystep}}
@@ -441,6 +467,7 @@ adjusting the scrollbars appropriately.
Set the horizontal and vertical scrolling increment only. See the pixelsPerUnit Set the horizontal and vertical scrolling increment only. See the pixelsPerUnit
parameter in SetScrollbars. parameter in SetScrollbars.
\membersection{wxScrolledWindow::SetTargetWindow}\label{wxscrolledwindowsettargetwindow} \membersection{wxScrolledWindow::SetTargetWindow}\label{wxscrolledwindowsettargetwindow}
\func{void}{SetTargetWindow}{\param{wxWindow* }{window}} \func{void}{SetTargetWindow}{\param{wxWindow* }{window}}