Add more comments about ref counting and cow to

brush, pen, font and region.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@43567 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Robert Roebling
2006-11-21 09:27:10 +00:00
parent 95c82627c8
commit a95bfca766
4 changed files with 25 additions and 10 deletions

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@@ -60,10 +60,11 @@ application may wish to get a pointer to a brush by using the global
list of brushes {\bf wxTheBrushList}, and calling the member function list of brushes {\bf wxTheBrushList}, and calling the member function
\rtfsp{\bf FindOrCreateBrush}. \rtfsp{\bf FindOrCreateBrush}.
wxBrush uses a reference counting system, so assignments between brushes are very This class uses \helpref{reference counting and copy-on-write}{trefcount}
cheap. You can therefore use actual wxBrush objects instead of pointers without internally so that assignments between two instances of this class are very
efficiency problems. Once one wxBrush object changes its data it will create its cheap. You can therefore use actual objects instead of pointers without
own brush data internally so that other brushes, which previously shared the efficiency problems. If an instance of this class is changed it will create
its own data internally so that other instances, which previously shared the
data using the reference counting, are not affected. data using the reference counting, are not affected.
%TODO: an overview for wxBrush. %TODO: an overview for wxBrush.

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@@ -4,6 +4,13 @@ A font is an object which determines the appearance of text. Fonts are
used for drawing text to a device context, and setting the appearance of used for drawing text to a device context, and setting the appearance of
a window's text. a window's text.
This class uses \helpref{reference counting and copy-on-write}{trefcount}
internally so that assignments between two instances of this class are very
cheap. You can therefore use actual objects instead of pointers without
efficiency problems. If an instance of this class is changed it will create
its own data internally so that other instances, which previously shared the
data using the reference counting, are not affected.
You can retrieve the current system font settings with \helpref{wxSystemSettings}{wxsystemsettings}. You can retrieve the current system font settings with \helpref{wxSystemSettings}{wxsystemsettings}.
\helpref{wxSystemSettings}{wxsystemsettings} \helpref{wxSystemSettings}{wxsystemsettings}

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@@ -59,10 +59,11 @@ get a pointer to a pen by using the global list of pens {\bf
wxThePenList}, and calling the member function {\bf FindOrCreatePen}. wxThePenList}, and calling the member function {\bf FindOrCreatePen}.
See the entry for \helpref{wxPenList}{wxpenlist}. See the entry for \helpref{wxPenList}{wxpenlist}.
wxPen uses a reference counting system, so assignments between pens are very This class uses \helpref{reference counting and copy-on-write}{trefcount}
cheap. You can therefore use actual wxPen objects instead of pointers without internally so that assignments between two instances of this class are very
efficiency problems. Once one wxPen object changes its data it will create its cheap. You can therefore use actual objects instead of pointers without
own pen data internally so that other pens, which previously shared the efficiency problems. If an instance of this class is changed it will create
its own data internally so that other instances, which previously shared the
data using the reference counting, are not affected. data using the reference counting, are not affected.
%TODO: an overview for wxPen. %TODO: an overview for wxPen.

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@@ -10,8 +10,14 @@
\section{\class{wxRegion}}\label{wxregion} \section{\class{wxRegion}}\label{wxregion}
A wxRegion represents a simple or complex region on a device context or window. It uses A wxRegion represents a simple or complex region on a device context or window.
reference counting, so copying and assignment operations are fast.
This class uses \helpref{reference counting and copy-on-write}{trefcount}
internally so that assignments between two instances of this class are very
cheap. You can therefore use actual objects instead of pointers without
efficiency problems. If an instance of this class is changed it will create
its own data internally so that other instances, which previously shared the
data using the reference counting, are not affected.
\wxheading{Derived from} \wxheading{Derived from}