fixed a bug in wxStopWatch::Pause() (wouldn't pause if called immediately after Start()) and changed Pause()/Resume() calls to nest

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15051 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -26,6 +26,8 @@ wxBase:
   documentation for details and revise your code accordingly: this change was
   unfortunately needed as the old class didn't behave correctly in all cases
 
+- small change to wxStopWatch::Pause() semantics, please see the documentation
+
 All (GUI):
 
 - the event type constants are not constants any more but are dynamically

docs/latex/wx/stopwtch.tex

@@ -1,6 +1,19 @@
 \section{\class{wxStopWatch}}\label{wxstopwatch}
 
-The wxStopWatch class allow you to measure time intervals.
+The wxStopWatch class allow you to measure time intervals. For example, you may
+use it to measure the time elapsed by some function:
+
+\begin{verbatim}
+    wxStopWatch sw;
+    CallLongRunningFunction();
+    wxLogMessage("The long running function took %ldms to execute",
+                 sw.Time());
+    sw.Pause();
+    ... stopwatch is stopped now ...
+    sw.Resume();
+    CallLongRunningFunction();
+    wxLogMessage("And calling it twice took $ldms in all", sw.Time());
+\end{verbatim}
 
 \wxheading{Include files}
 
@@ -25,17 +38,22 @@ Constructor. This starts the stop watch.
 Pauses the stop watch. Call \helpref{wxStopWatch::Resume}{wxstopwatchresume} to resume 
 time measuring again.
 
-\membersection{wxStopWatch::Start}
-
-\func{void}{Start}{\param{long}{ milliseconds = 0}}
-
-(Re)starts the stop watch with a given initial value.
+If this method is called several times, {\tt Resume()} must be called the same
+number of times to really resume the stop watch. You may, however, call 
+\helpref{Start}{wxstopwatchstart} to resume it unconditionally.
 
 \membersection{wxStopWatch::Resume}\label{wxstopwatchresume}
 
 \func{void}{Resume}{\void}
 
-Resumes the stop watch after having been paused with \helpref{wxStopWatch::Pause}{wxstopwatchpause}.
+Resumes the stop watch which had been paused with 
+\helpref{wxStopWatch::Pause}{wxstopwatchpause}.
+
+\membersection{wxStopWatch::Start}\label{wxstopwatchstart}
+
+\func{void}{Start}{\param{long}{ milliseconds = 0}}
+
+(Re)starts the stop watch with a given initial value.
 
 \membersection{wxStopWatch::Time}