Added wxTimePickerCtrl::GetTime() and SetTime().

These methods, taking broken down time representation, avoid the problems
arising due to DST complications when using wxDateTime to represent the time
as special care needs to be taken in this case to avoid using the date part
corresponding to a DST change date at which time is discontinuous.

Document the problem with the old functions and use the new ones in the
sample.

See #14137.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71004 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -494,6 +494,7 @@ All (GUI):
 - Added EVT_AUI_PANE_ACTIVATED event (Ronny Krüger).
 - Added wxSplitterWindow::SetSashInvisible() (Armel Asselin).
 - Enable/disable "Window" menu items in AUI MDI correctly (wsu).
+- Added wxTimePickerCtrl::Get/SetTime().
 
 
 GTK:

include/wx/timectrl.h

@@ -50,9 +50,42 @@ public:
     /*
         We also inherit Set/GetValue() methods from the base class which define
         our public API. Notice that the date portion of the date passed as
-        input is ignored and for the result date it's always today, but only
+        input or received as output is or should be ignored, only the time part
-        the time part of wxDateTime objects is really significant here.
+        of wxDateTime objects is really significant here. Use Set/GetTime()
+        below for possibly simpler interface.
      */
+
+    // Set the given time.
+    bool SetTime(int hour, int min, int sec)
+    {
+        // Notice that we should use a date on which DST doesn't change to
+        // avoid any problems with time discontinuity so use a fixed date (on
+        // which nobody changes DST) instead of e.g. today.
+        wxDateTime dt(1, wxDateTime::Jan, 2012, hour, min, sec);
+        if ( !dt.IsValid() )
+        {
+            // No need to assert here, wxDateTime already does it for us.
+            return false;
+        }
+
+        SetValue(dt);
+
+        return true;
+    }
+
+    // Get the current time components. All pointers must be non-NULL.
+    bool GetTime(int* hour, int* min, int* sec) const
+    {
+        wxCHECK_MSG( hour && min && sec, false,
+                     wxS("Time component pointers must be non-NULL") );
+
+        const wxDateTime::Tm tm = GetValue().GetTm();
+        *hour = tm.hour;
+        *min = tm.min;
+        *sec = tm.sec;
+
+        return true;
+    }
 };
 
 #if defined(__WXMSW__) && !defined(__WXUNIVERSAL__)

interface/wx/timectrl.h

@@ -88,6 +88,18 @@ public:
                 const wxValidator& validator = wxDefaultValidator,
                 const wxString& name = "timectrl");
 
+    /**
+        Returns the currently entered time as hours, minutes and seconds.
+
+        All the arguments must be non-@NULL, @false is returned otherwise and
+        none of them is modified.
+
+        @see SetTime()
+
+        @since 2.9.4
+     */
+    bool GetTime(int* hour, int* min, int* sec) const;
+
     /**
         Returns the currently entered time.
 
@@ -96,12 +108,38 @@ public:
     */
     virtual wxDateTime GetValue() const = 0;
 
+    /**
+        Changes the current time of the control.
+
+        Calling this method does not result in a time change event.
+
+        @param hour The new hour value in 0..23 interval.
+        @param min The new minute value in 0..59 interval.
+        @param sec The new second value in 0..59 interval.
+        @return @true if the time was changed or @false on failure, e.g. if the
+            time components were invalid.
+
+        @see GetTime()
+
+        @since 2.9.4
+     */
+    bool SetTime(int hour, int min, int sec);
+
     /**
         Changes the current value of the control.
 
         The date part of @a dt is ignored, only the time part is displayed in
         the control. The @a dt object must however be valid.
 
+        In particular notice that it is a bad idea to use default wxDateTime
+        constructor from hour, minute and second values as it uses the today
+        date for the date part which means that some times can be invalid if
+        today happens to be the day of DST change. For example, when switching
+        to summer time the time 2:00 typically doesn't exist as the clocks jump
+        directly to 3:00. To avoid this problem, use a fixed date on which DST
+        is known not to change (e.g. Jan 1, 2012) for the date part of the
+        argument or use SetTime().
+
         Calling this method does not result in a time change event.
     */
     virtual void SetValue(const wxDateTime& dt) = 0;

samples/widgets/timepick.cpp

@@ -217,21 +217,23 @@ void TimePickerWidgetsPage::OnButtonReset(wxCommandEvent& WXUNUSED(event))
 
 void TimePickerWidgetsPage::OnButtonSet(wxCommandEvent& WXUNUSED(event))
 {
-    wxDateTime dt;
+    int h, m, s;
-    if ( !dt.ParseISOTime(m_textCur->GetValue()) )
+    if ( wxSscanf(m_textCur->GetValue(), "%d:%d:%d", &h, &m, &s) != 3 )
     {
         wxLogError("Invalid time, please use HH:MM:SS format.");
         return;
     }
 
-    m_timePicker->SetValue(dt);
+    m_timePicker->SetTime(h, m, s);
 }
 
 void TimePickerWidgetsPage::OnTimeChanged(wxDateEvent& event)
 {
-    wxLogMessage("Time changed, now is %s (control value is %s).",
+    int h, m, s;
-                 event.GetDate().FormatISOTime(),
+    m_timePicker->GetTime(&h, &m, &s);
-                 m_timePicker->GetValue().FormatISOTime());
+
+    wxLogMessage("Time changed, now is %s (control value is %02d:%02d:%02d).",
+                 event.GetDate().FormatISOTime(), h, m, s);
 }
 
 #endif // wxUSE_TIMEPICKCTRL