fixes to handling of 0 and negative splitter position when splitting it initially

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14344 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/splitter.h

@@ -237,8 +237,13 @@ protected:
 
     // get either width or height depending on the split mode
     int GetWindowSize() const;
-    
-    // set m_sashPosition w/ safeguards
+
+    // convert the user specified sash position which may be > 0 (as is), < 0
+    // (specifying the size of the right pane) or 0 (use default) to the real
+    // position to be passed to DoSetSashPosition()
+    int ConvertSashPosition(int sashPos) const;
+
+    // set the real sash position, sashPos here must be positive
     void DoSetSashPosition(int sashPos);
 
     wxSplitMode m_splitMode;

samples/splitter/splitter.cpp

@@ -186,6 +186,7 @@ MyFrame::MyFrame()
     m_right->Show(FALSE);
     m_splitter->Initialize(m_left);
 #else
+    // you can also try -100
     m_splitter->SplitVertically(m_left, m_right, 100);
 #endif
 
@@ -210,6 +211,8 @@ void MyFrame::SplitHorizontal(wxCommandEvent& WXUNUSED(event) )
     m_left->Show(TRUE);
     m_right->Show(TRUE);
     m_splitter->SplitHorizontally( m_left, m_right );
+
+    SetStatusText(_T("Splitter split horizontally"), 1);
 }
 
 void MyFrame::SplitVertical(wxCommandEvent& WXUNUSED(event) )
@@ -219,6 +222,8 @@ void MyFrame::SplitVertical(wxCommandEvent& WXUNUSED(event) )
     m_left->Show(TRUE);
     m_right->Show(TRUE);
     m_splitter->SplitVertically( m_left, m_right );
+
+    SetStatusText(_T("Splitter split vertically"), 1);
 }
 
 void MyFrame::Unsplit(wxCommandEvent& WXUNUSED(event) )

src/generic/splitter.cpp

@@ -718,13 +718,17 @@ int wxSplitterWindow::AdjustSashPosition(int sashPos) const
 
 void wxSplitterWindow::DoSetSashPosition(int sashPos)
 {
-    m_requestedSashPosition = sashPos;
-    m_sashPosition = sashPos == 0 ? 0 : AdjustSashPosition(sashPos);
+    int newSashPosition = AdjustSashPosition(sashPos);
 
-    wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED, this);
-    event.m_data.pos = m_sashPosition;
+    if ( newSashPosition != m_sashPosition )
+    {
+        m_sashPosition = newSashPosition;
 
-    (void)DoSendEvent(event);
+        wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED, this);
+        event.m_data.pos = m_sashPosition;
+
+        (void)DoSendEvent(event);
+    }
 }
 
 // Position and size subwindows.
@@ -732,8 +736,21 @@ void wxSplitterWindow::DoSetSashPosition(int sashPos)
 // including the edges next to the sash.
 void wxSplitterWindow::SizeWindows()
 {
-    if ( m_requestedSashPosition != m_sashPosition )
-        DoSetSashPosition(m_requestedSashPosition);
+    // check if we have delayed setting the real sash position
+    if ( m_requestedSashPosition != INT_MAX )
+    {
+        int newSashPosition = ConvertSashPosition(m_requestedSashPosition);
+        if ( newSashPosition != m_sashPosition )
+        {
+            DoSetSashPosition(newSashPosition);
+        }
+
+        if ( newSashPosition == m_sashPosition )
+        {
+            // don't update it any more
+            m_requestedSashPosition = INT_MAX;
+        }
+    }
 
     int w, h;
     GetClientSize(&w, &h);
@@ -794,32 +811,39 @@ bool wxSplitterWindow::DoSplit(wxSplitMode mode,
     if ( IsSplit() )
         return FALSE;
 
-    int window_size = GetWindowSize();
-
     m_splitMode = mode;
     m_windowOne = window1;
     m_windowTwo = window2;
 
-    if ( sashPosition > 0 )
-    {
-        DoSetSashPosition(sashPosition);
-    }
-    else if ( sashPosition < 0 )
-    {
-        // It's negative so adding is subtracting
-        DoSetSashPosition(window_size + sashPosition);
-    }
-    else
-    {
-        // default
-        DoSetSashPosition(window_size/2);
-    }
+    // remember the sash position we want to set for later if we can't set it
+    // right now (e.g. because the window is too small)
+    m_requestedSashPosition = sashPosition;
+
+    DoSetSashPosition(ConvertSashPosition(sashPosition));
 
     SizeWindows();
 
     return TRUE;
 }
 
+int wxSplitterWindow::ConvertSashPosition(int sashPosition) const
+{
+    if ( sashPosition > 0 )
+    {
+        return sashPosition;
+    }
+    else if ( sashPosition < 0 )
+    {
+        // It's negative so adding is subtracting
+        return GetWindowSize() + sashPosition;
+    }
+    else // sashPosition == 0
+    {
+        // default, put it in the centre
+        return GetWindowSize() / 2;
+    }
+}
+
 // Remove the specified (or second) window from the view
 // Doesn't actually delete the window.
 bool wxSplitterWindow::Unsplit(wxWindow *toRemove)