X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/63916e4494c0f0d382f9ed3337d1fcec900028d1..6b4f099df5e71af0449049ce0a19e7863915ee44:/src/generic/vscroll.cpp

diff --git a/src/generic/vscroll.cpp b/src/generic/vscroll.cpp
index 3fc8a940d5..ec48cb9103 100644
--- a/src/generic/vscroll.cpp
+++ b/src/generic/vscroll.cpp
@@ -24,6 +24,10 @@
 #pragma hdrstop
 #endif
 
+#ifndef WX_PRECOMP
+    #include "wx/sizer.h"
+#endif
+
 #include "wx/vscroll.h"
 
 // ----------------------------------------------------------------------------
@@ -156,8 +160,22 @@ size_t wxVScrolledWindow::FindFirstFromBottom(size_t lineLast, bool full)
     return lineFirst;
 }
 
+void wxVScrolledWindow::RemoveScrollbar()
+{
+    m_lineFirst = 0;
+    m_nVisible = m_lineMax;
+    SetScrollbar(wxVERTICAL, 0, 0, 0);
+}
+
 void wxVScrolledWindow::UpdateScrollbar()
 {
+    // if there is nothing to scroll, remove the scrollbar
+    if ( !m_lineMax )
+    {
+        RemoveScrollbar();
+        return;
+    }
+
     // see how many lines can we fit on screen
     const wxCoord hWindow = GetClientSize().y;
 
@@ -185,8 +203,8 @@ void wxVScrolledWindow::UpdateScrollbar()
         if ( hAll < hWindow )
         {
             // we don't need scrollbar at all
-            m_lineFirst = 0;
-            SetScrollbar(wxVERTICAL, 0, 0, 0);
+            RemoveScrollbar();
+            return;
         }
     }
 
@@ -217,9 +235,16 @@ void wxVScrolledWindow::SetLineCount(size_t count)
     // and our estimate for their total height
     m_heightTotal = EstimateTotalHeight();
 
-    // recalculate the scrollbars parameters
-    m_lineFirst = 1;    // make sure it is != 0
-    ScrollToLine(0);
+    // ScrollToLine() will update the scrollbar itself if it changes the line
+    // we pass to it because it's out of [new] range
+    size_t oldScrollPos = m_lineFirst;
+    ScrollToLine(m_lineFirst);
+    if ( oldScrollPos == m_lineFirst )
+    {
+        // but if it didn't do it, we still need to update the scrollbar to
+        // reflect the changed number of lines ourselves
+        UpdateScrollbar();
+    }
 }
 
 void wxVScrolledWindow::RefreshLine(size_t line)
@@ -282,6 +307,27 @@ void wxVScrolledWindow::RefreshAll()
     Refresh();
 }
 
+bool wxVScrolledWindow::Layout()
+{
+    if ( GetSizer() )
+    {
+        // adjust the sizer dimensions/position taking into account the
+        // virtual size and scrolled position of the window.
+
+        int w = 0, h = 0;
+        GetVirtualSize(&w, &h);
+
+        // x is always 0 so no variable needed
+        int y = -GetLinesHeight(0, GetFirstVisibleLine());
+
+        GetSizer()->SetDimension(0, y, w, h);
+        return true;
+    }
+
+    // fall back to default for LayoutConstraints
+    return wxPanel::Layout();
+}
+
 int wxVScrolledWindow::HitTest(wxCoord WXUNUSED(x), wxCoord y) const
 {
     const size_t lineMax = GetVisibleEnd();