don't assume there's always an active wxEventLoop instance

[wxWidgets.git] / src / generic / vscroll.cpp

diff --git a/src/generic/vscroll.cpp b/src/generic/vscroll.cpp
index d8d57b6e97f46986d00bdef1bc229bdb4a5f1d4b..a7d388a9bf4bb4af08507786f1c8db052e3a87b4 100644 (file)
--- a/src/generic/vscroll.cpp
+++ b/src/generic/vscroll.cpp
@@ -17,10 +17,6 @@
 // headers
 // ----------------------------------------------------------------------------
 
-#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
-#pragma implementation "vscroll.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
@@ -28,6 +24,10 @@
 #pragma hdrstop
 #endif
 
+#ifndef WX_PRECOMP
+    #include "wx/sizer.h"
+#endif
+
 #include "wx/vscroll.h"
 
 // ----------------------------------------------------------------------------
@@ -160,6 +160,13 @@ 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()
 {
     // see how many lines can we fit on screen
@@ -175,6 +182,25 @@ void wxVScrolledWindow::UpdateScrollbar()
         h += OnGetLineHeight(line);
     }
 
+    // if we still have remaining space below, maybe we can fit everything?
+    if ( h < hWindow )
+    {
+        wxCoord hAll = h;
+        for ( size_t lineFirst = m_lineFirst; lineFirst > 0; lineFirst-- )
+        {
+            hAll += OnGetLineHeight(m_lineFirst - 1);
+            if ( hAll > hWindow )
+                break;
+        }
+
+        if ( hAll < hWindow )
+        {
+            // we don't need scrollbar at all
+            RemoveScrollbar();
+            return;
+        }
+    }
+
     m_nVisible = line - m_lineFirst;
 
     int pageSize = m_nVisible;
@@ -203,8 +229,15 @@ void wxVScrolledWindow::SetLineCount(size_t count)
     m_heightTotal = EstimateTotalHeight();
 
     // recalculate the scrollbars parameters
-    m_lineFirst = 1;    // make sure it is != 0
-    ScrollToLine(0);
+    if ( count )
+    {
+        m_lineFirst = 1;    // make sure it is != 0
+        ScrollToLine(0);
+    }
+    else // no items
+    {
+        RemoveScrollbar();
+    }
 }
 
 void wxVScrolledWindow::RefreshLine(size_t line)
@@ -220,7 +253,7 @@ void wxVScrolledWindow::RefreshLine(size_t line)
     wxRect rect;
     rect.width = GetClientSize().x;
     rect.height = OnGetLineHeight(line);
-    for ( size_t n = GetFirstVisibleLine(); n < line; n++ )
+    for ( size_t n = GetVisibleBegin(); n < line; n++ )
     {
         rect.y += OnGetLineHeight(n);
     }
@@ -235,21 +268,23 @@ void wxVScrolledWindow::RefreshLines(size_t from, size_t to)
 
     // clump the range to just the visible lines -- it is useless to refresh
     // the other ones
-    if ( from < GetFirstVisibleLine() )
-        from = GetFirstVisibleLine();
+    if ( from < GetVisibleBegin() )
+        from = GetVisibleBegin();
 
-    if ( to > GetLastVisibleLine() )
-        to = GetLastVisibleLine();
+    if ( to >= GetVisibleEnd() )
+        to = GetVisibleEnd();
+    else
+        to++;
 
     // calculate the rect occupied by these lines on screen
     wxRect rect;
     rect.width = GetClientSize().x;
-    for ( size_t nBefore = GetFirstVisibleLine(); nBefore < from; nBefore++ )
+    for ( size_t nBefore = GetVisibleBegin(); nBefore < from; nBefore++ )
     {
         rect.y += OnGetLineHeight(nBefore);
     }
 
-    for ( size_t nBetween = from; nBetween <= to; nBetween++ )
+    for ( size_t nBetween = from; nBetween < to; nBetween++ )
     {
         rect.height += OnGetLineHeight(nBetween);
     }
@@ -265,10 +300,31 @@ 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 = GetLastVisibleLine();
-    for ( size_t line = GetFirstVisibleLine(); line <= lineMax; line++ )
+    const size_t lineMax = GetVisibleEnd();
+    for ( size_t line = GetVisibleBegin(); line < lineMax; line++ )
     {
         y -= OnGetLineHeight(line);
         if ( y < 0 )
@@ -305,8 +361,8 @@ bool wxVScrolledWindow::ScrollToLine(size_t line)
 
 
     // remember the currently shown lines for the refresh code below
-    size_t lineFirstOld = GetFirstVisibleLine(),
-           lineLastOld = GetLastVisibleLine();
+    size_t lineFirstOld = GetVisibleBegin(),
+           lineLastOld = GetVisibleEnd();
 
     m_lineFirst = line;
 
@@ -317,8 +373,8 @@ bool wxVScrolledWindow::ScrollToLine(size_t line)
 
     // finally refresh the display -- but only redraw as few lines as possible
     // to avoid flicker
-    if ( GetFirstVisibleLine() > lineLastOld ||
-            GetLastVisibleLine() < lineFirstOld )
+    if ( GetVisibleBegin() >= lineLastOld ||
+            GetVisibleEnd() <= lineFirstOld )
     {
         // the simplest case: we don't have any old lines left, just redraw
         // everything
@@ -326,7 +382,7 @@ bool wxVScrolledWindow::ScrollToLine(size_t line)
     }
     else // overlap between the lines we showed before and should show now
     {
-        ScrollWindow(0, GetLinesHeight(GetFirstVisibleLine(), lineFirstOld));
+        ScrollWindow(0, GetLinesHeight(GetVisibleBegin(), lineFirstOld));
     }
 
     return true;
@@ -350,12 +406,14 @@ bool wxVScrolledWindow::ScrollPages(int pages)
         int line;
         if ( pages > 0 )
         {
-            line = GetLastVisibleLine();
+            line = GetVisibleEnd();
+            if ( line )
+                line--;
             pages--;
         }
         else // pages < 0
         {
-            line = FindFirstFromBottom(GetFirstVisibleLine());
+            line = FindFirstFromBottom(GetVisibleBegin());
             pages++;
         }
 
@@ -404,7 +462,9 @@ void wxVScrolledWindow::OnScroll(wxScrollWinEvent& event)
     }
     else if ( evtType == wxEVT_SCROLLWIN_PAGEDOWN )
     {
-        lineFirstNew = GetLastVisibleLine();
+        lineFirstNew = GetVisibleEnd();
+        if ( lineFirstNew )
+            lineFirstNew--;
     }
     else if ( evtType == wxEVT_SCROLLWIN_THUMBRELEASE )
     {
@@ -449,4 +509,5 @@ void wxVScrolledWindow::OnMouseWheel(wxMouseEvent& event)
         ScrollPages( units_to_scroll );
 }
 
-#endif
+#endif // wxUSE_MOUSEWHEEL
+