X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/1e6feb95a79834836e88143b15d9f424ebe79621..23d2edff3505385801313910ece449bdb959f0f1:/src/msw/scrolbar.cpp

diff --git a/src/msw/scrolbar.cpp b/src/msw/scrolbar.cpp
index 5cfec12c46..d10d08daad 100644
--- a/src/msw/scrolbar.cpp
+++ b/src/msw/scrolbar.cpp
@@ -122,9 +122,40 @@ wxScrollBar::~wxScrollBar(void)
 bool wxScrollBar::MSWOnScroll(int WXUNUSED(orientation), WXWORD wParam,
                               WXWORD pos, WXHWND control)
 {
-    int position = ::GetScrollPos((HWND) control, SB_CTL);
-    int minPos, maxPos;
-    ::GetScrollRange((HWND) control, SB_CTL, &minPos, &maxPos);
+    // current and max positions
+    int position,
+        maxPos, trackPos = pos;
+
+#ifdef __WIN32__
+    // when we're dragging the scrollbar we can't use pos parameter because it
+    // is limited to 16 bits
+    if ( wParam == SB_THUMBPOSITION || wParam == SB_THUMBTRACK )
+    {
+        SCROLLINFO scrollInfo;
+        wxZeroMemory(scrollInfo);
+        scrollInfo.cbSize = sizeof(SCROLLINFO);
+
+        // also get the range if we call GetScrollInfo() anyhow -- this is less
+        // expensive than call it once here and then call GetScrollRange()
+        // below
+        scrollInfo.fMask = SIF_RANGE | SIF_POS | SIF_TRACKPOS;
+
+        if ( !::GetScrollInfo(GetHwnd(), SB_CTL, &scrollInfo) )
+        {
+            wxLogLastError(_T("GetScrollInfo"));
+        }
+
+        trackPos = scrollInfo.nTrackPos;
+        position = scrollInfo.nPos;
+        maxPos = scrollInfo.nMax;
+    }
+    else
+#endif // Win32
+    {
+        position = ::GetScrollPos((HWND) control, SB_CTL);
+        int minPos;
+        ::GetScrollRange((HWND) control, SB_CTL, &minPos, &maxPos);
+    }
 
 #if defined(__WIN95__)
     // A page size greater than one has the effect of reducing the effective
@@ -139,13 +170,13 @@ bool wxScrollBar::MSWOnScroll(int WXUNUSED(orientation), WXWORD wParam,
     int nScrollInc;
     switch ( wParam )
     {
-        case SB_TOP:
+        case SB_BOTTOM:
             nScrollInc = maxPos - position;
             scrollEvent = wxEVT_SCROLL_TOP;
             break;
 
-        case SB_BOTTOM:
-            nScrollInc = - position;
+        case SB_TOP:
+            nScrollInc = -position;
             scrollEvent = wxEVT_SCROLL_BOTTOM;
             break;
 
@@ -170,36 +201,45 @@ bool wxScrollBar::MSWOnScroll(int WXUNUSED(orientation), WXWORD wParam,
             break;
 
         case SB_THUMBPOSITION:
-            nScrollInc = pos - position;
+            nScrollInc = trackPos - position;
             scrollEvent = wxEVT_SCROLL_THUMBRELEASE;
             break;
 
         case SB_THUMBTRACK:
-            nScrollInc = pos - position;
+            nScrollInc = trackPos - position;
             scrollEvent = wxEVT_SCROLL_THUMBTRACK;
             break;
 
+        case SB_ENDSCROLL:
+            nScrollInc = 0;
+            scrollEvent = wxEVT_SCROLL_ENDSCROLL;
+            break;
+
         default:
             nScrollInc = 0;
     }
 
-    // don't process the event if there is no displacement,
-    // unless this is a thumb release event.
-    if (( nScrollInc == 0 ) && ( scrollEvent != wxEVT_SCROLL_THUMBRELEASE ))
+    if ( nScrollInc )
     {
-        return FALSE;
-    }
+        position += nScrollInc;
 
-    int new_pos = position + nScrollInc;
+        if ( position < 0 )
+            position = 0;
+        if ( position > maxPos )
+            position = maxPos;
 
-    if (new_pos < 0)
-        new_pos = 0;
-    if (new_pos > maxPos)
-        new_pos = maxPos;
+        SetThumbPosition(position);
+    }
+    else if ( scrollEvent != wxEVT_SCROLL_THUMBRELEASE &&
+                scrollEvent != wxEVT_SCROLL_ENDSCROLL )
+    {
+        // don't process the event if there is no displacement,
+        // unless this is a thumb release or end scroll event.
+        return FALSE;
+    }
 
-    SetThumbPosition(new_pos);
     wxScrollEvent event(scrollEvent, m_windowId);
-    event.SetPosition(new_pos);
+    event.SetPosition(position);
     event.SetEventObject( this );
 
     return GetEventHandler()->ProcessEvent(event);
@@ -208,16 +248,16 @@ bool wxScrollBar::MSWOnScroll(int WXUNUSED(orientation), WXWORD wParam,
 void wxScrollBar::SetThumbPosition(int viewStart)
 {
 #if defined(__WIN95__)
-  SCROLLINFO info;
-  info.cbSize = sizeof(SCROLLINFO);
-  info.nPage = 0;
-  info.nMin = 0;
-  info.nPos = viewStart;
-  info.fMask = SIF_POS ;
-
-  ::SetScrollInfo((HWND) GetHWND(), SB_CTL, &info, TRUE);
+    SCROLLINFO info;
+    info.cbSize = sizeof(SCROLLINFO);
+    info.nPage = 0;
+    info.nMin = 0;
+    info.nPos = viewStart;
+    info.fMask = SIF_POS ;
+
+    ::SetScrollInfo((HWND) GetHWND(), SB_CTL, &info, TRUE);
 #else
-  ::SetScrollPos((HWND) GetHWND(), SB_CTL, viewStart, TRUE);
+    ::SetScrollPos((HWND) GetHWND(), SB_CTL, viewStart, TRUE);
 #endif
 }