honour column min width when resizing in wxHeaderCtrl, no need to do it in wxDataViewCtrl

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57201 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/headerctrlg.h

@@ -94,9 +94,19 @@ private:
     // end any drag operation currently in progress (resizing or reordering)
     void EndDragging();
 
-    // and the resizing operation currently in progress and generate an event
-    // about it with its cancelled flag set if width is -1
-    void EndResizing(int width);
+    // start (if m_colBeingResized is -1) or continue resizing the column
+    //
+    // this generates wxEVT_COMMAND_HEADER_BEGIN_RESIZE/RESIZING events and can
+    // cancel the operation if the user handler decides so
+    void StartOrContinueResizing(unsigned int col, int xPhysical);
+
+    // end the resizing operation currently in progress and generate an event
+    // about it with its cancelled flag set if xPhysical is -1
+    void EndResizing(int xPhysical);
+
+    // constrain the given position to be larger than the start position of the
+    // given column plus its minimal width and return the effective width
+    int ConstrainByMinWidth(unsigned int col, int& xPhysical);
 
     // update the current position of the resizing marker if xPhysical is a
     // valid physical coordinate value or remove it entirely if it is -1

src/generic/datavgen.cpp

@@ -143,15 +143,6 @@ private:
             event.Veto();
     }
 
-    void OnResizing(wxHeaderCtrlEvent& event)
-    {
-        const wxHeaderColumnBase& col = GetColumn(event.GetColumn());
-
-        const int minWidth = col.GetMinWidth();
-        if ( event.GetWidth() < minWidth )
-            event.Veto();
-    }
-
     void OnEndResize(wxHeaderCtrlEvent& event)
     {
         if ( !event.IsCancelled() )
@@ -171,7 +162,6 @@ BEGIN_EVENT_TABLE(wxDataViewHeaderWindow, wxHeaderCtrl)
     EVT_HEADER_RIGHT_CLICK(wxID_ANY, wxDataViewHeaderWindow::OnRClick)
 
     EVT_HEADER_BEGIN_RESIZE(wxID_ANY, wxDataViewHeaderWindow::OnBeginResize)
-    EVT_HEADER_RESIZING(wxID_ANY, wxDataViewHeaderWindow::OnResizing)
     EVT_HEADER_END_RESIZE(wxID_ANY, wxDataViewHeaderWindow::OnEndResize)
 END_EVENT_TABLE()
 

src/generic/headerctrlg.cpp

@@ -247,7 +247,54 @@ void wxHeaderCtrl::EndDragging()
     SetCursor(wxNullCursor);
 }
 
-void wxHeaderCtrl::EndResizing(int width)
+int wxHeaderCtrl::ConstrainByMinWidth(unsigned int col, int& xPhysical)
+{
+    const int xStart = GetColStart(col);
+
+    // notice that GetMinWidth() returns 0 if there is no minimal width so it
+    // still makes sense to use it even in this case
+    const int xMinEnd = xStart + GetColumn(col).GetMinWidth();
+
+    if ( xPhysical < xMinEnd )
+        xPhysical = xMinEnd;
+
+    return xPhysical - xStart;
+}
+
+void wxHeaderCtrl::StartOrContinueResizing(unsigned int col, int xPhysical)
+{
+    wxHeaderCtrlEvent event(IsResizing() ? wxEVT_COMMAND_HEADER_RESIZING
+                                         : wxEVT_COMMAND_HEADER_BEGIN_RESIZE,
+                            GetId());
+    event.SetEventObject(this);
+    event.SetColumn(col);
+
+    event.SetWidth(ConstrainByMinWidth(col, xPhysical));
+
+    if ( GetEventHandler()->ProcessEvent(event) && !event.IsAllowed() )
+    {
+        if ( IsResizing() )
+        {
+            ReleaseMouse();
+            EndResizing(-1);
+        }
+        //else: nothing to do -- we just don't start to resize
+    }
+    else // go ahead with resizing
+    {
+        if ( !IsResizing() )
+        {
+            m_colBeingResized = col;
+            SetCursor(wxCursor(wxCURSOR_SIZEWE));
+            CaptureMouse();
+        }
+        //else: we had already done the above when we started
+
+        UpdateResizingMarker(xPhysical);
+    }
+}
+
+void wxHeaderCtrl::EndResizing(int xPhysical)
 {
     wxASSERT_MSG( IsResizing(), "shouldn't be called if we're not resizing" );
 
@@ -255,16 +302,16 @@ void wxHeaderCtrl::EndResizing(int width)
 
     // if dragging was cancelled we must have already lost the mouse capture so
     // don't try to release it
-    if ( width != -1 )
+    if ( xPhysical != -1 )
         ReleaseMouse();
 
     wxHeaderCtrlEvent event(wxEVT_COMMAND_HEADER_END_RESIZE, GetId());
     event.SetEventObject(this);
     event.SetColumn(m_colBeingResized);
-    if ( width == -1 )
+    if ( xPhysical == -1 )
         event.SetCancelled();
     else
-        event.SetWidth(width);
+        event.SetWidth(ConstrainByMinWidth(m_colBeingResized, xPhysical));
 
     GetEventHandler()->ProcessEvent(event);
 
@@ -384,9 +431,9 @@ void wxHeaderCtrl::OnMouse(wxMouseEvent& mevent)
     if ( IsResizing() )
     {
         if ( mevent.LeftUp() )
-            EndResizing(xPhysical - GetColStart(m_colBeingResized));
+            EndResizing(xPhysical);
         else // update the live separator position
-            UpdateResizingMarker(xPhysical);
+            StartOrContinueResizing(m_colBeingResized, xPhysical);
 
         return;
     }
@@ -427,10 +474,8 @@ void wxHeaderCtrl::OnMouse(wxMouseEvent& mevent)
         if ( onSeparator )
         {
             // start resizing the column
-            m_colBeingResized = col;
-            SetCursor(wxCursor(wxCURSOR_SIZEWE));
-            CaptureMouse();
-            UpdateResizingMarker(xPhysical);
+            wxASSERT_MSG( !IsResizing(), "reentering resize mode?" );
+            StartOrContinueResizing(col, xPhysical);
         }
         else // on column itself
         {

src/msw/headerctrl.cpp

@@ -295,6 +295,7 @@ bool wxHeaderCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
     wxEventType evtType = wxEVT_NULL;
     int idx = nmhdr->iItem;
     int width = 0;
+    bool cancelled = false;
     const UINT code = nmhdr->hdr.code;
     switch ( code )
     {
@@ -343,10 +344,34 @@ bool wxHeaderCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
 
         case HDN_ENDTRACKA:
         case HDN_ENDTRACKW:
+            width = nmhdr->pitem->cxy;
+
             if ( evtType == wxEVT_NULL )
+            {
                 evtType = wxEVT_COMMAND_HEADER_END_RESIZE;
 
-            width = nmhdr->pitem->cxy;
+                // don't generate events with invalid width
+                const int minWidth = GetColumn(idx).GetMinWidth();
+                if ( width < minWidth )
+                    width = minWidth;
+            }
+            break;
+
+        case HDN_ITEMCHANGING:
+            if ( nmhdr->pitem && (nmhdr->pitem->mask & HDI_WIDTH) )
+            {
+                // prevent the column from being shrunk beneath its min width
+                if ( nmhdr->pitem->cxy < GetColumn(idx).GetMinWidth() )
+                {
+                    *result = TRUE;
+
+                    return true;
+                }
+            }
+            break;
+
+        case NM_RELEASEDCAPTURE:
+            cancelled = true;
             break;
     }
 
@@ -358,6 +383,8 @@ bool wxHeaderCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
         event.SetEventObject(this);
         event.SetColumn(idx);
         event.SetWidth(width);
+        if ( cancelled )
+            event.SetCancelled();
 
         if ( GetEventHandler()->ProcessEvent(event) )
         {