Improve wxDataView on DPI change

Fix the row heights after a DPI change and adjust the column widths.
Use DPIChangedEvent instead of MSWUpdateFontOnDPIChange because the child
controls (m_clientArea, m_headerArea) need to update their font sizes first.

include/wx/dataview.h

@@ -895,9 +895,9 @@ public:
     void SetDropEffect( wxDragResult effect ) { m_dropEffect = effect; }
     wxDragResult GetDropEffect() const { return m_dropEffect; }
     // for plaforms (currently only OSX) that support Drag/Drop insertion of items,
-	// this is the proposed child index for the insertion
-	void SetProposedDropIndex(int index) { m_proposedDropIndex = index; }
-	int GetProposedDropIndex() const { return m_proposedDropIndex;}
+    // this is the proposed child index for the insertion
+    void SetProposedDropIndex(int index) { m_proposedDropIndex = index; }
+    int GetProposedDropIndex() const { return m_proposedDropIndex;}
 #endif // wxUSE_DRAG_AND_DROP
 
     virtual wxEvent *Clone() const wxOVERRIDE { return new wxDataViewEvent(*this); }

include/wx/generic/dataview.h

@@ -316,6 +316,8 @@ protected:
 
     virtual void DoEnableSystemTheme(bool enable, wxWindow* window) wxOVERRIDE;
 
+    void OnDPIChanged(wxDPIChangedEvent& event);
+
 public:     // utility functions not part of the API
 
     // returns the "best" width for the idx-th column

src/generic/datavgen.cpp

@@ -193,7 +193,7 @@ int wxDataViewColumn::GetWidth() const
     switch ( m_width )
     {
         case wxCOL_WIDTH_DEFAULT:
-            return wxDVC_DEFAULT_WIDTH;
+            return wxWindow::FromDIP(wxDVC_DEFAULT_WIDTH, m_owner);
 
         case wxCOL_WIDTH_AUTOSIZE:
             wxCHECK_MSG( m_owner, wxDVC_DEFAULT_WIDTH, "no owner control" );
@@ -709,8 +709,7 @@ public:
     bool Cleared();
     void Resort()
     {
-        if ( m_rowHeightCache )
-            m_rowHeightCache->Clear();
+        ClearRowHeightCache();
 
         if (!IsVirtualList())
         {
@@ -718,6 +717,11 @@ public:
         }
         UpdateDisplay();
     }
+    void ClearRowHeightCache()
+    {
+        if ( m_rowHeightCache )
+            m_rowHeightCache->Clear();
+    }
 
     SortOrder GetSortOrder() const
     {
@@ -1188,7 +1192,8 @@ wxSize wxDataViewTextRenderer::GetSize() const
         return GetTextExtent(m_text);
     }
     else
-        return wxSize(wxDVC_DEFAULT_RENDERER_SIZE,wxDVC_DEFAULT_RENDERER_SIZE);
+        return GetView()->FromDIP(wxSize(wxDVC_DEFAULT_RENDERER_SIZE,
+                                         wxDVC_DEFAULT_RENDERER_SIZE));
 }
 
 // ---------------------------------------------------------
@@ -1251,7 +1256,8 @@ wxSize wxDataViewBitmapRenderer::GetSize() const
     else if (m_icon.IsOk())
         return wxSize( m_icon.GetWidth(), m_icon.GetHeight() );
 
-    return wxSize(wxDVC_DEFAULT_RENDERER_SIZE,wxDVC_DEFAULT_RENDERER_SIZE);
+    return GetView()->FromDIP(wxSize(wxDVC_DEFAULT_RENDERER_SIZE,
+                                     wxDVC_DEFAULT_RENDERER_SIZE));
 }
 
 // ---------------------------------------------------------
@@ -2770,11 +2776,8 @@ bool wxDataViewMainWindow::ItemAdded(const wxDataViewItem & parent, const wxData
     }
     else
     {
-        if ( m_rowHeightCache )
-        {
-            // specific position (row) is unclear, so clear whole height cache
-            m_rowHeightCache->Clear();
-        }
+        // specific position (row) is unclear, so clear whole height cache
+        ClearRowHeightCache();
 
         wxDataViewTreeNode *parentNode = FindNode(parent);
 
@@ -3039,8 +3042,7 @@ bool wxDataViewMainWindow::Cleared()
     m_selection.Clear();
     m_currentRow = (unsigned)-1;
 
-    if ( m_rowHeightCache )
-        m_rowHeightCache->Clear();
+    ClearRowHeightCache();
 
     if (GetModel())
     {
@@ -5107,6 +5109,7 @@ void wxDataViewMainWindow::UpdateColumnSizes()
 wxIMPLEMENT_DYNAMIC_CLASS(wxDataViewCtrl, wxDataViewCtrlBase);
 wxBEGIN_EVENT_TABLE(wxDataViewCtrl, wxDataViewCtrlBase)
     EVT_SIZE(wxDataViewCtrl::OnSize)
+    EVT_DPI_CHANGED(wxDataViewCtrl::OnDPIChanged)
 wxEND_EVENT_TABLE()
 
 wxDataViewCtrl::~wxDataViewCtrl()
@@ -5251,6 +5254,28 @@ void wxDataViewCtrl::OnSize( wxSizeEvent &WXUNUSED(event) )
     }
 }
 
+void wxDataViewCtrl::OnDPIChanged(wxDPIChangedEvent& event)
+{
+    if ( m_clientArea )
+    {
+        m_clientArea->ClearRowHeightCache();
+        m_clientArea->SetRowHeight(m_clientArea->GetDefaultRowHeight());
+    }
+
+    for ( unsigned i = 0; i < m_cols.size(); ++i )
+    {
+        int minWidth = m_cols[i]->GetMinWidth();
+        if ( minWidth > 0 )
+            minWidth = minWidth * event.GetNewDPI().x / event.GetOldDPI().x;
+        m_cols[i]->SetMinWidth(minWidth);
+
+        int width = m_cols[i]->WXGetManuallySetWidth();
+        if ( width > 0 )
+            width = width * event.GetNewDPI().x / event.GetOldDPI().x;
+        m_cols[i]->SetWidth(width);
+    }
+}
+
 void wxDataViewCtrl::SetFocus()
 {
     if (m_clientArea)