Add wxDataViewValueAdjuster

Add wxDataViewRenderer:: SetValueAdjuster() and a
wxDataViewValueAdjuster class. This can be used to customize rendering
of values depending on whether they are highlighted (selection) or not,
without having to implement an entire new custom renderer.

include/wx/dvrenderers.h

@@ -96,6 +96,16 @@ enum wxDataViewCellRenderState
     wxDATAVIEW_CELL_FOCUSED     = 8
 };
 
+// helper for fine-tuning rendering of values depending on row's state
+class WXDLLIMPEXP_ADV wxDataViewValueAdjuster
+{
+public:
+    virtual ~wxDataViewValueAdjuster() {}
+
+    // changes the value to have appearance suitable for highlighted rows
+    virtual wxVariant MakeHighlighted(const wxVariant& value) const { return value; }
+};
+
 class WXDLLIMPEXP_ADV wxDataViewRendererBase: public wxObject
 {
 public:
@@ -190,6 +200,10 @@ public:
     // Send wxEVT_DATAVIEW_ITEM_EDITING_STARTED event.
     void NotifyEditingStarted(const wxDataViewItem& item);
 
+    // Sets the transformer for fine-tuning rendering of values depending on row's state
+    void SetValueAdjuster(wxDataViewValueAdjuster *transformer)
+        { delete m_valueAdjuster; m_valueAdjuster = transformer; }
+
 protected:
     // These methods are called from PrepareForItem() and should do whatever is
     // needed for the current platform to ensure that the item is rendered
@@ -197,6 +211,10 @@ protected:
     virtual void SetAttr(const wxDataViewItemAttr& attr) = 0;
     virtual void SetEnabled(bool enabled) = 0;
 
+    // Return whether the currently rendered item is on a highlighted row
+    // (typically selection with dark background). For internal use only.
+    virtual bool IsHighlighted() const = 0;
+
     // Called from {Cancel,Finish}Editing() to cleanup m_editorCtrl
     void DestroyEditControl();
 
@@ -211,6 +229,8 @@ protected:
     wxWeakRef<wxWindow>     m_editorCtrl;
     wxDataViewItem          m_item; // Item being currently edited, if valid.
 
+    wxDataViewValueAdjuster *m_valueAdjuster;
+
     // internal utility, may be used anywhere the window associated with the
     // renderer is required
     wxDataViewCtrl* GetView() const;

include/wx/generic/dvrenderer.h

@@ -52,6 +52,12 @@ public:
                                 const wxMouseEvent* WXUNUSED(mouseEvent))
         { return false; }
 
+    void SetState(int state) { m_state = state; }
+
+protected:
+    virtual bool IsHighlighted() const wxOVERRIDE
+        { return m_state & wxDATAVIEW_CELL_SELECTED; }
+
 private:
     int                          m_align;
     wxDataViewCellMode           m_mode;
@@ -60,6 +66,8 @@ private:
 
     wxDC *m_dc;
 
+    int m_state;
+
     wxDECLARE_DYNAMIC_CLASS_NO_COPY(wxDataViewRenderer);
 };
 

include/wx/gtk/dvrenderer.h

@@ -64,6 +64,8 @@ public:
     // different from the editor control widget for the custom renderers
     virtual GtkWidget* GtkGetEditorWidget() const;
 
+    void GtkSetCurrentItem(const wxDataViewItem& item) { m_itemBeingRendered = item; }
+
 private:
     // Change the mode at GTK level without touching m_mode, this is useful for
     // temporarily making the renderer insensitive but does mean that GetMode()
@@ -74,6 +76,8 @@ protected:
     virtual void SetAttr(const wxDataViewItemAttr& attr) wxOVERRIDE;
     virtual void SetEnabled(bool enabled) wxOVERRIDE;
 
+    virtual bool IsHighlighted() const wxOVERRIDE;
+
     virtual void GtkOnCellChanged(const wxVariant& value,
                                   const wxDataViewItem& item,
                                   unsigned col);
@@ -93,6 +97,9 @@ protected:
     // doing this
     bool m_usingDefaultAttrs;
 
+    // the item currently being rendered
+    wxDataViewItem m_itemBeingRendered;
+
 protected:
     wxDECLARE_DYNAMIC_CLASS_NO_COPY(wxDataViewRenderer);
 };

include/wx/osx/dvrenderer.h

@@ -93,6 +93,8 @@ protected:
     void SetEnabled(bool WXUNUSED(enabled)) wxOVERRIDE { };
 #endif
 
+    virtual bool IsHighlighted() const wxOVERRIDE;
+
 private:
     // contains the alignment flags
     int m_alignment;

interface/wx/dataview.h

@@ -1925,6 +1925,28 @@ public:
     */
     virtual bool SetValue(const wxVariant& value) = 0;
 
+    /**
+        Set the transformer object to be used to customize values before they
+        are rendered.
+
+        Can be used to change the value if it is shown on a highlighted row
+        (i.e. in selection) which typically has dark background. It is useful
+        in combination with wxDataViewTextRenderer with markup and can be used
+        e.g. to remove background color attributes inside selection, as a
+        lightweight alternative to implementing an entire
+        wxDataViewCustomRenderer specialization.
+
+        @a transformer can be @NULL to reset any transformer currently being
+        used.
+
+        Takes ownership of @a transformer.
+
+        @see wxDataViewValueAdjuster
+
+        @since 3.1.1
+    */
+    void SetValueAdjuster(wxDataViewValueAdjuster *transformer);
+
     /**
         Before data is committed to the data model, it is passed to this
         method where it can be checked for validity. This can also be
@@ -3662,3 +3684,66 @@ public:
 
 };
 
+
+/**
+    @class wxDataViewValueAdjuster
+
+    This class can be used with wxDataViewRenderer::SetValueAdjuster() to
+    customize rendering of model values with standard renderers.
+
+    Can be used to change the value if it is shown on a highlighted row (i.e.
+    in selection) which typically has dark background. It is useful in
+    combination with wxDataViewTextRenderer with markup and can be used e.g. to
+    remove background color attributes inside selection, as a lightweight
+    alternative to implementing an entire wxDataViewCustomRenderer
+    specialization.
+
+    @example
+    // Markup renderer that removes bgcolor attributes when in selection
+    class DataViewMarkupRenderer : public wxDataViewTextRenderer
+    {
+    public:
+        DataViewMarkupRenderer()
+        {
+            EnableMarkup();
+            SetValueAdjuster(new Adjuster());
+        }
+
+    private:
+        class Adjuster : public wxDataViewValueAdjuster
+        {
+        public:
+            wxVariant MakeHighlighted(const wxVariant& value) const override
+            {
+                wxString s = value.GetString();
+                size_t pos = s.find(" bgcolor=\"");
+                if (pos != wxString::npos)
+                {
+                    size_t pos2 = s.find('"', pos + 10);
+                    s.erase(pos, pos2 - pos + 1);
+                    return s;
+                }
+                return value;
+            }
+        };
+    };
+    @endexample
+
+    @since 3.1.1
+
+    @library{wxadv}
+    @category{dvc}
+*/
+class wxDataViewValueAdjuster
+{
+public:
+    /**
+        Change value for rendering when highlighted.
+
+        Override to customize the value when it is shown in a highlighted
+        (selected) row, typically on a dark background.
+
+        Default implementation returns @a value unmodified.
+    */
+    virtual wxVariant MakeHighlighted(const wxVariant& value) const;
+};

src/common/datavcmn.cpp

@@ -658,12 +658,14 @@ wxDataViewRendererBase::wxDataViewRendererBase( const wxString &varianttype,
 {
     m_variantType = varianttype;
     m_owner = NULL;
+    m_valueAdjuster = NULL;
 }
 
 wxDataViewRendererBase::~wxDataViewRendererBase()
 {
     if ( m_editorCtrl )
         DestroyEditControl();
+    delete m_valueAdjuster;
 }
 
 wxDataViewCtrl* wxDataViewRendererBase::GetView() const
@@ -830,7 +832,14 @@ wxDataViewRendererBase::PrepareForItem(const wxDataViewModel *model,
     // Now check if we have a value and remember it for rendering it later.
     // Notice that we do it even if it's null, as the cell should be empty then
     // and not show the last used value.
-    const wxVariant& value = CheckedGetValue(model, item, column);
+    wxVariant value = CheckedGetValue(model, item, column);
+
+    if ( m_valueAdjuster )
+    {
+        if ( IsHighlighted() )
+            value = m_valueAdjuster->MakeHighlighted(value);
+    }
+
     SetValue(value);
 
     if ( !value.IsNull() )

src/generic/datavgen.cpp

@@ -969,6 +969,7 @@ wxDataViewRenderer::wxDataViewRenderer( const wxString &varianttype,
     m_mode = mode;
     m_ellipsizeMode = wxELLIPSIZE_MIDDLE;
     m_dc = NULL;
+    m_state = 0;
 }
 
 wxDataViewRenderer::~wxDataViewRenderer()
@@ -2264,10 +2265,16 @@ void wxDataViewMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
             cell_rect.y = GetLineStart( item );
             cell_rect.height = GetLineHeight( item );
 
+            bool selected = m_selection.IsSelected(item);
+
+            int state = 0;
+            if (m_hasFocus && selected)
+                state |= wxDATAVIEW_CELL_SELECTED;
+
+            cell->SetState(state);
             cell->PrepareForItem(model, dataitem, col->GetModelColumn());
 
             // draw the background
-            bool selected = m_selection.IsSelected(item);
             if ( !selected )
                 DrawCellBackground( cell, dc, cell_rect );
 
@@ -2323,10 +2330,6 @@ void wxDataViewMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
             if ( item_rect.width <= 0 )
                 continue;
 
-            int state = 0;
-            if (m_hasFocus && selected)
-                state |= wxDATAVIEW_CELL_SELECTED;
-
             // TODO: it would be much more efficient to create a clipping
             //       region for the entire column being rendered (in the OnPaint
             //       of wxDataViewMainWindow) instead of a single clip region for

src/gtk/dataview.cpp

@@ -2128,6 +2128,12 @@ wxEllipsizeMode wxDataViewRenderer::GetEllipsizeMode() const
     return mode;
 }
 
+bool wxDataViewRenderer::IsHighlighted() const
+{
+    return m_itemBeingRendered.IsOk() &&
+           GetOwner()->GetOwner()->IsSelected(m_itemBeingRendered);
+}
+
 void
 wxDataViewRenderer::GtkOnTextEdited(const char *itempath, const wxString& str)
 {
@@ -3078,6 +3084,7 @@ static void wxGtkTreeCellDataFunc( GtkTreeViewColumn *WXUNUSED(column),
             return;
     }
 
+    cell->GtkSetCurrentItem(item);
     cell->PrepareForItem(wx_model, item, column);
 }
 

src/osx/cocoa/dataview.mm

@@ -2767,6 +2767,11 @@ wxEllipsizeMode wxDataViewRenderer::GetEllipsizeMode() const
     return GetNativeData()->GetEllipsizeMode();
 }
 
+bool wxDataViewRenderer::IsHighlighted() const
+{
+    return [GetNativeData()->GetColumnCell() backgroundStyle] == NSBackgroundStyleDark;
+}
+
 void
 wxDataViewRenderer::OSXOnCellChanged(NSObject *object,
                                      const wxDataViewItem& item,