+// ----------------------------------------------------------------------------
+// This class is our userdata/lParam for the TV_ITEMs stored in the treeview.
+//
+// We need this for a couple of reasons:
+//
+// 1) This class is needed for support of different images: the Win32 common
+// control natively supports only 2 images (the normal one and another for the
+// selected state). We wish to provide support for 2 more of them for folder
+// items (i.e. those which have children): for expanded state and for expanded
+// selected state. For this we use this structure to store the additional items
+// images.
+//
+// 2) This class is also needed to hold the HITEM so that we can sort
+// it correctly in the MSW sort callback.
+//
+// In addition it makes other workarounds such as this easier and helps
+// simplify the code.
+// ----------------------------------------------------------------------------
+
+class wxTreeItemParam
+{
+public:
+ wxTreeItemParam()
+ : m_item((long int)0),
+ m_data(NULL)
+ {
+ for ( size_t n = 0; n < WXSIZEOF(m_images); n++ )
+ {
+ m_images[n] = -1;
+ }
+ }
+
+ // dtor deletes the associated data as well
+ virtual ~wxTreeItemParam() { delete m_data; }
+
+ // accessors
+ // get the real data associated with the item
+ wxTreeItemData *GetData() const { return m_data; }
+ // change it
+ void SetData(wxTreeItemData *data) { m_data = data; }
+
+ // do we have such image?
+ bool HasImage(wxTreeItemIcon which) const { return m_images[which] != -1; }
+ // get image, falling back to the other images if this one is not
+ // specified
+ int GetImage(wxTreeItemIcon which) const
+ {
+ int image = m_images[which];
+ if ( image == -1 )
+ {
+ switch ( which )
+ {
+ case wxTreeItemIcon_SelectedExpanded:
+ image = GetImage(wxTreeItemIcon_Expanded);
+ if ( image != -1 )
+ break;
+ //else: fall through
+
+ case wxTreeItemIcon_Selected:
+ case wxTreeItemIcon_Expanded:
+ image = GetImage(wxTreeItemIcon_Normal);
+ break;
+
+ case wxTreeItemIcon_Normal:
+ // no fallback
+ break;
+
+ default:
+ wxFAIL_MSG( _T("unsupported wxTreeItemIcon value") );
+ }
+ }
+
+ return image;
+ }
+ // change the given image
+ void SetImage(int image, wxTreeItemIcon which) { m_images[which] = image; }
+
+ // get item
+ const wxTreeItemId& GetItem() const { return m_item; }
+ // set item
+ void SetItem(const wxTreeItemId& item) { m_item = item; }
+
+protected:
+ // all the images associated with the item
+ int m_images[wxTreeItemIcon_Max];
+
+ // item for sort callbacks
+ wxTreeItemId m_item;
+
+ // the real client data
+ wxTreeItemData *m_data;
+
+ DECLARE_NO_COPY_CLASS(wxTreeItemParam)
+};
+