Add wxCollapsibleHeaderCtrl widget.

This simple class has a collapsed state which is indicated by a small button and a label. It is now used in the generic implementation of wxCollapsiblePane.

It could be used in more complex layouts than wxCollapsiblePane and is therefore available and documented to the user.

include/wx/collheaderctrl.h

@@ -0,0 +1,97 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/collheaderctrl.h
+// Purpose:     wxCollapsibleHeaderCtrl
+// Author:      Tobias Taschner
+// Created:     2015-09-19
+// Copyright:   (c) 2015 wxWidgets development team
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_COLLAPSIBLEHEADER_CTRL_H_
+#define _WX_COLLAPSIBLEHEADER_CTRL_H_
+
+#include "wx/defs.h"
+
+#if wxUSE_COLLPANE
+
+#include "wx/control.h"
+
+// class name
+extern WXDLLIMPEXP_DATA_CORE(const char) wxCollapsibleHeaderCtrlNameStr[];
+
+//
+// wxGenericCollapsibleHeaderCtrl
+//
+
+class wxCollapsibleHeaderCtrlBase : public wxControl
+{
+public:
+    wxCollapsibleHeaderCtrlBase() { }
+
+    wxCollapsibleHeaderCtrlBase(wxWindow *parent,
+        wxWindowID id,
+        const wxString& label,
+        const wxPoint& pos = wxDefaultPosition,
+        const wxSize& size = wxDefaultSize,
+        long style = wxBORDER_NONE,
+        const wxValidator& validator = wxDefaultValidator,
+        const wxString& name = wxCollapsibleHeaderCtrlNameStr)
+    {
+        Create(parent, id, label, pos, size, style, validator, name);
+    }
+
+    bool Create(wxWindow *parent,
+        wxWindowID id,
+        const wxString& label,
+        const wxPoint& pos = wxDefaultPosition,
+        const wxSize& size = wxDefaultSize,
+        long style = wxBORDER_NONE,
+        const wxValidator& validator = wxDefaultValidator,
+        const wxString& name = wxCollapsibleHeaderCtrlNameStr);
+
+    virtual void SetCollapsed(bool collapsed = true) = 0;
+
+    virtual bool IsCollapsed() const = 0;
+
+private:
+
+    wxDECLARE_NO_COPY_CLASS(wxCollapsibleHeaderCtrlBase);
+};
+
+wxDECLARE_EXPORTED_EVENT(WXDLLIMPEXP_CORE, wxEVT_COLLAPSIBLEHEADER_CHANGED, wxCommandEvent);
+
+#define wxCollapsibleHeaderChangedHandler(func) \
+    wxEVENT_HANDLER_CAST(wxCommandEventFunction, func)
+
+#define EVT_COLLAPSIBLEHEADER_CHANGED(id, fn) \
+    wx__DECLARE_EVT1(wxEVT_COLLAPSIBLEHEADER_CHANGED, id, wxCollapsibleHeaderChangedHandler(fn))
+
+// There currently only is the native implementation, use for all ports
+
+#include "wx/generic/collheaderctrl.h"
+
+class wxCollapsibleHeaderCtrl : public wxGenericCollapsibleHeaderCtrl
+{
+public:
+    wxCollapsibleHeaderCtrl() { }
+
+    wxCollapsibleHeaderCtrl(wxWindow *parent,
+        wxWindowID id,
+        const wxString& label,
+        const wxPoint& pos = wxDefaultPosition,
+        const wxSize& size = wxDefaultSize,
+        long style = wxBORDER_NONE,
+        const wxValidator& validator = wxDefaultValidator,
+        const wxString& name = wxCollapsibleHeaderCtrlNameStr)
+    {
+        Create(parent, id, label, pos, size, style, validator, name);
+    }
+
+private:
+
+    wxDECLARE_NO_COPY_CLASS(wxCollapsibleHeaderCtrl);
+};
+
+#endif // wxUSE_COLLPANE
+
+#endif // _WX_COLLAPSIBLEHEADER_CTRL_H_