Creating an editor with a COM interface for incoming data.

1. Setup the project.

   Go through the "MFC AppWizard(exe)". Call the project "OutputCOMEditor".
   Install the "Automation" option.
   Keep defaults "Multiple Documents" and "Document/View architecture support".
   Change the basic view class to "CEditView".
   Install other options on your preference.
   
   

2. Implement the automation interface.

   Use automation menu of the Class Wizard to add COM visible member functions to the COutputCOMEditorDoc class .
   
   Add a member variable kaBasicClasses::CEditOutputStream COutputCOMEditorDoc::controlStream;
   
   Include the file CEditOutputStream.h to the OutputCOMEditorDoc.h
   
   The added functions should be implemented as follows
   void COutputCOMEditorDoc::ShowWindow();
   void COutputCOMEditorDoc::AddText(LPCTSTR text);
   void COutputCOMEditorDoc::EndLine();
   long COutputCOMEditorDoc::GetCursorPosition();
   long COutputCOMEditorDoc::GetMaximalCursorPosition();
   void COutputCOMEditorDoc::MoveCursorBy(long offset);
   void COutputCOMEditorDoc::SetCursorAtEnd();
   void COutputCOMEditorDoc::SetCursorAtPosition(long position);
   void COutputCOMEditorDoc::SetCursorAtStart();
   Note that the implementations are preceeded by using namespace kaBasicClasses; and using namespace std;
   



3. Test the program (calling the COM object from Excel).

   Create an empty Excel spreadsheet. Program access to the functions ShowWindow and AddText from the spreadsheet using VBA's CreateObject function and information from the OutputCOMEditor.odl .
   

Minor changes.

4. Insure that the Editor only ask to save changes on closure if there are changes. Add the line
   SetModifiedFlag(FALSE);
   before the "return" statement in the function
   COutputCOMEditorDoc::OnNewDocument().
   Add the line
   SetModifiedFlag(TRUE);
   to the end of the functions void COutputCOMEditorDoc::AddText(LPCTSTR text). and void COutputCOMEditorDoc::EndLine();



5. The child editor window looks better maximised within the main frame of the application.
   To make this happen edit the functions COutputCOMEditorDoc::ShowWindow() , COutputCOMEditorDoc::OnNewDocument() and include the directive
   #include "MainFrm.h"
   into the file EditWindowDoc.cpp.
   
   

Debugging

Calling from an MFC application.

1. Setup the project. Go through the "MFC AppWizard(exe)". Call the project "testingOutputCOMEditor".
   Make it "Dialog based".
   Install "Automation"!
   Install other options on your preference.
2. Edit the dialog window. The result should look like this.
3. Use "Properties" to set the following properties

   Component	Property name	Property value
   Small editor box in the position section	ID	IDC_POSITIONEDITORBOX
   Small editor box in the text section	ID	IDC_TEXTEDITORBOX
   Small editor box in the text section	Styles->Multiline	Checked
   Small editor box in the text section	Styles->Want return	Checked
   Small editor box in the text section	Styles->Vertical Scroll	Checked
   "Get" button	ID	IDC_GET
   "Set" button	ID	IDC_SET
   "Get max" button	ID	IDC_GETMAX
   "Move by" button	ID	IDC_MOVEBY
   "Set at end" button	ID	IDC_SETATEND
   "Set at start" button	ID	IDC_SETATSTART
   "Insert" button	ID	IDC_INSERT
   "Load" button	ID	ID_LOAD
   "Unload" button	ID	ID_UNLOAD
   "OK" button	ID	ID_OKBUTTON

4. Use Class Wizard to add the message handlers to the created resources as shown in the table.

   ID of the resource	ID of the Event	Name of the Handler
   ID_LOAD	BN_CLICKED	OnLoad
   ID_INSERT	BN_CLICKED	OnInsert
   ID_UNLOAD	BN_CLICKED	OnUnload

5. Use Class Wizard to add a member variable
   CString m_text;
   to the "text controls" edit box.
6. Generate an interface class IOutputCOMEditor for the OutputCOMEditor.
7. Edit the functions
   void CTestingOutputCOMEditorDlg::OnLoad();
   void CTestingOutputCOMEditorDlg::OnUnload();
   void CTestingOutputCOMEditorDlg::OnInsert();
   
8. Add definitions of a "class OutputCOMEditorStream: public std::ostream { ... };" to the files OutputCOMEditorStream.h and OutputCOMEditorStream.cpp .
9. Add the variable kaBasicClasses::OutputCOMEditorStream* theEditor;
   to the definition of the dialog class CTestingOutputCOMEditorDlg. 
10. Insert the statement class kaBasicClasses::OutputCOMEditorStream; before definition of the class CTestingOutputCOMEditorDlg and include the OutputCOMEditorStream.h header file to the cpp file.
11. Add initialization theEditor=NULL in the constructor and the clean up if( theEditor!=NULL ) delete theEditor; in the destructor.
12. Attach OutputStream.cpp, OutputStream.h, EditorOutputStream.h to the project.
13. Add the variable int m_position to the editor box in the cursor control section.
14. Add the message handlers to the rest of the buttons and provide the following implementation.
15. Check how it works.