Advanced MFC Programming

Chapter 14. Views
ID_EDIT_PASTE
paste
The reason for this is that CEditView already maps commands with the above-mentioned IDs to its
built-in member functions that handle undo, cut, copy and paste commands. The name of these functions
are not documented in the current version of Visual C++, this means these function are not guaranteed to be
supported in the future.
If we want to use other command IDs instead of the recommended ones, we need to implement
command message mapping by ourselves. In order to do so, we need to look at the MFC source code that
contains member functions of class CEditView, find out the function names that support these commands,
and map the WM_COMMAND type messages to the appropriate functions.
Search Related Commands
In the sample, three other standard commands, Search | Find…, Search | Replace…, and Search |
Find Next are implemented this way. The three commands are used for searching a specific string in the
text contained in the view, replacing an old string with a new one, or repeating searching. The default IDs
for these commands are listed in the following table:
Command ID Functionality WM_COMMADN message handler UPDATE_COMMAND_UI message
handler
ID_EDIT_FIND Search OnEditFind OnUpdateNeedText
ID_EDIT_REPLACE Find/replace OnEditReplace OnUpdateNeedText
ID_EDIT_REPEAT Repeat searching OnEditRepeat OnUpdateNeedFind
Message UPDATE_COMMAND_UI is also handled for the above commands.
In the sample, we use following non-standard command IDs to implement find, replace, and repeat
commands:
Command ID
ID_SEARCH_FIND
ID_SEARCH_REPLACE
ID_SEARCH_FINDNEXT
Functionality
Find
Find and replace
Repeat
The message mapping is done in the implementation file “NPView.cpp”:
ON_COMMAND(ID_SEARCH_FIND, CEditView::OnEditFind)
ON_COMMAND(ID_SEARCH_REPLACE, CEditView::OnEditReplace)
ON_COMMAND(ID_SEARCH_FINDNEXT, CEditView::OnEditRepeat)
ON_UPDATE_COMMAND_UI(ID_SEARCH_FIND, CEditView::OnUpdateNeedText)
ON_UPDATE_COMMAND_UI(ID_SEARCH_REPLACE, CEditView::OnUpdateNeedText)
ON_UPDATE_COMMAND_UI(ID_SEARCH_FINDNEXT, CEditView::OnUpdateNeedFind)
With the above implementation, there is no need for us to declare and define new member functions to
handle the above commands, everything will be handled automatically.
Other Commands
In the sample, some other commands that are not supported by class CEditVew are also implemented.
These command include Edit | Delete, which can be used to delete the current selection; Edit | Select All,
which can be used to select all the text contained in the window, and Edit | Time/Date, which can be used
to insert a time/date stamp at the current caret position. For these commands, the message mapping and
message handlers need to be implemented by ourselves.
Edit view is implemented by an embedded edit control, which can be accessed by calling function
CEditView::GetEditCtrl(). Once this is done, we can call any member function of CEdit and make
change to the text contained in the window. For example, if we want to replace the selected text with a new
string or insert a string at the current caret position, we can call function CEdit::ReplaceSel(…) to do so.
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