Insert / overwrite modes of RTE

Does anyone know of a simple way to test if a RTE is in insert or overwrite
mode. I can't find any listed messages / properties in the windows docs - in
fact the only mention I can find is in the discussion of the Text Object
Model in the ITextSelection interface and it seems a little OTT to have to
start digging around with this.

It  *appears* that the RTE always begins life in insert mode so the easiest
way would be to assume this is the case and then monitor the keyboard event
for the insert key - is this a safe assumption?


TIA

David

David

You wrote in message news:94ecd5$7vj$[hidden email]...
> Does anyone know of a simple way to test if a RTE is in insert or
overwrite
> mode. I can't find any listed messages / properties in the windows docs -
in
> fact the only mention I can find is in the discussion of the Text Object
> Model in the ITextSelection interface and it seems a little OTT to have to
> start digging around with this.

That is the only method I can find too. I wouldn't dismiss it entirely, as I
think you will find it is actually pretty easy to use the COM interface.
However it looks as if it requires the use of version 2.0 (or later) of the
RTE, and Dolphin wraps v1.0 for historical reasons related to Win95. This
might mean further work in creating a RichTextEdit2 subclass of RichTextEdit
as I seem to recall that the behaviour of v2 differs in some significant
ways such as the treatment of line-terminators.

> It  *appears* that the RTE always begins life in insert mode so the
easiest
> way would be to assume this is the case and then monitor the keyboard
event
> for the insert key - is this a safe assumption?

Hmmm, perhaps but I would be worried about keeping it in step.

Regards

Blair

> That is the only method I can find too. I wouldn't dismiss it entirely, as
I
> think you will find it is actually pretty easy to use the COM interface.
> However it looks as if it requires the use of version 2.0 (or later) of
the
> RTE, and Dolphin wraps v1.0 for historical reasons related to Win95. This
> might mean further work in creating a RichTextEdit2 subclass of
RichTextEdit
> as I seem to recall that the behaviour of v2 differs in some significant
> ways such as the treatment of line-terminators.
>

Blair

Thanks for the reply Blair - I've had a look at the COM interfaces and as
you say it does it look pretty straightforward -  the AXComponent wizard
does a tremendous job in generating the Smalltalk classes and methods.

I think I'll have a go at wrapping the RichEd20.dll - it seems all that is
needed in addition is to generate the PARAFORMAT2 and CHARFORMAT2 structures
so I'll have a go and see how I get on.

One query though -  to get to the RTE COM interface I need to send
EM_GETOLEINTERFACE with 0 as wParam .The lParam requires " a Pointer to a
pointer that receives the IRichEditOle object" - what on earth do I send as
the parameter here?.

Best Wishes

David

David

You wrote in message news:94pcps$rlr$[hidden email]...
> ...
> Thanks for the reply Blair - I've had a look at the COM interfaces and as
> you say it does it look pretty straightforward -  the AXComponent wizard
> does a tremendous job in generating the Smalltalk classes and methods.
>
> I think I'll have a go at wrapping the RichEd20.dll - it seems all that is
> needed in addition is to generate the PARAFORMAT2 and CHARFORMAT2
structures
> so I'll have a go and see how I get on.

If you are using D4 the wizard can generate those too.

> One query though -  to get to the RTE COM interface I need to send
> EM_GETOLEINTERFACE with 0 as wParam .The lParam requires " a Pointer to a
> pointer that receives the IRichEditOle object" - what on earth do I send
as
> the parameter here?.

Normally one would simply pass the result of an "IUnknown newPointer", but
because this is using a SendMessage() call we need to manually coerce the
argument instead of just letting the VM do it, e.g. we might implement
RichTextEdit>>getOleInterface as follows (though note this causes a circular
dependency between OLE COM and Dolphin packages, and so must be repackaged
as a loose method in another package):

getOleInterface
    | answer |
    answer := IUnknown newPointer.
    (self sendMessage: "EM_GETOLEINTERFACE" WM_USER + 60
            wParam: 0
            lParam: answer bytes basicYourAddress) isZero
        ifTrue: [self error: 'Failed to retrieve IRichEditOle'].
^answer

If you've generated IRichEditOle then you could substitute that for IUnknown
above, on the other hand if you don't need that interface at all then leave
it as it is. You can query off the ITextDocument interface, e.g.

rte := RichTextEdit allInstances first
ole := rte getOleInterface.
"Generate the interfaces and the constants pool - we need only do this once"
tlb := (ole queryInterface: IDispatch) typeInfo typeLib.
tlb prefix: ''.
tlb generateInterfaceWrappers.
tlb generateConstantsPool.

"Now we can retrieve ITextSelection"
sel := (ole queryInterface: ITextDocument) selection.

"Finally: Is it in overtype mode?"
sel flags allMask: (TomConstants at: 'tomSelOvertype')

The above works on Win2k even using Rich Edit 1.0 because Win2k implements
all the RTE versions in the same component. I doubt it will work on older
systems which have separate RichEd32 (1.0) and RichEd20 (2.0) DLLs, so a
generic solution will probably require a subclass for 2.0.

Regards

Blair

Superb - many thanks Blair. I was stumbling down the path towards this but
I'm not sure when I would have arrived at the solution!

>>it seems all that is  needed in addition is to generate the PARAFORMAT2
and >>CHARFORMAT2 structures

>>If you are using D4 the wizard can generate those too.

This is interesting -I am using D4P. I have added these structures "by
hand" - i.e defined the fields and then run compileDefinition to generate
accessors - is there an easier way?

One more query - when subclassing RichTextEdit to RichTextEdit2 all works as
expected apart from registering the class name. According to my Header files
( from C++ Builder4) when using the ANSI form the class name should be
'RichEdit20A' but this results in a incorrect parameter walkback - ( as does
'RichEdit20' and 'RichEdit20W' ) leaving it as 'RichEdit' appears to work
but I'm not sure why I'm getting this problem.

David

> One more query - when subclassing RichTextEdit to RichTextEdit2 all works
as
> expected apart from registering the class name. According to my Header
files
> ( from C++ Builder4) when using the ANSI form the class name should be
> 'RichEdit20A' but this results in a incorrect parameter walkback - ( as
does
> 'RichEdit20' and 'RichEdit20W' ) leaving it as 'RichEdit' appears to work
> but I'm not sure why I'm getting this problem.
>

Please ignore this  -its my spelling at fault ( dyslexics of the world
untie!)

David