4. Undo question

Undo question

  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 19/02/2006 at 11:40, xxxxxxxx wrote:

    User Information:
    Cinema 4D Version:   9.0+ 
    Platform:   Windows  ; Mac  ;  Mac OSX  ; 
    Language(s) :     C++  ;

    ---------
    Howdy,

    Here's the problem:
    From a CommandData plugin, I'm adding 3 tags to the document and making one of them the active tag. This is all being done between a StartUndo()/EndUndo() call, but setting the tag as the active tag is not being logged into the undo group, and it takes two undos to undo the command.

      
doc->StartUndo();  
  
//...allocate and add tagA code here  
doc->AddUndo(UNDO_NEW,tagA);  
  
//...allocate and add tagB code here  
doc->AddUndo(UNDO_NEW,tagB);  
  
//...allocate and add tagC code here  
doc->AddUndo(UNDO_NEW,tagC);  
  
doc->SetActiveTag(tagB);  
  
doc->EndUndo();

    I see there is an UNDO_ACTIVATE flag, but the SDK documentation says this:
    **UNDO_ACTIVATE

    Automatically managed by SetActiveObject()/Tag()/Material() etc. No need to use manually.**

    But it doesn't seem to add it to the undo group.
    I did try adding the line:

        doc->AddUndo(UNDO_ACTIVATE, tagB);

    ...both before and after the SetActiveTag() call, but neither one had an effect, and it still takes two undos to undo the command.

    Any ideas?

    Adios,
    Cactus Dan

    0
  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/02/2006 at 04:32, xxxxxxxx wrote:

    Perhaps it makes a difference if you reverse the order to:

      
.. create tagB  
doc->SetActiveTag(tagB)  
doc->AddUndo(UNDO_NEW,tagB)

    you could also try to set the active bit manually.

      
.. create tagB  
doc->AddUndo(UNDO_NEW,tagB)  
  
doc->AddUndo(UNDO_ACTIVEATE,tagB);  
tagB->SetBit(ACTIVE_BIT);

    i think this will most likely work. As well as this:

      
.. create tagB  
tagB->SetBit(ACTIVE_BIT);  
doc->AddUndo(UNDO_NEW,tagB)

    but then you loose all the convenience of SetActiveTag(). Perhaps you must write your own SetActiveTag which adds all the selection undos to your undo block.

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/02/2006 at 16:56, xxxxxxxx wrote:

    Howdy,

    Thanks Michael, for the reply, but I've since discovered that it's something else that's wrong, because if I comment out the line...

      
//doc->SetActiveTag(tagB);

    ...it still needs two undos to undo the command. :o(

    I'm wondering if there is a problem because the actual program flow is like this:

      
create tagA  
create tagB  
branch to initialize data in tagB  
create tagC

    ... I reckon I better put on the debugging hat.

    Adios,
    Cactus Dan

    0
  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/02/2006 at 17:21, xxxxxxxx wrote:

    Howdy,

    AHA!

    I found the problem. It seems that you can't have a StartUndo()/EndUndo() nested within a StartUndo()/EndUndo(). The problem is that after adding tagC, I'm sending a MSG_DESCRIPTION_COMMAND to tagC to simulate the pressing of a button, but within that button's routine in tagC, there is another StartUndo()/EndUndo() group. If I don't send the message, then undoing the command works fine with only one undo.

    I reckon I'll have to add a separate routine to handle invoking that button from the command tool. ;o)

    Adios,
    Cactus Dan

    0
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