Inside Macintosh: QuickTime Components

Managing Your Panel's Settings

To allow the sequence grabber to work with your panel's settings, your panel component must allow the sequence grabber to

retrieve the panel's current settings by calling your SGPanelGetSettings function (described on SGPanelGetSettings )
restore those settings to some previous values by using your SGPanelSetSettings function (described on SGPanelSetSettings )

Listing 3 gives an example in which the settings are managed in a user list that contains tick count information for a panel component for PICT images.

Listing 3 Managing the settings for a panel component



 
pascal ComponentResult PictPanelPanelGetSettings 

                            (PictPanelGlobals store, SGChannel c,

                             UserData *result, long flags)

{

    OSErr           err;

    UserData        ud;

    Boolean         ticksShowing;



 
    /* create a user data list containing your state */

    if (err = NewUserData (&ud)) goto bail;

    if (err = SGGetShowTickCount (c, &ticksShowing)) goto bail;

    if (err = SetUserDataItem (ud, &ticksShowing, 

                                        sizeof (ticksShowing), 

                                        sgcPictShowTicksType, 1)) goto bail;



bail:

    if (err) {

        DisposeUserData(ud);

        ud = 0;

    }

    *result = ud;



    return err;

}



pascal ComponentResult PictPanelPanelSetSettings 

                                    (PictPanelGlobals store, SGChannel c,

                                     UserData ud, long flags)

{

    Boolean ticksShowing;



    /* restore the state from the specified user data list */

    if (GetUserDataItem (ud, &ticksShowing, 

                                sizeof (ticksShowing),

                                sgcPictShowTicksType, 1) == noErr)

        SGSetShowTickCount (c, ticksShowing);



    return noErr;

}

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