[Name] ACTIVECHOICE

[Description] A variation of the normal CHOICE drop down; ACTIVECHOICE allows each
              item to be associated with another GUI element - if an item is
              chosen, the corresponding GUI element becomes disabled. 
              
               - If the ACTIVECHOICE is used to disable some parameters, those
                 parameters will end up having the value <Unused> placed into
                 them when the transformer template is expanded. Then you may
                 require special Tcl processing or upgrading of their underlying
                 functions/factories so that they correctly ignore <Unused> for
                 such parameters. When writing this processing code do NOT check for
                 <Unused> but rather check the value of the ACTIVECHOICE.
                  
               - Be aware that if the ACTIVECHOICE parameter is linked to a user
                 parameter, the GUI can NOT know the value of the choice until
                 runtime. As a result, it will write out ALL the dependent
                 parameters to the mapping file.
                  
               - When setting the default values for your transformer with
                 ACTIVECHOICE, set them consistently to what the GUI would
                 normally save. This probably means the default value for some
                 dependent parameters will be <Unused>.
                  
               - If your CHOICE part in ACTIVECHOICE contains spaces, you'll
                 have to escape some quotes (see under Example).
                                
               - If the parameter disabled by ACTIVECHOICE is required (not
                 OPTIONAL), doesn't have a default value but the initial state
                 of transformer is such that the parameter is disabled,
                 then that parameter should be set to an internal default value
                 of "<Unused>". This will prevent the transformer to appear as
                 "incomplete" when it is dropped on the workspace canvas.
                 
               - For the ACTIVECHOICE, prefixing the parameter name with '++'
                 will force the value of the referenced parameter to be set
                 regardless of whether or not the user has edited the value
                 prior. A '+' will not overwrite user edits of the referenced
                 parameter. For example transformers that use the '+' and '++'
                 syntax see PointCloudSplitter and PointCloudCoercer.


In a Transformer (*.fmx) File

   Syntax

      PARAMETER_NAME: <macroName>
      PARAMETER_TYPE: ACTIVECHOICE <value1>[,<disableMacro>]*[,++<setMacro>+value]*[,+<setMacro>+value]*[%<value2>[,<disableMacro2>]*[,++<setMacro>+value]*[,+<setMacro>+value]*]*
      PARAMETER_PROMPT: <label>
      PARAMETER_DEFAULT: [<defaultValue>]
   
   Example

      PARAMETER_NAME: RESAMPLING_TYPE 
      PARAMETER_TYPE: ACTIVECHOICE Dimensions,X_CELL_SIZE,Y_CELL_SIZE%"\"Cell Size\",ROWS,COLUMNS"
      PARAMETER_PROMPT: Resampling Type:
      PARAMETER_DEFAULT:

   From PointCloudCoercer - when 'Spatial Equal Points Multipoints is selected, then POINT_COMPONENTS_PRESERVE_DISPLAY will be set to 'Measures'
   regardless of current value.
      PARAMETER_NAME: CONVERT_TO_DISPLAY
      PARAMETER_TYPE: ACTIVECHOICE "\"Spatial Equal Points Multipoints\",POINT_COMPONENTS_PRESERVE_DISPLAY,++POINT_COMPONENTS_PRESERVE_DISPLAY+Measures"%"\"Sequential Equal Points Multipoints\",POINT_COMPONENTS_PRESERVE_DISPLAY,++POINT_COMPONENTS_PRESERVE_DISPLAY+Measures"%"\"Nested Equal Area Multipoints\",POINT_COMPONENTS_PRESERVE_DISPLAY,++POINT_COMPONENTS_PRESERVE_DISPLAY+Measures"%"\"Single Multipoint\",MULTIPOINT_SIZE,POINT_COMPONENTS_PRESERVE_DISPLAY,++POINT_COMPONENTS_PRESERVE_DISPLAY+Measures"%"\"Individual Points\",MULTIPOINT_SIZE,+POINT_COMPONENTS_PRESERVE_DISPLAY+Attributes"
      PARAMETER_PROMPT: Output Geometry:
      PARAMETER_DEFAULT: Spatial Equal Points Multipoints
      PARAMETER_LOOKUP: CONVERT_TO BOXEDMULTIPOINT%SEQUENTIALMULTIPOINT%NESTEDEQUALAREAMULTIPOINT%SINGLEMULTIPOINT%POINT

      
In a Reader/Writer (*.fmf, *.fmi) File

   Syntax
   
      [DEFAULT_VALUE <macroName> <defaultValue>]
      GUI ACTIVECHOICE <macroName> <value1>[,<disableMacro>]*[,++<setMacro>+value]*[,+<setMacro>+value]*[%<value2>[,<disableMacro2>]*[,++<setMacro>+value]*[,+<setMacro>+value]*]* <label>
   
   Example
   
      GUI ACTIVECHOICE RESAMPLING_TYPE Dimensions,X_CELL_SIZE,Y_CELL_SIZE%"\"Cell Size\",ROWS,COLUMNS" Resampling Type: