Tag Parameters

All the tags parameters are declared in the src/engine/abstract/TagParameterStrings.cpp file. It consists in a set of constant strings, consistently named according to the AR class that uses the parameters. For example: tag parameters for the ARMeter class is named kARMeterParams.

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Tag parameters string

A tag parameters string is a list of semicolon separated parameters. Each parameter is a string in the following format:

"TYPE,NAME,DEFVALUE,REQUIRED"

where:

• TYPE is the parameter type and must be in:
  • 'U' : a unit parameter i.e. a numeric value with an optional unit ('cm', 'hs',...). When omitted, the default unit is used.
  • 'S' : a string parameter.
  • 'I' : an integer parameter.
  • 'F' : a float parameter.
• NAME is the parameter name.
• DEFVALUE is the parameter default value.
• REQUIRED is either 'r' or 'o' for required or optional parameters.

Example:

The ARMeter tag parameters are described with:

"S,type,4/4,r;S,autoBarlines,on,o;S,autoMeasuresNum,off,o;S,group,off,o"

see the \meter documentation for the parameters description.

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Shared Parameters

The following parameters are shared by all the AR classes:

const char* kCommonParams       = "S,color,black,o;U,dx,0,o;U,dy,0,o;F,size,1.0,o";

The following parameters are shared by all the ARFontAble derived classes:

const char* kARFontAbleParams   = "S,textformat,rc,o;S,font,Times,o;U,fsize,9pt,o;S,fattrib,,o";

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Initialisation

All the tag parameters strings are stored in a TagParametersMaps structure that is initialised by GuidoInit()and released by GuidoShutdown().

Each AR class is responsible to:

• setup its parameters at construction time using setupTagParameters (_a_param_map_)
• handle the current parameters by overriding the setTagParametersmethod

For example, see the ARFermata implementation.

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Creating a new parameters string

It requires the following steps:

• implement the new parameter string in TagParameterStrings.cpp
• declare the new string in TagParameterStrings.h
• add a new parameters map in TagParametersMaps.h