EngineCallBacks.textCallBack
call back function for handling text messages
Calling Sequence
Parameters
Description
Examples
void textCallBack( Object data, int tag, String msg ) throws MapleException
data
-
arbitrary data that was passed to the Engine constructor
tag
identifies the type of message
msg
text of the message
textCallBack is a member function of the com.maplesoft.openmaple.EngineCallBacks interface. It is called when the Maple session wants to send the user a text message. For example, to display output from the evaluation of a function or from calls to the printing functions.
The following exports of EngineCallBacks are the possible values for tag.
MAPLE\_TEXT\_OUTPUT is used to indicate that the text is output generated from the evaluation of a Maple statement.
MAPLE\_TEXT\_DIAG is used to indicate that the text is diagnostic output, for example, from high printlevel or trace output.
MAPLE\_TEXT\_MISC is used to indicate that the text is from a miscellaneous source, for example, the Maple printf function.
MAPLE\_TEXT\_HELP is used to indicate that the text is the output of a help request. For a more comprehensive help facility, see getHelp.
MAPLE\_TEXT\_QUIT is used to indicate that the text is output generated in response to a quit, done or stop command.
MAPLE\_TEXT\_WARNING is used to indicate that the text is output from a warning generated during a computation.
MAPLE\_TEXT\_ERROR is used to indicate that the text is output from an error raised during parsing or evaluating. This will occur only if the errorCallBack function redirects the error message to the textCallBack function.
MAPLE\_TEXT\_STATUS is used to indicate that the text is output generated from a kernel status message, (the "bytes used" message). This will occur only if the statusCallBack function redirects the status messages into the textCallBack function. This is the default behavior when using the EngineCallBacksDefault class.
MAPLE\_TEXT\_DEBUG is used to indicate that the text is output generated from the Maple debugger.
import com.maplesoft.openmaple.*;
import com.maplesoft.externalcall.MapleException;
class Example
{
static private class CallBacks implements EngineCallBacks
boolean limitExceeded;
CallBacks()
limitExceeded = false;
}
public void textCallBack( Object data, int tag, String output )
throws MapleException
switch ( tag )
case MAPLE_TEXT_OUTPUT:
System.out.print( "Text: " );
break;
case MAPLE_TEXT_DIAG:
System.out.print( "Diag: " );
case MAPLE_TEXT_MISC:
System.out.print( "Misc: " );
case MAPLE_TEXT_HELP:
System.out.print( "Help: " );
case MAPLE_TEXT_QUIT:
System.out.print( "Quit: " );
case MAPLE_TEXT_WARNING:
System.out.print( "Warning: " );
case MAPLE_TEXT_DEBUG:
System.out.print( "Debug: " );
System.out.println( output );
public void errorCallBack( Object data, int offset, String msg )
if ( offset >= 0 )
throw new MapleException( "Error: "+msg );
else
throw new MapleException( "syntax error at offset "+offset+
": "+msg );
public void statusCallBack( Object data, long kbused, long kballoced,
double timeused )
if ( timeused > 5 )
limitExceeded = true;
System.out.println( "Status: used = "+kbused+", alloced = "+
kballoced+", time = "+timeused );
public String readLineCallBack( Object data, boolean debug )
return "readline";
public boolean redirectCallBack( Object data, String output, boolean
append )
System.out.println( "redirect to "+output+" append = "+append );
return true;
public String callBackCallBack( Object data, String output )
System.out.println( "callback: "+output );
return output+";";
public boolean queryInterrupt( Object data )
return limitExceeded;
public String streamCallBack( Object data, String name, String args[] )
StringBuffer sbuf;
int i;
System.out.print( name+"( " );
for ( i = 0; i < args.length; i++ )
System.out.print( args[i]+" " );
System.out.println( ")" );
return args[0]+":";
public static void main( String notused[] ) throws MapleException
String mapleArgs[];
Engine engine;
mapleArgs = new String[1];
mapleArgs[0] = "java";
engine = new Engine( mapleArgs, new CallBacks(), null, null );
engine.evaluate( "192+291;" );
engine.evaluate( "printf( \%a\, x^n+y^n=z^n );" );
engine.evaluate( "printlevel:=5;" );
engine.evaluate( "int(x,x);" );
engine.evaluate( "printlevel:=1;" );
engine.evaluate( "WARNING( \be warned!\ );" );
Executing this code produces the following output.
Text: 483
Misc: x^n+y^n = z^n
Text: printlevel := 5
Diag: {--> enter int, args = x, x
Text: answer := 1/2*x^2
Text: 1/2*x^2
Diag: <-- exit int (now at top level) = 1/2*x^2}
Text: printlevel := 1
Warning: Warning, be warned!
See Also
ExternalCalling/Java/MapleException
OpenMaple
OpenMaple/Java/Engine
OpenMaple/Java/Engine/Engine
OpenMaple/Java/EngineCallBacks
OpenMaple/Java/EngineCallBacksDefault
OpenMaple/Java/EngineCallBacksDefault/textCallBack
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