varcomparison.cpp

/***************************************************************************
 *   Copyright (C) 2003 by David Saxton                                    *
 *   david@bluehaze.org                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include "varcomparison.h"

#include "libraryitem.h"
#include "flowcode.h"

#include <klocale.h>

Item* VarComparison::construct( ItemDocument *itemDocument, bool newItem, const char *id )
{
        return new VarComparison( (ICNDocument*)itemDocument, newItem, id );
}

LibraryItem* VarComparison::libraryItem()
{
        return new LibraryItem(
                QString("flow/varcomparison"),
                i18n("Comparison"),
                i18n("Variables"),
                "branch.png",
                LibraryItem::lit_flowpart,
                VarComparison::construct );
}

VarComparison::VarComparison( ICNDocument *icnDocument, bool newItem, const char *id )
        : FlowPart( icnDocument, newItem, (id) ? id : "varcomparison" )
{
        m_name = i18n("Variable Comparison");
        m_desc = i18n("Conditional branch point, depending on the comparison of two values. The supported comparisons are:<ul><li><b>x == y</b> - Equality: true if x has the same value as y.</li><li><b>x &lt; y</b> - Less than: true if x is smaller than y.</li><li><b>x &gt; y</b> - Greater than: true if x is bigger than y.</li><li><b>x &lt;= y</b> - Less than or equal: true if x is less than or equal to y.</li><li><b>x &gt;= y</b> - Greater than or equal: true if x is greater than or equal to y.</li><li><b>x != y</b> - Does not equal: true if x does not have the same value as y.</li></ul>");
        initDecisionSymbol();
        createStdInput();
        createStdOutput();
        createAltOutput();
        
        createProperty( "0var1", Variant::Type::Combo );
        property("0var1")->setCaption( i18n("Variable") );
        property("0var1")->setValue("x");
        
        createProperty( "1op", Variant::Type::Select );
        property("1op")->setAllowed( QStringList::split( ',', "==,<,>,<=,>=,!=" ) );
        property("1op")->setValue("==");
        property("1op")->setToolbarCaption(" ");
        property("1op")->setEditorCaption( i18n("Operation") );
        
        createProperty( "2var2", Variant::Type::Combo );
        property("2var2")->setToolbarCaption(" ");
        property("2var2")->setEditorCaption( i18n("Value") );
        property("2var2")->setValue("0");
        
        addDisplayText( "output_false", QRect( offsetX()+width(), 2, 40, 20 ), "No" );
        addDisplayText( "output_true", QRect( 0, offsetY()+height(), 50, 20 ), "Yes" ); 
}

VarComparison::~VarComparison()
{
}

void VarComparison::dataChanged()
{
        setCaption( dataString("0var1") + " " + dataString("1op") + " " + dataString("2var2") + " ?" );
}

QString VarComparison::oppOp( const QString &op )
{
        if              ( op == "==" )  return "!=";
        if              ( op == "!=" )  return "==";
        else if ( op == "<" )   return ">=";
        else if ( op == ">=" )  return "<";
        else if ( op == ">" )   return "<=";
        else if ( op == "<=" )  return ">";
        else return "__UNKNOWN_OP__";
}

void VarComparison::generateMicrobe( FlowCode *code )
{
        QString var1 = dataString("0var1");
        QString var2 = dataString("2var2");
        QString test = dataString("1op");
        
        handleIfElse( code, var1+" "+test+" "+var2, var1+" "+oppOp(test)+" "+var2, "stdoutput", "altoutput" );
        
#if 0
        code->addCode( "if "+var1+" "+test+" "+var2+"\n{\n" );
        code->addCodeBranch( outputPart("stdoutput") );
        code->addCode("}");
        if ( outputPart("altoutput") )
        {
                code->addCode("else\n{");
                code->addCodeBranch( outputPart("altoutput") );
                code->addCode("}");
        }
#endif
        
#if 0
        QString newCode;
        
        if ( FlowCode::isLiteral(var2) ) newCode += "movlw " + var2 + " ; Move literal to register w\n";
        else
        {
                code->addVariable(var2);
                newCode += "movf " + var2 + ",0 ; Move " + var2 + " to register w\n";
        }
        
        if ( FlowCode::isLiteral(var1) ) newCode += "sublw " + var1 + " ; Subtract register w from " + var1 + ", placing result in w\n";
        else
        {
                code->addVariable(var1);
                newCode += "subwf " + var1 + ",0 ; Subtract register w from " + var1 + ", placing result in w\n";
        }
        
        
        if              ( test == "==" )
        {
                // check: works
                newCode += "btfss STATUS,2 ; Check if zero flag is set\n";
                newCode += gotoCode("altoutput") + " ; Result from calculation was non-zero; hence comparison is false\n";
                newCode += gotoCode("stdoutput") + " ; Ouput was zero; hence comparison is true, so continue from this point\n";
        }
        else if ( test == "!=" )
        {
                // check: works
                newCode += "btfsc STATUS,2 ; Check if zero flag is clear\n";
                newCode += gotoCode("altoutput") + " ; Result from calculation was zero; hence comparison is false\n";
                newCode += gotoCode("stdoutput") + " ; Output was non-zero; hence comparison is true, so continue from this point\n";
        }
        else if ( test == ">=" )
        {
                // check: works
                newCode += "btfss STATUS,0 ; Check if carry flag is set\n";
                newCode += gotoCode("altoutput") + " ; Result from calculation is negative; hence comparison is false\n";
                newCode += gotoCode("stdoutput") + " ; Result from calculation is positive or zero; so continue from this point\n";
        }
        else if ( test == ">" )
        {
                // check: works
                newCode += "btfss STATUS,0 ; Check if carry flag is set\n";
                newCode += gotoCode("altoutput") + " ; Result is negative; hence comparison is false\n";
                newCode += "btfsc STATUS,2 ; Check if zero flag is set\n";
                newCode += gotoCode("altoutput") + " ; Result is zero; hence comparison is false\n";
                newCode += gotoCode("stdoutput") + " ; Comparison is true, so continue from this point\n";
        }
        else if ( test == "<" )
        {
                // check: works
                newCode += "btfsc STATUS,0 ; Check if carry flag is set\n";
                newCode += gotoCode("altoutput");
                newCode += gotoCode("stdoutput");
        }
        else if ( test == "<=" )
        {
                // check: works
                newCode += "btfsc STATUS,2 ; Check if result is zero\n";
                newCode += gotoCode("stdoutput") + " ; Result is zero; hence comparison is true\n";
                newCode += "btfsc STATUS,0 ; Check if carry flag is set\n";
                newCode += gotoCode("altoutput") + " ; Result is positive (not zero, has already tested for this); hence comparison is false\n";
                newCode += gotoCode("stdoutput") + " ; Result is negative, hence comparison is true\n";
        }
        
        code->addCodeBlock( id(), newCode );
#endif
}

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