funcptg.java

来自「EXCEL read and write」· Java 代码 · 共 79 行

/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
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package org.apache.poi.hssf.record.formula;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.hssf.record.RecordInputStream;
import org.apache.poi.hssf.record.formula.function.FunctionMetadata;
import org.apache.poi.hssf.record.formula.function.FunctionMetadataRegistry;

/**
 * @author aviks
 * @author Jason Height (jheight at chariot dot net dot au)
 * @author Danny Mui (dmui at apache dot org) (Leftover handling)
 */
public final class FuncPtg extends AbstractFunctionPtg {

    public final static byte sid  = 0x21;
    public final static int  SIZE = 3;
    private int numParams=0;

    /**Creates new function pointer from a byte array
     * usually called while reading an excel file.
     */
    public FuncPtg(RecordInputStream in) {
        //field_1_num_args = data[ offset + 0 ];
        field_2_fnc_index  = in.readShort();

        FunctionMetadata fm = FunctionMetadataRegistry.getFunctionByIndex(field_2_fnc_index);
        if(fm == null) {
            throw new RuntimeException("Invalid built-in function index (" + field_2_fnc_index + ")");
        }
        numParams = fm.getMinParams();
        returnClass = fm.getReturnClassCode();
        paramClass = fm.getParameterClassCodes();
    }
    public FuncPtg(int functionIndex) {
        field_2_fnc_index = (short) functionIndex;
        FunctionMetadata fm = FunctionMetadataRegistry.getFunctionByIndex(functionIndex);
        numParams = fm.getMinParams(); // same as max since these are not var-arg funcs
        returnClass = fm.getReturnClassCode();
        paramClass = fm.getParameterClassCodes();
    }

    public void writeBytes(byte[] array, int offset) {
        array[offset+0]= (byte) (sid + getPtgClass());
        LittleEndian.putShort(array,offset+1,field_2_fnc_index);
    }

    public int getNumberOfOperands() {
        return numParams;
    }

    public int getSize() {
        return SIZE;
    }

    public String toString() {
        StringBuffer sb = new StringBuffer(64);
        sb.append(getClass().getName()).append(" [");
        sb.append(lookupName(field_2_fnc_index));
        sb.append(" nArgs=").append(numParams);
        sb.append("]");
        return sb.toString();
    }
}