plugins/IntentionPowerPak/src/com/siyeh/ipp/integer/ConvertToScientificNotationIntention.java

/*
 * Copyright 2000-2010 JetBrains s.r.o.
 *
 * Licensed 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.
 */
package com.siyeh.ipp.integer;

import com.intellij.psi.PsiType;
import com.siyeh.ipp.base.PsiElementPredicate;
import org.jetbrains.annotations.NotNull;

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;

/**
 * @author Konstantin Bulenkov
 */
public class ConvertToScientificNotationIntention extends ConvertNumberIntentionBase {
  private static final DecimalFormat FORMAT = new DecimalFormat("0.0#############E00", new DecimalFormatSymbols(Locale.US));

  @Override
  protected String convertValue(final Number value, final PsiType type, final boolean negated) {
    final double doubleValue = Double.parseDouble(value.toString());  // convert to double w/o adding parasitic digits
    final String text = FORMAT.format(negated ? -doubleValue : doubleValue);
    return PsiType.FLOAT.equals(type) ? text + "f" : text;
  }

  @NotNull
  @Override
  protected PsiElementPredicate getElementPredicate() {
    return new ConvertToScientificNotationPredicate();
  }
}