/*
* Copyright 2013 serso aka se.solovyev
*
* 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.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Contact details
*
* Email: se.solovyev@gmail.com
* Site: http://se.solovyev.org
*/
package org.solovyev.android.calculator;
import android.text.SpannableStringBuilder;
import com.google.common.base.Strings;
import jscl.NumeralBase;
import org.solovyev.android.calculator.math.MathType;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
public abstract class BaseNumberBuilder {
@Nonnull
protected final Engine engine;
@Nullable
protected StringBuilder numberBuilder = null;
@Nullable
protected NumeralBase nb;
protected BaseNumberBuilder(@Nonnull Engine engine) {
this.engine = engine;
this.nb = engine.getMathEngine().getNumeralBase();
}
/**
* Method determines if we can continue to process current number
*
* @param result current math type result
* @return true if we can continue of processing of current number, if false - new number should be constructed
*/
protected boolean canContinue(@Nonnull MathType.Result result) {
final boolean number = result.type.getGroupType() == MathType.MathGroupType.number;
return number && !spaceBefore(result) &&
numeralBaseCheck(result) &&
numeralBaseInTheStart(result.type)
|| isSignAfterE(result);
}
private boolean spaceBefore(@Nonnull MathType.Result mathTypeResult) {
return numberBuilder == null && Strings.isNullOrEmpty(mathTypeResult.match.trim());
}
private boolean numeralBaseInTheStart(@Nonnull MathType result) {
return result != MathType.numeral_base || numberBuilder == null;
}
private boolean numeralBaseCheck(@Nonnull MathType.Result result) {
return result.type != MathType.digit || getNumeralBase().getAcceptableCharacters().contains(result.match.charAt(0));
}
private boolean isSignAfterE(@Nonnull MathType.Result mathTypeResult) {
if (isHexMode()) {
return false;
}
final String match = mathTypeResult.match;
if (!"−".equals(match) && !"-".equals(match) && !"+".equals(match)) {
return false;
}
final StringBuilder nb = numberBuilder;
if (nb == null || nb.length() == 0) {
return false;
}
return nb.charAt(nb.length() - 1) == MathType.EXPONENT;
}
public boolean isHexMode() {
return getNumeralBase() == NumeralBase.hex;
}
@Nonnull
protected NumeralBase getNumeralBase() {
return nb == null ? engine.getMathEngine().getNumeralBase() : nb;
}
public abstract int process(@Nonnull SpannableStringBuilder sb, @Nonnull MathType.Result result);
}