Android Open Source - customhellochartdemo Simple Value Formatter

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License

The source code is released under:

Apache License

Java Source Code

package lecho.lib.hellocharts.model;
//from   www  .java2 s .  c  o  m
import java.text.DecimalFormat;
import java.text.NumberFormat;

import lecho.lib.hellocharts.util.Utils;

/**
 * Default value formatter. Can be used for axes and for value labels. Method
 * {@link #formatValue(char[], float, char[], int)} is used only if formatter is used for auto-generated axis. Note:
 * Maximum number of characters in formated value should be less or equals 32 so be careful with appended text length.
 * Note2: this formatter skips value formating if label is not null, in that case it will return label, not formatted
 * number value. Note3: only last value from values array is formated, for LineChart that is Y value, for BubbleChart
 * that is Z value.
 * 
 */
public class SimpleValueFormatter implements ValueFormatter {
  protected static final int DEFAULT_DIGITS_NUMBER = 0;
  protected final int digitsNumber;
  protected final char[] appendedText;
  protected final char[] prependedText;
  protected final char separator;
  protected boolean manualDigitsForAutoAxes = false;

  /**
   * Creates formatter with default configuration, 0 number of digits after separator and no text appended to value.
   */
  public SimpleValueFormatter() {
    this(DEFAULT_DIGITS_NUMBER, false, null, null);
  }

  /**
   * Creates formatter with given number of digits after decimal separator.
   */
  public SimpleValueFormatter(int digitsNumber) {
    this(digitsNumber, false, null, null);
  }

  /**
   * Creates formatter with given number of digits after decimal separator and with text prepended and appended to
   * formated value.
   */
  public SimpleValueFormatter(int digitsNumber, boolean manualDigitsForAutoAxes, char[] prependedText,
      char[] appendedText) {
    this.digitsNumber = digitsNumber;
    this.manualDigitsForAutoAxes = manualDigitsForAutoAxes;

    if (null == prependedText) {
      this.prependedText = new char[0];
    } else {
      this.prependedText = prependedText;
    }

    if (null == appendedText) {
      this.appendedText = new char[0];
    } else {
      this.appendedText = appendedText;
    }

    // Get decimal point separator for default locale.
    NumberFormat numberFormat = NumberFormat.getInstance();
    if (numberFormat instanceof DecimalFormat) {
      separator = ((DecimalFormat) numberFormat).getDecimalFormatSymbols().getDecimalSeparator();
    } else {
      separator = '.';
    }
  }

  @Override
  public int formatValue(char[] formattedValue, float[] values, char[] label) {

    return format(formattedValue, values, label, digitsNumber);

  }

  @Override
  public int formatAutoValue(char[] formattedValue, float[] values, int digits) {

    return format(formattedValue, values, null, digits);

  }

  private int format(char[] formattedValue, float[] values, char[] label, int digits) {
    if (manualDigitsForAutoAxes) {
      digits = digitsNumber;
    }

    if (null != label) {
      // If custom label is not null use only name characters as formatted value.
      // Copy label into formatted value array.
      System.arraycopy(label, 0, formattedValue, formattedValue.length - label.length, label.length);
      return label.length;
    }

    if (null == values || values.length == 0) {
      return 0;
    }

    // Manual label is null so format value as number.
    // Format only last value, in most cases that is enough.
    float value = values[values.length - 1];

    final int numChars = Utils.formatFloat(formattedValue, value, formattedValue.length - appendedText.length,
        digits, separator);

    if (prependedText.length > 0) {
      System.arraycopy(prependedText, 0, formattedValue, formattedValue.length - numChars - appendedText.length
          - prependedText.length, prependedText.length);
    }

    if (appendedText.length > 0) {
      System.arraycopy(appendedText, 0, formattedValue, formattedValue.length - appendedText.length,
          appendedText.length);
    }

    return numChars + prependedText.length + appendedText.length;
  }
}

Java Source Code List

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