DoubleFieldEditor.java

/*
 * Copyright (c) 2012, 2013 Hemanta Sapkota.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * Hemanta Sapkota (laex.pearl@gmail.com)
 */
package org.eclipse.wb.swt;

import org.eclipse.jface.preference.StringFieldEditor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;

/**
 * A field editor for a double type preference.
 * <p>
 * This class may be freely distributed as part of any application or plugin.
 * <p>
 * 
 * @author scheglov_ke
 */
public class DoubleFieldEditor extends StringFieldEditor {

  /** The Constant DEFAULT_TEXT_LIMIT. */
  private static final int DEFAULT_TEXT_LIMIT = 10;

  /** The m_min valid value. */
  private double m_minValidValue;

  /** The m_max valid value. */
  private double m_maxValidValue = Double.MAX_VALUE;

  // //////////////////////////////////////////////////////////////////////////
  //
  // Constructors
  //
  // //////////////////////////////////////////////////////////////////////////
  /**
   * Creates a new double field editor.
   */
  protected DoubleFieldEditor() {
  }

  /**
   * Creates a double field editor.
   * 
   * @param name
   *          the name of the preference this field editor works on
   * @param labelText
   *          the label text of the field editor
   * @param parent
   *          the parent of the field editor's control
   */
  public DoubleFieldEditor(String name, String labelText, Composite parent) {
    this(name, labelText, parent, DEFAULT_TEXT_LIMIT);
  }

  /**
   * Creates a double field editor.
   * 
   * @param name
   *          the name of the preference this field editor works on
   * @param labelText
   *          the label text of the field editor
   * @param parent
   *          the parent of the field editor's control
   * @param textLimit
   *          the maximum number of characters in the text.
   */
  public DoubleFieldEditor(String name, String labelText, Composite parent, int textLimit) {
    init(name, labelText);
    setTextLimit(textLimit);
    setEmptyStringAllowed(false);
    setErrorMessage(getMessage_notDouble());
    createControl(parent);
  }

  // //////////////////////////////////////////////////////////////////////////
  //
  // Messages
  //
  // //////////////////////////////////////////////////////////////////////////
  /**
   * Gets the message_not double.
   * 
   * @return the message_not double
   */
  private static String getMessage_notDouble() {
    String message = JFaceResources.getString("IntegerFieldEditor.errorMessage"); //$NON-NLS-1$
    return replaceInteger_withDouble(message);
  }

  /**
   * Gets the message_invalid range.
   * 
   * @param min
   *          the min
   * @param max
   *          the max
   * @return the message_invalid range
   */
  private static String getMessage_invalidRange(double min, double max) {
    String message = JFaceResources.format("IntegerFieldEditor.errorMessageRange", //$NON-NLS-1$
        new Object[]
          { new Double(min), new Double(max) });
    return replaceInteger_withDouble(message);
  }

  /**
   * Replace integer_with double.
   * 
   * @param message
   *          the message
   * @return the string
   */
  private static String replaceInteger_withDouble(String message) {
    int index = message.indexOf("Integer"); //$NON-NLS-1$
    if (index != -1) {
      String prefix = message.substring(0, index);
      String suffix = message.substring(index + "Integer".length()); //$NON-NLS-1$
      message = prefix + "Double" + suffix; //$NON-NLS-1$
    }
    return message;
  }

  // //////////////////////////////////////////////////////////////////////////
  //
  // FieldEditor
  //
  // //////////////////////////////////////////////////////////////////////////
  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.jface.preference.StringFieldEditor#checkState()
   */
  @Override
  protected boolean checkState() {
    Text text = getTextControl();
    if (text == null) {
      return false;
    }
    String numberString = text.getText();
    try {
      double number = Double.valueOf(numberString).doubleValue();
      if ((number >= m_minValidValue) && (number <= m_maxValidValue)) {
        clearErrorMessage();
        return true;
      }
      showErrorMessage();
      return false;
    } catch (NumberFormatException e) {
      showErrorMessage();
    }
    return false;
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.jface.preference.StringFieldEditor#doLoad()
   */
  @Override
  protected void doLoad() {
    Text text = getTextControl();
    if (text != null) {
      double value = getPreferenceStore().getDouble(getPreferenceName());
      text.setText("" + value); //$NON-NLS-1$
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.jface.preference.StringFieldEditor#doLoadDefault()
   */
  @Override
  protected void doLoadDefault() {
    Text text = getTextControl();
    if (text != null) {
      double value = getPreferenceStore().getDefaultDouble(getPreferenceName());
      text.setText("" + value); //$NON-NLS-1$
    }
    valueChanged();
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.jface.preference.StringFieldEditor#doStore()
   */
  @Override
  protected void doStore() {
    Text text = getTextControl();
    if (text != null) {
      Double i = new Double(text.getText());
      getPreferenceStore().setValue(getPreferenceName(), i.doubleValue());
    }
  }

  // //////////////////////////////////////////////////////////////////////////
  //
  // Access
  //
  // //////////////////////////////////////////////////////////////////////////
  /**
   * Returns this field editor's current value as a double.
   * 
   * @return the value
   * @throws NumberFormatException
   *           if the <code>String</code> does not contain a parsable double
   */
  public double getDoubleValue() throws NumberFormatException {
    return Double.parseDouble(getStringValue());
  }

  /**
   * Sets the tool tip text of the label and text control.
   * 
   * @param text
   *          the text to set
   */
  public void setToolTipText(String text) {
    getLabelControl().setToolTipText(text);
    getTextControl().setToolTipText(text);
  }

  /**
   * Sets the range of valid values for this field.
   * 
   * @param min
   *          the minimum allowed value (inclusive)
   * @param max
   *          the maximum allowed value (inclusive)
   */
  public void setValidRange(double min, double max) {
    m_minValidValue = min;
    m_maxValidValue = max;
    setErrorMessage(getMessage_invalidRange(min, max));
  }
}