ScalableIcon.java

/*
 * Copyright 2015 Igor Maznitsa.
 *
 * 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.igormaznitsa.mindmap.swing.panel.utils;

import static com.igormaznitsa.meta.common.utils.Assertions.assertNotNull;
import java.awt.Image;
import java.io.InputStream;

import javax.annotation.Nonnull;
import javax.imageio.ImageIO;

import org.apache.commons.io.IOUtils;

public final class ScalableIcon {
  public static final ScalableIcon FILE = new ScalableIcon("extra_file.png"); //NOI18N
  public static final ScalableIcon FILE_WARN = new ScalableIcon("extra_file_warn.png"); //NOI18N
  public static final ScalableIcon FILE_MMD = new ScalableIcon("extra_mmd.png"); //NOI18N
  public static final ScalableIcon FILE_MMD_WARN = new ScalableIcon("extra_mmd_warn.png"); //NOI18N
  public static final ScalableIcon TOPIC = new ScalableIcon("extra_topic.png"); //NOI18N
  public static final ScalableIcon TEXT = new ScalableIcon("extra_note.png"); //NOI18N
  public static final ScalableIcon LINK = new ScalableIcon ("extra_uri.png"); //NOI18N

  public static final int BASE_WIDTH = 16;
  public static final int BASE_HEIGHT = 16;
  
  private double currentScaleFactor = -1.0d;
  
  private final Image baseImage;
  private Image scaledCachedImage;
  
  private final float baseScaleX;
  private final float baseScaleY;
  
  public ScalableIcon(@Nonnull final Image image) {
    this.baseImage = assertNotNull("Image must not be null",image);
    this.baseScaleX = (float) BASE_WIDTH / (float) this.baseImage.getWidth(null);
    this.baseScaleY = (float) BASE_HEIGHT / (float) this.baseImage.getHeight(null);
  }
  
  private ScalableIcon(@Nonnull final String name) {
    this(loadStandardImage(name));
  }

  @Nonnull
  public static Image loadStandardImage(@Nonnull final String name) {
    final InputStream in = ScalableIcon.class.getClassLoader().getResourceAsStream("com/igormaznitsa/mindmap/swing/panel/icons/" + name); //NOI18N
    try {
      return ImageIO.read(in);
    } catch (Exception ex) {
      throw new Error("Can't load resource image " + name, ex); //NOI18N
    } finally {
      IOUtils.closeQuietly(in);
    }
  }
  
  public synchronized double getScaleFactor(){
    return this.currentScaleFactor;
  }
  
  @Nonnull
  public synchronized Image getImage(final double scale){
    if (Double.compare(this.currentScaleFactor, scale)!=0){
      this.scaledCachedImage = null;
    }
    
    if (this.scaledCachedImage == null){
      this.scaledCachedImage = Utils.scaleImage(this.baseImage, this.baseScaleX, this.baseScaleY, scale);
      this.currentScaleFactor = scale;
    }
    return this.scaledCachedImage;
  }
}