tmf/org.lttng.scope.tmf2.views.ui/src/org/lttng/scope/tmf2/views/ui/jfx/JfxImageFactory.java

   1 /*
   2  * Copyright (C) 2017 EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  */
   9
  10 package org.lttng.scope.tmf2.views.ui.jfx;
  11
  12 import java.io.IOException;
  13 import java.io.InputStream;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16
  17 import org.eclipse.jdt.annotation.Nullable;
  18
  19 import javafx.scene.image.Image;
  20
  21 /**
  22  * Factory for JavaFX {@link Image}s. This will allow caching the Image objects,
  23  * allowing any class to re-use already read images.
  24  *
  25  * @author Alexandre Montplaisir
  26  * @noreference This cache is only valid for classes within the same jar/plugin.
  27  *              The resource paths would not work from different plugins.
  28  */
  29 public final class JfxImageFactory {
  30
  31     private static final JfxImageFactory INSTANCE = new JfxImageFactory();
  32
  33     private JfxImageFactory() {}
  34
  35     /**
  36      * Get the singleton instance of this factory.
  37      *
  38      * @return The instance
  39      */
  40     public static JfxImageFactory instance() {
  41         return INSTANCE;
  42     }
  43
  44     private final Map<String, Image> fImages = new HashMap<>();
  45
  46     /**
  47      * Get the {@link Image} for a given path within the jar's resources.
  48      *
  49      * @param resourcePath
  50      *            The path to the image resource. It should be a standard
  51      *            .gif/.png/.jpg etc. file.
  52      * @return The corresponding Image.
  53      */
  54     public synchronized @Nullable Image getImageFromResource(String resourcePath) {
  55         Image image = fImages.get(resourcePath);
  56         if (image == null) {
  57             try (InputStream is = getClass().getResourceAsStream(resourcePath)) {
  58                 if (is == null) {
  59                     /* The image was not found, the path is invalid */
  60                     return null;
  61                 }
  62                 image = new Image(is);
  63             } catch (IOException e) {
  64                 return null;
  65             }
  66             fImages.put(resourcePath, image);
  67         }
  68         return image;
  69     }
  70
  71 }