Embed Fluff Images in the Unit Files (MM part)

megamek/src/megamek/client/ui/Base64Image.java

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+/*
+ * Copyright (c) 2024 - The MegaMek Team. All Rights Reserved.
+ *
+ * This file is part of MegaMek.
+ *
+ * MegaMek is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MegaMek is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MegaMek. If not, see <http://www.gnu.org/licenses/>.
+ */
+package megamek.client.ui;
+
+import megamek.common.annotations.Nullable;
+import megamek.common.util.ImageUtil;
+import org.apache.logging.log4j.LogManager;
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Serializable;
+import java.util.Base64;
+import java.util.Objects;
+
+/**
+ * This is a form of an Image that is based on a base64-encoded form, e.g. loaded from file. The base64 is retained
+ * and the actual image only created when {@link #getImage()} is called. This class is serializable;
+ * the internal Image object is transient and the base64 String is used for serialization.
+ * Decoding the base64 image uses {@link ImageIO#read(InputStream)}.
+ *
+ * @implNote Threadsafe; Immutable. The displayable Image is created only when needed and uses synchronized access
+ */
+public class Base64Image implements Serializable {
+
+    /** The base64 representation of the image. */
+    private final String base64encodedImage;
+
+    /** The displayable image. Created lazily by {@link #getImage()}. */
+    private transient Image image;
+
+    /** Creates an empty Base64Image. */
+    public Base64Image() {
+        this("");
+    }
+
+    /** Creates a Base64Image with the given base64-encoded image. */
+    public Base64Image(String base64) {
+        this.base64encodedImage = Objects.requireNonNullElse(base64, "");
+    }
+
+    /** @return True when there is no image, i.e. the base64 encoded form is blank. */
+    public boolean isEmpty() {
+        return base64encodedImage.isBlank();
+    }
+
+    /** @return The base64 representation of the image.  */
+    public String getBase64String() {
+        return base64encodedImage;
+    }
+
+    /**
+     * Returns the image in displayable form. When first called, the base64 representation is converted to an Image.
+     * When conversion fails, returns {@link ImageUtil#failStandardImage()}. When the base64 representation is
+     * blank, returns null.
+     *
+     * @return The image in displayable form
+     */
+    public @Nullable Image getImage() {
+        if (isEmpty()) {
+            return null;
+        } else {
+            synchronized (this) {
+                if (image == null) {
+                    byte[] imageBytes = Base64.getDecoder().decode(base64encodedImage);
+                    try (ByteArrayInputStream inStreambj = new ByteArrayInputStream(imageBytes)) {
+                        image = ImageIO.read(inStreambj);
+                    } catch (IOException ex) {
+                        LogManager.getLogger().warn("Could not convert base64 to image", ex);
+                        image = ImageUtil.failStandardImage();
+                    }
+                }
+                return image;
+            }
+        }
+    }
+}