TMI-139: Work in progress: TIFF image metadata.

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/AbstractMetadata.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2014, Harald Kuhr
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name "TwelveMonkeys" nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.twelvemonkeys.imageio;
+
+import org.w3c.dom.Node;
+
+import javax.imageio.metadata.IIOInvalidTreeException;
+import javax.imageio.metadata.IIOMetadata;
+import javax.imageio.metadata.IIOMetadataFormatImpl;
+import java.util.Arrays;
+
+/**
+ * AbstractMetadata
+ *
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ * @author last modified by $Author: haraldk$
+ * @version $Id: AbstractMetadata.java,v 1.0 Nov 13, 2009 1:02:12 AM haraldk Exp$
+ */
+public abstract class AbstractMetadata extends IIOMetadata implements Cloneable {
+    protected AbstractMetadata(final boolean standardFormatSupported,
+                               final String nativeFormatName, final String nativeFormatClassName,
+                               final String[] extraFormatNames, final String[] extraFormatClassNames) {
+        super(standardFormatSupported, nativeFormatName, nativeFormatClassName, extraFormatNames, extraFormatClassNames);
+    }
+
+    protected AbstractMetadata() {
+        super(true, null, null, null, null);
+    }
+
+    /**
+     * Default implementation returns {@code true}.
+     * Mutable subclasses should override this method.
+     *
+     * @return {@code true}.
+     */
+    @Override
+    public boolean isReadOnly() {
+        return true;
+    }
+
+    @Override
+    public Node getAsTree(final String formatName) {
+        validateFormatName(formatName);
+
+        if (formatName.equals(nativeMetadataFormatName)) {
+            return getNativeTree();
+        }
+        else if (formatName.equals(IIOMetadataFormatImpl.standardMetadataFormatName)) {
+            return getStandardTree();
+        }
+
+        // Subclasses that supports extra formats need to check for these formats themselves...
+        return null;
+    }
+
+    /**
+     * Default implementation that throws {@code UnsupportedOperationException}.
+     * Subclasses that supports formats other than standard metadata should override this method.
+     *
+     * @throws UnsupportedOperationException
+     */
+    protected Node getNativeTree() {
+        throw new UnsupportedOperationException("getNativeTree");
+    }
+
+    @Override
+    public void mergeTree(final String formatName, final Node root) throws IIOInvalidTreeException {
+        assertMutable();
+
+        validateFormatName(formatName);
+
+        if (!root.getNodeName().equals(formatName)) {
+            throw new IIOInvalidTreeException("Root must be " + formatName, root);
+        }
+
+        // TODO: Merge both native and standard!
+        Node node = root.getFirstChild();
+        while (node != null) {
+            // TODO: Merge values from node into this
+
+            // Move to the next sibling
+            node = node.getNextSibling();
+        }
+    }
+
+    @Override
+    public void reset() {
+        assertMutable();
+    }
+
+    /**
+     * Asserts that this meta data is mutable.
+     *
+     * @throws IllegalStateException if {@link #isReadOnly()} returns {@code true}.
+     */
+    protected final void assertMutable() {
+        if (isReadOnly()) {
+            throw new IllegalStateException("Metadata is read-only");
+        }
+    }
+
+    protected final void validateFormatName(final String formatName) {
+        String[] metadataFormatNames = getMetadataFormatNames();
+
+        if (metadataFormatNames != null) {
+            for (String metadataFormatName : metadataFormatNames) {
+                if (metadataFormatName.equals(formatName)) {
+                    return; // Found, we're ok!
+                }
+            }
+        }
+
+        throw new IllegalArgumentException(
+                String.format("Bad format name: \"%s\". Expected one of %s", formatName, Arrays.toString(metadataFormatNames))
+        );
+    }
+
+    protected static String toListString(short[] values) {
+        String string = Arrays.toString(values);
+        return string.substring(1, string.length() - 1);
+    }
+}