Unify ImageLoader implementations and extract differences

Extract existing differences in the ImageLoader implementation for
Linux/GTK into an InternalImageFileLoader class that also exists for
Windows and MacOS but just delegates to FileFormat.

Author: HannesWell

bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/graphics/InternalImageLoader.java

@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * Copyright (c) 2025, 2025 Hannes Wellmann and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Hannes Wellmann - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.graphics;
+
+import java.io.*;
+
+import org.eclipse.swt.internal.image.*;
+
+class InternalImageLoader {
+
+	static ImageData[] load(InputStream stream, ImageLoader imageLoader) {
+		return FileFormat.load(stream, imageLoader);
+	}
+
+	static void save(OutputStream stream, int format, ImageLoader imageLoader) {
+		FileFormat.save(stream, format, imageLoader);
+	}
+}

bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/graphics/ImageLoader.java renamed to bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageLoader.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2016 IBM Corporation and others.
+ * Copyright (c) 2000, 2025 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -10,15 +10,14 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Hannes Wellmann - Unify ImageLoader implementations and extract differences into InternalImageLoader
  *******************************************************************************/
 package org.eclipse.swt.graphics;
 
-
 import java.io.*;
 import java.util.*;
 
 import org.eclipse.swt.*;
-import org.eclipse.swt.internal.image.*;
 
 /**
  * Instances of this class are used to load images from,
@@ -151,7 +150,7 @@ void reset() {
 public ImageData[] load(InputStream stream) {
 	if (stream == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
 	reset();
-	data = FileFormat.load(stream, this);
+	data = InternalImageLoader.load(stream, this);
 	return data;
 }
 
@@ -217,7 +216,7 @@ public ImageData[] load(String filename) {
  */
 public void save(OutputStream stream, int format) {
 	if (stream == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
-	FileFormat.save(stream, format, this);
+	InternalImageLoader.save(stream, format, this);
 }
 
 /**