Moving TabFolderLayout into SWT. Updated as per review comments.

Fixes #1317

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/layout/TabFolderLayout.java

@@ -0,0 +1,68 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 IBM Corporation 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:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.swt.layout;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.graphics.*;
+import org.eclipse.swt.widgets.*;
+
+/**
+ * This layout controls the position and size
+ * of the children of a tab folder.
+ *
+ * @since 3.127
+ */
+class TabFolderLayout extends Layout {
+
+	/*
+	 * @see org.eclipse.swt.widgets.Layout#computeSize(org.eclipse.swt.widgets.Composite, int, int, boolean)
+	 */
+	@Override
+	protected Point computeSize (Composite composite, int wHint, int hHint, boolean flushCache) {
+		if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT)
+			return new Point(wHint, hHint);
+
+		Control [] children = composite.getChildren ();
+		int count = children.length;
+		int maxWidth = 0, maxHeight = 0;
+		for (int i=0; i<count; i++) {
+			Control child = children [i];
+			Point pt = child.computeSize (SWT.DEFAULT, SWT.DEFAULT, flushCache);
+			maxWidth = Math.max (maxWidth, pt.x);
+			maxHeight = Math.max (maxHeight, pt.y);
+		}
+
+		if (wHint != SWT.DEFAULT)
+			maxWidth= wHint;
+		if (hHint != SWT.DEFAULT)
+			maxHeight= hHint;
+
+		return new Point(maxWidth, maxHeight);
+
+	}
+
+	/*
+	 * @see org.eclipse.swt.widgets.Layout#layout(org.eclipse.swt.widgets.Composite, boolean)
+	 */
+	@Override
+	protected void layout (Composite composite, boolean flushCache) {
+		Rectangle rect= composite.getClientArea();
+
+		Control[] children = composite.getChildren();
+		for (Control c : children) {
+			c.setBounds(rect);
+		}
+	}
+}