LayoutUtil.java

/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Guven Demir <guven.internet+eclipse@gmail.com> - [package explorer] Alternative package name shortening: abbreviation - https://bugs.eclipse.org/bugs/show_bug.cgi?id=299514
 *******************************************************************************/
package org.eclipse.jdt.internal.ui.wizards.dialogfields;

import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

import org.eclipse.jface.layout.LayoutConstants;

public class LayoutUtil {

	/**
	 * Calculates the number of columns needed by field editors
	 */
	public static int getNumberOfColumns(DialogField[] editors) {
		int nCulumns= 0;
		for (int i= 0; i < editors.length; i++) {
			nCulumns= Math.max(editors[i].getNumberOfControls(), nCulumns);
		}
		return nCulumns;
	}

	/**
	 * Creates a composite and fills in the given editors.
	 * @param labelOnTop Defines if the label of all fields should be on top of the fields
	 */
	public static void doDefaultLayout(Composite parent, DialogField[] editors, boolean labelOnTop) {
		doDefaultLayout(parent, editors, labelOnTop, 0, 0);
	}

	/**
	 * Creates a composite and fills in the given editors.
	 * @param labelOnTop Defines if the label of all fields should be on top of the fields
	 * @param marginWidth The margin width to be used by the composite
	 * @param marginHeight The margin height to be used by the composite
	 */
	public static void doDefaultLayout(Composite parent, DialogField[] editors, boolean labelOnTop, int marginWidth, int marginHeight) {
		int nCulumns= getNumberOfColumns(editors);
		Control[][] controls= new Control[editors.length][];
		for (int i= 0; i < editors.length; i++) {
			controls[i]= editors[i].doFillIntoGrid(parent, nCulumns);
		}
		if (labelOnTop) {
			nCulumns--;
			modifyLabelSpans(controls, nCulumns);
		}
		GridLayout layout= null;
		if (parent.getLayout() instanceof GridLayout) {
			layout= (GridLayout) parent.getLayout();
		} else {
			layout= new GridLayout();
		}
		if (marginWidth != SWT.DEFAULT) {
			layout.marginWidth= marginWidth;
		}
		if (marginHeight != SWT.DEFAULT) {
			layout.marginHeight= marginHeight;
		}
		layout.numColumns= nCulumns;
		parent.setLayout(layout);
	}

	private static void modifyLabelSpans(Control[][] controls, int nCulumns) {
		for (int i= 0; i < controls.length; i++) {
			setHorizontalSpan(controls[i][0], nCulumns);
		}
	}

	/**
	 * Sets the span of a control. Assumes that GridData is used.
	 */
	public static void setHorizontalSpan(Control control, int span) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			((GridData)ld).horizontalSpan= span;
		} else if (span != 1) {
			GridData gd= new GridData();
			gd.horizontalSpan= span;
			control.setLayoutData(gd);
		}
	}

	/**
	 * Sets the width hint of a control. Assumes that GridData is used.
	 */
	public static void setWidthHint(Control control, int widthHint) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			((GridData)ld).widthHint= widthHint;
		}
	}

	/**
	 * Sets the heightHint hint of a control. Assumes that GridData is used.
	 */
	public static void setHeightHint(Control control, int heightHint) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			((GridData)ld).heightHint= heightHint;
		}
	}

	/**
	 * Sets the horizontal indent of a dependent control. Assumes that GridData is used.
	 */
	public static void setHorizontalIndent(Control control) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			((GridData) ld).horizontalIndent= LayoutUtil.getIndent();
		}
	}

	/**
	 * Sets the horizontal grabbing of a control to true. Assumes that GridData is used.
	 */
	public static void setHorizontalGrabbing(Control control) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			((GridData)ld).grabExcessHorizontalSpace= true;
		}
	}

	/**
	 * Sets the vertical grabbing of a control to true. Assumes that GridData is used.
	 * @since 3.6
	 */
	public static void setVerticalGrabbing(Control control) {
		Object ld= control.getLayoutData();
		if (ld instanceof GridData) {
			GridData gd= ((GridData)ld);
			gd.grabExcessVerticalSpace= true;
			gd.verticalAlignment= SWT.FILL;
		}
	}

	/**
	 * Returns the indent of dependent controls, in pixels.
	 * <p>
	 * <strong>Note:</strong> Use this method instead of {@link LayoutConstants#getIndent()} for
	 * compatibility reasons.
	 * </p>
	 * 
	 * @return the indent of dependent controls, in pixels.
	 * @since 3.9
	 */
	public static final int getIndent() {
		return LayoutConstants.getIndent();
	}

}