org.eclipse.jst.jsf.common.ui.internal.dialogfield.LayoutUtil.java Source code

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Here is the source code for org.eclipse.jst.jsf.common.ui.internal.dialogfield.LayoutUtil.java

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/*******************************************************************************
 * Copyright (c) 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.jsf.common.ui.internal.dialogfield;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.forms.widgets.FormToolkit;

/**
 * A layout utility class
 *
 */
public final class LayoutUtil {
    // The Text control looks higher then Button control when they have the same
    // height,
    // Increasing the height of 5 pixels will make them looks the same height.
    private final static int BUTTON_HEIGHT_ADJUSTMENT = 5;

    /**
     * @param control
     * @param grab
     */
    public static void setGrabHorizontal(Control control, boolean grab) {
        Object ld = control.getLayoutData();
        if (ld instanceof GridData) {
            ((GridData) ld).grabExcessHorizontalSpace = grab;
        }
    }

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

    /**
     * Sets the horizontal indent of a control. Assumes that GridData is used.
     * @param control 
     * @param horizontalIndent 
     */
    static void setHorizontalIndent(Control control, int horizontalIndent) {
        Object ld = control.getLayoutData();
        if (ld instanceof GridData) {
            ((GridData) ld).horizontalIndent = horizontalIndent;
        }
    }

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

    /**
     * Returns a width hint for a button control.
     * @param button 
     * @return the hint value
     */
    static int getButtonWidthHint(Button button) {
        if (button.getFont().equals(JFaceResources.getDefaultFont()))
            button.setFont(JFaceResources.getDialogFont());

        GC gc = new GC(button);
        gc.setFont(button.getFont());
        FontMetrics fontMetrics = gc.getFontMetrics();
        gc.dispose();

        int length = button.getText().length();
        int widthHint = Dialog.convertWidthInCharsToPixels(fontMetrics, length < 2 ? 2 : length);
        return Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x);
    }

    static int getButtonHeightHint(FormToolkit toolkit, Text text) {
        if (toolkit != null) {
            return text.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).y + BUTTON_HEIGHT_ADJUSTMENT;
        }
        return text.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).y;
    }

    private LayoutUtil() {
        // static utility class; no instantiation
    }
}