/*******************************************************************************
 * Copyright (c) 2005, 2006 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.layout.LayoutConstants;


import dwt.graphics.FontMetrics;
import dwt.graphics.GC;
import dwt.graphics.Point;
import dwt.widgets.Display;
import dwtx.jface.dialogs.Dialog;
import dwtx.jface.dialogs.IDialogConstants;
import dwtx.jface.resource.JFaceResources;

/**
 * Contains various layout constants
 *
 * @since 3.2
 */
public final class LayoutConstants {
    private static Point dialogMargins = null;
    private static Point dialogSpacing = null;
    private static Point minButtonSize = null;

    private static void initializeConstants() {
        if (dialogMargins !is null) {
            return;
        }

        GC gc = new GC(Display.getCurrent());
        gc.setFont(JFaceResources.getDialogFont());
        FontMetrics fontMetrics = gc.getFontMetrics();

        dialogMargins = new Point(Dialog.convertHorizontalDLUsToPixels(fontMetrics, IDialogConstants.HORIZONTAL_MARGIN),
                Dialog.convertVerticalDLUsToPixels(fontMetrics, IDialogConstants.VERTICAL_MARGIN));

        dialogSpacing = new Point(Dialog.convertHorizontalDLUsToPixels(fontMetrics, IDialogConstants.HORIZONTAL_SPACING),
                Dialog.convertVerticalDLUsToPixels(fontMetrics, IDialogConstants.VERTICAL_SPACING));

        minButtonSize  = new Point(Dialog.convertHorizontalDLUsToPixels(fontMetrics, IDialogConstants.BUTTON_WIDTH), 0);

        gc.dispose();
    }

    /**
     * Returns the default dialog margins, in pixels
     *
     * @return the default dialog margins, in pixels
     */
    public static final Point getMargins() {
        initializeConstants();
        return dialogMargins;
    }

    /**
     * Returns the default dialog spacing, in pixels
     *
     * @return the default dialog spacing, in pixels
     */
    public static final Point getSpacing() {
        initializeConstants();
        return dialogSpacing;
    }

    /**
     * Returns the default minimum button size, in pixels
     *
     * @return the default minimum button size, in pixels
     */
    public static final Point getMinButtonSize() {
        initializeConstants();
        return minButtonSize;
    }
}