/*******************************************************************************
 * Copyright (c) 2000, 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:
 *     Jacob Carlborg <jacob.carlborg@gmail.com>
 *******************************************************************************/
module dwt.custom.CBannerLayout;

import Math = tango.math.Math;

import dwt.DWT;
import dwt.custom.CBanner;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.widgets.Composite;
import dwt.widgets.Control;
import dwt.widgets.Layout;
import dwt.widgets.Scrollable;

/**
 * This class provides the layout for CBanner
 * 
 * @see CBanner
 */
class CBannerLayout : Layout {

    protected Point computeSize (Composite composite, int wHint, int hHint, bool flushCache) {
        CBanner banner = cast(CBanner) composite;
        Control left = banner.left;
        Control right = banner.right;
        Control bottom = banner.bottom;
        bool showCurve = left !is null && right !is null;
        int height = hHint;
        int width = wHint;

        // Calculate component sizes
        Point bottomSize = new Point(0, 0);
        if (bottom !is null) {
            int trim = computeTrim(bottom);
            int w = wHint is DWT.DEFAULT ? DWT.DEFAULT : Math.max(0, width - trim);
            bottomSize = computeChildSize(bottom, w, DWT.DEFAULT, flushCache);
        }
        Point rightSize = new Point(0, 0);
        if (right !is null) {
            int trim = computeTrim(right);
            int w = DWT.DEFAULT;
            if (banner.rightWidth !is DWT.DEFAULT) {
                w = banner.rightWidth - trim;
                if (left !is null) {
                    w = Math.min(w, width - banner.curve_width + 2 * banner.curve_indent - CBanner.MIN_LEFT - trim);
                }
                w = Math.max(0, w);
            }
            rightSize = computeChildSize(right, w, DWT.DEFAULT, flushCache);
            if (wHint !is DWT.DEFAULT) {
                width -= rightSize.x + banner.curve_width - 2 * banner.curve_indent;
            }
        }
        Point leftSize = new Point(0, 0);
        if (left !is null) {
            int trim = computeTrim(left);
            int w = wHint is DWT.DEFAULT ? DWT.DEFAULT : Math.max(0, width - trim);
            leftSize = computeChildSize(left, w, DWT.DEFAULT, flushCache);
        }

        // Add up sizes
        width = leftSize.x + rightSize.x;
        height = bottomSize.y;
        if (bottom !is null && (left !is null || right !is null)) {
            height += CBanner.BORDER_STRIPE + 2;
        }
        if (left !is null) {
            if (right is null) {
                height += leftSize.y;
            }
            else {
                height += Math.max(leftSize.y, banner.rightMinHeight is DWT.DEFAULT ? rightSize.y : banner.rightMinHeight);
            }
        }
        else {
            height += rightSize.y;
        }
        if (showCurve) {
            width += banner.curve_width - 2 * banner.curve_indent;
            height += CBanner.BORDER_TOP + CBanner.BORDER_BOTTOM + 2 * CBanner.BORDER_STRIPE;
        }

        if (wHint !is DWT.DEFAULT)
            width = wHint;
        if (hHint !is DWT.DEFAULT)
            height = hHint;

        return new Point(width, height);
    }

    Point computeChildSize (Control control, int wHint, int hHint, bool flushCache) {
        Object data = control.getLayoutData();
        if (data is null || !(cast(CLayoutData) data)) {
            data = new CLayoutData();
            control.setLayoutData(data);
        }
        return (cast(CLayoutData) data).computeSize(control, wHint, hHint, flushCache);
    }

    int computeTrim (Control c) {
        if (cast(Scrollable) c) {
            Rectangle rect = (cast(Scrollable) c).computeTrim(0, 0, 0, 0);
            return rect.width;
        }
        return c.getBorderWidth() * 2;
    }

    protected bool flushCache (Control control) {
        Object data = control.getLayoutData();
        if (data !is null && cast(CLayoutData) data)
            (cast(CLayoutData) data).flushCache();
        return true;
    }

    protected void layout (Composite composite, bool flushCache) {
        CBanner banner = cast(CBanner) composite;
        Control left = banner.left;
        Control right = banner.right;
        Control bottom = banner.bottom;

        Point size = banner.getSize();
        bool showCurve = left !is null && right !is null;
        int width = size.x - 2 * banner.getBorderWidth();
        int height = size.y - 2 * banner.getBorderWidth();

        Point bottomSize = new Point(0, 0);
        if (bottom !is null) {
            int trim = computeTrim(bottom);
            int w = Math.max(0, width - trim);
            bottomSize = computeChildSize(bottom, w, DWT.DEFAULT, flushCache);
            height -= bottomSize.y + CBanner.BORDER_STRIPE + 2;
        }
        if (showCurve)
            height -= CBanner.BORDER_TOP + CBanner.BORDER_BOTTOM + 2 * CBanner.BORDER_STRIPE;
        height = Math.max(0, height);
        Point rightSize = new Point(0, 0);
        if (right !is null) {
            int trim = computeTrim(right);
            int w = DWT.DEFAULT;
            if (banner.rightWidth !is DWT.DEFAULT) {
                w = banner.rightWidth - trim;
                if (left !is null) {
                    w = Math.min(w, width - banner.curve_width + 2 * banner.curve_indent - CBanner.MIN_LEFT - trim);
                }
                w = Math.max(0, w);
            }
            rightSize = computeChildSize(right, w, DWT.DEFAULT, flushCache);
            width = width - (rightSize.x - banner.curve_indent + banner.curve_width - banner.curve_indent);
        }
        Point leftSize = new Point(0, 0);
        if (left !is null) {
            int trim = computeTrim(left);
            int w = Math.max(0, width - trim);
            leftSize = computeChildSize(left, w, DWT.DEFAULT, flushCache);
        }

        int x = 0;
        int y = 0;
        int oldStart = banner.curveStart;
        Rectangle leftRect = null;
        Rectangle rightRect = null;
        Rectangle bottomRect = null;
        if (bottom !is null) {
            bottomRect = new Rectangle(x, y + size.y - bottomSize.y, bottomSize.x, bottomSize.y);
        }
        if (showCurve)
            y += CBanner.BORDER_TOP + CBanner.BORDER_STRIPE;
        if (left !is null) {
            leftRect = new Rectangle(x, y, leftSize.x, leftSize.y);
            banner.curveStart = x + leftSize.x - banner.curve_indent;
            x += leftSize.x - banner.curve_indent + banner.curve_width - banner.curve_indent;
        }
        if (right !is null) {
            if (left !is null) {
                rightSize.y = Math.max(leftSize.y, banner.rightMinHeight is DWT.DEFAULT ? rightSize.y : banner.rightMinHeight);
            }
            rightRect = new Rectangle(x, y, rightSize.x, rightSize.y);
        }
        if (banner.curveStart < oldStart) {
            banner.redraw(banner.curveStart - CBanner.CURVE_TAIL, 0, oldStart + banner.curve_width - banner.curveStart + CBanner.CURVE_TAIL + 5,
                    size.y, false);
        }
        if (banner.curveStart > oldStart) {
            banner.redraw(oldStart - CBanner.CURVE_TAIL, 0, banner.curveStart + banner.curve_width - oldStart + CBanner.CURVE_TAIL + 5, size.y, false);
        }
        /*
         * The paint events must be flushed in order to make the curve draw smoothly
         * while the user drags the divider.
         * On Windows, it is necessary to flush the paints before the children are 
         * resized because otherwise the children (particularly toolbars) will flash.
         */
        banner.update();
        banner.curveRect = new Rectangle(banner.curveStart, 0, banner.curve_width, size.y);
        if (bottomRect !is null)
            bottom.setBounds(bottomRect);
        if (rightRect !is null)
            right.setBounds(rightRect);
        if (leftRect !is null)
            left.setBounds(leftRect);
    }
}