/*******************************************************************************
 * Copyright (c) 2000, 2008 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 dwt.layout.RowLayout;

import dwt.DWT;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.widgets.Control;
import dwt.widgets.Layout;
import dwt.widgets.Composite;
import dwt.layout.RowData;
import tango.util.Convert;
import Math = tango.math.Math;
import dwt.dwthelper.utils;


/**
 * Instances of this class determine the size and position of the
 * children of a <code>Composite</code> by placing them either in
 * horizontal rows or vertical columns within the parent <code>Composite</code>.
 * <p>
 * <code>RowLayout</code> aligns all controls in one row if the
 * <code>type</code> is set to horizontal, and one column if it is
 * set to vertical. It has the ability to wrap, and provides configurable
 * margins and spacing. <code>RowLayout</code> has a number of configuration
 * fields. In addition, the height and width of each control in a
 * <code>RowLayout</code> can be specified by setting a <code>RowData</code>
 * object into the control using <code>setLayoutData ()</code>.
 * </p>
 * <p>
 * The following example code creates a <code>RowLayout</code>, sets all
 * of its fields to non-default values, and then sets it into a
 * <code>Shell</code>.
 * <pre>
 *      RowLayout rowLayout = new RowLayout();
 *      rowLayout.wrap = false;
 *      rowLayout.pack = false;
 *      rowLayout.justify = true;
 *      rowLayout.type = DWT.VERTICAL;
 *      rowLayout.marginLeft = 5;
 *      rowLayout.marginTop = 5;
 *      rowLayout.marginRight = 5;
 *      rowLayout.marginBottom = 5;
 *      rowLayout.spacing = 0;
 *      shell.setLayout(rowLayout);
 * </pre>
 * If you are using the default field values, you only need one line of code:
 * <pre>
 *      shell.setLayout(new RowLayout());
 * </pre>
 * </p>
 *
 * @see RowData
 * @see <a href="http://www.eclipse.org/swt/snippets/#rowlayout">RowLayout snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">DWT Example: LayoutExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */
public final class RowLayout : Layout {

    /**
     * type specifies whether the layout places controls in rows or
     * columns.
     *
     * The default value is HORIZONTAL.
     *
     * Possible values are: <ul>
     *    <li>HORIZONTAL: Position the controls horizontally from left to right</li>
     *    <li>VERTICAL: Position the controls vertically from top to bottom</li>
     * </ul>
     *
     * @since 2.0
     */
    public int type = DWT.HORIZONTAL;

    /**
     * marginWidth specifies the number of pixels of horizontal margin
     * that will be placed along the left and right edges of the layout.
     *
     * The default value is 0.
     *
     * @since 3.0
     */
    public int marginWidth = 0;

    /**
     * marginHeight specifies the number of pixels of vertical margin
     * that will be placed along the top and bottom edges of the layout.
     *
     * The default value is 0.
     *
     * @since 3.0
     */
    public int marginHeight = 0;

    /**
     * spacing specifies the number of pixels between the edge of one cell
     * and the edge of its neighbouring cell.
     *
     * The default value is 3.
     */
    public int spacing = 3;

    /**
     * wrap specifies whether a control will be wrapped to the next
     * row if there is insufficient space on the current row.
     *
     * The default value is true.
     */
    public bool wrap = true;

    /**
     * pack specifies whether all controls in the layout take
     * their preferred size.  If pack is false, all controls will
     * have the same size which is the size required to accommodate the
     * largest preferred height and the largest preferred width of all
     * the controls in the layout.
     *
     * The default value is true.
     */
    public bool pack = true;

    /**
     * fill specifies whether the controls in a row should be
     * all the same height for horizontal layouts, or the same
     * width for vertical layouts.
     *
     * The default value is false.
     *
     * @since 3.0
     */
    public bool fill = false;

    /**
     * center specifies whether the controls in a row should be
     * centered vertically in each cell for horizontal layouts,
     * or centered horizontally in each cell for vertical layouts.
     *
     * The default value is false.
     * 
     * @since 3.4
     */
    public bool center = false;
    
    /**
     * justify specifies whether the controls in a row should be
     * fully justified, with any extra space placed between the controls.
     *
     * The default value is false.
     */
    public bool justify = false;

    /**
     * marginLeft specifies the number of pixels of horizontal margin
     * that will be placed along the left edge of the layout.
     *
     * The default value is 3.
     */
    public int marginLeft = 3;

    /**
     * marginTop specifies the number of pixels of vertical margin
     * that will be placed along the top edge of the layout.
     *
     * The default value is 3.
     */
    public int marginTop = 3;

    /**
     * marginRight specifies the number of pixels of horizontal margin
     * that will be placed along the right edge of the layout.
     *
     * The default value is 3.
     */
    public int marginRight = 3;

    /**
     * marginBottom specifies the number of pixels of vertical margin
     * that will be placed along the bottom edge of the layout.
     *
     * The default value is 3.
     */
    public int marginBottom = 3;

/**
 * Constructs a new instance of this class.
 */
public this () {
}

/**
 * Constructs a new instance of this class given the type.
 *
 * @param type the type of row layout
 *
 * @since 2.0
 */
public this (int type) {
    this.type = type;
}

override protected Point computeSize (Composite composite, int wHint, int hHint, bool flushCache_) {
    Point extent;
    if (type is DWT.HORIZONTAL) {
        extent = layoutHorizontal (composite, false, (wHint !is DWT.DEFAULT) && wrap, wHint, flushCache_);
    } else {
        extent = layoutVertical (composite, false, (hHint !is DWT.DEFAULT) && wrap, hHint, flushCache_);
    }
    if (wHint !is DWT.DEFAULT) extent.x = wHint;
    if (hHint !is DWT.DEFAULT) extent.y = hHint;
    return extent;
}

Point computeSize (Control control, bool flushCache_) {
    int wHint = DWT.DEFAULT, hHint = DWT.DEFAULT;
    RowData data = cast(RowData) control.getLayoutData ();
    if (data !is null) {
        wHint = data.width;
        hHint = data.height;
    }
    return control.computeSize (wHint, hHint, flushCache_);
}

override protected bool flushCache (Control control) {
    return true;
}

String getName () {
    String string = this.classinfo.name;
    int index = string.lastIndexOf('.');
    if (index is -1 ) return string;
    return string[ index + 1 .. string.length ];
}

override protected void layout (Composite composite, bool flushCache_) {
    Rectangle clientArea = composite.getClientArea ();
    if (type is DWT.HORIZONTAL) {
        layoutHorizontal (composite, true, wrap, clientArea.width, flushCache_);
    } else {
        layoutVertical (composite, true, wrap, clientArea.height, flushCache_);
    }
}

Point layoutHorizontal (Composite composite, bool move, bool wrap, int width, bool flushCache_) {
    Control [] children = composite.getChildren ();
    int count = 0;
    for (int i=0; i<children.length; i++) {
        Control control = children [i];
        RowData data = cast(RowData) control.getLayoutData ();
        if (data is null || !data.exclude) {
            children [count++] = children [i];
        }
    }
    if (count is 0) {
        return new Point (marginLeft + marginWidth * 2 + marginRight, marginTop + marginHeight * 2 + marginBottom);
    }
    int childWidth = 0, childHeight = 0, maxHeight = 0;
    if (!pack) {
        for (int i=0; i<count; i++) {
            Control child = children [i];
            Point size = computeSize (child, flushCache_);
            childWidth = Math.max (childWidth, size.x);
            childHeight = Math.max (childHeight, size.y);
        }
        maxHeight = childHeight;
    }
    int clientX = 0, clientY = 0;
    if (move) {
        Rectangle rect = composite.getClientArea ();
        clientX = rect.x;
        clientY = rect.y;
    }
    int [] wraps = null;
    bool wrapped = false;
    Rectangle [] bounds = null;
    if (move && (justify || fill || center)) {
        bounds = new Rectangle [count];
        wraps = new int [count];
    }
    int maxX = 0, x = marginLeft + marginWidth, y = marginTop + marginHeight;
    for (int i=0; i<count; i++) {
        Control child = children [i];
        if (pack) {
            Point size = computeSize (child, flushCache_);
            childWidth = size.x;
            childHeight = size.y;
        }
        if (wrap && (i !is 0) && (x + childWidth > width)) {
            wrapped = true;
            if (move && (justify || fill || center)) wraps [i - 1] = maxHeight;
            x = marginLeft + marginWidth;
            y += spacing + maxHeight;
            if (pack) maxHeight = 0;
        }
        if (pack || fill || center) {
            maxHeight = Math.max (maxHeight, childHeight);
        }
        if (move) {
            int childX = x + clientX, childY = y + clientY;
            if (justify || fill || center) {
                bounds [i] = new Rectangle (childX, childY, childWidth, childHeight);
            } else {
                child.setBounds (childX, childY, childWidth, childHeight);
            }
        }
        x += spacing + childWidth;
        maxX = Math.max (maxX, x);
    }
    maxX = Math.max (clientX + marginLeft + marginWidth, maxX - spacing);
    if (!wrapped) maxX += marginRight + marginWidth;
    if (move && (justify || fill || center)) {
        int space = 0, margin = 0;
        if (!wrapped) {
            space = Math.max (0, (width - maxX) / (count + 1));
            margin = Math.max (0, ((width - maxX) % (count + 1)) / 2);
        } else {
            if (fill || justify || center) {
                int last = 0;
                if (count > 0) wraps [count - 1] = maxHeight;
                for (int i=0; i<count; i++) {
                    if (wraps [i] !is 0) {
                        int wrapCount = i - last + 1;
                        if (justify) {
                            int wrapX = 0;
                            for (int j=last; j<=i; j++) {
                                wrapX += bounds [j].width + spacing;
                            }
                            space = Math.max (0, (width - wrapX) / (wrapCount + 1));
                            margin = Math.max (0, ((width - wrapX) % (wrapCount + 1)) / 2);
                        }
                        for (int j=last; j<=i; j++) {
                            if (justify) bounds [j].x += (space * (j - last + 1)) + margin;
                            if (fill) {
                                bounds [j].height = wraps [i];
                            } else {
                                if (center) {
                                    bounds [j].y += Math.max (0, (wraps [i] - bounds [j].height) / 2);
                                }
                            }
                        }
                        last = i + 1;
                    }
                }
            }
        }
        for (int i=0; i<count; i++) {
            if (!wrapped) {
                if (justify) bounds [i].x += (space * (i + 1)) + margin;
                if (fill) {
                    bounds [i].height = maxHeight;
                } else {
                    if (center) {
                        bounds [i].y += Math.max (0, (maxHeight - bounds [i].height) / 2);
                    }
                }
            }
            children [i].setBounds (bounds [i]);
        }
    }
    return new Point (maxX, y + maxHeight + marginBottom + marginHeight);
}

Point layoutVertical (Composite composite, bool move, bool wrap, int height, bool flushCache_) {
    Control [] children = composite.getChildren ();
    int count = 0;
    for (int i=0; i<children.length; i++) {
        Control control = children [i];
        RowData data = cast(RowData) control.getLayoutData ();
        if (data is null || !data.exclude) {
            children [count++] = children [i];
        }
    }
    if (count is 0) {
        return new Point (marginLeft + marginWidth * 2 + marginRight, marginTop + marginHeight * 2 + marginBottom);
    }
    int childWidth = 0, childHeight = 0, maxWidth = 0;
    if (!pack) {
        for (int i=0; i<count; i++) {
            Control child = children [i];
            Point size = computeSize (child, flushCache_);
            childWidth = Math.max (childWidth, size.x);
            childHeight = Math.max (childHeight, size.y);
        }
        maxWidth = childWidth;
    }
    int clientX = 0, clientY = 0;
    if (move) {
        Rectangle rect = composite.getClientArea ();
        clientX = rect.x;
        clientY = rect.y;
    }
    int [] wraps = null;
    bool wrapped = false;
    Rectangle [] bounds = null;
    if (move && (justify || fill || center)) {
        bounds = new Rectangle [count];
        wraps = new int [count];
    }
    int maxY = 0, x = marginLeft + marginWidth, y = marginTop + marginHeight;
    for (int i=0; i<count; i++) {
        Control child = children [i];
        if (pack) {
            Point size = computeSize (child, flushCache_);
            childWidth = size.x;
            childHeight = size.y;
        }
        if (wrap && (i !is 0) && (y + childHeight > height)) {
            wrapped = true;
            if (move && (justify || fill || center)) wraps [i - 1] = maxWidth;
            x += spacing + maxWidth;
            y = marginTop + marginHeight;
            if (pack) maxWidth = 0;
        }
        if (pack || fill || center) {
            maxWidth = Math.max (maxWidth, childWidth);
        }
        if (move) {
            int childX = x + clientX, childY = y + clientY;
            if (justify || fill || center) {
                bounds [i] = new Rectangle (childX, childY, childWidth, childHeight);
            } else {
                child.setBounds (childX, childY, childWidth, childHeight);
            }
        }
        y += spacing + childHeight;
        maxY = Math.max (maxY, y);
    }
    maxY = Math.max (clientY + marginTop + marginHeight, maxY - spacing);
    if (!wrapped) maxY += marginBottom + marginHeight;
    if (move && (justify || fill || center)) {
        int space = 0, margin = 0;
        if (!wrapped) {
            space = Math.max (0, (height - maxY) / (count + 1));
            margin = Math.max (0, ((height - maxY) % (count + 1)) / 2);
        } else {
            if (fill || justify || center) {
                int last = 0;
                if (count > 0) wraps [count - 1] = maxWidth;
                for (int i=0; i<count; i++) {
                    if (wraps [i] !is 0) {
                        int wrapCount = i - last + 1;
                        if (justify) {
                            int wrapY = 0;
                            for (int j=last; j<=i; j++) {
                                wrapY += bounds [j].height + spacing;
                            }
                            space = Math.max (0, (height - wrapY) / (wrapCount + 1));
                            margin = Math.max (0, ((height - wrapY) % (wrapCount + 1)) / 2);
                        }
                        for (int j=last; j<=i; j++) {
                            if (justify) bounds [j].y += (space * (j - last + 1)) + margin;
                            if (fill) {
                                bounds [j].width = wraps [i];
                            } else {
                                if (center) {
                                    bounds [j].x += Math.max (0, (wraps [i] - bounds [j].width) / 2);
                                }
                            }
                        }
                        last = i + 1;
                    }
                }
            }
        }
        for (int i=0; i<count; i++) {
            if (!wrapped) {
                if (justify) bounds [i].y += (space * (i + 1)) + margin;
                if (fill) {
                    bounds [i].width = maxWidth;
                } else {
                    if (center) {
                        bounds [i].x += Math.max (0, (maxWidth - bounds [i].width) / 2);
                    }
                }

            }
            children [i].setBounds (bounds [i]);
        }
    }
    return new Point (x + maxWidth + marginRight + marginWidth, maxY);
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the layout
 */
override public String toString () {
    String string = getName ()~" {";
    string ~= "type="~((type !is DWT.HORIZONTAL) ? "DWT.VERTICAL" : "DWT.HORIZONTAL")~" ";
    if (marginWidth !is 0) string ~= "marginWidth="~to!(String)(marginWidth)~" ";
    if (marginHeight !is 0) string ~= "marginHeight="~to!(String)(marginHeight)~" ";
    if (marginLeft !is 0) string ~= "marginLeft="~to!(String)(marginLeft)~" ";
    if (marginTop !is 0) string ~= "marginTop="~to!(String)(marginTop)~" ";
    if (marginRight !is 0) string ~= "marginRight="~to!(String)(marginRight)~" ";
    if (marginBottom !is 0) string ~= "marginBottom="~to!(String)(marginBottom)~" ";
    if (spacing !is 0) string ~= "spacing="~to!(String)(spacing)~" ";
    string ~= "wrap="~to!(String)(wrap)~" ";
    string ~= "pack="~to!(String)(pack)~" ";
    string ~= "fill="~to!(String)(fill)~" ";
    string ~= "justify="~to!(String)(justify)~" ";
    string = string.trim();
    string ~= "}";
    return string;
}
}