import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.draw2d.AbstractLayout;
import org.eclipse.draw2d.Figure;
import org.eclipse.draw2d.IFigure;
import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Rectangle;
import org.eclipse.swt.SWT;

/**
 * @author <a href="mailto:kjwenger@yahoo.com?subject=GridLayout">Klaus Wenger</a>
 */
public final class GridLayout extends AbstractLayout {
    /**
     * Constructs a new instance of this layout manager.
     */
    public GridLayout() {
        super();
    }
    /**
     * Constructs a new instance of this class given the number of columns, and
     * whether or not the columns should be forced to have the same width.
     *
     * @param numColumns The number of columns in the grid.
     * @param makeColumnsEqualWidth Whether or not the columns will have equal width.
     * 
     * @since 2.0
     */
    public GridLayout(int numColumns, boolean makeColumnsEqualWidth) {
        this.numColumns = numColumns;
        this.makeColumnsEqualWidth = makeColumnsEqualWidth;
    }
    /**
     * Sets the layout constraint of the given figure. The constraints can only be of type 
     * {@link Rectangle}.
     *
     * @see org.eclipse.draw2d.LayoutManager#setConstraint(org.eclipse.draw2d.IFigure, java.lang.Object)
     * @since 2.0
     */
    public void setConstraint(IFigure figure, Object newConstraint) {
        super.setConstraint(figure, newConstraint);
        if (newConstraint != null) {
            this.constraints.put(figure, newConstraint);
        }
    }
    /**
     * @see org.eclipse.draw2d.LayoutManager#getConstraint(org.eclipse.draw2d.IFigure)
     */
    public Object getConstraint(IFigure figure) {
        return (GridData) this.constraints.get(figure);
    }
    /**
     * @see org.eclipse.draw2d.AbstractLayout#calculatePreferredSize(org.eclipse.draw2d.IFigure, int, int)
     */
    protected Dimension calculatePreferredSize(IFigure containerFigure,
        int wHint, int hHint) {
        return calculatePreferredSize(containerFigure, wHint, hHint, false);
    }
    /**
     * @param containerFigure
     * @param wHint
     * @param hHint
     * @param flushCache
     * @return The calculated <code>Dimension</code>.
     */
    protected Dimension calculatePreferredSize(
        IFigure containerFigure, int wHint, int hHint, boolean flushCache) {
        Dimension size = layout(
            containerFigure, false, 0, 0, wHint, hHint, flushCache);
        if (wHint != SWT.DEFAULT) {
            size.width = wHint;
        }
        if (hHint != SWT.DEFAULT) {
            size.height = hHint;
        }
        return size;
    }
    /**
     * @param control
     * @return <code>true</code> in any case.
     */
    protected boolean flushCache(Figure control) {
        Object constraint = getConstraint(control);
        if (constraint != null) {
            ((GridData) constraint).flushCache();
        }
        return true;
    }
    /**
     * @param grid
     * @param row
     * @param column
     * @param rowCount
     * @param columnCount
     * @param first
     * @return The <code>GridData</code> instance if available or <code>null</code>.
     */
    /* package */ GridData getData(IFigure[][] grid, int row, int column,
        int rowCount, int columnCount, boolean first) {
        IFigure figure = grid[row][column];
        if (figure != null) {
            GridData gridData = (GridData) getConstraint(figure);
            int hSpan = Math.max(1,
                Math.min(gridData.horizontalSpan, columnCount));
            int vSpan = Math.max(1, gridData.verticalSpan);
            int i = first ? row + vSpan - 1 : row - vSpan + 1;
            int j = first ? column + hSpan - 1 : column - hSpan + 1;
            if (0 <= i && i < rowCount) {
                if (0 <= j && j < columnCount) {
                    if (figure == grid[i][j]) return gridData;
                }
            }
        }
        return null;
    }
    /**
     * @see org.eclipse.draw2d.LayoutManager#layout(org.eclipse.draw2d.IFigure)
     */
    public void layout(IFigure container) {
        layout(container, false);
    }
    /**
     * @param containerFigure
     * @param flushCache
     */
    protected void layout(IFigure containerFigure, boolean flushCache) {
        Rectangle clientArea = containerFigure.getClientArea();
        layout(containerFigure, true,
            clientArea.x, clientArea.y, clientArea.width, clientArea.height,
            flushCache);
    }
    /**
     * @param containerFigure
     * @param move
     * @param x
     * @param y
     * @param width
     * @param height
     * @param flushCache
     * @return The <code>Dimension</code> the layout filled.
     */
    /* package */ Dimension layout(IFigure containerFigure, boolean move,
        int x, int y, int width, int height, boolean flushCache) {
        if (this.numColumns < 1) {
            return new Dimension(
                this.marginLeft + this.marginWidth * 2 + this.marginRight,
                this.marginTop + this.marginHeight * 2 + this.marginBottom);
        }
        List childList = containerFigure.getChildren();
        for (int i = 0; i < childList.size(); i++) {
            IFigure child = (IFigure) childList.get(i);
            GridData gridData = (GridData) getConstraint(child);
        if (gridData == null) {
            setConstraint(child, gridData = new GridData());
        }
        if (flushCache) {
            gridData.flushCache();
        }
        gridData.getPreferredSize(child,
            gridData.widthHint, gridData.heightHint, flushCache);
        if (gridData.grabExcessHorizontalSpace && gridData.minimumWidth > 0) {
            if (gridData.cacheWidth < gridData.minimumWidth) {
                int trim = 0;
                //TEMPORARY CODE
//                if (child instanceof Scrollable) {
//                    Rectangle rect = ((Scrollable) child).computeTrim(0, 0, 0, 0);
//                    trim = rect.width;
//                } else {
//                    trim = child.getBorderWidth() * 2;
//                }
                gridData.cacheWidth = gridData.cacheHeight = SWT.DEFAULT;
                gridData.getPreferredSize(child, Math.max(0,
                    gridData.minimumWidth - trim), gridData.heightHint, false);
            }
        }
        if (gridData.grabExcessVerticalSpace && gridData.minimumHeight > 0) {
            gridData.cacheHeight = Math.max(gridData.cacheHeight,
                gridData.minimumHeight);
        }
    }

    /* Build the grid */
    int row = 0, column = 0, rowCount = 0, columnCount = this.numColumns;
    IFigure[][] grid = new IFigure[4][columnCount];
    for (int i = 0; i < childList.size(); i++) { 
        IFigure child = (IFigure) childList.get(i);
        GridData gridData = (GridData) getConstraint(child);
        int hSpan = Math.max(1, Math.min(gridData.horizontalSpan, columnCount));
        int vSpan = Math.max(1, gridData.verticalSpan);
        while (true) {
            int lastRow = row + vSpan;
            if (lastRow >= grid.length) {
                IFigure[][] newGrid = new IFigure[lastRow + 4][columnCount];
                System.arraycopy(grid, 0, newGrid, 0, grid.length);
                grid = newGrid;
            }
            if (grid[row] == null) {
                grid[row] = new IFigure[columnCount];
            }
            while (column < columnCount && grid[row][column] != null) {
                column++;
            }
            int endCount = column + hSpan;
            if (endCount <= columnCount) {
                int index = column;
                while (index < endCount && grid[row][index] == null) {
                    index++;
                }
                if (index == endCount) {
                    break;
                }
                column = index;
            }
            if (column + hSpan >= columnCount) {
                column = 0;
                row++;
            }
        }
        for (int j = 0; j < vSpan; j++) {
            if (grid[row + j] == null) {
                grid[row + j] = new IFigure[columnCount];
            }
            for (int k = 0; k < hSpan; k++) {
                grid[row + j][column + k] = child;
            }
        }
        rowCount = Math.max(rowCount, row + vSpan);
        column += hSpan;
    }

    /* Column widths */
    int availableWidth = width - this.horizontalSpacing * (columnCount - 1) -
        (this.marginLeft + this.marginWidth * 2 + this.marginRight);
    int expandCount = 0;
    int[] widths = new int[columnCount];
    int[] minWidths = new int[columnCount];
    boolean[] expandColumn = new boolean[columnCount];
    for (int j = 0; j < columnCount; j++) {
        for (int i = 0; i < rowCount; i++) {
            GridData gridData =
                getData(grid, i, j, rowCount, columnCount, true);
            if (gridData != null) {
                int hSpan = Math.max(1, Math.min(
                    gridData.horizontalSpan, columnCount));
                if (hSpan == 1) {
                    int w = gridData.cacheWidth + gridData.horizontalIndent;
                    widths[j] = Math.max(widths[j], w);
                    if (gridData.grabExcessHorizontalSpace) {
                        if (!expandColumn[j]) {
                            expandCount++;
                        }
                        expandColumn[j] = true;
                    }
                    if (!gridData.grabExcessHorizontalSpace
                        || gridData.minimumWidth != 0) {
                        w = !gridData.grabExcessHorizontalSpace
                            || gridData.minimumWidth == SWT.DEFAULT
                            ? gridData.cacheWidth : gridData.minimumWidth;
                        w += gridData.horizontalIndent;
                        minWidths[j] = Math.max(minWidths[j], w);
                    }
                }
            }
        }
        for (int i = 0; i < rowCount; i++) {
            GridData gridData =
                getData(grid, i, j, rowCount, columnCount, false);
            if (gridData != null) {
                int hSpan = Math.max(1, Math.min(
                    gridData.horizontalSpan, columnCount));
                if (hSpan > 1) {
                    int spanWidth = 0, spanMinWidth = 0, spanExpandCount = 0;
                    for (int k = 0; k < hSpan; k++) {
                        spanWidth += widths[j-k];
                        spanMinWidth += minWidths[j-k];
                        if (expandColumn[j-k]) {
                            spanExpandCount++;
                        }
                    }
                    if (gridData.grabExcessHorizontalSpace
                        && spanExpandCount == 0) {
                        expandCount++;
                        expandColumn[j] = true;
                    }
                    int w = gridData.cacheWidth + gridData.horizontalIndent -
                        spanWidth -(hSpan - 1) * this.horizontalSpacing;
                    if (w > 0) {
                        if (spanExpandCount == 0) {
                            widths[j] += w;
                        } else {
                            int delta = w / spanExpandCount;
                            int remainder = w % spanExpandCount, last = -1;
                            for (int k = 0; k < hSpan; k++) {
                                if (expandColumn[j-k]) {
                                    widths[last=j-k] += delta;
                                }
                            }
                            if (last > -1) widths[last] += remainder;
                        }
                    }
                    if (!gridData.grabExcessHorizontalSpace
                        || gridData.minimumWidth != 0) {
                        w = !gridData.grabExcessHorizontalSpace
                            || gridData.minimumWidth == SWT.DEFAULT
                            ? gridData.cacheWidth : gridData.minimumWidth;
                        w += gridData.horizontalIndent - spanMinWidth -
                            (hSpan - 1) * this.horizontalSpacing;
                        if (w > 0) {
                            if (spanExpandCount == 0) {
                                minWidths[j] += w;
                            } else {
                                int delta = w / spanExpandCount;
                                int remainder = w % spanExpandCount, last = -1;
                                for (int k = 0; k < hSpan; k++) {
                                    if (expandColumn[j-k]) {
                                        minWidths[last=j-k] += delta;
                                    }
                                }
                                if (last > -1) minWidths[last] += remainder;
                            }
                        }
                    }
                }
            }
        }
    }
    if (this.makeColumnsEqualWidth) {
        int minColumnWidth = 0;
        int columnWidth = 0;
        for (int i = 0; i < columnCount; i++) {
            minColumnWidth = Math.max(minColumnWidth, minWidths[i]);
            columnWidth = Math.max(columnWidth, widths[i]);
        }
        columnWidth = width == SWT.DEFAULT || expandCount == 0 ? columnWidth
            : Math.max(minColumnWidth, availableWidth / columnCount);
        for (int i = 0; i < columnCount; i++) {
            expandColumn[i] = expandCount > 0;
            widths[i] = columnWidth;
        }
    } else {
        if (width != SWT.DEFAULT && expandCount > 0) {
            int totalWidth = 0;
            for (int i = 0; i < columnCount; i++) {
                totalWidth += widths[i];
            }
            int count = expandCount;
            int delta = (availableWidth - totalWidth) / count;
            int remainder = (availableWidth - totalWidth) % count;
            int last = -1;
            while (totalWidth != availableWidth) {
                for (int j = 0; j < columnCount; j++) {
                    if (expandColumn[j]) {
                        if (widths[j] + delta > minWidths[j]) {
                            widths[last = j] = widths[j] + delta;
                        } else {
                            widths[j] = minWidths[j];
                            expandColumn[j] = false;
                            count--;
                        }
                    }
                }
                if (last > -1) widths[last] += remainder;
                
                for (int j = 0; j < columnCount; j++) {
                    for (int i = 0; i < rowCount; i++) {
                        GridData data =
                            getData(grid, i, j, rowCount, columnCount, false);
                        if (data != null) {
                            int hSpan = Math.max(1, Math.min(
                                data.horizontalSpan, columnCount));
                            if (hSpan > 1) {
                                if (!data.grabExcessHorizontalSpace
                                    || data.minimumWidth != 0) {
                                    int spanWidth = 0, spanExpandCount = 0;
                                    for (int k=0; k<hSpan; k++) {
                                        spanWidth += widths[j-k];
                                        if (expandColumn[j-k]) {
                                            spanExpandCount++;
                                        }
                                    }
                                    int w = !data.grabExcessHorizontalSpace
                                        || data.minimumWidth == SWT.DEFAULT
                                        ? data.cacheWidth : data.minimumWidth;
                                    w += data.horizontalIndent - spanWidth -
                                        (hSpan - 1) * this.horizontalSpacing;
                                    if (w > 0) {
                                        if (spanExpandCount == 0) {
                                            widths[j] += w;
                                        } else {
                                            int delta2 = w / spanExpandCount;
                                            int remainder2 =
                                                w % spanExpandCount, last2 = -1;
                                            for (int k = 0; k < hSpan; k++) {
                                                if (expandColumn[j-k]) {
                                                    widths[last2=j-k] += delta2;
                                                }
                                            }
                                            if (last2 > -1) {
                                                widths[last2] += remainder2;
                                            }   
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
                if (count == 0) {
                    break;
                }
                totalWidth = 0;
                for (int i = 0; i < columnCount; i++) {
                    totalWidth += widths[i];
                }
                delta = (availableWidth - totalWidth) / count;
                remainder = (availableWidth - totalWidth) % count;
                last = -1;
            }
        }
    }

    /* Wrapping */
    GridData[] flush = null;
    int flushLength = 0;
    if (width != SWT.DEFAULT) {
        for (int j = 0; j < columnCount; j++) {
            for (int i = 0; i < rowCount; i++) {
                GridData data =
                    getData(grid, i, j, rowCount, columnCount, false);
                if (data != null) {
                    if (data.heightHint == SWT.DEFAULT) {
                        IFigure child = grid[i][j];
                        //TEMPORARY CODE
                        int hSpan = Math.max(1, Math.min(
                            data.horizontalSpan, columnCount));
                        int currentWidth = 0;
                        for (int k = 0; k < hSpan; k++) {
                            currentWidth += widths[j-k];
                        }
                        currentWidth += (hSpan - 1) * this.horizontalSpacing -
                            data.horizontalIndent;
                        if ((currentWidth != data.cacheWidth
                            && data.horizontalAlignment == SWT.FILL)
                            ||(data.cacheWidth > currentWidth)) {
                            int trim = 0;
//                            if (child instanceof Scrollable) {
//                                Rectangle rect = ((Scrollable) child).computeTrim(0, 0, 0, 0);
//                                trim = rect.width;
//                            } else {
//                                trim = child.getBorderWidth() * 2;
//                            }
                            data.cacheWidth = data.cacheHeight = SWT.DEFAULT;
                            data.getPreferredSize(child,
                                Math.max(0, currentWidth - trim),
                                data.heightHint, false);
                            if (data.grabExcessVerticalSpace
                                && data.minimumHeight > 0) {
                                data.cacheHeight = Math.max(
                                    data.cacheHeight, data.minimumHeight);
                            }
                            if (flush == null) {
                                flush = new GridData[childList.size()];
                            }
                            flush[flushLength++] = data;
                        }
                    }
                }
            }
        }
    }

    /* Row heights */
    int availableHeight = height - this.verticalSpacing * (rowCount - 1) -
        (this.marginTop + this.marginHeight * 2 + this.marginBottom);
    expandCount = 0;
    int[] heights = new int[rowCount];
    int[] minHeights = new int[rowCount];
    boolean[] expandRow = new boolean[rowCount];
    for (int i = 0; i < rowCount; i++) {
        for (int j = 0; j < columnCount; j++) {
            GridData data = getData(grid, i, j, rowCount, columnCount, true);
            if (data != null) {
                int vSpan = Math.max(1, Math.min(data.verticalSpan, rowCount));
                if (vSpan == 1) {
                    int h = data.cacheHeight + data.verticalIndent;
                    heights[i] = Math.max(heights[i], h);
                    if (data.grabExcessVerticalSpace) {
                        if (!expandRow[i]) {
                            expandCount++;
                        }
                        expandRow[i] = true;
                    }
                    if (!data.grabExcessVerticalSpace
                        || data.minimumHeight != 0) {
                        h = !data.grabExcessVerticalSpace
                            || data.minimumHeight == SWT.DEFAULT
                            ? data.cacheHeight : data.minimumHeight;
                        h += data.verticalIndent;
                        minHeights[i] = Math.max(minHeights[i], h);
                    }
                }
            }
        }
        for (int j = 0; j < columnCount; j++) {
            GridData data = getData(grid, i, j, rowCount, columnCount, false);
            if (data != null) {
                int vSpan = Math.max(1, Math.min(data.verticalSpan, rowCount));
                if (vSpan > 1) {
                    int spanHeight = 0, spanMinHeight = 0, spanExpandCount = 0;
                    for (int k = 0; k < vSpan; k++) {
                        spanHeight += heights[i-k];
                        spanMinHeight += minHeights[i-k];
                        if (expandRow[i-k]) {
                            spanExpandCount++;
                        }
                    }
                    if (data.grabExcessVerticalSpace && spanExpandCount == 0) {
                        expandCount++;
                        expandRow[i] = true;
                    }
                    int h = data.cacheHeight + data.verticalIndent -
                        spanHeight - (vSpan - 1) * this.verticalSpacing;
                    if (h > 0) {
                        if (spanExpandCount == 0) {
                            heights[i] += h;
                        } else {
                            int delta = h / spanExpandCount;
                            int remainder = h % spanExpandCount, last = -1;
                            for (int k = 0; k < vSpan; k++) {
                                if (expandRow[i-k]) {
                                    heights[last=i-k] += delta;
                                }
                            }
                            if (last > -1) {
                                heights[last] += remainder;
                            } 
                        }
                    }
                    if (!data.grabExcessVerticalSpace
                        || data.minimumHeight != 0) {
                        h = !data.grabExcessVerticalSpace
                            || data.minimumHeight == SWT.DEFAULT
                            ? data.cacheHeight : data.minimumHeight;
                        h += data.verticalIndent - spanMinHeight - (vSpan - 1) *
                            this.verticalSpacing;
                        if (h > 0) {
                            if (spanExpandCount == 0) {
                                minHeights[i] += h;
                            } else {
                                int delta = h / spanExpandCount;
                                int remainder = h % spanExpandCount, last = -1;
                                for (int k = 0; k < vSpan; k++) {
                                    if (expandRow[i-k]) {
                                        minHeights[last=i-k] += delta;
                                    }
                                }
                                if (last > -1) {
                                    minHeights[last] += remainder;
                                }  
                            }
                        }
                    }
                }
            }
        }
    }
    if (height != SWT.DEFAULT && expandCount > 0) {
        int totalHeight = 0;
        for (int i = 0; i < rowCount; i++) {
            totalHeight += heights[i];
        }
        int count = expandCount;
        int delta = (availableHeight - totalHeight) / count;
        int remainder = (availableHeight - totalHeight) % count;
        int last = -1;
        while (totalHeight != availableHeight) {
            for (int i = 0; i < rowCount; i++) {
                if (expandRow[i]) {
                    if (heights[i] + delta > minHeights[i]) {
                        heights[last = i] = heights[i] + delta;
                    } else {
                        heights[i] = minHeights[i];
                        expandRow[i] = false;
                        count--;
                    }
                }
            }
            if (last > -1) {
                heights[last] += remainder;
            }
            
            for (int i = 0; i < rowCount; i++) {
                for (int j = 0; j < columnCount; j++) {
                    GridData gridData =
                        getData(grid, i, j, rowCount, columnCount, false);
                    if (gridData != null) {
                        int vSpan = Math.max(1, Math.min(
                            gridData.verticalSpan, rowCount));
                        if (vSpan > 1) {
                            if (!gridData.grabExcessVerticalSpace
                                || gridData.minimumHeight != 0) {
                                int spanHeight = 0, spanExpandCount = 0;
                                for (int k = 0; k < vSpan; k++) {
                                    spanHeight += heights[i-k];
                                    if (expandRow[i-k]) {
                                        spanExpandCount++;
                                    }
                                }
                                int h = !gridData.grabExcessVerticalSpace
                                    || gridData.minimumHeight == SWT.DEFAULT
                                    ? gridData.cacheHeight
                                    : gridData.minimumHeight;
                                h += gridData.verticalIndent - spanHeight -
                                    (vSpan - 1) * this.verticalSpacing;
                                if (h > 0) {
                                    if (spanExpandCount == 0) {
                                        heights[i] += h;
                                    } else {
                                        int delta2 = h / spanExpandCount;
                                        int remainder2 = h % spanExpandCount,
                                            last2 = -1;
                                        for (int k = 0; k < vSpan; k++) {
                                            if (expandRow[i-k]) {
                                                heights[last2=i-k] += delta2;
                                            }
                                        }
                                        if (last2 > -1) {
                                            heights[last2] += remainder2;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            if (count == 0) break;
            totalHeight = 0;
            for (int i = 0; i < rowCount; i++) {
                totalHeight += heights[i];
            }
            delta = (availableHeight - totalHeight) / count;
            remainder = (availableHeight - totalHeight) % count;
            last = -1;
        }
    }

    /* Position the controls */
    if (move) {
        int gridY = y + this.marginTop + this.marginHeight;
        for (int i = 0; i < rowCount; i++) {
            int gridX = x + this.marginLeft + this.marginWidth;
            for (int j=0; j<columnCount; j++) {
                GridData gridData =
                    getData(grid, i, j, rowCount, columnCount, true);
                if (gridData != null) {
                    int hSpan = Math.max(1, Math.min(
                        gridData.horizontalSpan, columnCount));
                    int vSpan = Math.max(1, gridData.verticalSpan);
                    int cellWidth = 0, cellHeight = 0;
                    for (int k=0; k<hSpan; k++) {
                        cellWidth += widths[j+k];
                    }
                    for (int k=0; k<vSpan; k++) {
                        cellHeight += heights[i+k];
                    }
                    cellWidth += this.horizontalSpacing * (hSpan - 1);
                    int childX = gridX + gridData.horizontalIndent;
                    int childWidth = Math.min(gridData.cacheWidth, cellWidth);
                    switch(gridData.horizontalAlignment) {
                        case SWT.CENTER:
                        case GridData.CENTER:
                            childX = gridX +
                                Math.max(0,(cellWidth - childWidth) / 2);
                            break;
                        case SWT.RIGHT:
                        case SWT.END:
                        case GridData.END:
                            childX = gridX +
                                Math.max(0, cellWidth - childWidth);
                            break;
                        case SWT.FILL:
                            childWidth = cellWidth - gridData.horizontalIndent;
                            break;
                    }
                    cellHeight += this.verticalSpacing * (vSpan - 1);
                    int childY = gridY + gridData.verticalIndent;
                    int childHeight =
                        Math.min(gridData.cacheHeight, cellHeight);
                    switch(gridData.verticalAlignment) {
                        case SWT.CENTER:
                        case GridData.CENTER:
                            childY = gridY +
                                Math.max(0,(cellHeight - childHeight) / 2);
                            break;
                        case SWT.BOTTOM:
                        case SWT.END:
                        case GridData.END:
                            childY = gridY +
                                Math.max(0, cellHeight - childHeight);
                            break;
                        case SWT.FILL:
                            childHeight = cellHeight - gridData.verticalIndent;
                            break;
                    }
                    IFigure child = grid[i][j];
                    if (child != null) {
                        child.setBounds(new Rectangle(
                            childX, childY, childWidth, childHeight));
                    }
                }
                gridX += widths[j] + this.horizontalSpacing;
            }
            gridY += heights[i] + this.verticalSpacing;
        }
    }

    // clean up cache
    for (int i = 0; i < flushLength; i++) {
        flush[i].cacheWidth = flush[i].cacheHeight = -1;
    }

    int totalDefaultWidth = 0;
    int totalDefaultHeight = 0;
    for (int i=0; i<columnCount; i++) {
        totalDefaultWidth += widths[i];
    }
    for (int i=0; i<rowCount; i++) {
        totalDefaultHeight += heights[i];
    }
    totalDefaultWidth += this.horizontalSpacing * (columnCount - 1) +
        this.marginLeft + this.marginWidth * 2 + this.marginRight;
    totalDefaultHeight += this.verticalSpacing * (rowCount - 1) +
        this.marginTop + this.marginHeight * 2 + this.marginBottom;
    return new Dimension(totalDefaultWidth, totalDefaultHeight);
}
    /**
     * @return The basename of this class.
     */
    /* package */ String getName() {
        String string = getClass().getName();
        int index = string.lastIndexOf('.');
        if (index == -1) {
            return string;
        }
        return string.substring(index + 1, string.length());
    }
    /**
     * @see java.lang.Object#toString()
     */
    public String toString() {
        String string = getName() + " {"; //$NON-NLS-1$
        if (this.numColumns != 1) string +=
            "numColumns=" + this.numColumns + " "; //$NON-NLS-1$ //$NON-NLS-2$
        if (this.makeColumnsEqualWidth) string +=
            "makeColumnsEqualWidth=" +  //$NON-NLS-1$
            this.makeColumnsEqualWidth + " "; //$NON-NLS-1$
        if (this.marginWidth != 0) string += "marginWidth=" + //$NON-NLS-1$
            this.marginWidth + " "; //$NON-NLS-1$
        if (this.marginHeight != 0) string += "marginHeight=" + //$NON-NLS-1$
            this.marginHeight + " "; //$NON-NLS-1$
        if (this.marginLeft != 0) string += "marginLeft=" + //$NON-NLS-1$
            this.marginLeft + " "; //$NON-NLS-1$
        if (this.marginRight != 0) string += "marginRight=" + //$NON-NLS-1$
            this.marginRight + " "; //$NON-NLS-1$
        if (this.marginTop != 0) string += "marginTop=" + //$NON-NLS-1$
            this.marginTop + " "; //$NON-NLS-1$
        if (this.marginBottom != 0) string += "marginBottom=" +  //$NON-NLS-1$
            this.marginBottom + " "; //$NON-NLS-1$
        if (this.horizontalSpacing != 0) string +=
            "horizontalSpacing=" + //$NON-NLS-1$
            this.horizontalSpacing + " "; //$NON-NLS-1$
        if (this.verticalSpacing != 0) string +=
            "verticalSpacing=" + //$NON-NLS-1$
            this.verticalSpacing + " "; //$NON-NLS-1$
        string = string.trim();
        string += "}"; //$NON-NLS-1$
        return string;
    }
    /**
     * numColumns specifies the number of cell columns in the layout.
     *
     * The default value is 1.
     */
    public int numColumns = 1;
    /**
     * makeColumnsEqualWidth specifies whether all columns in the layout
     * will be forced to have the same width.
     *
     * The default value is false.
     */
    public boolean makeColumnsEqualWidth = false;
    /**
     * 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 5.
     */
    public int marginWidth = 5;
    /**
     * 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 5.
     */
    public int marginHeight = 5;
    /**
     * horizontalSpacing specifies the number of pixels between the right
     * edge of one cell and the left edge of its neighbouring cell to
     * the right.
     *
     * The default value is 5.
     */
    public int horizontalSpacing = 5;
    /**
     * verticalSpacing specifies the number of pixels between the bottom
     * edge of one cell and the top edge of its neighbouring cell underneath.
     *
     * The default value is 5.
     */
    public int verticalSpacing = 5;
    /**
     * marginLeft specifies the number of pixels of horizontal margin
     * that will be placed along the left edge of the layout.
     *
     * The default value is 0.
     * 
     * @since 3.1
     */
    public int marginLeft = 0;
    /**
     * marginTop specifies the number of pixels of vertical margin
     * that will be placed along the top edge of the layout.
     *
     * The default value is 0.
     * 
     * @since 3.1
     */
    public int marginTop = 0;
    /**
     * marginRight specifies the number of pixels of horizontal margin
     * that will be placed along the right edge of the layout.
     *
     * The default value is 0.
     * 
     * @since 3.1
     */
    public int marginRight = 0;
    /**
     * marginBottom specifies the number of pixels of vertical margin
     * that will be placed along the bottom edge of the layout.
     *
     * The default value is 0.
     * 
     * @since 3.1
     */
    public int marginBottom = 0;
    protected Map constraints = new HashMap();
}