/*
 * Copyright (c) 2011, Nikolaus Moll
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the jo-widgets.org nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.jowidgets.spi.impl.swt.common.widgets.base;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Layout;
import org.jowidgets.common.types.SplitResizePolicy;

final class JoSashFormLayout extends Layout {

    private final JoSashForm parent;
    private final ISashOrientationUtil sashUtil;

    private boolean initialized;
    private int fixedChildRegularSize = 0;

    JoSashFormLayout(final JoSashForm parent, final ISashOrientationUtil calculator) {
        this.parent = parent;
        this.sashUtil = calculator;
        initialized = false;
    }

    @Override
    protected Point computeSize(final Composite composite, final int wHint, final int hHint, final boolean flushCache) {
        return new Point(SWT.DEFAULT, SWT.DEFAULT);
    }

    @Override
    protected void layout(final Composite composite, final boolean flushCache) {
        final Rectangle area = parent.getClientArea();

        //CHECKSTYLE:OFF
        //seems to be a bug in LocalVariableFinal because variable is not final
        int firstSize;
        int secondSize;
        //CHECKSTYLE:ON
        final int firstMinSize = sashUtil.getSize(parent.getFirstMinSize());
        final int secondMinSize = sashUtil.getSize(parent.getSecondMinSize());

        final int effectiveSize = sashUtil.getSize(area) - parent.getSashSize();
        if (effectiveSize <= 0) {
            // no reasonable parent size set, so do not layout anything
            return;
        }

        final Rectangle firstBounds = parent.getFirst().getBounds();
        final Rectangle secondBounds = parent.getSecond().getBounds();

        // always use weight when layouting first time
        if (!initialized || (parent.getResizePolicy() == SplitResizePolicy.RESIZE_BOTH)) {
            initialized = true;

            firstSize = (int) (parent.getWeight() * effectiveSize);
            secondSize = effectiveSize - firstSize;
        }
        else if (parent.getResizePolicy() == SplitResizePolicy.RESIZE_FIRST) {
            secondSize = Math.max(sashUtil.getSize(secondBounds), fixedChildRegularSize);
            firstSize = effectiveSize - secondSize;

            if (firstSize < firstMinSize) {
                fixedChildRegularSize = Math.max(fixedChildRegularSize, secondSize);
            }
            else {
                fixedChildRegularSize = 0;
            }
        }
        else if (parent.getResizePolicy() == SplitResizePolicy.RESIZE_SECOND) {
            firstSize = Math.max(sashUtil.getSize(firstBounds), fixedChildRegularSize);
            secondSize = effectiveSize - firstSize;

            if (secondSize < secondMinSize) {
                fixedChildRegularSize = Math.max(fixedChildRegularSize, firstSize);
            }
            else {
                fixedChildRegularSize = 0;
            }
        }
        else {
            throw new IllegalStateException("Wrong Orientation is set");
        }

        if (firstSize < firstMinSize) {
            secondSize = secondSize - (firstMinSize - firstSize);
            firstSize = firstMinSize;
        }
        if (secondSize < secondMinSize) {
            firstSize = Math.max(firstMinSize, firstSize - (secondMinSize - secondSize));
            secondSize = secondMinSize;
        }

        parent.setChildrenBounds(area, firstSize, secondSize);
    }

    void resetRemeberedSize() {
        fixedChildRegularSize = 0;
    }
}