WrapLayout.java

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/*
 * Autopsy Forensic Browser
 *
 * Copyright 2019 Basis Technology Corp.
 * Contact: carrier <at> sleuthkit <dot> org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.sleuthkit.autopsy.uicomponents;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Insets;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class WrapLayout extends FlowLayout {
    
        private static final long serialVersionUID = 1L;
        public WrapLayout() {
            super();
        }

        public WrapLayout(int align) {
            super(align);
        }

        public WrapLayout(int align, int hgap, int vgap) {
            super(align, hgap, vgap);
        }

        @Override
        public Dimension preferredLayoutSize(Container target) {
            return layoutSize(target, true);
        }

        @Override
        public Dimension minimumLayoutSize(Container target) {
            Dimension minimum = layoutSize(target, false);
            minimum.width -= (getHgap() + 1);
            return minimum;
        }

        private Dimension layoutSize(Container target, boolean preferred) {
            synchronized (target.getTreeLock()) {
                //  Each row must fit with the width allocated to the containter.
                //  When the container width = 0, the preferred width of the container
                //  has not yet been calculated so lets ask for the maximum.

                int targetWidth = target.getSize().width;
                Container container = target;

                while (container.getSize().width == 0 && container.getParent() != null) {
                    container = container.getParent();
                }

                targetWidth = container.getSize().width;

                if (targetWidth == 0) {
                    targetWidth = Integer.MAX_VALUE;
                }

                int hgap = getHgap();
                int vgap = getVgap();
                Insets insets = target.getInsets();
                int horizontalInsetsAndGap = insets.left + insets.right + (hgap * 2);
                int maxWidth = targetWidth - horizontalInsetsAndGap;

                //  Fit components into the allowed width
                Dimension dim = new Dimension(0, 0);
                int rowWidth = 0;
                int rowHeight = 0;

                int nmembers = target.getComponentCount();

                for (int i = 0; i < nmembers; i++) {
                    Component m = target.getComponent(i);

                    if (m.isVisible()) {
                        Dimension d = preferred ? m.getPreferredSize() : m.getMinimumSize();

                        //  Can't add the component to current row. Start a new row.
                        if (rowWidth + d.width > maxWidth) {
                            addRow(dim, rowWidth, rowHeight);
                            rowWidth = 0;
                            rowHeight = 0;
                        }

                        //  Add a horizontal gap for all components after the first
                        if (rowWidth != 0) {
                            rowWidth += hgap;
                        }

                        rowWidth += d.width;
                        rowHeight = Math.max(rowHeight, d.height);
                    }
                }

                addRow(dim, rowWidth, rowHeight);

                dim.width += horizontalInsetsAndGap;
                dim.height += insets.top + insets.bottom + vgap * 2;

                //      When using a scroll pane or the DecoratedLookAndFeel we need to
                //  make sure the preferred size is less than the size of the
                //  target containter so shrinking the container size works
                //  correctly. Removing the horizontal gap is an easy way to do this.
                Container scrollPane = SwingUtilities.getAncestorOfClass(JScrollPane.class, target);

                if (scrollPane != null && target.isValid()) {
                    dim.width -= (hgap + 1);
                }

                return dim;
            }
        }

        /*
         * A new row has been completed. Use the dimensions of this row to
         * update the preferred size for the container.
         *
         * @param dim update the width and height when appropriate @param
         * rowWidth the width of the row to add @param rowHeight the height of
         * the row to add
         */
        private void addRow(Dimension dim, int rowWidth, int rowHeight) {
            dim.width = Math.max(dim.width, rowWidth);

            if (dim.height > 0) {
                dim.height += getVgap();
            }

            dim.height += rowHeight;
        }
    }