move Up in JTree - Java Swing

Java examples for Swing:JTree

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Description

move Up in JTree

Demo Code

/*/*from www.java  2s  . com*/
 * Copyright 2003-2011 JetBrains s.r.o.
 *
 * 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 com.java2s;

import javax.swing.JTree;

import javax.swing.tree.TreePath;
import java.awt.Rectangle;

public class Main {
    public static void moveUp(JTree tree) {
        int row = getSelectedRow(tree);
        if (row > 0) {
            row--;
            showAndSelect(tree, row - 2, row, row, true);
        }
    }

    private static int getSelectedRow(JTree tree) {
        return tree.getRowForPath(tree.getSelectionPath());
    }

    private static void showAndSelect(JTree tree, int top, int bottom,
            int row, boolean centerHorizontally) {
        int size = tree.getRowCount();
        if (size == 0) {
            tree.clearSelection();
            return;
        }
        if (top < 0) {
            top = 0;
        }
        if (bottom >= size) {
            bottom = size - 1;
        }
        Rectangle topBounds = tree.getRowBounds(top);
        Rectangle bottomBounds = tree.getRowBounds(bottom);
        Rectangle bounds;
        if (topBounds == null) {
            bounds = bottomBounds;
        } else if (bottomBounds == null) {
            bounds = topBounds;
        } else {
            bounds = topBounds.union(bottomBounds);
        }
        if (bounds != null) {
            TreePath path = tree.getPathForRow(row);
            if (path != null && path.getParentPath() != null) {
                Rectangle parentBounds = tree.getPathBounds(path
                        .getParentPath());
                if (parentBounds != null) {
                    bounds.x = parentBounds.x;
                }
            }
            if (!centerHorizontally) {
                bounds.x = 0;
                bounds.width = tree.getWidth();
            } else {
                bounds.width = Math.min(bounds.width,
                        tree.getVisibleRect().width);
            }
            tree.scrollRectToVisible(bounds);
        }
        tree.setSelectionRow(row);
    }
}

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