/*

 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

package javax.swing.tree;

import javax.swing.event.TreeModelEvent;

import java.awt.Dimension;

import java.awt.Rectangle;

import java.util.Enumeration;

/**

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans™

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Scott Violet

 */

@SuppressWarnings("serial") // Same-version serialization only

public abstract class AbstractLayoutCache implements RowMapper {

    /** Object responsible for getting the size of a node. */

    protected NodeDimensions     nodeDimensions;

    /** Model providing information. */

    protected TreeModel          treeModel;

    /** Selection model. */

    protected TreeSelectionModel treeSelectionModel;

    /**

     * True if the root node is displayed, false if its children are

     * the highest visible nodes.

     */

    protected boolean            rootVisible;

    /**

      * Height to use for each row.  If this is <= 0 the renderer will be

      * used to determine the height for each row.

      */

    protected int                rowHeight;

    /**

     * Sets the renderer that is responsible for drawing nodes in the tree

     * and which is therefore responsible for calculating the dimensions of

     * individual nodes.

     *

     * @param nd a <code>NodeDimensions</code> object

     */

    public void setNodeDimensions(NodeDimensions nd) {

        this.nodeDimensions = nd;

    }

    /**

     * Returns the object that renders nodes in the tree, and which is

     * responsible for calculating the dimensions of individual nodes.

     *

     * @return the <code>NodeDimensions</code> object

     */

    public NodeDimensions getNodeDimensions() {

        return nodeDimensions;

    }

    /**

     * Sets the <code>TreeModel</code> that will provide the data.

     *

     * @param newModel the <code>TreeModel</code> that is to

     *          provide the data

     */

    public void setModel(TreeModel newModel) {

        treeModel = newModel;

    }

    /**

     * Returns the <code>TreeModel</code> that is providing the data.

     *

     * @return the <code>TreeModel</code> that is providing the data

     */

    public TreeModel getModel() {

        return treeModel;

    }

    /**

     * Determines whether or not the root node from

     * the <code>TreeModel</code> is visible.

     *

     * @param rootVisible true if the root node of the tree is to be displayed

     * @see #rootVisible

     * @beaninfo

     *        bound: true

     *  description: Whether or not the root node

     *               from the TreeModel is visible.

     */

    public void setRootVisible(boolean rootVisible) {

        this.rootVisible = rootVisible;

    }

    /**

     * Returns true if the root node of the tree is displayed.

     *

     * @return true if the root node of the tree is displayed

     * @see #rootVisible

     */

    public boolean isRootVisible() {

        return rootVisible;

    }

    /**

     * Sets the height of each cell.  If the specified value

     * is less than or equal to zero the current cell renderer is

     * queried for each row's height.

     *

     * @param rowHeight the height of each cell, in pixels

     * @beaninfo

     *        bound: true

     *  description: The height of each cell.

     */

    public void setRowHeight(int rowHeight) {

        this.rowHeight = rowHeight;

    }

    /**

     * Returns the height of each row.  If the returned value is less than

     * or equal to 0 the height for each row is determined by the

     * renderer.

     *

     * @return the height of each row

     */

    public int getRowHeight() {

        return rowHeight;

    }

    /**

     * Sets the <code>TreeSelectionModel</code> used to manage the

     * selection to new LSM.

     *

     * @param newLSM  the new <code>TreeSelectionModel</code>

     */

    public void setSelectionModel(TreeSelectionModel newLSM) {

        if(treeSelectionModel != null)

            treeSelectionModel.setRowMapper(null);

        treeSelectionModel = newLSM;

        if(treeSelectionModel != null)

            treeSelectionModel.setRowMapper(this);

    }

    /**

     * Returns the model used to maintain the selection.

     *

     * @return the <code>treeSelectionModel</code>

     */

    public TreeSelectionModel getSelectionModel() {

        return treeSelectionModel;

    }

    /**

     * Returns the preferred height.

     *

     * @return the preferred height

     */

    public int getPreferredHeight() {

        // Get the height

        int           rowCount = getRowCount();

        if(rowCount > 0) {

            Rectangle     bounds = getBounds(getPathForRow(rowCount - 1),

                                             null);

            if(bounds != null)

                return bounds.y + bounds.height;

        }

        return 0;

    }

    /**

     * Returns the preferred width for the passed in region.

     * The region is defined by the path closest to

     * <code>(bounds.x, bounds.y)</code> and

     * ends at <code>bounds.height + bounds.y</code>.

     * If <code>bounds</code> is <code>null</code>,

     * the preferred width for all the nodes

     * will be returned (and this may be a VERY expensive

     * computation).

     *

     * @param bounds the region being queried

     * @return the preferred width for the passed in region

     */

    public int getPreferredWidth(Rectangle bounds) {

        int           rowCount = getRowCount();

        if(rowCount > 0) {

            // Get the width

            TreePath      firstPath;

            int           endY;

            if(bounds == null) {

                firstPath = getPathForRow(0);

                endY = Integer.MAX_VALUE;

            }

            else {

                firstPath = getPathClosestTo(bounds.x, bounds.y);

                endY = bounds.height + bounds.y;

            }

            Enumeration   paths = getVisiblePathsFrom(firstPath);

            if(paths != null && paths.hasMoreElements()) {

                Rectangle   pBounds = getBounds((TreePath)paths.nextElement(),

                                                null);

                int         width;

                if(pBounds != null) {

                    width = pBounds.x + pBounds.width;

                    if (pBounds.y >= endY) {

                        return width;

                    }

                }

                else

                    width = 0;

                while (pBounds != null && paths.hasMoreElements()) {

                    pBounds = getBounds((TreePath)paths.nextElement(),

                                        pBounds);

                    if (pBounds != null && pBounds.y < endY) {

                        width = Math.max(width, pBounds.x + pBounds.width);

                    }

                    else {

                        pBounds = null;

                    }

                }

                return width;

            }

        }

        return 0;

    }

    //

    // Abstract methods that must be implemented to be concrete.

    //

    /**

      * Returns true if the value identified by row is currently expanded.

      *

      * @param path TreePath to check

      * @return whether TreePath is expanded

      */

    public abstract boolean isExpanded(TreePath path);

    /**

     * Returns a rectangle giving the bounds needed to draw path.

     *

     * @param path     a <code>TreePath</code> specifying a node

     * @param placeIn  a <code>Rectangle</code> object giving the

     *          available space

     * @return a <code>Rectangle</code> object specifying the space to be used

     */

    public abstract Rectangle getBounds(TreePath path, Rectangle placeIn);

    /**

      * Returns the path for passed in row.  If row is not visible

      * <code>null</code> is returned.

      *

      * @param row  the row being queried

      * @return the <code>TreePath</code> for the given row

      */

    public abstract TreePath getPathForRow(int row);

    /**

      * Returns the row that the last item identified in path is visible

      * at.  Will return -1 if any of the elements in path are not

      * currently visible.

      *

      * @param path the <code>TreePath</code> being queried

      * @return the row where the last item in path is visible or -1

      *         if any elements in path aren't currently visible

      */

    public abstract int getRowForPath(TreePath path);

    /**

      * Returns the path to the node that is closest to x,y.  If

      * there is nothing currently visible this will return <code>null</code>,

      * otherwise it'll always return a valid path.

      * If you need to test if the

      * returned object is exactly at x, y you should get the bounds for

      * the returned path and test x, y against that.

      *

      * @param x the horizontal component of the desired location

      * @param y the vertical component of the desired location

      * @return the <code>TreePath</code> closest to the specified point

      */

    public abstract TreePath getPathClosestTo(int x, int y);

    /**

     * Returns an <code>Enumerator</code> that increments over the visible

     * paths starting at the passed in location. The ordering of the

     * enumeration is based on how the paths are displayed.

     * The first element of the returned enumeration will be path,

     * unless it isn't visible,

     * in which case <code>null</code> will be returned.

     *

     * @param path the starting location for the enumeration

     * @return the <code>Enumerator</code> starting at the desired location

     */

    public abstract Enumeration<TreePath> getVisiblePathsFrom(TreePath path);

    /**

     * Returns the number of visible children for row.

     *

     * @param path  the path being queried

     * @return the number of visible children for the specified path

     */

    public abstract int getVisibleChildCount(TreePath path);

    /**

     * Marks the path <code>path</code> expanded state to

     * <code>isExpanded</code>.

     *

     * @param path  the path being expanded or collapsed

     * @param isExpanded true if the path should be expanded, false otherwise

     */

    public abstract void setExpandedState(TreePath path, boolean isExpanded);

    /**

     * Returns true if the path is expanded, and visible.

     *

     * @param path  the path being queried

     * @return true if the path is expanded and visible, false otherwise

     */

    public abstract boolean getExpandedState(TreePath path);

    /**

     * Number of rows being displayed.

     *

     * @return the number of rows being displayed

     */

    public abstract int getRowCount();

    /**

     * Informs the <code>TreeState</code> that it needs to recalculate

     * all the sizes it is referencing.

     */

    public abstract void invalidateSizes();

    /**

     * Instructs the <code>LayoutCache</code> that the bounds for

     * <code>path</code> are invalid, and need to be updated.

     *

     * @param path the path being updated

     */

    public abstract void invalidatePathBounds(TreePath path);

    //

    // TreeModelListener methods

    // AbstractTreeState does not directly become a TreeModelListener on

    // the model, it is up to some other object to forward these methods.

    //

    /**

     * <p>

     * Invoked after a node (or a set of siblings) has changed in some

     * way. The node(s) have not changed locations in the tree or

     * altered their children arrays, but other attributes have

     * changed and may affect presentation. Example: the name of a

     * file has changed, but it is in the same location in the file

     * system.</p>

     *

     * <p>e.path() returns the path the parent of the changed node(s).</p>

     *

     * <p>e.childIndices() returns the index(es) of the changed node(s).</p>

     *

     * @param e  the <code>TreeModelEvent</code>

     */

    public abstract void treeNodesChanged(TreeModelEvent e);

    /**

     * <p>Invoked after nodes have been inserted into the tree.</p>

     *

     * <p>e.path() returns the parent of the new nodes</p>

     * <p>e.childIndices() returns the indices of the new nodes in

     * ascending order.</p>

     *

     * @param e the <code>TreeModelEvent</code>

     */

    public abstract void treeNodesInserted(TreeModelEvent e);

    /**

     * <p>Invoked after nodes have been removed from the tree.  Note that

     * if a subtree is removed from the tree, this method may only be

     * invoked once for the root of the removed subtree, not once for

     * each individual set of siblings removed.</p>

     *

     * <p>e.path() returns the former parent of the deleted nodes.</p>

     *

     * <p>e.childIndices() returns the indices the nodes had before they were deleted in ascending order.</p>

     *

     * @param e the <code>TreeModelEvent</code>

     */

    public abstract void treeNodesRemoved(TreeModelEvent e);

    /**

     * <p>Invoked after the tree has drastically changed structure from a

     * given node down.  If the path returned by <code>e.getPath()</code>

     * is of length one and the first element does not identify the

     * current root node the first element should become the new root

     * of the tree.</p>

     *

     * <p>e.path() holds the path to the node.</p>

     * <p>e.childIndices() returns null.</p>

     *

     * @param e the <code>TreeModelEvent</code>

     */

    public abstract void treeStructureChanged(TreeModelEvent e);

    //

    // RowMapper

    //

    /**

     * Returns the rows that the <code>TreePath</code> instances in

     * <code>path</code> are being displayed at.

     * This method should return an array of the same length as that passed

     * in, and if one of the <code>TreePaths</code>

     * in <code>path</code> is not valid its entry in the array should

     * be set to -1.

     *

     * @param paths the array of <code>TreePath</code>s being queried

     * @return an array of the same length that is passed in containing

     *          the rows that each corresponding where each

     *          <code>TreePath</code> is displayed; if <code>paths</code>

     *          is <code>null</code>, <code>null</code> is returned

     */

    public int[] getRowsForPaths(TreePath[] paths) {

        if(paths == null)

            return null;

        int               numPaths = paths.length;

        int[]             rows = new int[numPaths];

        for(int counter = 0; counter < numPaths; counter++)

            rows[counter] = getRowForPath(paths[counter]);

        return rows;

    }

    //

    // Local methods that subclassers may wish to use that are primarly

    // convenience methods.

    //

    /**

     * Returns, by reference in <code>placeIn</code>,

     * the size needed to represent <code>value</code>.

     * If <code>inPlace</code> is <code>null</code>, a newly created

     * <code>Rectangle</code> should be returned, otherwise the value

     * should be placed in <code>inPlace</code> and returned. This will

     * return <code>null</code> if there is no renderer.

     *

     * @param value the <code>value</code> to be represented

     * @param row  row being queried

     * @param depth the depth of the row

     * @param expanded true if row is expanded, false otherwise

     * @param placeIn  a <code>Rectangle</code> containing the size needed

     *          to represent <code>value</code>

     * @return a <code>Rectangle</code> containing the node dimensions,

     *          or <code>null</code> if node has no dimension

     */

    protected Rectangle getNodeDimensions(Object value, int row, int depth,

                                          boolean expanded,

                                          Rectangle placeIn) {

        NodeDimensions            nd = getNodeDimensions();

        if(nd != null) {

            return nd.getNodeDimensions(value, row, depth, expanded, placeIn);

        }

        return null;

    }

    /**

      * Returns true if the height of each row is a fixed size.

      *

      * @return whether the height of each row is a fixed size

      */

    protected boolean isFixedRowHeight() {

        return (rowHeight > 0);

    }

    /**

     * Used by <code>AbstractLayoutCache</code> to determine the size

     * and x origin of a particular node.

     */

    static public abstract class NodeDimensions {

        /**

         * Returns, by reference in bounds, the size and x origin to

         * place value at. The calling method is responsible for determining

         * the Y location. If bounds is <code>null</code>, a newly created

         * <code>Rectangle</code> should be returned,

         * otherwise the value should be placed in bounds and returned.

         *

         * @param value the <code>value</code> to be represented

         * @param row row being queried

         * @param depth the depth of the row