AbstractParentNode.java

/*
 * Copyright 2010-2011 Øyvind Berg (elacin@gmail.com)
 *
 *    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.elacin.pdfextract.tree;

import org.elacin.pdfextract.geom.MathUtils;
import org.elacin.pdfextract.style.Style;
import org.elacin.pdfextract.style.TextUtils;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.io.Serializable;

import java.util.*;

/**
 * Created by IntelliJ IDEA. User: elacin Date: Mar 18, 2010 Time: 3:16:53 PM To change this
 * template use File | Settings | File Templates.
 */
public abstract class AbstractParentNode<ChildType extends AbstractNode,
        ParentType extends AbstractParentNode> extends AbstractNode<ParentType> {

// ------------------------------ FIELDS ------------------------------

    /* caches */
    @Nullable
    protected transient String textCache;
    @Nullable
    protected transient Style  styleCache;
    @Nullable
    protected transient String toStringCache;

    /* children nodes */
    @NotNull
    private final List<ChildType> children = new ArrayList<ChildType>();

// --------------------------- CONSTRUCTORS ---------------------------
    public AbstractParentNode() {}

    public AbstractParentNode(@NotNull final ChildType child) {
        addChild(child);
    }

// ------------------------ INTERFACE METHODS ------------------------
// --------------------- Interface HasPosition ---------------------
    public void calculatePos() {
        setPos(MathUtils.findBounds(children));
    }

// --------------------- Interface StyledText ---------------------
    @NotNull
    public Style getStyle() {

        if (styleCache == null) {
            styleCache = TextUtils.findDominatingStyle(children);
        }

        return styleCache;
    }

    @NotNull
    @Override
    public String getText() {

        if (textCache == null) {
            StringBuilder sb = new StringBuilder();

            if (!children.isEmpty()) {
                for (ChildType child : children) {
                    sb.append(child.getText()).append(" ");
                }

                sb.setLength(sb.length() - 1);
            }

            textCache = sb.toString();
        }

        return textCache;
    }

// ------------------------ CANONICAL METHODS ------------------------
    @NotNull
    @Override
    public String toString() {

        if (toStringCache == null) {
            final StringBuilder sb = new StringBuilder();

            sb.append(getText());
            toStringCache = sb.toString();
        }

        return toStringCache;
    }

// ------------------------ OVERRIDING METHODS ------------------------
    @SuppressWarnings({ "unchecked" })    /* wtf */
    @NotNull
    public EnumSet<Role> getRoles() {

        EnumSet<Role> ret = EnumSet.noneOf(Role.class);

        for (ChildType child : children) {
            ret.addAll(child.getRoles());
        }

        return ret;
    }

// --------------------- GETTER / SETTER METHODS ---------------------
    @NotNull
    public List<ChildType> getChildren() {
        return children;
    }

// -------------------------- PUBLIC METHODS --------------------------
    public final void addChild(@NotNull final ChildType child) {

        child.invalidateThisAndParents();
        children.add(child);
        child.parent = this;
        child.invalidateThisAndParents();
        Collections.sort(children, getChildComparator());
    }

    public final void addChildren(@NotNull final List<ChildType> newChildren) {

        for (ChildType child : newChildren) {
            child.invalidateThisAndParents();
            children.add(child);
            child.parent = this;
        }

        Collections.sort(children, getChildComparator());
        invalidateThisAndParents();
    }

    @NotNull
    public abstract Comparator<ChildType> getChildComparator();

    public void removeChild(ChildType child) {

        child.invalidateThisAndParents();
        children.remove(child);
        child.parent = null;
    }

    public void removeChildren(List<ChildType> childrenToRemove) {

        for (ChildType child : childrenToRemove) {
            child.invalidateThisAndParents();
            children.remove(child);
            child.parent = null;
        }
    }

// -------------------------- OTHER METHODS --------------------------
    protected void invalidateThisAndParents() {

        invalidatePos();
        textCache     = null;
        toStringCache = null;
        styleCache    = null;

        if (getParent() != null) {
            getParent().invalidateThisAndParents();
        }
    }

// -------------------------- INNER CLASSES --------------------------

    /**
     * This comparator will compare two nodes based on their position within a page TODO: add page
     * number here
     */
    protected class StandardNodeComparator implements Comparator<ChildType>, Serializable {

        private static final long serialVersionUID = 3903290320365277004L;

        public int compare(@NotNull final ChildType o1, @NotNull final ChildType o2) {

            if (o1.getPos().y < o2.getPos().y) {
                return -1;
            } else if (o1.getPos().y > o2.getPos().y) {
                return 1;
            }

            if (o1.getPos().x < o2.getPos().x) {
                return -1;
            } else if (o1.getPos().x > o2.getPos().x) {
                return 1;
            }

            return 0;
        }
    }
}