// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.client.widgets.nonpublic;

import org.litesoft.commonfoundation.typeutils.*;

import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.*;

import java.util.*;

public abstract class AbstractSizeableComplexPanel extends AbstractSizeablePanel {
    private WidgetCollection mChildren = new WidgetCollection( this );

    /**
     * Gets the list of children contained in this panel.
     *
     * @return a collection of child widgets
     */
    protected WidgetCollection getChildren() {
        return mChildren;
    }

    protected Widget getWidget( int index ) {
        return getChildren().get( index );
    }

    protected int getWidgetCount() {
        return getChildren().size();
    }

    protected int getWidgetIndex( Widget child ) {
        return getChildren().indexOf( child );
    }

    @Override
    public boolean anyChildren() {
        return (mChildren.size() != 0);
    }

    @SuppressWarnings({"unchecked"})
    @Override
    public Iterator iterator() {
        return mChildren.iterator();
    }

    @Override
    public boolean remove( Widget w ) {
        // Make sure this panel actually contains the child widget.
        if ( !mChildren.contains( w ) ) {
            return false;
        }

        // Disown it.
        disown( w );

        mChildren.remove( w );
        return true;
    }

    /**
     * Adds a new child widget to the panel.
     *
     * @param w         the child widget to be added
     * @param container the element within which the child will be contained
     */
    protected void add( Widget w, Element container ) {
        insert( w, container, mChildren.size() );
    }

    /**
     * Inserts a new child widget into the panel.
     *
     * @param child       the child widget to be added
     * @param container   the element within which the child will be contained
     * @param beforeIndex the index before which the widget will be added
     */
    protected void insert( Widget child, Element container, int beforeIndex ) {
        beforeIndex = adjustIndexIfChildInteracts( beforeIndex, child );

        adopt( child, container );

        mChildren.insert( child, beforeIndex );
    }

    protected int adjustIndexIfChildInteracts( int pBeforeIndex, Widget pChild ) {
        validateInsertionIndex( pBeforeIndex );

        if ( (pChild.getParent() == this) && (getWidgetIndex( pChild ) < pBeforeIndex) ) {
            return pBeforeIndex - 1;
        }

        return pBeforeIndex;
    }

    protected void validateReadIndex( int pIndex ) {
        Integers.validateIndex( pIndex, getWidgetCount(), false );
    }

    protected void validateInsertionIndex( int pIndex ) {
        Integers.validateIndex( pIndex, getWidgetCount(), true );
    }
}