/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package javax.microedition.lcdui;

import java.util.Vector;

/**

 * ChoiceImpl class implements the basic functionality of the Choice interface.

 * <br> List and ChoiceGroup class use this class as their member to implement

 * their own functionality.

 */

final class ChoiceImpl {

    /**

     * Internal class for storing Choice data.

     */

    private class ChoiceData {

        String text;

        Image img;

        Font font;

        boolean sel;

        ChoiceData(String text, Image img, Font font, boolean sel) {

            this.text = text;

            this.img = img;

            this.font = font;

            this.sel = sel;

        }

    }

    /**

     * Array of ChoiceData items.

     */

    private Vector items = new Vector();

    /**

     * Fit policy flag.

     */

    private int fitPolicy;

    /**

     * Stores if the choice allows single or multiple selections.

     */

    private boolean multiSel;

    /**

     * Constructor.

     *

     * @param multiSel multi or single selection

     */

    ChoiceImpl(boolean multiSel) {

        this.multiSel = multiSel;

    }

    /**

     * Check if the arrays are valid.

     *

     * @param textElements string array

     * @param imgElements  image array

     */

    void check(String[] textElements, Image[] imgElements) {

        // check textElements

        if (textElements == null) {

            throw new NullPointerException(

                    MsgRepository.CHOICE_EXCEPTION_TEXT_ARRAY_NULL);

        }

        // check every text element

        for (int i = 0; i < textElements.length; i++) {

            if (textElements[i] == null) {

                throw new NullPointerException(

                        MsgRepository.CHOICE_EXCEPTION_ITEM_NULL + i);

            }

        }

        // check imgElements array length

        if (imgElements != null && imgElements.length != textElements.length) {

            throw new IllegalArgumentException(

                    MsgRepository.CHOICE_EXCEPTION_INVALID_ARRAY_LENGTHS);

        }

    }

    /**

     * Append item with specified text and image.

     */

    int append(String text, Image image) {

        validateString(text);

        ChoiceData data = new ChoiceData(text, image, Font.getDefaultFont(),

                (!multiSel && size() == 0));

        items.addElement(data);

        // return index of added element

        return size() - 1;

    }

    /**

     * Insert item with specified text and image.

     */

    void insert(int elementNum, String text, Image image) {

        validateString(text);

        validatePosition(elementNum, size() + 1);

        ChoiceData data = new ChoiceData(text, image, Font.getDefaultFont(),

                (!multiSel && size() == 0));

        items.insertElementAt(data, elementNum);

    }

    /**

     * Set item with specified text and image.

     */

    void set(int elementNum, String text, Image image) {

        validateString(text);

        validatePosition(elementNum, size());

        ChoiceData data = (ChoiceData) items.elementAt(elementNum);

        data.text = text;

        data.img = image;

    }

    /**

     * Set item's font.

     */

    void setFont(int elementNum, Font font) {

        validatePosition(elementNum, size());

        Font checkedFont = (font == null ? Font.getDefaultFont() : font);

        ((ChoiceData) items.elementAt(elementNum)).font = checkedFont;

    }

    /**

     * Delete item from specified position.

     */

    void delete(int elementNum) {

        validatePosition(elementNum, size());

        if (!multiSel && isSelected(elementNum) && size() > 1) {

            // we are removing the selected item and there are more

            if (elementNum == size() - 1) {

                // select previous item

                setSelected(elementNum - 1, true);

            }

            else {

                // select next item

                setSelected(elementNum + 1, true);

            }

        }

        items.removeElementAt(elementNum);

    }

    /**

     * Delete all items.

     */

    void deleteAll() {

        items.removeAllElements();

    }

    /**

     * Get fit policy.

     */

    int getFitPolicy() {

        return fitPolicy;

    }

    /**

     * Get the Font of a given item.

     */

    Font getFont(int elementNum) {

        validatePosition(elementNum, size());

        return ((ChoiceData) items.elementAt(elementNum)).font;

    }

    /**

     * Get the image of a given item.

     */

    Image getImage(int elementNum) {

        validatePosition(elementNum, size());

        return ((ChoiceData) items.elementAt(elementNum)).img;

    }

    /**

     * Get the text of a given item.

     */

    String getString(int elementNum) {

        validatePosition(elementNum, size());

        return ((ChoiceData) items.elementAt(elementNum)).text;

    }

    /**

     * Set fit policy.

     */

    void setFitPolicy(int newFitPolicy) {

        switch (newFitPolicy) {

            case Choice.TEXT_WRAP_DEFAULT:

            case Choice.TEXT_WRAP_OFF:

            case Choice.TEXT_WRAP_ON:

                fitPolicy = newFitPolicy;

                break;

            default:

                throw new IllegalArgumentException(

                        MsgRepository.CHOICE_EXCEPTION_INVALID_FIT_POLICY);

        }

    }

    /**

     * Get the selection index. Returns the first selection index if multiple

     * selection is allowed.

     */

    int getSelectedIndex() {

        final int size = size();

        if (!multiSel) {

            for (int i = 0; i < size; i++) {

                if (isSelected(i)) {

                    return i;

                }

            }

        }

        return -1;

    }

    /**

     * Checks if an item is selected.

     */

    boolean isSelected(int elementNum) {

        validatePosition(elementNum, size());

        return ((ChoiceData) items.elementAt(elementNum)).sel;

    }

    /**

     * Sets an item's selection.

     */

    void setSelected(int elementNum, boolean select) {

        validatePosition(elementNum, size());

        if (multiSel) {

            ((ChoiceData) items.elementAt(elementNum)).sel = select;

        }

        else {

            if (select) {

                // clear all

                final int size = size();

                for (int i = 0; i < size; i++) {

                    ((ChoiceData) items.elementAt(i)).sel = false;

                }

                // set just one

                ((ChoiceData) items.elementAt(elementNum)).sel = true;

            }

        }

    }

    /**

     * Get selection flags.

     */

    int getSelectedFlags(boolean[] selectedArray) {

        validateSelectedArray(selectedArray);

        final int size = size();

        int numSelected = 0;

        for (int i = 0; i < size; i++) {

            if (((ChoiceData) items.elementAt(i)).sel) {

                selectedArray[i] = true;

                numSelected++;

            }

            else {

                selectedArray[i] = false;

            }

        }

        return numSelected;

    }

    /**

     * Set selection flags.

     */

    void setSelectedFlags(boolean[] selectedArray) {

        validateSelectedArray(selectedArray);

        final int size = size();

        if (size > 0) {

            if (multiSel) {

                for (int i = 0; i < size; i++) {

                    ((ChoiceData) items.elementAt(i)).sel = selectedArray[i];

                }

            }

            else {

                int firstSelected = 0;

                for (int i = 0; i < size; i++) {

                    if (selectedArray[i]) {

                        firstSelected = i;

                        break;

                    }

                }

                setSelected(firstSelected, true);

            }

        }

    }

    /**

     * Returns the size of the list.

     *

     * @return the lists size

     */

    int size() {

        return items.size();

    }

    /**

     * Validates position.

     *

     * @param position an index of the text array

     * @param upperBoundary upper boundary for position

     */

    private void validatePosition(int position, int upperBoundary) {

        if (position < 0 || position >= upperBoundary) {

            throw new IndexOutOfBoundsException(

                    MsgRepository.CHOICE_EXCEPTION_INVALID_ITEM_INDEX);

        }

    }

    /**

     * Validates a string.

     *

     * @param str string

     */

    private void validateString(String str) {

        if (str == null) {

            throw new NullPointerException(

                    MsgRepository.CHOICE_EXCEPTION_STRING_NULL);

        }

    }

    /**

     * Validates an array containing selections.

     *

     * @param selectedArray selected array

     */

    private void validateSelectedArray(boolean[] selectedArray) {

        if (selectedArray == null) {

            throw new NullPointerException(

                    MsgRepository.CHOICE_EXCEPTION_ARRAY_NULL);

        }

        if (selectedArray.length < size()) {

            throw new IllegalArgumentException(

                    MsgRepository.CHOICE_EXCEPTION_INVALID_ARRAY_SIZE);

        }

    }

}