UIInput.java

package org.terasology.rendering.gui.components;

import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import org.lwjgl.opengl.Display;
import org.newdawn.slick.Color;
import org.terasology.asset.AssetType;
import org.terasology.asset.AssetUri;
import org.terasology.logic.manager.AudioManager;
import org.terasology.rendering.gui.framework.IInputDataElement;
import org.terasology.rendering.gui.framework.IInputListener;
import org.terasology.rendering.gui.framework.UIDisplayContainer;

import javax.vecmath.Vector2f;
import java.util.ArrayList;

/**
 * A simple graphical input
 *
 * @author Anton Kireev <adeon.k87@gmail.com>
 * @version 0.23
 */
public class UIInput extends UIDisplayContainer implements IInputDataElement {
    //	TODO: Add text selection and paste from clipboard
    private final ArrayList<IInputListener> _inputListeners = new ArrayList<IInputListener>();

    private final StringBuffer _inputValue = new StringBuffer();
    private final UIText _inputText;
    private final UITextCursor _textCursor;
    private final Vector2f _padding = new Vector2f(10f, 10f);

    private int _cursorPosition = 0;  //The current position of the carriage
    private int _maxLength = 255; //The maximum number of characters that will be accepted as input
    private float _textWidthInContainer = 0;  //The width of the text inside the INPUT field.

    private String _prevInputValue = new String();

    public UIInput(Vector2f size) {
        setSize(size);
        setCrop(true);
        setStyle("background-image", "engine:gui_menu 256/512 30/512 0 90/512");

        _inputText = new UIText();
        _inputText.setVisible(true);
        _inputText.setColor(Color.black);
        _inputText.setPosition(new Vector2f(getPosition().x + _padding.x, getPosition().y + _padding.y));

        _textCursor = new UITextCursor();
        _textCursor.setVisible(true);
        _textCursor.setPosition(new Vector2f(getPosition().x + _padding.x, getPosition().y + _padding.y / 2));

        addDisplayElement(_inputText);
        addDisplayElement(_textCursor);
    }

    @Override
    public void update() {
        Vector2f mousePos = new Vector2f(Mouse.getX(), Display.getHeight() - Mouse.getY());

        if (intersects(mousePos)) {

            if (!_clickSoundPlayed) {
                AudioManager.play(new AssetUri(AssetType.SOUND, "engine:PlaceBlock"));
                _clickSoundPlayed = true;
            }

            if (_mouseUp) {
                _mouseUp = false;
            }

            if (_mouseDown) {
                clicked(mousePos);
            }

        } else {
            if (_mouseDown) {
                _focused = false;
            }
            _clickSoundPlayed = false;
            _mouseUp = false;
            _mouseDown = false;
            setStyle("background-position", "0 90/512");
        }

        if (isFocused()) {
            if (!_textCursor.isVisible()) {
                _textCursor.setVisible(true);
            }
            setStyle("background-position", "0 120/512");
        } else {
            if (_textCursor.isVisible()) {
                _textCursor.setVisible(false);
            }
            setStyle("background-position", "0 90/512");
        }
        updateTextShift();
        super.update();
    }

    public void clicked(Vector2f mousePos) {
        _focused = true;

        if (_inputValue.length() > 0 && _inputText.getTextWidth() > 0) {
            Vector2f absolutePosition = _inputText.calcAbsolutePosition();
            float positionRelativeElement = absolutePosition.x + _inputText.getTextWidth() - mousePos.x;
            float averageSymbols = _inputText.getTextWidth() / _inputValue.length();

            int pos = Math.abs((int) (positionRelativeElement / averageSymbols) - _inputValue.length());

            if (pos > _inputValue.length()) {
                pos = _inputValue.length();
            } else if (pos < 0) {
                pos = 0;
            }
            _cursorPosition = pos;
        }

    }

    @Override
    public void processKeyboardInput(int key) {
        if (isFocused()) {
            if (key == Keyboard.KEY_BACK) {

                _cursorPosition--;

                if (_cursorPosition < 0) {
                    _cursorPosition = 0;
                }

                if (_inputValue.length() > 0) {
                    _prevInputValue = _inputValue.toString();
                    _inputValue.deleteCharAt(_cursorPosition);
                }
            } else if (key == Keyboard.KEY_LEFT) {
                _cursorPosition--;
                if (_cursorPosition < 0) {
                    _cursorPosition = 0;
                }
            } else if (key == Keyboard.KEY_RIGHT) {
                _cursorPosition++;
                if (_cursorPosition > _inputValue.length()) {
                    _cursorPosition = _inputValue.length();
                }
            } else {
                if (_inputValue.length() > _maxLength) {
                    return;
                }
                char c = Keyboard.getEventCharacter();
                if (c >= 'a' && c < 'z' + 1 || c >= '0' && c < '9' + 1 || c >= 'A' && c < 'Z' + 1 || c == ' ' || c == '_' || c == '.' || c == ',' || c == '!' || c == '-' || c == '(' || c == ')' || c == '"' || c == '\'' || c == ';' || c == '+') {
                    _prevInputValue = _inputValue.toString();
                    _inputValue.insert(_cursorPosition, c);
                    _cursorPosition++;
                }
            }
            _inputText.setText(_inputValue.toString());
            updateTextShift();
        }
    }

    public void keyPressed() {
        for (int i = 0; i < _inputListeners.size(); i++) {
            _inputListeners.get(i).keyPressed(this);
        }
    }

    /*
    * Get current input value
    */
    @Override
    public String getValue() {
        return _inputValue.toString();
    }

    /*
    * Clear _inputValue; set cursor position to "0"; set input text to "";
    */
    @Override
    public void clearData() {
        if (_inputValue.length() > 0) {
            _inputValue.delete(0, _inputValue.length() - 1);
        }
        _cursorPosition = 0;
        _inputText.setText("");
    }

    /*
    * Set current input value
    */
    public void setValue(String value) {
        _inputValue.setLength(0);
        _inputValue.append(value);
        _inputText.setText(value);
        updateTextShift();
    }

    /*
    * Set color text into input field
    */
    public void setTextColor(Color color) {
        _inputText.setColor(color);
    }

    /*
    * Moves the text and the graphic text cursor accourding to the cursor's position.
    *
    */
    private void updateTextShift() {
        float cursorPos = 0f;
        _textWidthInContainer = _inputText.getTextWidth() + _padding.x + _inputText.getPosition().x;
        if (_textWidthInContainer > getPosition().x + getSize().x || getPosition().x + _inputText.getPosition().x < 0) {
            _inputText.setPosition(new Vector2f(_inputText.getPosition().x + (getPosition().x + getSize().x - _textWidthInContainer), _inputText.getPosition().y));
        }
        if (_cursorPosition != _inputValue.length()) {
            cursorPos = (_inputText.getFont().getWidth(_inputValue.toString().substring(0, _cursorPosition)) - _textCursor.getSize().x + _inputText.getPosition().x) / 2;
        } else {
            cursorPos = (_textWidthInContainer - _padding.x) / 2;
        }
        _textCursor.setPosition(new Vector2f(cursorPos, _textCursor.getPosition().y));
    }

    @Override
    public boolean isFocused() {
        return _focused;
    }

    /*
    *Change the maximum number of characters that will be accepted as input
    */
    public void setMaxLength(int max) {
        _maxLength = max;
    }

    /*
    * Get the maximum number of characters that will be accepted as input
    */
    public int getMaxLength() {
        return _maxLength;
    }

}