/*
 * LCD2797X.java
 * 
 * Copyright © 2005, Ryan C. Payne. All Rights Reserved
 */
package stamp.peripheral.display.lcd.serial;

import stamp.core.CPU;
import stamp.core.Uart;


/**
 * This class is for the Parallax 27976/27977 Serial LCD Module
 * 
 * Revision History: Ver 1.0 - 07/24/05: Initial release
 * 
 * @author Ryan C. Payne (ryan-payne@comcast.net)
 * @version 1.0 July 24, 2005
 */
public class LCD2797X
{
    private Uart lcdUart; // uart control object

    /**
     * Display custom character 0
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_0 = 0x00;

    /**
     * Display custom character 1
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_1 = 0x01;

    /**
     * Display custom character 2
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_2 = 0x02;

    /**
     * Display custom character 3
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_3 = 0x03;

    /**
     * Display custom character 4
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_4 = 0x04;

    /**
     * Display custom character 5
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_5 = 0x05;

    /**
     * Display custom character 6
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_6 = 0x06;

    /**
     * Display custom character 7
     */
    private static final int CMD_DISPLAY_CUSTOM_CHAR_7 = 0x07;

    /**
     * Backspace/Left - The cursor is moved one position to the left. The
     * command doesn't erase the character.
     */
    private static final int CMD_BACKSPACE = 0x08;

    /**
     * Right - The cursor is moved one position to the right. The command
     * doesn't erase the character.
     */
    private static final int CMD_MOVE_RIGHT = 0x09;

    /**
     * Line Feed - The cursor is moved down one line. If on like 0, it goes to
     * line 1. If on line 1, it wraps around to line 0. The horizontal position
     * remains the same.
     */
    private static final int CMD_LINE_FEED = 0x0A;

    /**
     * Form Feed - The cursor is moved to position 0 on line 0 and the entire
     * display is cleared. Users must pause 5mS after this command.
     */
    private static final int CMD_FORM_FEED = 0x0C;

    /**
     * Carriage Return - If on line 0, the cursor is moved to position 0 on line
     * 1. If on line 1, it wraps around to position 0 on line 0.
     */
    private static final int CMD_CARRIAGE_RETURN = 0x0D;

    /**
     * Turn backlight on (only on model 27977)
     */
    private static final int CMD_BACKLIGHT_ON = 0x11;

    /**
     * Turn back light off (Default)
     */
    private static final int CMD_BACKLIGHT_OFF = 0x12;

    /**
     * Turn the display off
     */
    private static final int CMD_DISPLAY_OFF = 0x15;

    /**
     * Turn the display on, with the cursor off and no blink
     */
    private static final int CMD_DISPLAY_ON_CURSOR_OFF_BLINK_OFF = 0x16;

    /**
     * Turn the display on, with cursor off and character blink
     */
    private static final int CMD_DISPLAY_ON_CURSOR_OFF_BLINK_ON = 0x17;

    /**
     * Turn the display on, with cursor on and no blink (Default)
     */
    private static final int CMD_DISPLAY_ON_CURSOR_ON_BLINK_OFF = 0x18;

    /**
     * Turn the display on, with cursor on and character blink
     */
    private static final int CMD_DISPLAY_ON_CURSOR_ON_BLINK_ON = 0x19;

    /**
     * Move cursor to line 0, position 0
     */
    private static final int CMD_MOVE_LINE_0_POSITION_0 = 0x80;

    /**
     * Move cursor to line 0, position 1
     */
    private static final int CMD_MOVE_LINE_0_POSITION_1 = 0x81;

    /**
     * Move cursor to line 0, position 2
     */
    private static final int CMD_MOVE_LINE_0_POSITION_2 = 0x82;

    /**
     * Move cursor to line 0, position 3
     */
    private static final int CMD_MOVE_LINE_0_POSITION_3 = 0x83;

    /**
     * Move cursor to line 0, position 4
     */
    private static final int CMD_MOVE_LINE_0_POSITION_4 = 0x84;

    /**
     * Move cursor to line 0, position 5
     */
    private static final int CMD_MOVE_LINE_0_POSITION_5 = 0x85;

    /**
     * Move cursor to line 0, position 6
     */
    private static final int CMD_MOVE_LINE_0_POSITION_6 = 0x86;

    /**
     * Move cursor to line 0, position 7
     */
    private static final int CMD_MOVE_LINE_0_POSITION_7 = 0x87;

    /**
     * Move cursor to line 0, position 8
     */
    private static final int CMD_MOVE_LINE_0_POSITION_8 = 0x88;

    /**
     * Move cursor to line 0, position 9
     */
    private static final int CMD_MOVE_LINE_0_POSITION_9 = 0x89;

    /**
     * Move cursor to line 0, position 10
     */
    private static final int CMD_MOVE_LINE_0_POSITION_10 = 0x8A;

    /**
     * Move cursor to line 0, position 11
     */
    private static final int CMD_MOVE_LINE_0_POSITION_11 = 0x8B;

    /**
     * Move cursor to line 0, position 12
     */
    private static final int CMD_MOVE_LINE_0_POSITION_12 = 0x8C;

    /**
     * Move cursor to line 0, position 13
     */
    private static final int CMD_MOVE_LINE_0_POSITION_13 = 0x8D;

    /**
     * Move cursor to line 0, position 14
     */
    private static final int CMD_MOVE_LINE_0_POSITION_14 = 0x8E;

    /**
     * Move cursor to line 0, position 15
     */
    private static final int CMD_MOVE_LINE_0_POSITION_15 = 0x8F;

    /**
     * Move cursor to line 1, position 0
     */
    private static final int CMD_MOVE_LINE_1_POSITION_0 = 0x94;

    /**
     * Move cursor to line 1, position 1
     */
    private static final int CMD_MOVE_LINE_1_POSITION_1 = 0x95;

    /**
     * Move cursor to line 1, position 2
     */
    private static final int CMD_MOVE_LINE_1_POSITION_2 = 0x96;

    /**
     * Move cursor to line 1, position 3
     */
    private static final int CMD_MOVE_LINE_1_POSITION_3 = 0x97;

    /**
     * Move cursor to line 1, position 4
     */
    private static final int CMD_MOVE_LINE_1_POSITION_4 = 0x98;

    /**
     * Move cursor to line 1, position 5
     */
    private static final int CMD_MOVE_LINE_1_POSITION_5 = 0x99;

    /**
     * Move cursor to line 1, position 6
     */
    private static final int CMD_MOVE_LINE_1_POSITION_6 = 0x9A;

    /**
     * Move cursor to line 1, position 7
     */
    private static final int CMD_MOVE_LINE_1_POSITION_7 = 0x9B;

    /**
     * Move cursor to line 1, position 8
     */
    private static final int CMD_MOVE_LINE_1_POSITION_8 = 0x9C;

    /**
     * Move cursor to line 1, position 9
     */
    private static final int CMD_MOVE_LINE_1_POSITION_9 = 0x9D;

    /**
     * Move cursor to line 1, position 10
     */
    private static final int CMD_MOVE_LINE_1_POSITION_10 = 0x9E;

    /**
     * Move cursor to line 1, position 11
     */
    private static final int CMD_MOVE_LINE_1_POSITION_11 = 0x9F;

    /**
     * Move cursor to line 1, position 12
     */
    private static final int CMD_MOVE_LINE_1_POSITION_12 = 0xA0;

    /**
     * Move cursor to line 1, position 13
     */
    private static final int CMD_MOVE_LINE_1_POSITION_13 = 0xA1;

    /**
     * Move cursor to line 1, position 14
     */
    private static final int CMD_MOVE_LINE_1_POSITION_14 = 0xA2;

    /**
     * Move cursor to line 1, position 15
     */
    private static final int CMD_MOVE_LINE_1_POSITION_15 = 0xA3;

    /**
     * Define custom character 0. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_0 = 0xF8;

    /**
     * Define custom character 1. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_1 = 0xF9;

    /**
     * Define custom character 2. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_2 = 0xFA;

    /**
     * Define custom character 3. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_3 = 0xFB;

    /**
     * Define custom character 4. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_4 = 0xFC;

    /**
     * Define custom character 5. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_5 = 0xFD;

    /**
     * Define custom character 6. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_6 = 0xFE;

    /**
     * Define custom character 7. This command must be followed by eight data
     * bytes
     */
    private static final int CMD_DEFINE_CUSTOM_CHAR_7 = 0xFF;

    /**
     * Creates a new serial LCD display object
     * 
     * @param lcdUart TX uart object setup for LCD control
     */
    public LCD2797X(Uart lcdUart)
    {
        this.lcdUart = lcdUart;

        // Pause for 100 ms for start up delay
        CPU.delay(1000);
    }

    /**
     * Clears the display and the cursor is moved to position 0 on line 0
     */
    public void clearDisplay()
    {
        this.sendCommand(LCD2797X.CMD_FORM_FEED);

        // Pause the required 5 ms per data sheet
        CPU.delay(50);
    }

    /**
     * Turns the display off
     */
    public void displayOff()
    {
        this.sendCommand(LCD2797X.CMD_DISPLAY_OFF);
    }

    /**
     * Turns the display on using the 2797X's default cursor settings
     */
    public void displayOn()
    {
        this.sendCommand(LCD2797X.CMD_DISPLAY_ON_CURSOR_ON_BLINK_OFF);
    }

    /**
     * Turns the display on
     * 
     * @param cursor When <code>true</code> the cursor is displayed
     * @param blink When <code>true</code> the current character blinks
     */
    public void displayOn(boolean cursor, boolean blink)
    {
        if (cursor == false && blink == false)
        {
            this.sendCommand(LCD2797X.CMD_DISPLAY_ON_CURSOR_OFF_BLINK_OFF);
        }
        else if (cursor == true && blink == true)
        {
            this.sendCommand(LCD2797X.CMD_DISPLAY_ON_CURSOR_ON_BLINK_ON);
        }
        else if (cursor == true)
        {
            this.sendCommand(LCD2797X.CMD_DISPLAY_ON_CURSOR_ON_BLINK_OFF);
        }
        else
        {
            this.sendCommand(LCD2797X.CMD_DISPLAY_ON_CURSOR_OFF_BLINK_ON);
        }
    }

    /**
     * Turns the backlight on (27977 only)
     */
    public void backlightOn()
    {
        this.setBacklight(true);
    }

    /**
     * Turns the backlight off
     */
    public void backlightOff()
    {
        this.setBacklight(false);
    }

    /**
     * Sets the state of the backlight
     * 
     * @param isOn <code>true</code> to turn the backlight on
     *            <code>false</code> to turn the backlight off
     */
    public void setBacklight(boolean isOn)
    {
        if (isOn)
        {
            this.sendCommand(LCD2797X.CMD_BACKLIGHT_ON);
        }
        else
        {
            this.sendCommand(LCD2797X.CMD_BACKLIGHT_OFF);
        }
    }

    /**
     * Writes character on LCD at current cursor position
     * 
     * @param c Character to write on LCD
     */
    public void write(char c)
    {
        this.sendCommand(c);
    }

    /**
     * Writes string on LCD at current cursor position
     * 
     * @param s String to write on LCD
     */
    public void write(String s)
    {
        for (int i = 0; i < s.length(); i++)
        {
            this.write(s.charAt(i));
        }
    }

    /**
     * Writes string buffer on LCD at current cursor position
     * 
     * @param sb StringBuffer to write on LCD
     */
    public void write(StringBuffer sb)
    {
        for (int i = 0; i < sb.length(); i++)
        {
            this.write(sb.charAt(i));
        }
    }

    /**
     * Sets the cursor to the home position: line 0, position 0
     */
    public void home()
    {
        this.sendCommand(LCD2797X.CMD_MOVE_LINE_0_POSITION_0);
    }

    /**
     * Moves the cursor one position to the right. Contents of the position are
     * not erased.
     */
    public void moveRight()
    {
        this.sendCommand(LCD2797X.CMD_MOVE_RIGHT);
    }

    /**
     * Moves the cursor one position to the left. Contents of the position are
     * not erased.
     */
    public void moveLeft()
    {
        this.sendCommand(LCD2797X.CMD_BACKSPACE);
    }

    /**
     * Sends a carriage return to the LCD
     * 
     * If on line 0, the cursor is moved to position 0 on line 1. If on line 1,
     * it wraps around to position 0 on line 0.
     */
    public void carriageReturn()
    {
        this.sendCommand(LCD2797X.CMD_CARRIAGE_RETURN);
    }

    /**
     * Sends a line feed to the LCD
     * 
     * If on line 0, it goes to line 1. If on line 1, it wraps around to line 0.
     * The horizontal position remains the same.
     */
    public void lineFeed()
    {
        this.sendCommand(LCD2797X.CMD_LINE_FEED);
    }

    /**
     * Sets the cursor to a specified position. If an invalid line or position
     * is specified, the cursor is set to the home position
     * 
     * @param line 0 or 1
     * @param position 0 through 15
     */
    public void setPosition(int line, int position)
    {
        // Check for out of range values. If anything is fishy, send them home!
        if (line < 0 || line > 1 || position < 0 || position > 15)
        {
            this.home();
            return;
        }

        int location = LCD2797X.CMD_MOVE_LINE_0_POSITION_0 + (line * 20) + position;

        this.sendCommand(location);
    }

    /**
     * Displays the specified custom character
     * 
     * @param charIndex The index custom character to be displayed; 0 - 8
     */
    public void displayCustomChar(int charIndex)
    {
        // If the index is out of range, don't do anything
        if (charIndex >= 0 || charIndex <= 7)
        {
            this.sendCommand(LCD2797X.CMD_DISPLAY_CUSTOM_CHAR_0 + charIndex);
        }
    }

    /**
     * Defines a custom character
     * 
     * @param charIndex The index of the custom character to be defined; 0 - 8
     * @param bytes The array of bytes that define the custom character; must be
     *            an array of eight bytes
     */
    public void defineCustomChar(int charIndex, byte[] bytes)
    {
        // If the index is out of range, don't do anything
        if (charIndex >= 0 || charIndex <= 7)
        {
            // If the byte array does not contain eight bytes, don't do anything
            if (bytes.length == 8)
            {
                this.sendCommand(LCD2797X.CMD_DEFINE_CUSTOM_CHAR_0 + charIndex);

                for (int i = 0; i < 8; i++)
                {
                    this.sendCommand(bytes[i]);
                }
            }
        }
    }

    /**
     * Sends a command to the LCD display
     * 
     * @param command the command to send
     */
    private void sendCommand(int command)
    {
        this.lcdUart.sendByte(command);
    }
}// end class: LCD2797X