lejos.utility

Class TextMenu

java.lang.Object

lejos.utility.TextMenu

public class TextMenu
extends java.lang.Object

Displays a list of items. The select() method allows the user to scroll the list using the right and left keys to scroll forward and backward through the list. The location of the list , and an optional title can be specified.

Author:

Roger Glassey Feb 20, 2007

Field Summary

Fields

Modifier and Type	Field and Description
protected int	_height number of rows displayed; set by constructor, used by display()
protected java.lang.String[]	_items array of items to be displayed ;set by constructor, used by select();
protected int	_length effective length of items array - number of items before null
protected boolean	_quit boolean to cause select to quit
protected int	_startTime start time for select()
protected java.lang.String	_title optional menu title displayed immediately above the list of items
protected int	_topIndex index of the list item at the top of the list; set by constructor, used by select()
protected int	_topRow location of the top row of the list; set by constructor, used by display()
protected static int	BUTTON_POLL_INTERVAL Timout used for Button.waitForAnyPress(int) in select(int, int).
protected TextLCD	lcd
protected static char	SEL_CHAR identifies the currently selected item

Constructor Summary

Constructors

Constructor and Description
TextMenu(java.lang.String[] items) This constructor sets location of the top row of the item list to row 0 of the display.
TextMenu(java.lang.String[] items, int topRow) This constructor allows specification location of the item list .
TextMenu(java.lang.String[] items, int topRow, java.lang.String title) This constuctor allows the specfication of a title (of up to 16 characters) and the location of the item list The title is displayed in the row above the item list.

Method Summary

Modifier and Type	Method and Description
protected void	display(int selectedIndex, int topIndex) helper method used by select()
java.lang.String[]	getItems() Returns list of items in this menu;
void	quit() method to call from another thread to quit the menu
void	resetTimeout() Reset the timeout period.
int	select() Allows the user to scroll through the items, using the right and left buttons (forward and back) The Enter key closes the menu and returns the index of the selected item.
int	select(int selectedIndex) Version of select without timeout
int	select(int selectedIndex, int timeout) Allows the user to scroll through the items, using the right and left buttons (forward and back) The Enter key closes the menu and returns the index of the selected item.
void	setItems(java.lang.String[] items) set the array of items to be displayed
void	setTitle(java.lang.String title) set menu title.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

_topRow

protected int _topRow

location of the top row of the list; set by constructor, used by display()

_height

protected int _height

number of rows displayed; set by constructor, used by display()

_title

protected java.lang.String _title

optional menu title displayed immediately above the list of items

_items

protected java.lang.String[] _items

array of items to be displayed ;set by constructor, used by select();

_length

protected int _length

effective length of items array - number of items before null

_topIndex

protected int _topIndex

index of the list item at the top of the list; set by constructor, used by select()

SEL_CHAR

protected static final char SEL_CHAR

identifies the currently selected item

See Also:

Constant Field Values

_quit

protected boolean _quit

boolean to cause select to quit

_startTime

protected int _startTime

start time for select()

BUTTON_POLL_INTERVAL

protected static final int BUTTON_POLL_INTERVAL

Timout used for Button.waitForAnyPress(int) in select(int, int).

See Also:

Constant Field Values

lcd

protected TextLCD lcd

Constructor Detail

TextMenu

public TextMenu(java.lang.String[] items)

This constructor sets location of the top row of the item list to row 0 of the display.

TextMenu

public TextMenu(java.lang.String[] items,
                int topRow)

This constructor allows specification location of the item list .

TextMenu

public TextMenu(java.lang.String[] items,
                int topRow,
                java.lang.String title)

This constuctor allows the specfication of a title (of up to 16 characters) and the location of the item list
The title is displayed in the row above the item list.

Parameters:

items - - string array containing the menu items. No items beyond the first null will be displayed.

Method Detail

setTitle

public void setTitle(java.lang.String title)

set menu title.

Parameters:

title - the new title

setItems

public void setItems(java.lang.String[] items)

set the array of items to be displayed

Parameters:

items -

select

public int select()

Allows the user to scroll through the items, using the right and left buttons (forward and back) The Enter key closes the menu
and returns the index of the selected item.
The menu display wraps items that scroll off the top will reappear on the bottom and vice versa. The selectedIndex is set to the first menu item.

Returns:

the index of the selected item

select

public int select(int selectedIndex)

Version of select without timeout

select

public int select(int selectedIndex,
                  int timeout)

Allows the user to scroll through the items, using the right and left buttons (forward and back) The Enter key closes the menu
and returns the index of the selected item.
The menu display wraps items that scroll off the top will reappear on the bottom and vice versa. This version of select allows the selected index to be set when the menu is first displayed.

Parameters:

selectedIndex - the index to start the menu on

Returns:

the index of the selected item

quit

public void quit()

method to call from another thread to quit the menu

display

protected void display(int selectedIndex,
                       int topIndex)

helper method used by select()

getItems

public java.lang.String[] getItems()

Returns list of items in this menu;

Returns:

the array of item names

resetTimeout

public void resetTimeout()

Reset the timeout period.