| lcdui.canvas | ||
|---|---|---|
 | Hecl Java ME MIDP2.0 Commands |  |
| lcdui.canvas | ||
|---|---|---|
| | Hecl Java ME MIDP2.0 Commands | |
lcdui.canvas — Creates a canvas
lcdui.canvas
[-autoflush
1
| 0
]
[-cmdbg
color
]
[-cmdfg
color
]
[-eventhandler
code
]
[-fullscreen
1
| 0
]
[-title title]
[-suppresskeys
1
| 0
]
$canvascmd-optname
]
[configure
-optname
optval
]
[flush
[x y width height]
]
[graphics]
[repaint]
[servicerepaints]
The lcdui.canvas command creates a canvas that can be used to draw arbitrary items, such as rectangles, text, circles, and respond to keyboard events. For an in-depth look at the Java code that this command is based on, see: javax.microedition.lcdui.game.GameCanvas
The options describing the canvas are as follows:
-autoflush: Takes a boolean
argument (1 or 0) indicating FIXME
-cmdbg: Selects a background color for
the command background.
-cmdfg: Selects a background color for
the command foreground.
-eventhandler: The Hecl code to execute
when an event is generated.
-fullscreen: A boolean switch
specifying whether to run in "full screen" mode.
"Full screen" mode means that commands, which would
normally be accessible via certain keys on the cell
phone, are not accessible, and that those keys
generate regular events instead of calling commands.
-suppresskeys: A boolean switch
specifying whether to suppress key events or not.
Suppressing these events, if the application does not
need to keep track of them, may improve performance
some.
The lcdui.canvas command returns an object that is itself a command, and can be called with several subcommands:
flush: With no argument, flushes
(displays) the off-screen buffer to the visible
display. With arguments x y
width height
graphics: Returns a graphics object that acts as a command to manipulate the Canvas' graphics buffer.
repaint: Repaints the entire canvas.
servicerepaints: Forces any repaints that haven't occured yet to be performed immediately.
set canvas [lcdui.canvas -title "Test Canvas" -commandaction backToMainMenu \
-eventhandler canvasEvents]
set graphics [$canvas graphics]
$graphics frect [list 10 10] [list 10 80]
$graphics frect [list 80 10] [list 10 80]
$graphics frect [list 10 50] [list 80 10]
$canvas setcurrent
Live example: http://www.heclbuilder.com/scripts/show/142
| |  | |
| lcdui.alert |  | lcdui.choicegroup |