Lua Programming: Difference between revisions

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[[Image: See-the-link-here |thumb||right| [http://i.imgur.com/LTznh.jpg The Hexadecimal view of all the api functions, readable in an extraded phoenix.raw file]]]
The TI-Nspire allows, since OS v3.0, users to run Lua scripts.


==Prerequisites==


The TI-Nspire allows, since OS v3.0, programming with the Lua language through a hidden application "TI.ScriptApp".
Lua is only supported starting from OS v3.0.1. You can create Lua applications using the built-in script editor in the TI-Nspire computer software or one of the following third-party tools:
 
This page describes how to setup a Lua development environment and documents the currently known Lua functions for the Nspire, and a brief description of how to use the functions.
 
Note: Neither the ''io'' nor ''os'' libraries are present for the TI-Nspire, which seems to be running a light version of Lua 5.1.4.
 
Here's a dump of a lot of functions available in the API : [http://adriweb.free.fr/upload/ti/dump.html Link to the dump].
 
==Prerequisites==


Lua is only supported starting from OS v3.0.1. Creating Lua scripts is currently not officially supported by TI, you need one of the following third-party tools to convert Lua scripts to TI-Nspire documents:
'''For any OS''':
*[https://github.com/ndless-nspire/Luna Luna] (cross-platform) [[https://www.omnimaga.org/news/'luna'-is-here-and-converts-your-lua-files-into-3-0-2-compatible-tns-files/ forum thread]]
'''For OS < 3.0.1''': these tools won't work with the OS 3.0.2 since the format used is now blocked
*[http://www.ticalc.org/archives/files/fileinfo/437/43704.html LUAtoTNS.sh] (bash script, works on Linux, Mac OS and Unix, or Windows + Cygwin or Windows + MSYS).
*[http://www.ticalc.org/archives/files/fileinfo/437/43704.html LUAtoTNS.sh] (bash script, works on Linux, Mac OS and Unix, or Windows + Cygwin or Windows + MSYS).
*[http://www.mirari.fr/KbOD maketns.py] (Python script, cross-platform)
*[http://www.mirari.fr/KbOD maketns.py] (Python script, cross-platform)
*[http://www.omnimaga.org/index.php?action=downloads;sa=view;down=651 lua2ti] (Windows + .NET Framework v4.0)
*[https://www.omnimaga.org/files/User-Contributed-Calculator-Games-amp-Development-Tools/TI-Nspire-amp-TI-Nspire-CAS/TI-Nspire-Programming-Tools/lua2ti.zip lua2ti] (Windows + .NET Framework v4.0)
*[http://www.omnimaga.org/index.php?action=downloads;sa=view;down=652 lua2ti_linux] (Linux (No longer requires Mono, it is now a native Linux binary!))
*[https://www.omnimaga.org/files/User-Contributed-Calculator-Games-amp-Development-Tools/TI-Nspire-amp-TI-Nspire-CAS/TI-Nspire-Programming-Tools/lua2ti_linux.zip lua2ti_linux] (Linux (No longer requires Mono, it is now a native Linux binary!))
You may also want to install Lua [http://www.lua.org/download.html on your computer]: <tt>luac -p</tt> can be used to check the syntax of your script before running it on a TI-Nspire or an emulator.
You may also want to install Lua [https://www.lua.org/download.html on your computer]: <tt>luac -p</tt> can be used to check the syntax of your script before running it on a TI-Nspire or an emulator.
 
==Standard Library==
 
( This has been taken from [http://www.wowwiki.com/Lua_functions a WoWWiki page] - See the full, official documentation [http://www.lua.org/manual/5.1/manual.html here] )
 
*'''assert'''(value[, errormsg]) - asserts a value evaluates to true. If it is, returns value, otherwise causes a Lua error to be thrown.
*'''getfenv'''(function or integer) - Returns the table representing the stack frame of the given function or stack level.
*'''getmetatable'''(obj, mtable) - Returns the metatable of the given table or userdata object.
*'''next'''(table, index) - Returns the next key, value pair of the table, allowing you to walk over the table.
*'''newproxy'''(boolean or proxy) - Creates a userdata with a sharable metatable.
*'''select'''(index, list) - Returns the number of items in list or the value of the item in list at index.
*'''setfenv'''(function or integer, table) - Sets the table representing the stack frame of the given function or stack level.
*'''setmetatable'''(obj, mtable) - Sets the metatable of the given table or userdata object.
*'''type'''(var) - Returns the type of variable as a string, "number", "string", "table", "function" or "userdata".
*'''unpack'''(table[, start][, end]) - Returns the contents of its argument as separate values.
*'''xpcall'''(func, err) - Returns a boolean indicating successful execution of func and calls err on failure, additionally returning func's or err's results.
 
==Concepts and Basics==
 
This part will explain you how the Lua actually works inside the OS and help you to figure out what you're doing when you write a script for the TI-Nspire. Before reading this, you have to know all about the Lua basics.
 
The Lua is an interpreted script language which means that it isn't as fast as ASM/C programs, but is still better than the TI-BASIC.
One good thing is that this language is in a complete harmony with the OS with basic events and a powerfull graphic context.
First, we have to understand how this works. Basicly the script is launched before the executive engine. This means that we can neither evaluate expressions nor use some of the standard API (like platform, var) until the engine is launched. Here is a call summary :
 
*Launch string library
*Launch math library
* ...
*Open and launch User's Lua script
*...
*Launch var API (store, recall, ...)
*Launch platform API (window, gc, ...)
*...
*Link events (pseudo code)
while(Exit)
------- Some OS routines here
  ---- Begin of Event link
buffer:captureDataFromKeyPad() --  (N) some underground routines to catch events
if buffer.charInput ~= "" then --  (N)
on.charIn(buffer.charInput)
buffer.charInput= "" --  (N)
end
if buffer.arrowKey ~= "" then --  (N)
on.arrowKey(buffer.arrowKey)
buffer.arrowKey = "" --  (N)
end
----- etc ...
if platform.window.isInvalidate then
platform.gc():purge() --  (N) Empty buffer before starting to draw
on.paint(platform.gc())   -- save all the things we have to draw
platform:paint()   --  (N) draw all those things
platform.window.isInvalidate = false -- say that the window has been drawn
end
----- End of Event link
end
''Note : the (N) commented line only indicates the meaning of the routine. Those functions don't really exist.''
 
Now we can understand how everything is linked, just by a main loop. This helps you to understand that you don't have to code a loop yourself, because the screen wouldn't be refreshed. This also helps to see when the screen gets refreshed. In other words, we cannot use niether '''gc''' nor '''platform.gc()''' (which are the same) in order to draw somthing on the screen if we are outside of '''on.paint()''' (except if your outside function is called within on.paint() ). This also means that we don't need to pass '''gc''' as parameter, because we can rather use '''platform.gc()''' for any functions called within on.paint(). This is exactly what [https://github.com/adriweb/BetterLuaAPI-for-TI-Nspire/blob/master/BetterLuaAPI.lua the BetterLuaAPI library for Nspire] does.
 
Here is an example of a simple Lua program that displays a message only when a key is pressed (and let the screen blank otherwise).
 
function on.paint(gc)
if message then
gc:setFont("sansserif", "r", 10) -- initialize font drawing
gc:drawString(message, 0, 0, "top") -- display the message at (0, 0) coordinates
message = nil -- erase the message
timer.start(1) -- start a timer to exit on.paint() but keep in mind that we have to redraw the screen
end
end
function on.timer()
timer.stop()
platform.window:invalidate()
end
function on.charIn(ch)
message = "Hello World !" -- store a message
platform.window:invalidate() -- force display
end
 
When you open the document, the script is read once. It initializes and overwrites all the functions and globals with the ones you defined. Thus, '''message''' is nil. Once the '''on.paint()''' event is called, '''message''' is nil, thus, nothing is done. When you press a key that calls '''on.charIn()''' (see below for more information), '''message''' is now "Hello World" and we tell the '''platform''' that the screen has to be refreshed. Then, '''on.paint()''' is called again, '''message''' is not nil then we display it, erase '''message''' and launch a timer. Why is that ? Because if we call '''platform.window:invalidate()''' right there, we won't refresh the screen. Why again ? Just look at the pseudo-code above. We set the window as drawn after each call of on.paint(). Thus a timer is necessary to manually recall '''on.paint()''' and exit the '''on.paint()''' function to draw the screen. When the timer is ended, '''on.timer()''' is called and we refresh the screen. The screen is then redrawn but there is nothing to draw because '''message''' is nil. Thus, the graphic context lets the screen blank.
 
==GC (as in Graphics Context)==
 
Note: You need to add “gc:” before each of these commands in order to use them. ex. '''gc:setAlpha(...)'''.
You can also call gc like this : '''platform.gc():setAlpha(...)'''. Then you can use the gc library in a function where gc is not passed as an argument. but this function *has* to be called within '''on.paint(gc)'''
 
The maximum screen resolution available to Lua programs is 318 by 212 pixels.
 
*'''begin''' -
*'''clipRect''' -
*'''drawArc'''(x, y, width, height, start angle, finish angle) Note, to draw a circle, use drawArc(x - diameter/2, y - diameter/2, diameter,diameter,0,360) where x and y are the coordinates of the middle.
*'''drawImage'''(image,x,y) First argument in format “[[TI.Image]]”, x and y the coords.
*'''drawLine'''(xstart, ystart, xend, yend) Draws a line starting at the point (xstart,ystart) and ending at the point (xend, yend)
*'''drawPolyLine'''(int list1 [,int list2, .., int listN]) Draws a shape from a list contaning successively the x and y coordinates of each point the line have to draw.
For example
drawPolyLine({0,0, 0,100, 100,100, 100,0, 0,0})
and
drawRect(0,0,100,100)
do the same. If there are multiple argument (which can be 4 elements list to represent lines), each list has to contain an even number of element.
*'''drawRect'''(x, y, xwidth, yheight) Draws a rectangle at (x,y) with the “x” side being “xwidth” long and the “y” side being “yheight” long
*'''drawString'''(string, x, y, PositionString) PositionString is the string’s anchor point and can be “bottom”, “middle”, or “top”.
*'''fillArc'''(x, y, width, height, start angle, finish angle) see drawArc
*'''fillPolygon'''(int list1 [,int list2, .., int listN]) see drawPolyLine
*'''fillRect'''(x, y, width, height) see drawRect
*'''finish''' -
*'''getStringHeight'''(string)
*'''getStringWidth'''(string)
*'''isColorDisplay''' Bool (Read-only) Returns 1 if color, 0 if not.
*'''setAlpha'''(int) - where the argument is an int between 0 and 255. Sets the transparency.
*'''setColorRGB'''(red, green, blue) RGB values are integers, from 0 to 255.
*'''setFont'''(font, type, size), with font : {“sansserif”, "serif", ..}, type {“b”, “r”, “i”}, size(int)
*'''setPen'''(size, smooth) size {“thin”, “medium”, "thick", "dotted", "dashed"}, smooth {“smooth”, ..}
 
==platform==
These are mainly read-only. These work by writing "'''platform.'''" in front of them. Example : "'''platform.window:invalidate()'''"
*'''apilevel()''' : Returns the version of the API. Currently (OS 3.0.1) returns 1.0.0.
*'''window'''
: *'''width()''' - Returns the width of the window. Ex : ''platform.window:height()''
: *'''height()''' - Returns the height of the window
: *'''invalidate()''' - Repaints the window (it calls '''on.paint(gc)''')
*''' isDeviceModeRendering()''' Returns true or false whether the unit is "rendering" or not
*'''gc''' - Other way to call '''gc'''. Use it like that : '''platform.gc():setAlpha(...)''' for example. This is useful when you're in a function outside '''on.paint(gc)''' (but this function has to be called within on.paint(gc).
*'''isColorDisplay()''' Returns ''true'' if the unit the code is being run on has a color display (-> Nspire CX), and ''false'' otherwise.
 
==cursor==
*'''hide'''() - hides the cursor (mouse pointer)
*'''set'''(string) - string can be one of those : (interrogation, crosshair, text, pointer, link select, diag resize, wait busy, hollow pointer, rotation, pencil, zoom box, arrow, zoom out, dotted arrow, clear, animate, excel plus, mod label, writing, unavailable, resize row, resize column, drag grab, hand open, hand close, hand pointer, zoom in, dilation, translation).
*'''show'''() - Shows the cursor on screen
 
==document==
*'''markChanged'''() - Flag the document as "changed" so the user has to save it after using it.


==clipboard==
==API==
*'''addText'''()
*'''getText'''()


==locale==
The documentation is now maintained in the "[http://wiki.inspired-lua.org Inspired Lua Wiki]".
*'''name'''() - Returns the current language the calculator is set in, formatted as ISO-639 (i.e : "fr", "en", "it" ...).
Please go there in order to have a full detailed documentation based on TI's information.


==image==
==XML==
*'''__gc'''() - Do not use ! Causes crash : ''(Invalid memory access of location 0x0 eip=0x465cc7ac / Bus error)''
*'''copy'''()
*'''height'''()
*'''new'''() - Creates a new image
*'''width'''()


==timer==
===Basic structure===
*'''getMilliSecCounter'''() - Returns the millisecs elapsed since the timer.start(int)
*'''start'''(int) - Starts a timer with 1 second.
*'''stop'''() - Stops a timer


==toolpalette==
<syntaxhighlight lang="xml">
*'''enable'''(string)
<wdgt
*'''enableCopy'''()
    xmlns:sc="urn:TI.ScriptApp" type="TI.ScriptApp" ver="1.0">
*'''enableCut'''()
*'''enablePaste'''()
*'''register'''(table)


==var==
    <sc:mFlags>1024</sc:mFlags>
*'''list'''() - returns a list of all the variables in the entire Activity
    <sc:value>8</sc:value>
*'''monitor'''() - ?
    <sc:cry>0</sc:cry>
*'''recall'''(string) - returns the variable value which name is given in parameter
    <sc:legal>none</sc:legal>
*'''recallstr'''(string) - returns the variable value converted to string which name is given in parameter
    <sc:schk>false</sc:schk>
*'''store'''(string, value) - store in the variable, which name is given in parameter, the value
*'''unmonitor'''() - ?


==Events==
    <sc:md>
        <sc:mde name="_VER" prop="134217728">1:1</sc:mde>
        <sc:mde name="TITLE" prop="2147549184">Hello</sc:mde>
        <sc:mde name="TARAL" prop="134217728">2:5</sc:mde>
    </sc:md>


*'''on.paint'''(gc) is called when the GUI is painted. 'gc' is the Graphics Context (see above)
    <sc:script version="33882629" id="1">
*'''on.resize'''() is called when the window is rezised
-- Lua script, XML encoded
*'''on.timer'''() is called when the timer has been finished. Here an example of using timer to play an animation :  
    </sc:script>
x = 1
animating = false
function on.paint(gc)
gc:setFont("sansserif", "r", 10)
gc:drawString(tostring(x), 0, 0, "top")
if animating then
x = x + 1
timer.start(0.5)
end
end
function on.charIn(ch)
animating = not animating -- switch state
platform.window:invalidate() -- recall graph engine
end
function on.timer()
timer.stop()
platform.window:invalidate() -- recall graph engine
end


----
    <sc:state>
*'''on.arrowKey'''(key) is called when an '''arrow key''' from the clickPad/TouchPad is pressed (right, left, up, down)
        return {} -- Lua save state
*'''on.arrowLeft'''() is called when the '''left''' arrow is pressed
    </sc:state>
*'''on.arrowRight'''() is called when the '''right''' arrow is pressed
</wdgt></syntaxhighlight>
*'''on.arrowUp'''() is called when the up '''arrow''' is pressed
*'''on.arrowDown'''() is called when the '''down''' arrow is pressed
----
*'''on.up'''() -- probably for the touchpad up motion
*'''on.down'''() -- probably for the touchpad down motion
----
*'''on.enterKey'''() is called when the '''enter''' key is pressed.
*'''on.escapeKey'''() is called when the '''escape''' key is pressed.
*'''on.tabKey'''() is called when the '''tab''' key is pressed.
*'''on.deleteKey'''() is called when the '''delete''' key is pressed.
*'''on.backspaceKey'''() is called when the '''clear''' key is pressed.
*'''on.returnKey'''() is called when the '''return''' key is pressed.
*'''on.contextMenu'''() is called when the combo-key '''Ctrl Menu''' is pressed.
*'''on.backtabKey'''() is called when the combo-key '''Maj Tab''' is pressed.
*'''on.clearKey'''() is called when the combo-key '''Ctrl Clear''' is pressed.
*'''on.help'''() is called when the combo-key '''Ctrl H''' is pressed.


*'''on.charIn'''(string) is called when the Nspire detects a non arrow key being pressed. ch is the character it detect. If you want to auto start an event in the file linked to key r(like a reset) put on.charIn(“r”) where you want. This Lua program lets you display the value of a valid non arrow key :
===Script tags===


c = “”
====sc:script====
function on.charIn(ch)
c = ch
platform.window:invalidate() -- we force the screen draw
end
function on.paint(gc)
gc:setFont(“sansserif”, “r”, 10)
gc:drawString(c, 0, 0, “top”)
end


----
{| class="wikitable"
*'''on.blink'''() ? is called when the focus is lost on the page (like launching the document, changing page etc...)
|-
----
! scope="col"| attribute
*'''on.deactivate'''() ? is called when the focus is lost on the page (like launching the document, changing page etc...)
! scope="col"| description
*'''on.activate'''() ? is called when the focus is on the page (like launching the document, changing page etc...)
|-
----
| version
*'''on.mouseDown'''(x, y) is called when we press the left mouse button. X and Y are the pressed point coordinates.
| taral and reqal versions, one byte per digit (for older OSes?)
*'''on.mouseUp'''() is called when we release the left mouse button.
|-
*'''on.mouseMove'''() is called when the mouse moves
| id
*'''on.grabDown'''() ? (software only ?)
| 1 = normal script, 2 & 3 = Question and Answer
*'''on.grabMove'''() ? (software only ?)
|}
*'''on.grabUp'''() ? (software only ?)
*'''on.rightMouseDown'''() ? (software only ?)
*'''on.rightMouseUp'''() ? (software only ?)
----
*'''on.cutEnabled'''() ? (software only ?)
*'''on.copyEnabled'''() ? (software only ?)
*'''on.pasteEnabled'''() ? (software only ?)
*'''on.cut'''() ? (software only ?)
*'''on.copy'''() ? (software only ?)
*'''on.paste'''() ? (software only ?)
----


==D2Editor==
===Script metadata configuration===
*'''newRichText'''() creates a new RichText object (default values : x, y, width, height = 0)
*'''resize'''(width, height)
*'''move'''(x, y)
*'''setText'''(string)
*'''getText'''() returns the RichText value
*'''setReadOnly'''(bool) bool : true/false : If true, the content becomes read-only, i.e. non-editable.
*'''setFormattedText'''() - ?
Example of a valid function using the D2Editor
function createRichTextBox
box = D2Editor.newRichText()
box:move(50, 50)
box:resize(50, 50)
box:setText("Hello World !")
end


==External Links==
{| class="wikitable"
An interesting page about LUA code optimization, that can be really useful, especially for calculators : [http://trac.caspring.org/wiki/LuaPerformance Lua Performance]
|-
! scope="col"| Name
! scope="col"| Prop
! scope="col"| Description
! scope="col"| Example
|-
| TARAL
| 134217728
| TARget ApiLevel
| <code><nowiki><sc:mde name="TARAL" prop="134217728">2:2</sc:mde></nowiki></code>
|-
| REQAL
| 134217728
| REQuired ApiLevel
| <code><nowiki><sc:mde name="REQAL" prop="134217728">2:0</sc:mde></nowiki></code>
|-
| _VER
| 134217728
| TNS Version
| <code><nowiki><sc:mde name="_VER" prop="134217728">1:1</sc:mde></nowiki></code>
|-
| TITLE
| 2147549184
| ScriptApp title
| <code><nowiki><sc:mde name="TITLE" prop="2147549184">Hello</sc:mde></nowiki></code>
|-
| -
| 270532608
| Lua meta script
| <code><nowiki><sc:mde name="TEST" prop="270532608">--lua code</sc:mde></nowiki></code>
|-
| BLERQ
| 134217728
| BLE ReQuire - require ble libs
| <code><nowiki><sc:mde name="BLERQ" prop="134217728">1</sc:mde></nowiki></code>
|-
| _FFunc
| -
| FailMe function (error catching)
| Not known
|-
| _TRACE
| -
| Trace/log?
| Not known
|}

Latest revision as of 14:48, 21 June 2019

The TI-Nspire allows, since OS v3.0, users to run Lua scripts.

Prerequisites

Lua is only supported starting from OS v3.0.1. You can create Lua applications using the built-in script editor in the TI-Nspire computer software or one of the following third-party tools:

For any OS:

For OS < 3.0.1: these tools won't work with the OS 3.0.2 since the format used is now blocked

  • LUAtoTNS.sh (bash script, works on Linux, Mac OS and Unix, or Windows + Cygwin or Windows + MSYS).
  • maketns.py (Python script, cross-platform)
  • lua2ti (Windows + .NET Framework v4.0)
  • lua2ti_linux (Linux (No longer requires Mono, it is now a native Linux binary!))

You may also want to install Lua on your computer: luac -p can be used to check the syntax of your script before running it on a TI-Nspire or an emulator.

API

The documentation is now maintained in the "Inspired Lua Wiki". Please go there in order to have a full detailed documentation based on TI's information.

XML

Basic structure

<wdgt
    xmlns:sc="urn:TI.ScriptApp" type="TI.ScriptApp" ver="1.0">

    <sc:mFlags>1024</sc:mFlags>
    <sc:value>8</sc:value>
    <sc:cry>0</sc:cry>
    <sc:legal>none</sc:legal>
    <sc:schk>false</sc:schk>

    <sc:md>
        <sc:mde name="_VER" prop="134217728">1:1</sc:mde>
        <sc:mde name="TITLE" prop="2147549184">Hello</sc:mde>
        <sc:mde name="TARAL" prop="134217728">2:5</sc:mde>
    </sc:md>

    <sc:script version="33882629" id="1">
	-- Lua script, XML encoded
    </sc:script>

    <sc:state>
        return {} -- Lua save state
    </sc:state>
</wdgt>

Script tags

sc:script

attribute description
version taral and reqal versions, one byte per digit (for older OSes?)
id 1 = normal script, 2 & 3 = Question and Answer

Script metadata configuration

Name Prop Description Example
TARAL 134217728 TARget ApiLevel <sc:mde name="TARAL" prop="134217728">2:2</sc:mde>
REQAL 134217728 REQuired ApiLevel <sc:mde name="REQAL" prop="134217728">2:0</sc:mde>
_VER 134217728 TNS Version <sc:mde name="_VER" prop="134217728">1:1</sc:mde>
TITLE 2147549184 ScriptApp title <sc:mde name="TITLE" prop="2147549184">Hello</sc:mde>
- 270532608 Lua meta script <sc:mde name="TEST" prop="270532608">--lua code</sc:mde>
BLERQ 134217728 BLE ReQuire - require ble libs <sc:mde name="BLERQ" prop="134217728">1</sc:mde>
_FFunc - FailMe function (error catching) Not known
_TRACE - Trace/log? Not known
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