Activities/Turtle Art/Under the hood - Revision history

FGrose: moved Activities/TurtleArt/Under the hood to Activities/Turtle Art/Under the hood: deCamelCase

2012-07-23T15:37:30Z

moved Activities/TurtleArt/Under the hood to Activities/Turtle Art/Under the hood: deCamelCase

← Older revision		Revision as of 11:37, 23 July 2012
(No difference)

Walter: /* Modifying Turtle Art */

2011-06-17T01:39:12Z

Modifying Turtle Art

← Older revision		Revision as of 21:39, 16 June 2011
Line 70:		Line 70:
	that the icons should be the same size (55x55) as the others. (This is		that the icons should be the same size (55x55) as the others. (This is
	the default icon size for Sugar toolbars.)		the default icon size for Sugar toolbars.)

			=== How to write a plugin ===

			In Spanish: http://valentinbasel.fedorapeople.org/pdfs/turtle_art.pdf

Walter: /* Looking under the hood */

2011-05-19T16:41:03Z

Looking under the hood

← Older revision		Revision as of 12:41, 19 May 2011
Line 18:		Line 18:
	# block number		# block number
	# block name or [block name, block value]		# block name or [block name, block value]
	# x position (~~depreciated~~)		# x position (deprecated)
	# y position (~~depreciated~~)		# y position (deprecated)
	# list of connections to other blocks		# list of connections to other blocks

Walter: /* Modifying Turtle Art */

2011-05-19T16:39:30Z

Modifying Turtle Art

← Older revision		Revision as of 12:39, 19 May 2011
Line 57:		Line 57:
	help_string=_('turns the turtle 180 degrees'))		help_string=_('turns the turtle 180 degrees'))

	Next, you need to define what your block will do: def_prim takes 3 arguments: the primitive name, the number of arguments—0 in this case—and the function to call—in this case, the canvas.seth function to set the heading.		Next, you need to define what your block will do. def_prim takes 3 arguments: the primitive name, the number of arguments—0 in this case—and the function to call—in this case, the canvas.seth function to set the heading.

	self.tw.lc.def_prim('uturn', 0,		self.tw.lc.def_prim('uturn', 0,

Walter: /* Modifying Turtle Art */

2011-05-19T16:38:48Z

Modifying Turtle Art

← Older revision		Revision as of 12:38, 19 May 2011
Line 57:		Line 57:
	help_string=_('turns the turtle 180 degrees'))		help_string=_('turns the turtle 180 degrees'))

	# Next, you need to define what your block will do:		Next, you need to define what your block will do: def_prim takes 3 arguments: the primitive name, the number of arguments—0 in this case—and the function to call—in this case, the canvas.seth function to set the heading.
	# def_prim takes 3 arguments: the primitive name, the number of
	~~# of arguments, 0~~ in this ~~case, and~~ the function to ~~call, in~~ this
	# case, the canvas function to set the heading.
	self.tw.lc.def_prim('uturn', 0,		self.tw.lc.def_prim('uturn', 0,
	lambda self: self.tw.canvas.seth(self.tw.canvas.heading + 180))		lambda self: self.tw.canvas.seth(self.tw.canvas.heading + 180))

Walter: /* Modifying Turtle Art */ updated instructions for modifying TA

2011-05-19T16:36:57Z

Modifying Turtle Art: updated instructions for modifying TA

@@ Line 40: / Line 40: @@
 '''Note:''' As of Version 106, there is also support for plugins. If you can use the plugin mechanism to add support for additional devices, e.g., Arduino, or for making modifications such as are described below without making changes to the standard code base. (The advantage to the latter is that your changes will remain intact even after you upgrade to a newer version.)
-taconstants.py contains the constants that by-in-large determine the behavior of Turtle Art. Notably, the block palettes are defined below. If you want to add a new block to Turtle Art, it is generally a matter of modifying some tables below and then adding the primitive to talogo.py. For example, if we want to add a new turtle command, 'uturn', we'd make the following changes:
+The tabasics.py file contains the constants that by-in-large determine the behavior of Turtle Art. Notably, the block palettes are defined
-(1) We'd add 'uturn' to the PALETTES list of lists:
+Adding a new palette is simply a matter of:
- PALETTES = [['forward', 'back', 'clean', 'left', 'right', 'show',
+For example, if we want to add a new turtle command, 'uturn', we'd use the
-              'seth', 'setxy', 'heading', 'xcor', 'ycor', 'setscale',
+add_block method in the Palette class.
-              'arc', 'scale', 'left', 'top', 'right', 'bottom', 'uturn'],
+    palette.add_block('uturn',  # the name of your block
-             ['penup','pendown', 'setpensize', 'fillscreen', 'pensize',...
+                      style='basic-style',  # the block style
-(2) Then we'd add it to one of the block-style definitions. Since it takes
+    # Next, you need to define what your block will do:
-no arguments, we'd add it here:
+    # def_prim takes 3 arguments: the primitive name, the number of
- BASIC_STYLE = ['clean', 'penup', 'pendown', 'stack1', 'stack2', 'vspace',
+That's it. When you next run Turtle Art, you will have a 'uturn' block on the 'mypalette' palette.
-(3) Then we give it a name (Note the syntax _('string to be
+You will have to create icons for the palette-selector buttons. These
-translated') used by the language-internationalization system; also
+are kept in the icons subdirectory. You need two icons:
-note that the name is an array, as some blocks contain multiple
+mypaletteoff.svg and mypaletteon.svg, where 'mypalette' is the same
-strings.):
+string as the entry you used in instantiating the Palette class. Note
+that the icons should be the same size (55x55) as the others. (This is
- BLOCK_NAMES = {
+the default icon size for Sugar toolbars.)

Walter: /* Looking under the hood */

2011-03-01T23:07:37Z

Looking under the hood

← Older revision		Revision as of 19:07, 1 March 2011
Line 5:		Line 5:
	The json encoding of a repeat 4 forward 100 right 90 project:		The json encoding of a repeat 4 forward 100 right 90 project:

	[[0,"repeat",331,158,[null,1,2,null]],		[
	[1,["number","4"],417,167,[0,null]],		[0,"repeat",331,158,[null,1,2,null]],
	[2,"forward",426,207,[0,3,4]],		[1,["number","4"],417,167,[0,null]],
	[3,["number","100"],500,216,[2,null]],		[2,"forward",426,207,[0,3,4]],
	[4,"right",426,246,[2,5,null]],		[3,["number","100"],500,216,[2,null]],
	[5,["number","90"],500,255,[4,null]],		[4,"right",426,246,[2,5,null]],
	[-1,"turtle",0,0,0,0,50,5]]		[5,["number","90"],500,255,[4,null]],
			[-1,"turtle",0,0,0,0,50,5]
			]

	The basic structure of the encoding is a list of lists, where each block has these elements:		The basic structure of the encoding is a list of lists, where each block has these elements:

Walter: /* Looking under the hood */

2011-03-01T23:06:41Z

Looking under the hood

← Older revision		Revision as of 19:06, 1 March 2011
Line 5:		Line 5:
	The json encoding of a repeat 4 forward 100 right 90 project:		The json encoding of a repeat 4 forward 100 right 90 project:

	[[0,"repeat",331,158,[null,1,2,null]],[1,["number","4"],417,167,[0,null]],[2,"forward",426,207,[0,3,4]],[3,["number","100"],500,216,[2,null]],[4,"right",426,246,[2,5,null]],[5,["number","90"],500,255,[4,null]],[-1,"turtle",0,0,0,0,50,5]]		[[0,"repeat",331,158,[null,1,2,null]],
			[1,["number","4"],417,167,[0,null]],
			[2,"forward",426,207,[0,3,4]],
			[3,["number","100"],500,216,[2,null]],
			[4,"right",426,246,[2,5,null]],
			[5,["number","90"],500,255,[4,null]],
			[-1,"turtle",0,0,0,0,50,5]]

	The basic structure of the encoding is a list of lists, where each block has these elements:		The basic structure of the encoding is a list of lists, where each block has these elements:
Line 23:		Line 29:
	# pen shade		# pen shade
	# pen width		# pen width


	== Modifying Turtle Art ==		== Modifying Turtle Art ==

Walter: Created page with "==Looking under the hood== Turtle Art projects are stored as a .ta file contains a [http://docs.python.org/library/json.html json-encoded] serialization of the project. The jso..."

2011-02-28T00:30:31Z

Created page with "==Looking under the hood== Turtle Art projects are stored as a .ta file contains a [http://docs.python.org/library/json.html json-encoded] serialization of the project. The jso..."

New page

==Looking under the hood==

Turtle Art projects are stored as a .ta file contains a [http://docs.python.org/library/json.html json-encoded] serialization of the project.

The json encoding of a repeat 4 forward 100 right 90 project:

[[0,"repeat",331,158,[null,1,2,null]],[1,["number","4"],417,167,[0,null]],[2,"forward",426,207,[0,3,4]],[3,["number","100"],500,216,[2,null]],[4,"right",426,246,[2,5,null]],[5,["number","90"],500,255,[4,null]],[-1,"turtle",0,0,0,0,50,5]]

The basic structure of the encoding is a list of lists, where each block has these elements:
# block number
# block name or [block name, block value]
# x position (depreciated)
# y position (depreciated)
# list of connections to other blocks

Turtles are encoded at the end of the list:
# -1
# turtle or [turtle, turtle name]
# x position
# y position
# heading
# pen color
# pen shade
# pen width

== Modifying Turtle Art ==

Turtle Art is under the MIT license. You are free to use it and learn with it. You are also encourage to modify it to suit your needs or just for a further opportunity to learn.

Much of the motivation behind the Version 83 refactoring of the code was to make it easier for you to make changes. Most changes can be confined to two modules: taconstants.py and talogo.py. The former defines the blocks and palettes; the latter defines what code is executed by a block.

'''Note:''' As of Version 106, there is also support for plugins. If you can use the plugin mechanism to add support for additional devices, e.g., Arduino, or for making modifications such as are described below without making changes to the standard code base. (The advantage to the latter is that your changes will remain intact even after you upgrade to a newer version.)

taconstants.py contains the constants that by-in-large determine the behavior of Turtle Art. Notably, the block palettes are defined below. If you want to add a new block to Turtle Art, it is generally a matter of modifying some tables below and then adding the primitive to talogo.py. For example, if we want to add a new turtle command, 'uturn', we'd make the following changes:

(1) We'd add 'uturn' to the PALETTES list of lists:

PALETTES = [['forward', 'back', 'clean', 'left', 'right', 'show',
'seth', 'setxy', 'heading', 'xcor', 'ycor', 'setscale',
'arc', 'scale', 'left', 'top', 'right', 'bottom', 'uturn'],
['penup','pendown', 'setpensize', 'fillscreen', 'pensize',...

(2) Then we'd add it to one of the block-style definitions. Since it takes
no arguments, we'd add it here:

BASIC_STYLE = ['clean', 'penup', 'pendown', 'stack1', 'stack2', 'vspace',
'hideblocks', 'showblocks', 'clearheap', 'printheap', 'kbinput', 'uturn']

(3) Then we give it a name (Note the syntax _('string to be
translated') used by the language-internationalization system; also
note that the name is an array, as some blocks contain multiple
strings.):

BLOCK_NAMES = {
...
'uturn':[_('u-turn')],
...
}

(4) and a help-menu entry:

HELP_STRINGS = {
...
'uturn':_('change the heading of the turtle 180 degrees'),
...
}

(5) Next, we need to define it as a primitive for the Logo command
parser (generally just the same name):

PRIMITIVES = {
...
'uturn':'uturn',
...
}

(6) Since there are no default arguments, we don't need to do anything
else here. But we do need to define the actual function in talogo.py

DEFPRIM = {
...
'uturn':[0, lambda self: self.tw.canvas.seth(self.tw.canvas.heading+180)],
...
}

That's it. When you next run Turtle Art, you will have a 'uturn' block
on the Turtle Palette.

[[Image:TAuturn.png|300px]]

Adding a new palette is simply a matter of: (1) adding an additional entry to PALETTE_NAMES; (2) new list of blocks to PALETTES; and (3) an additional entry in COLORS. However you will have to: (4) create icons for the palette-selector buttons. These are kept in the icons subdirectory. You need two icons: yourpalettenameoff.svg and yourpalettenameon.svg, where yourpalettename is the same string as the entry you added to the PALETTE_NAMES list. Note that the icons should be the same size (55x55) as the others. This is the default icon size for Sugar toolbars.