Adobe 65010248 Scripting Guide - Page 29

C

HAPTER

3: Scripting Illustrator

Measurement units

29

Measurement units

Illustrator uses points as the unit of measurement for almost all distances. One inch equals 72 points. The

exception is values for properties like

kerning

,

tracking

, and the

aki

properties (used for Japanese text

composition), which use em units. (See

“

Em space units

” on page 29

.)

Illustrator uses points when communicating with your scripts

regardless of the current ruler units

. If your

script depends on adding, subtracting, multiplying, or dividing specific measurement values for units

other than points, it must perform any unit conversions needed to represent your measurements as

points. For example, to use inches for coordinates or measurement units, you must multiply all inch values

by 72 when entering the values in your script.

The following table shows conversion formulas for various units of measurement:

JavaScript provides the

UnitValue

object type, which offers unit-conversion utilities. For details, see

JavaScript Tools Guide

.

Em space units

Values that use em units instead of points are measured in thousandths of an em.

An em is proportional to the current font size. For example, in a 6-point font, 1 em equals 6 points; in a

10-point font, 1 em equals 10 points. In a 10-point font, a kerning value of 20 em units is equivalent to:

(20 units x 10 points) / 1000 units/em = 0.2 points

Page-item positioning and dimensions

Illustrator uses simple, two-dimensional geometry in the form of points to record the

position

of

pageitem

objects in a document. Every

page

item

object in a document has a

position

property that

defines a fixed point as a pair of page coordinates in the format [x, y]. The fixed point is the top-left corner

of the object’s bounding box.

For information on the types of objects that comprise the

page

items

collection, see

“

The artwork tree

” on

page 19

.

A point is designated by a pair of coordinates:

➤

The horizontal position,

x

➤

The vertical position,

y

Unit

Conversion formula

centimeters

28.346 points = 1 centimeter

inches

72 points = 1 inch

millimeters

2.834645 points = 1 millimeter

picas

12 points = 1 pica

Qs

0.709 point = 1 Q (1 Q equals 0.23 millimeter)

Section	Page
Introduction	6
What is scripting?	6
Why use scripting?	6
What about actions?	6
Script support in Adobe Illustrator CS4	7
ExtendScript features	7
ExtendScript tools	7
Script file extensions	7
Viewing sample scripts	8
Viewing the object model	8
Viewing the JavaScript object model	8
Viewing the AppleScript object model	8
Viewing the VBScript object model	9
Executing scripts	9
Installing scripts in the Scripts menu	10
Executing scripts from the Other Scripts menu item	10
Startup scripts (.jsx scripts only)	10
Application-specific startup scripts folder	10
General startup scripts folder	11
Changes since CS3	11
Known issues	16
The Illustrator Scripting Object Model	17
Object-naming conventions	18
Top-level (containing) objects	18
Application	18
Document	19
Layer	19
The artwork tree	19
Art styles	20
Color objects	21
Text objects	21
Text frames	21
Text geometry	22
Objects that represent text content	22
Text ranges	23
Text styles	23
Dynamic objects	24
Symbols	24
Transformations	24
Scripting Illustrator	25
Launching and quitting Illustrator from a script	25
Launching and activating Illustrator	25
AppleScript	25
JavaScript	25
VBScript	25
Quitting Illustrator	26
AppleScript	26
JavaScript	26
VBScript	26
Working with objects	26
Getting the frontmost document or layer	26
Creating new objects	26
Collection objects	27
AppleScript	27
JavaScript	27
VBScript	28
Selected objects	28
Selecting text	28
Selecting art items	28
Referring to selected art items	28
Notes on renaming objects stored in the application’s panels	28
Measurement units	29
Em space units	29
Page-item positioning and dimensions	29
Art item bounds	30
Paths and shapes	31
User-interaction levels	31
AppleScript	31
JavaScript	32
VBScript	32
Printing Illustrator documents	32
Scripting with AppleScript	33
For more information	33
Your first Illustrator script	33
Adding features to “Hello World”	34
Object references	34
Obtaining objects from documents and layers	35
Creating new objects	35
Working with selections	35
Selecting artwork objects	36
Working with text frames	36
Threaded frames	36
Threaded frames make one story object	37
Creating paths and shapes	37
Paths	37
Specifying a series of x-y coordinates	37
Using path point objects	37
Combining path point types	38
Shapes	38
Write-once access	39
Creating a rectangle	39
Creating a polygon	39
Scripting with JavaScript	40
For more information	40
Your first Illustrator script	40
Adding features to “Hello World”	41
Working with methods in JavaScript	41
Accessing and referencing objects	42
Referencing the application object	42
Accessing objects in collections	42
Creating new objects	43
Working with selections	44
Selecting artwork objects	44
Working with text frames	44
Threaded frames	44
Threaded frames make a single story object	45
Creating paths and shapes	45
Paths	45
Specifying a series of x-y coordinates	45
Using pathPoint objects	45
Combining path point types	46
Shapes	46
Creating a rectangle	47
Creating a polygon	47
Scripting with VBScript	48
For more information	48
Your first Illustrator script	48
Adding features to “Hello World”	49
Accessing and referencing objects	49
Obtaining objects from collections	49
Creating new objects	50
Working with selections	50
Selecting artwork objects	50
Working with text frames	51
Threaded frames	51
Threaded frames make a single story object	51
Creating paths and shapes	51
Paths	51
Specifying a series of x-y coordinates	52
Using path point objects	52
Combining path-point types	53
Shapes	53
Creating a rectangle	53
Creating a polygon	54
Working with enumeration values	54

Adobe 65010248 Scripting Guide - Page 29

Measurement units, Em space units, item positioning and dimensions

Page 29 highlights