Adobe 23101764 Scripting Guide - Page 12

Photoshop CS Scripting Guide

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2

Scripting basics

2.1 Documents as objects

If you use Photoshop, then you create documents, layers, channels and design elements and

probably think of a Photoshop document as a series of layers and channels — or objects.

Automating Photoshop with scripting requires the same object-oriented type of thinking.

The heart of a scriptable application is the object model. In Photoshop, the object model is

comprised of documents, layers and channels. Each object has its own special properties, and

every object in a Photoshop document has its own identity.

This chapter covers the basic concepts of scripting within this object-oriented environment.

2.2 Object model concepts

The terminology of object-oriented programming can initially be a formidable obstacle to

understanding. “Objects” belong to “classes” and have “properties” you manipulate using

“commands” (AppleScript) or “methods” (Visual Basic and JavaScript). What do these words

mean in this context?

It makes sense to think about objects and their properties as components of an object model.

Imagine that you live in a house that responds to your commands. The house is an object, and

its properties might include the number of rooms, the color of the exterior paint or the date of

its construction.

Your house can also contain other objects within. Each room, for example, is an object in the

house, while each window, door, or appliance is an object inside of the room. And each object

can respond to various commands according to its capabilities.

Now apply this object model concept to Photoshop. The Photoshop application is the house,

its documents are the rooms, and the objects in your documents are the windows and doors.

You can tell Photoshop documents to add and remove objects or manipulate individual

properties like color, size and shape. Actions can also be performed -- windows and doors, for

example, may open and close.

2.2.1

Object classes

Objects with the same properties and behaviors are grouped into “classes.” In the house

example, windows and doors belong to their own classes because they have unique properties.

In Photoshop, every type of object— document, art layer, etc.—belongs to its own class, each

with its own set of properties and behaviors.

Section	Page
Photoshop CS Scripting Guide	1
Table of contents	3
Introduction	5
1.1 About this manual	5
1.1.1 Conventions in this guide	5
1.2 What is scripting?	6
1.3 Why use scripting?	7
1.4 What about actions?	7
1.5 System requirements	8
1.5.1 Mac	8
1.5.2 Windows	8
1.6 JavaScript	9
1.7 Choosing a scripting language	9
1.8 Legacy COM scripting	10
1.9 New Features	10
1.10 What’s Next	11
Scripting basics	12
2.1 Documents as objects	12
2.2 Object model concepts	12
2.2.1 Object classes	12
2.2.2 Object inheritance	13
2.2.3 Object elements or collections	13
2.2.4 Object reference	13
2.3 Object Model	14
2.3.1 Additional Containment Classes	16
2.3.2 Hello World Sample Scripts	18
2.4 Documenting scripts	21
2.5 Values	22
2.6 Variables	24
2.6.1 Assigning values to variables	24
2.6.2 Using variables to store references	25
2.6.3 Naming variables	25
2.7 Operators	26
2.8 Commands and methods	26
2.8.1 Conditional statements	27
2.8.2 Control structures	28
2.9 Handlers, subroutines and functions	29
2.10 Debugging and Error Handling	30
2.10.1 AppleScript debugging	31
2.10.2 Visual Basic debugging	32
2.10.3 JavaScript Debugging	33
2.10.4 Error handling	33
2.11 What’s Next	34
Scripting Photoshop	35
3.1 Photoshop scripting guidelines	35
3.2 Viewing Photoshop objects, commands and methods	35
3.2.1 Viewing Photoshop’s AppleScript dictionary	36
3.2.2 Viewing Photoshop’s type library (VB)	37
3.2.3 Viewing the JavaScript Environment	37
3.3 Your first Photoshop script	39
3.3.1 AppleScript	39
3.3.2 Visual Basic	40
3.3.3 VBScript	42
3.3.4 JavaScript	43
3.4 Advanced Scripting	45
3.4.1 Advanced JavaScript	45
3.4.2 Advanced Visual Basic	50
3.4.3 Advanced AppleScript	54
3.5 Object references	59
3.5.1 AppleScript	59
3.5.2 Visual Basic and JavaScript	60
3.6 Working with units	61
3.6.1 Unit values	61
3.6.2 Unit value useage	64
3.6.3 Changing ruler and type units	65
3.7 Executing JavaScripts from AS or VB	66
3.7.1 Passing arguments to JavaScript	67
3.7.2 Executing one-line JavaScripts	68
3.8 The Application object	68
3.9 Document object	72
3.9.1 Saving documents and save options	72
3.9.2 Document information	74
3.9.3 Document manipulation	75
3.10 Layer objects	76
3.10.1 Setting the Active layer	79
3.10.2 Layer sets	79
3.10.3 Linking layers	80
3.10.4 Applying styles to layers	81
3.10.5 Rotating layers	81
3.11 Text item object	81
3.11.1 Setting the contents of the text item	83
3.11.2 Setting text stroke colors	84
3.11.3 Setting fonts	84
3.11.4 Warping text	85
3.12 Selections	85
3.12.1 Defining selections	86
3.12.2 Stroking the selection border	88
3.12.3 Inverting selections	88
3.12.4 Expand, contract and feather selections	88
3.12.5 Filling a selection	90
3.12.6 Rotating selections	91
3.12.7 Loading and storing selections	91
3.13 Working with Filters	92
3.13.1 Selecting channel(s) to filter	92
3.13.2 Other filters	93
3.14 Channel object	93
3.14.1 Channel types	93
3.14.2 Setting the active channel	94
3.14.3 Creating new channels	94
3.15 Color objects	95
3.15.1 Setting a Color	95
3.15.2 Getting and converting colors	97
3.15.3 Comparing Colors	98
3.15.4 Getting a Web Safe Color	98
3.16 History object	98
3.16.1 Filling a selection with a history state	99
3.17 Clipboard interaction	100
3.17.1 Copy	100
3.17.2 Copy merged	100
3.17.3 Cut	101
3.17.4 Paste	101
3.17.5 Paste into command	102

Adobe 23101764 Scripting Guide - Page 12

Scripting basics

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