contentstream

Documentation

Overview

Package contentstream provides parsing of PDF content streams.

Content streams contain the instructions for rendering page content, including text display, graphics operations, and image placement.

Content Stream Operations

PDF content streams consist of operators and their operands:

parser := contentstream.NewParser(streamData)
ops, err := parser.Parse()
for _, op := range ops {
    fmt.Printf("Operator: %s, Operands: %v\n", op.Operator, op.Operands)
}

Common Operators

Text operators:

• BT, ET - Begin/end text object
• Tf - Set font and size
• Tm - Set text matrix
• Tj, TJ - Show text
• Td, TD - Move text position

Graphics state operators:

• q, Q - Save/restore graphics state
• cm - Modify CTM (current transformation matrix)
• w - Set line width
• J, j - Set line cap/join style

Path operators:

• m, l - Move to, line to
• re - Rectangle
• S, s, f, f* - Stroke and fill paths

Operand Types

Operands can be any PDF object type:

• Numbers (core.Int, core.Real)
• Strings (core.String)
• Names (core.Name)
• Arrays (core.Array)
• Dictionaries (core.Dict)

Index

• type Operation
• type Parser
  • func NewParser(data []byte) *Parser
  • func (p *Parser) Parse() ([]Operation, error)

Types

type Operation

type Operation struct {
	Operator string        // The operator (e.g., "Tj", "Tm", "q")
	Operands []core.Object // The operands
}

Operation represents a single content stream operation consisting of an operator and its operands. Operands are PDF objects that precede the operator.

type Parser

type Parser struct {
	// contains filtered or unexported fields
}

Parser parses PDF content streams into a sequence of operations. Each operation consists of an operator and its operands.

func NewParser

func NewParser(data []byte) *Parser

NewParser creates a new content stream parser for the given data.

func (*Parser) Parse

func (p *Parser) Parse() ([]Operation, error)

Parse parses the content stream and returns all operations in order.