epaper::TextCommand Struct Reference

Command for drawing text. More...

#include <commands.hpp>

Collaboration diagram for epaper::TextCommand:

Public Member Functions
	TextCommand (Point pos, std::string_view txt, const Font *f, Color fg=Color::Black, Color bg=Color::White) noexcept
	Construct a text command with string content.
	TextCommand (Point pos, std::int32_t num, const Font *f, Color fg=Color::Black, Color bg=Color::White) noexcept
	Construct a text command with number content.
	TextCommand (Point pos, double dec, std::uint8_t places, const Font *f, Color fg=Color::Black, Color bg=Color::White) noexcept
	Construct a text command with decimal content.

Public Attributes
Point	position
	Text position.
std::string	text
	Text content (or converted number)
const Font *	font
	Font to use.
Color	foreground
	Foreground (text) color.
Color	background
	Background color.
TextContent	content_type
	Content type for internal use.
std::int32_t	number
	Number value (for Number type)
double	decimal
	Decimal value (for Decimal type)
std::uint8_t	decimal_places
	Decimal places (for Decimal type)

Detailed Description

Command for drawing text.

Encapsulates all parameters needed to draw text (string, number, or decimal). Constructed via TextBuilder.

Member Semantics:

• position: Text baseline position (top-left of first character cell)
• text: String content or converted number/decimal (read-only after construction)
• font: Pointer to loaded font (borrowed - must outlive command)
• foreground: Text ink color (1 bits in font bitmap)
• background: Paper color (0 bits in font bitmap)
• content_type: Internal discriminant for TextBuilder (user ignores this)
• number, decimal, decimal_places: Internal storage for numeric types

Font Requirements:

• Font must be loaded via Font::load() before command creation
• Font determines character dimensions (fixed-width bitmap)
• Missing characters render as blank space (no error)

Text Rendering:

• Characters rendered left-to-right, no line wrapping
• Cursor advances by font.metrics().width for each character
• Text may extend beyond display edges (clipped at framebuffer level)

Numeric Formatting:

• Number: sprintf("%d", number) → "-123", "0", "999"
• Decimal: sprintf("%.*f", decimal_places, decimal) → "3.14", "2.718"
• Formatted string stored in text field during TextBuilder::build()

Warning

Font pointer must remain valid for command lifetime. Do not pass temporary Font objects (use Font::load() and store result).

See also

TextBuilder, Font, Graphics::draw_text()

Constructor & Destructor Documentation

TextCommand() [1/3]

epaper::TextCommand::TextCommand ( Point  pos, std::string_view  txt, const Font *  f, Color  fg = Color::Black, Color  bg = Color::White  )

inlinenoexcept

Construct a text command with string content.

Parameters

pos	Text position
txt	Text content
f	Font to use
fg	Foreground color (default: Black)
bg	Background color (default: White)

TextCommand() [2/3]

epaper::TextCommand::TextCommand ( Point  pos, std::int32_t  num, const Font *  f, Color  fg = Color::Black, Color  bg = Color::White  )

inlinenoexcept

Construct a text command with number content.

Parameters

pos	Text position
num	Number value
f	Font to use
fg	Foreground color (default: Black)
bg	Background color (default: White)

TextCommand() [3/3]

epaper::TextCommand::TextCommand ( Point  pos, double  dec, std::uint8_t  places, const Font *  f, Color  fg = Color::Black, Color  bg = Color::White  )

inlinenoexcept

Construct a text command with decimal content.

Parameters

pos	Text position
dec	Decimal value
places	Decimal places
f	Font to use
fg	Foreground color (default: Black)
bg	Background color (default: White)

Member Data Documentation

background

Color epaper::TextCommand::background

Background color.

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

content_type

TextContent epaper::TextCommand::content_type

Content type for internal use.

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

decimal

double epaper::TextCommand::decimal

Decimal value (for Decimal type)

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

decimal_places

std::uint8_t epaper::TextCommand::decimal_places

Decimal places (for Decimal type)

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

font

const Font* epaper::TextCommand::font

Font to use.

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

foreground

Color epaper::TextCommand::foreground

Foreground (text) color.

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

number

std::int32_t epaper::TextCommand::number

Number value (for Number type)

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

position

Point epaper::TextCommand::position

Text position.

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

text

std::string epaper::TextCommand::text

Text content (or converted number)

Examples

/mnt/nas/libepaper/include/epaper/draw/commands.hpp.

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The documentation for this struct was generated from the following file:

• include/epaper/draw/commands.hpp