builders.hpp File Reference

Fluent builder pattern for constructing drawing commands. More...

#include "epaper/core/geometry.hpp"
#include "epaper/draw/commands.hpp"
#include "epaper/draw/styles.hpp"
#include "epaper/graphics/font.hpp"
#include <cstdint>
#include <string>
#include <string_view>

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Classes
class	epaper::LineBuilder
class	epaper::RectangleBuilder
class	epaper::CircleBuilder
class	epaper::PointBuilder
class	epaper::TextBuilder

Namespaces
namespace	epaper

Detailed Description

Fluent builder pattern for constructing drawing commands.

Provides type-safe, expressive builders for all drawing command types. Each builder follows the fluent interface pattern (method chaining) for readable, self-documenting code.

Design Pattern:

Builder Pattern (Fluent Interface)
├─ Default Construction: Provides sensible defaults
├─ Method Chaining: Each setter returns *this for chaining
├─ Type Safety: All parameters statically typed (no stringly-typed APIs)
└─ Finalization: build() produces immutable command struct

Benefits:

• Readability: line().from({0,0}).to({100,100}).color(Black) reads like English
• Discoverability: IDE autocomplete guides users through available options
• Flexibility: Optional parameters with sensible defaults
• Immutability: Built commands are const, preventing accidental modification
• Style Reuse: with_style() applies predefined style bundles

Usage Patterns:

// Direct builder usage
auto line_cmd = LineBuilder()
  .from({10, 10})
  .to({100, 100})
  .color(Color::Black)
  .build();
display.draw(line_cmd);
 
// Using Display::line() factory (preferred)
display.draw(
  display.line()
    .from({10, 10})
    .to({100, 100})
    .color(Color::Black)
    .build()
);
 
// Style reuse for consistent appearance
LineStyleSpec thick_black{Color::Black, DotPixel::Pixel3x3};
display.draw(display.line().from(a).to(b).with_style(thick_black).build());
display.draw(display.line().from(c).to(d).with_style(thick_black).build());

Implementation Details:

• All builders are value types (cheap to copy, no heap allocation)
• Private members hold intermediate state
• build() marked [[nodiscard]] to prevent unused command objects
• Setters are noexcept (no allocation, no exceptions)

See also

commands.hpp, styles.hpp, Display::line(), Display::rectangle()