Module: Postsvg::Translation::Handlers::Shared

Included in:
CircleHandler, EllipseHandler, GroupHandler, ImageHandler, LineHandler, PathHandler, PolygonHandler, PolylineHandler, RectHandler, SvgHandler, TextHandler
Defined in:
lib/postsvg/translation/handlers/shared.rb

Overview

Helpers shared by every handler. Mixed into each handler class via extend Shared so handler bodies stay declarative.

All element classes in Svg::Elements provide fill, stroke_paint, stroke, and transform getters (returning nil when not applicable). This module relies on those getters existing — no respond_to? checks.

Instance Method Summary collapse

Instance Method Details

#emit_fill(element, context) ⇒ Object 



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# File 'lib/postsvg/translation/handlers/shared.rb', line 53

def emit_fill(element, context)
  paint = element.fill
  return unless paint && paint.color?

  color = paint.value
  if color.gray?
    context.emitter.emit(Model::Operators::Color::Setgray.new(gray: color.gray_level))
  else
    context.emitter.emit(Model::Operators::Color::Setrgbcolor.new(
      red: color.red / 255.0, green: color.green / 255.0, blue: color.blue / 255.0,
    ))
  end
end

#emit_paint(element, context) ⇒ Object

Emit paint setup + paint terminator(s) for an element. When the element has only fill, emits color + fill. When only stroke, emits color + stroke. When both, emits a gsave / setrgbcolor(fill) / fill / grestore / setrgbcolor(stroke) / stroke sequence so each paint uses the right color.



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# File 'lib/postsvg/translation/handlers/shared.rb', line 20

def emit_paint(element, context)
  fill_paint = element.fill
  stroke_paint = element.stroke_paint
  fill_on = fill_paint && fill_paint.color?
  stroke_on = stroke_paint && stroke_paint.color?

  if fill_on && stroke_on
    emit_fill(element, context)
    context.emitter.emit(Model::Operators::GraphicsState::Gsave.new)
    context.emitter.emit(Model::Operators::Painting::Fill.new)
    context.emitter.emit(Model::Operators::GraphicsState::Grestore.new)
    emit_stroke(element, context)
    context.emitter.emit(Model::Operators::Painting::Stroke.new)
  elsif fill_on
    emit_fill(element, context)
    context.emitter.emit(Model::Operators::Painting::Fill.new)
  elsif stroke_on
    emit_stroke(element, context)
    context.emitter.emit(Model::Operators::Painting::Stroke.new)
  else
    # No explicit paint — fill with current color (default).
    context.emitter.emit(Model::Operators::Painting::Fill.new)
  end
end

#emit_paint_setup(element, context) ⇒ Object

Convenience for handlers that want to set up colors without emitting a paint terminator (e.g. LineHandler which always strokes).



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# File 'lib/postsvg/translation/handlers/shared.rb', line 48

def emit_paint_setup(element, context)
  emit_fill(element, context)
  emit_stroke(element, context)
end

#emit_stroke(element, context) ⇒ Object 



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# File 'lib/postsvg/translation/handlers/shared.rb', line 67

def emit_stroke(element, context)
  paint = element.stroke_paint
  return unless paint && paint.color?

  color = paint.value
  context.emitter.emit(Model::Operators::Color::Setrgbcolor.new(
    red: color.red / 255.0, green: color.green / 255.0, blue: color.blue / 255.0,
  ))
  stroke = element.stroke
  return unless stroke

  context.emitter.emit(Model::Operators::GraphicsState::Setlinewidth.new(width: stroke.width)) if stroke.width
  if stroke.linecap
    code = { butt: 0, round: 1, square: 2 }[stroke.linecap.to_sym]
    context.emitter.emit(Model::Operators::GraphicsState::Setlinecap.new(cap_code: code)) if code
  end
  if stroke.linejoin
    code = { miter: 0, round: 1, bevel: 2 }[stroke.linejoin.to_sym]
    context.emitter.emit(Model::Operators::GraphicsState::Setlinejoin.new(join_code: code)) if code
  end
end

#emit_transform(element, context) ⇒ Object 



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# File 'lib/postsvg/translation/handlers/shared.rb', line 89

def emit_transform(element, context)
  transform = element.transform
  return unless transform && !transform.empty?

  transform.matrices.each do |matrix|
    context.emitter.emit(Model::Operators::Transformations::Concat.new(matrix: [
      matrix.a, matrix.b, matrix.c, matrix.d, matrix.e, matrix.f,
    ]))
  end
end

#expand_bbox(context, *points) ⇒ Object 



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# File 'lib/postsvg/translation/handlers/shared.rb', line 100

def expand_bbox(context, *points)
  xs = points.each_slice(2).map(&:first)
  ys = points.each_slice(2).map(&:last)
  return if xs.empty?

  context.expand_bbox!((xs.min..xs.max), (ys.min..ys.max))
end