Class: HexaPDF::Layout::ImageBox

Inherits:
Box
  • Object
show all
Defined in:
lib/hexapdf/layout/image_box.rb

Overview

An Image box object is used for displaying an image.

It can either be used directly or through the HexaPDF::Composer#image method.

How an image is displayed inside an image box, depends on whether the width and/or height of the box has been set:

  • If one of them has been set, the other is adjusted to retain the image ratio.

    #>pdf-composer100
composer.image(machu_picchu, width: 40)
composer.image(machu_picchu, height: 40)

  • If both have been set, both are used as is.

    #>pdf-composer100
composer.image(machu_picchu, width: 100, height: 30)

  • If neither has been set, the image is scaled to fit the current region.

    #>pdf-composer100
composer.image(machu_picchu)

Also see: HexaPDF::Content::Canvas#image

Constant Summary

Constants included from Utils

Utils::EPSILON

Instance Attribute Summary collapse

Attributes inherited from Box

#height, #properties, #style, #width

Instance Method Summary collapse

Methods inherited from Box

#content_height, #content_width, create, #draw, #split, #split_box?, #supports_position_flow?

Constructor Details

#initialize(image:, **kwargs) ⇒ ImageBox

Creates a new Image box object for the given image argument which needs to be an image object (e.g. returned by HexaPDF::Document::Images#add).



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# File 'lib/hexapdf/layout/image_box.rb', line 72

def initialize(image:, **kwargs)
  super(**kwargs)
  @image = image
end

Instance Attribute Details

#image ⇒ Object (readonly)

The image that is shown in the box.



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# File 'lib/hexapdf/layout/image_box.rb', line 68

def image
  @image
end

Instance Method Details

#empty? ⇒ Boolean

Returns false since the image is always drawn if it fits.

Returns:

  • (Boolean) 


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# File 'lib/hexapdf/layout/image_box.rb', line 78

def empty?
  false
end

#fit(available_width, available_height, _frame) ⇒ Object

Fits the image into the current region of the frame, taking the initially set width and height into account (see the class description for details).



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# File 'lib/hexapdf/layout/image_box.rb', line 84

def fit(available_width, available_height, _frame)
  image_width = @image.width.to_f
  image_height = @image.height.to_f
  image_ratio = image_width / image_height

  if @initial_width > 0 && @initial_height > 0
    @width = @initial_width
    @height = @initial_height
  elsif @initial_width > 0
    @width = @initial_width
    @height = (@width - reserved_width) / image_ratio + reserved_height
  elsif @initial_height > 0
    @height = @initial_height
    @width = (@height - reserved_height) * image_ratio + reserved_width
  else
    rw = reserved_width
    rh = reserved_height
    ratio = [(available_width - rw) / image_width, (available_height - rh) / image_height].min
    @width = image_width * ratio + rw
    @height = image_height * ratio + rh
  end

  @fit_successful = float_compare(@width, available_width) <= 0 &&
    float_compare(@height, available_height) <= 0
end