class HexaPDF::Composer

Parent	Object

The composer class can be used to create PDF documents from scratch. It uses HexaPDF::Layout::Frame and HexaPDF::Layout::Box objects underneath and binds them together to provide a convenient interface for working with them.

Usage¶ ↑

First, a new Composer objects needs to be created, either using ::new or the utility method ::create.

On creation a HexaPDF::Document object is created as well the first page and an accompanying HexaPDF::Layout::Frame object. The frame is used by the various methods for general document layout tasks, like positioning of text, images, and so on. By default, it covers the whole page except the margin area. How the frame gets created can be customized by overriding the create_frame method.

Once the Composer object is created, its methods can be used to draw text, images, … on the page. Behind the scenes HexaPDF::Layout::Box (and subclass) objects are created and drawn on the page via the frame.

If the frame of a page is full and a box doesn't fit anymore, a new page is automatically created. The box is either split into two boxes where one fits on the first page and the other on the new page, or it is drawn completely on the new page. A new page can also be created by calling the new_page method.

The x and y methods provide the point where the next box would be drawn if it fits the available space. This information can be used, for example, for custom drawing operations through canvas which provides direct access to the HexaPDF::Content::Canvas object of the current page.

When using canvas and modifying the graphics state, care has to be taken to avoid problems with later box drawing operations since the graphics state cannot completely be reset (e.g. transformations of the canvas cannot always be undone). So it is best to save the graphics state before and restore it afterwards.

Example¶ ↑

HexaPDF::Composer.create('output.pdf', margin: 36) do |pdf|
  pdf.base_style.font_size(20).align(:center)
  pdf.text("Hello World", valign: :center)
end

Attributes

canvas[R]¶

The Content::Canvas of the current page. Can be used to perform arbitrary drawing operations.

document[R]¶

The PDF document that is created.

frame[R]¶

The HexaPDF::Layout::Frame for automatic box placement.

page[R]¶

The current page (a HexaPDF::Type::Page object).

Public Class Methods

create(output, **options, &block)¶

Creates a new PDF document and writes it to output. The options are passed to ::new.

Example:

HexaPDF::Composer.create('output.pdf', margin: 36) do |pdf|
  ...
end

new(skip_page_creation: false, page_size: :A4, page_orientation: :portrait, margin: 36) { |composer| ... }¶

Creates a new Composer object and optionally yields it to the given block.

skip_page_creation

If this argument is true (the default), the arguments page_size, page_orientation and margin are used to create a page style with the name :default and an initial page is created as well.

Otherwise, i.e. when this argument is false, no initial page or default page style is created. This has to be done manually using the page_style and new_page methods.

page_size

Can be any valid predefined page size (see Type::Page::PAPER_SIZE) or an array [llx, lly, urx, ury] specifying a custom page size.

page_orientation

Specifies the orientation of the page, either :portrait or :landscape. Only used if page_size is one of the predefined page sizes.

margin

The margin to use. See HexaPDF::Layout::Style::Quad#set for possible values.

Example:

composer = HexaPDF::Composer.new            # uses the default values

HexaPDF::Composer.new(page_size: :Letter, margin: 72) do |composer|
  #...
end

HexaPDF::Composer.new(skip_page_creation: true) do |composer|
  page_template = lambda {|canvas, style| style.create_frame(canvas.context, 36) }
  page_style(:default, template: page_template)
  new_page
  # ...
end

Public Instance Methods

box(name, width: 0, height: 0, style: nil, **box_options, &block)¶

Draws the named box at the current position.

It uses HexaPDF::Document::Layout#box behind the scenes to create the named box. See that method for details on the arguments.

Examples:

composer.box(:image, image: composer.document.images.add(machu_picchu))

See: HexaPDF::Document::Layout#box

formatted_text(data, width: 0, height: 0, style: nil, box_style: nil, **style_properties)¶

Draws text like text but allows parts of the text to be formatted differently.

It uses HexaPDF::Document::Layout#formatted_text_box behind the scenes to create the HexaPDF::Layout::TextBox that does the actual work. See that method for details on the arguments.

Examples:

composer.formatted_text(["Some string"])
composer.formatted_text(["Some ", {text: "string", fill_color: 128}])
composer.formatted_text(["Some ", {link: "https://example.com",
                                   fill_color: 'blue', text: "Example"}])
composer.formatted_text(["Some ", {text: "string", style: {font_size: 20}}])

See: text, HexaPDF::Layout::TextBox, HexaPDF::Layout::TextFragment

image(file, width: 0, height: 0, style: nil, **style_properties)¶

Draws the given image at the current position.

It uses HexaPDF::Document::Layout#image_box behind the scenes to create the HexaPDF::Layout::ImageBox that does the actual work. See that method for details on the arguments.

Examples:

composer.image(machu_picchu, border: {width: 3})
composer.image(machu_picchu, height: 30)

See: HexaPDF::Layout::ImageBox

method_missing(name, *args, **kwargs, &block)¶

Draws any custom box that can be created using HexaPDF::Document::Layout.

Examples:

composer.lorem_ipsum
composer.column {|column| column.lorem_ipsum }

Calls superclass method

new_page(style = @page_style)¶

Creates a new page, making it the current one.

The page style to use for the new page can be set via the style argument. If not provided, the currently set page style is used.

The used page style determines the page style that should be used for the following new pages. If this information is not provided, the used page style is used again.

Examples:

composer.page_style(:cover, page_size: :A4).next_style = :content
composer.page_style(:content, page_size: :A4)
composer.new_page(:cover)           # uses the :cover style, set next style to :content
composer.new_page                   # uses the :content style, next style again :content

page_style(name) → page_style ¶

page_style(name, **attributes, &template_block) → page_style ¶

Creates and/or returns the page style name.

If no attributes are given, the page style name is returned. In case it does not exist, nil is returned.

If one or more page style attributes are given, a new HexaPDF::Layout::PageStyle object with those attribute values is created, stored under name and returned. If a block is provided, it is used to define the page template.

Example:

composer.page_style(:default)
composer.page_style(:cover, page_size: :A4) do |canvas, style|
  page_box = canvas.context.box
  canvas.fill_color("fd0") do
    canvas.rectangle(0, 0, page_box.width, page_box.height).
      fill
  end
  style.frame = style.create_frame(canvas.context, 36)
end

See: HexaPDF::Layout::PageStyle

style(name) → style ¶

style(name, base: :base, **properties) → style ¶

Creates or updates the HexaPDF::Layout::Style object called name with the given property values and returns it.

See HexaPDF::Document::Layout#style for details; this method is just a thin wrapper around that method.

Example:

composer.style(:base, font_size: 12, leading: 1.2)
composer.style(:header, font: 'Helvetica', fill_color: "008")
composer.style(:header1, base: :header, font_size: 30)

See: HexaPDF::Layout::Style

text(str, width: 0, height: 0, style: nil, box_style: nil, **style_properties)¶

Draws the given text at the current position into the current frame.

The text will be positioned at the current position if possible. Otherwise the next best position is used. If the text doesn't fit onto the current page or only partially, new pages are created automatically.

This method is of the two main methods for creating text boxes, the other being formatted_text. It uses HexaPDF::Document::Layout#text_box behind the scenes to create the HexaPDF::Layout::TextBox that does the actual work.

See HexaPDF::Document::Layout#text_box for details on the arguments.

Examples:

composer.text("Test " * 15)
composer.text("Now " * 7, width: 100)
composer.text("Another test", font_size: 15, fill_color: "green")
composer.text("Different box style", fill_color: 'white', box_style: {
  underlays: [->(c, b) { c.rectangle(0, 0, b.content_width, b.content_height).fill }]
})

write(output, optimize: true, **options)¶

Writes the PDF document to the given output.

See Document#write for details.

x()¶

The x-position of the cursor inside the current frame.

y()¶

The y-position of the cursor inside the current frame.

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Classes and Modules

class HexaPDF::Composer

Usage¶ ↑

Example¶ ↑

Attributes

Public Class Methods

Public Instance Methods