Class: LayoutItem

Inherits:
CompositionItem show all
Defined in:
app/models/layout_item.rb

Overview

A LayoutItem places a specific thing in a Layout.

Only a LayoutItem::GroupItem may be the parent of a LayoutItem, so that a Layout's items only ever nest by translation (see GroupItem). Arbitrary parent/child transforms (zoom and rotation inherited about a parent's center) would oblige every renderer to compose, invert and decompose them, and would conflict with members stacking by their own z. Loosen deliberately if a feature needs it, e.g. an annotation pinned to an image.

What a LayoutItem class may place comes from object concerns it includes (e.g. Shared::Render::DepictionItem), several per class. So that they combine safely, an object concern:

  • permits its class in a .composition_item_object_permitted? that falls back to super, so a class permits whatever any of its concerns permit
  • guards its validations and callbacks by the object's type
  • prefixes any other methods with its type (e.g. depiction_...), so that no concern overrides another's

Direct Known Subclasses

GroupItem, LightTableItem

Defined Under Namespace

Classes: GroupItem, LightTableItem

Instance Attribute Summary

Attributes inherited from CompositionItem

#composition_id, #composition_item_object_id, #composition_item_object_type, #css_style, #height, #is_visible, #opacity, #parent_id, #position, #project_id, #rotation_z, #svg_clip, #svg_view_box, #text, #total, #type, #width, #x, #y, #z, #zoom

Instance Method Summary collapse

Methods inherited from CompositionItem

#annotates_community_object?, #community_composition_has_no_object, #composition_is_unchanged, #composition_item_object_is_permitted, composition_item_object_permitted?, is_community?, #is_community?, #parent_is_in_composition, #parent_is_not_self_or_descendant, #set_community_project_id

Methods included from Housekeeping

#has_polymorphic_relationship?

Methods inherited from ApplicationRecord

transaction_with_retry

Instance Method Details

#composition_is_layout ⇒ Object (protected) 



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# File 'app/models/layout_item.rb', line 33

def composition_is_layout
  if composition && !composition.is_a?(Layout)
    errors.add(:composition, 'must be a Layout')
  end
end

#parent_is_group ⇒ Object (protected) 



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# File 'app/models/layout_item.rb', line 27

def parent_is_group
  if parent && !parent.is_a?(LayoutItem::GroupItem)
    errors.add(:parent, 'must be a group')
  end
end