Class: Teacup::Constraint

Inherits:
Object
  • Object
show all
Defined in:
lib/teacup/constraint.rb

Constant Summary collapse

Priorities = 
{
  required: 1000,  # NSLayoutPriorityRequired
  high: 750,  # NSLayoutPriorityDefaultHigh
  medium: 500,
  low: 250,  # NSLayoutPriorityDefaultLow
}
Relationships =

NSLayoutPriorityDefaultLow

{}
Attributes = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(target = nil, attribute = nil) ⇒ Constraint

Returns a new instance of Constraint.



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# File 'lib/teacup/constraint.rb', line 117

def initialize(target=nil, attribute=nil)
  self.target = target
  self.attribute = attribute
  self.constant = 0
  self.multiplier = 1
  self.priority = :high  # this is the xcode default
end

Instance Attribute Details

#attribute ⇒ Object

Returns the value of attribute attribute.



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# File 'lib/teacup/constraint.rb', line 4

def attribute
  @attribute
end

#attribute2 ⇒ Object

Returns the value of attribute attribute2.



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# File 'lib/teacup/constraint.rb', line 7

def attribute2
  @attribute2
end

#constant ⇒ Object

Returns the value of attribute constant.



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# File 'lib/teacup/constraint.rb', line 9

def constant
  @constant
end

#identifier(identifier = nil) ⇒ Object

Returns the value of attribute identifier.



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# File 'lib/teacup/constraint.rb', line 11

def identifier
  @identifier
end

#multiplier ⇒ Object

Returns the value of attribute multiplier.



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# File 'lib/teacup/constraint.rb', line 8

def multiplier
  @multiplier
end

#priority(priority = nil) ⇒ Object

Returns the value of attribute priority.



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# File 'lib/teacup/constraint.rb', line 10

def priority
  @priority
end

#relationship ⇒ Object

Returns the value of attribute relationship.



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# File 'lib/teacup/constraint.rb', line 5

def relationship
  @relationship
end

#relative_to ⇒ Object

Returns the value of attribute relative_to.



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# File 'lib/teacup/constraint.rb', line 6

def relative_to
  @relative_to
end

#target ⇒ Object

Returns the value of attribute target.



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# File 'lib/teacup/constraint.rb', line 3

def target
  @target
end

Class Method Details

.from_sym(sym, relative_to = :superview) ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 44

def self.from_sym(sym, relative_to=:superview)
  case sym
  when :full
    [
      self.new(:self, :left).equals(relative_to, :left),
      self.new(:self, :top).equals(relative_to, :top),
      self.new(:self, :width).equals(relative_to, :width),
      self.new(:self, :height).equals(relative_to, :height),
    ]
  when :full_width
    [
      self.new(:self, :center_x).equals(relative_to, :center_x),
      self.new(:self, :width).equals(relative_to, :width),
    ]
  when :full_height
    [
      self.new(:self, :center_y).equals(relative_to, :center_y),
      self.new(:self, :height).equals(relative_to, :height),
    ]
  when :center_x
    [
      self.new(:self, :center_x).equals(:superview, :center_x),
    ]
  when :center_y
    [
      self.new(:self, :center_y).equals(:superview, :center_y),
    ]
  when :centered
    [
      self.new(:self, :center_x).equals(:superview, :center_x),
      self.new(:self, :center_y).equals(:superview, :center_y),
    ]
  when :top
    [
      self.new(:self, :top).equals(relative_to, :top),
    ]
  when :right
    [
      self.new(:self, :right).equals(relative_to, :right),
    ]
  when :bottom
    [
      self.new(:self, :bottom).equals(relative_to, :bottom),
    ]
  when :left
    [
      self.new(:self, :left).equals(relative_to, :left),
    ]
  when :top_left, :topleft
    [
      self.new(:self, :left).equals(relative_to, :left),
      self.new(:self, :top).equals(relative_to, :top),
    ]
  when :top_right, :topright
    [
      self.new(:self, :right).equals(relative_to, :right),
      self.new(:self, :top).equals(relative_to, :top),
    ]
  when :bottom_right, :bottomright
    [
      self.new(:self, :right).equals(relative_to, :right),
      self.new(:self, :bottom).equals(relative_to, :bottom),
    ]
  when :bottom_left, :bottomleft
    [
      self.new(:self, :left).equals(relative_to, :left),
      self.new(:self, :bottom).equals(relative_to, :bottom),
    ]
  else
    raise "Unknown symbol #{sym.inspect}"
  end
end

Instance Method Details

#copy ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 207

def copy
  copy = self.class.new(self.target, self.attribute)
  copy.relationship = self.relationship
  copy.relative_to = self.relative_to
  copy.attribute2 = self.attribute2
  copy.multiplier = self.multiplier
  copy.constant = self.constant
  copy.priority = self.priority
  copy.identifier = self.identifier
  copy
end

#divided_by(multiplier) ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 170

def divided_by(multiplier)
  times 1.0/multiplier
end

#equals(relative_to, attribute2 = nil) ⇒ Object

c.equals(100) c.equals(:superview, :width)



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# File 'lib/teacup/constraint.rb', line 127

def equals(relative_to, attribute2=nil)
  self.set_relationship(NSLayoutRelationEqual, relative_to, attribute2)
end

#gte(relative_to, attribute2 = nil) ⇒ Object Also known as: at_least, is_at_least 



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# File 'lib/teacup/constraint.rb', line 137

def gte(relative_to, attribute2=nil)
  self.set_relationship(NSLayoutRelationGreaterThanOrEqual, relative_to, attribute2)
end

#inspect ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 219

def inspect
  "#<#{self.class.name} ##{object_id.to_s(16)}" +
  " target=#{target.inspect}" +
  " attribute=#{attribute_reverse(attribute).inspect}" +
  " relationship=#{relationship_reverse(relationship).inspect}" +
  " relative_to=#{relative_to.inspect}" +
  " attribute2=#{attribute_reverse(attribute2).inspect}" +
  " multiplier=#{multiplier.inspect}" +
  " constant=#{constant.inspect}" +
  ">"
end

#lte(relative_to, attribute2 = nil) ⇒ Object Also known as: at_most, is_at_most 



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# File 'lib/teacup/constraint.rb', line 131

def lte(relative_to, attribute2=nil)
  self.set_relationship(NSLayoutRelationLessThanOrEqual, relative_to, attribute2)
end

#minus(constant) ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 189

def minus(constant)
  plus -constant
end

#nslayoutconstraint ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 231

def nslayoutconstraint
  nsconstraint = NSLayoutConstraint.constraintWithItem( self.target,
                              attribute: self.attribute,
                              relatedBy: self.relationship,
                                 toItem: self.relative_to,
                              attribute: self.attribute2,
                             multiplier: self.multiplier,
                               constant: self.constant
                                       )
  nsconstraint.priority = priority_lookup(self.priority)
  nsconstraint.setIdentifier(self.identifier) if self.identifier
  return nsconstraint
end

#plus(constant) ⇒ Object

If no relationship has been set, the “use case” here is:

c.plus(10).equals(:view, :x)

Which is the same as

c.equals(:view, :x).minus(10)



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# File 'lib/teacup/constraint.rb', line 181

def plus(constant)
  if not self.relationship
    constant = -constant
  end
  self.constant += constant
  self
end

#set_relationship(relation, relative_to, attribute2) ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 143

def set_relationship(relation, relative_to, attribute2)
  if attribute2.nil?
    self.constant = relative_to
    self.relative_to = nil
    self.attribute2 = :none
  else
    self.relative_to = relative_to
    self.attribute2 = attribute2
  end
  self.relationship = relation

  self
end

#times(multiplier) ⇒ Object 



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# File 'lib/teacup/constraint.rb', line 165

def times(multiplier)
  self.multiplier *= multiplier
  self
end