Class: Clogs::Slot

Inherits:
Drawable
  • Object
show all
Defined in:
lib/clogs/drawables/slot.rb

Overview

A slot: the container drawable that does Shoes' layout.

Shoes has exactly two layout modes and they are both simple:

stack - children are placed one below another, each as wide as the slot
flow  - children are placed left to right and wrap when they run out of
      room, like words in a paragraph

Anything with an explicit left and top is lifted out of that flow and placed at those coordinates relative to the slot, which is how Shoes programs do absolute positioning.

Direct Known Subclasses

Flow, Mask, Stack, Widget

Instance Attribute Summary

Attributes inherited from Drawable

#abs_x, #abs_y, #children, #height, #parent, #shoes_linkable_id, #styles, #width, #x, #y

Instance Method Summary collapse

Methods inherited from Drawable

#add_child, #app, #clickable?, #contains?, #destroy_self, #draw, #each_peer, #focus_gained, #focus_lost, #focusable?, for_shoes_class, #hidden?, #initialize, #margin, #needs_layout!, #notify, #on_click, #on_key, #on_mouse_move, #on_release, #positioned?, #properties_changed, #redraw!, #remove_child, #requested_height, #requested_width, #set_parent, #style

Constructor Details

This class inherits a constructor from Clogs::Drawable

Instance Method Details

#decorations ⇒ Object

Backgrounds and borders are children in the Shoes tree but they are not laid out: they cover the whole slot.



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# File 'lib/clogs/drawables/slot.rb', line 28

def decorations
  @children.select { |c| c.is_a?(Background) || c.is_a?(Border) }
end

#flow? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/clogs/drawables/slot.rb', line 18

def flow?
  false
end

#laid_out_children ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 32

def laid_out_children
  @children.reject { |c| c.is_a?(Background) || c.is_a?(Border) || c.hidden? }
end

#layout_flow(kids, content_width) ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 73

def layout_flow(kids, content_width)
  pl, pt, = padding
  x = 0
  y = 0
  line_height = 0
  kids.each do |child|
    cml, cmt, cmr, cmb = child.margin
    child.measure(content_width)
    advance = cml + child.width + cmr
    if x.positive? && x + advance > content_width
      y += line_height
      x = 0
      line_height = 0
    end
    child.x = pl + x + cml
    child.y = pt + y + cmt
    x += advance
    line_height = [line_height, cmt + child.height + cmb].max
  end
  y + line_height
end

#layout_stack(kids, content_width) ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 59

def layout_stack(kids, content_width)
  _pl, pt, = padding
  pl = padding[0]
  y = pt
  kids.each do |child|
    cml, cmt, _cmr, cmb = child.margin
    child.measure(content_width)
    child.x = pl + cml
    child.y = y + cmt
    y += cmt + child.height + cmb
  end
  y - pt
end

#measure(available_width) ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 36

def measure(available_width)
  ml, _mt, mr, _mb = margin
  pl, pt, pr, pb = padding

  outer_width = requested_width(available_width) || (available_width - ml - mr)
  outer_width = 0 if outer_width.negative?
  content_width = [outer_width - pl - pr, 0].max

  flowed, positioned = laid_out_children.partition { |c| !c.positioned? }
  content_height = flow? ? layout_flow(flowed, content_width) : layout_stack(flowed, content_width)

  positioned.each do |child|
    child.measure(content_width)
    child.x = pl + Style.dimension(child.style(:left), content_width).to_i
    child.y = pt + Style.dimension(child.style(:top), outer_width).to_i
  end

  @content_width = content_width
  @width = outer_width
  @height = requested_height(available_width) || (content_height + pt + pb)
  decorations.each { |d| d.measure_for_slot(@width, @height) }
end

#padding ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 22

def padding
  @padding ||= Style.paddings(@styles)
end

#paint(painter, ox, oy) ⇒ Object 



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# File 'lib/clogs/drawables/slot.rb', line 95

def paint(painter, ox, oy)
  @abs_x = ox + @x
  @abs_y = oy + @y

  decorations.grep(Background).each { |d| d.paint_for_slot(painter, @abs_x, @abs_y, @width, @height) }
  @children.each do |child|
    next if child.hidden? || child.is_a?(Background) || child.is_a?(Border)

    child.paint(painter, @abs_x, @abs_y)
  end
  decorations.grep(Border).each { |d| d.paint_for_slot(painter, @abs_x, @abs_y, @width, @height) }
end