-- A new piece that takes care of the special functionality of a design portal piece.
-- Design portal pieces must indicate to the user not only their status as selected or
-- unselected, but also their status as selcted for linking and unselected for linking.

class
  V_DESIGN_PORTAL

inherit

  V_DESIGN_PIECE
  rename
    set_special_bitmaps as set_link_bitmaps 
  undefine
    vacate
  redefine 
    on_left_button_down, make, highlight, unhighlight, on_paint,
    on_right_button_down, set_link_bitmaps
  select
    cell
  end

  DESIGN_PORTAL
  rename
    cell as cell_dp
  redefine 
    set_link_id
  end
	
  WEL_TA_CONSTANTS
	
creation
  make

feature 

--ensure that we only create a portal piece here.
  make( s : STRING ; vdr : V_DESIGN_ROOM ; pp : V_PALETTE_PIECE ; c : V_DESIGN_CELL ; is_fg : BOOLEAN ) is
  -- Make myself a V_DESIGN_PIECE with name `s', parent `vdr', palette piece `pp' and put me in cell `c'.
  do
    Precursor ( s, vdr, pp, c, is_fg  ) 
    !!text_color.make_rgb (10, 10, 100)
  end

  set_link_bitmaps( ln, lh : WEL_BITMAP ) is
  -- Receive my normal and highlighted link bitmaps, normally immediately after creation.
  do
    link_normal := ln
    link_highlighted := lh
  end
 
  -- Handle a shift-left click on a portal piece here.
  on_left_button_down( keys, x_pos, y_pos : INTEGER ) is
  -- Call room's `sselect' feature.
  do
    if keys /= Mk_shift + Mk_lbutton then
      room.sselect( Current )		 
    else
      room.sselect_for_linking (Current)
    end
  end

-- Either the portal is leaving with its link
-- or just the link is going.
  on_right_button_down( keys, x_pos, y_pos : INTEGER ) is
  -- delete piece or delete link, depending upon shift key state.
  do

      room.try_to_delete_link(Current, TRUE)

-- No shift with the right button. Remove the piece also.
    if keys /= Mk_shift + Mk_rbutton then
      Precursor (0, x_pos, y_pos)
    end
  end

  -- redefined for extra functionality of portals
  highlight is
  -- Show myself off.
  require else 
    has_bitmaps: link_highlighted /= Void
    has_bitmaps: highlighted /= Void
  do
    if is_sel_for_link then
      bitmap := link_highlighted
    else
      bitmap := highlighted
    end
    invalidate
  end

  unhighlight is
  -- Return to normal.
  require else
    has_bitmaps: link_normal /= Void
    has_bitmaps: normal /= Void
  do
    if is_sel_for_link then
      bitmap := link_normal
    else
      bitmap := normal
    end
    invalidate
  end

-- Design portals also have "link numbers on them"
  on_paint (paint_dc: WEL_PAINT_DC; invalid_rect: WEL_RECT) is
  -- Draw my bitmap
  do
    paint_dc.draw_bitmap (bitmap, 0, 0, width, height )
    if link_id /= 0 then
      paint_dc.set_text_alignment (Ta_left)
      paint_dc.set_text_color (text_color)
      paint_dc.set_background_opaque
      paint_dc.text_out (0, 0 , link_id.out )
    end	
  end

-- Changing the link number need to force a re-paint
   set_link_id (i : INTEGER) is
   do
     {DESIGN_PORTAL} Precursor (i)
     invalidate
   end

feature {NONE}

   text_color : WEL_COLOR_REF	

end -- class V_DESIGN_PIECE_PORTAL