module Draw;
from Layers import all;
export all;

object ColorPalette is
   components:cl:Color*, pc:PrimaryColor, sc:SecondaryColor;
   operations:SetPrimary, SetSecondary;
   description:(*
      ColorPalette is used for the drawing tools.
   *);
end ColorPalette;

object PrimaryColor is 
   components: col:Color;
   description:(*
      Primary Color is the color used when using the left mouse button.
   *);
end PrimaryColor;

object SecondaryColor is 
   components: col:Color;
   description:(*
      Secondary Color is the color used when using the left mouse button.
   *);
end SecondaryColor;

operation SetPrimary is
   inputs:cp:ColorPalette, c:Color;
   outputs:cp':ColorPalette;
   precondition:
      (*The list of colors must contain c*)
      c in cp.cl;
   postcondition:
      (*The primary color is changed*)
      cp'.pc = c;
   description:(*
      This operation sets the primary color to the given color.
   *);
end SetPrimary;

operation SetSecondary is
   inputs:cp:ColorPalette, c:Color;
   outputs:cp':ColorPalette;
   precondition:
      (*The list of colors must contain c*)
      c in cp.cl;
   postcondition:
      (*The primary color is changed*)
      cp'.sc = c;
   description:(*
      This operation sets the secondary color to the given color.
   *);
end SetSecondary;

object CurrentTool is Tool
   description:(*
      Drawing tools are used to edit a layer.
   *);
end CurrentTool;

object Tool is
   components:X1, Y1, X2, Y2, Color;
   description:(*
      A tool has a start, finish and color.
   *);
end Tool;

object X1 is 
   components:XCoordinate;
   description:(*
      X1 is an address on the x axis of a layer.
   *);
end X1;

object X2 is 
   components:XCoordinate;
   description:(*
      X2 is an address on the x axis of a layer.
   *);
end X2;

object Y1 is
   components:YCoordinate;
   description:(*
      Y1 is an address on the y axis of a layer.
   *);
end Y1;

object Y2 is 
   components:YCoordinate;
   description:(*
      Y2 is an address on the y axis of a layer.
   *);
end Y2;

object Ellipse inherits from Tool
   description:(*
      An ellipse is a circular object.
   *);
end Ellipse;

object Rectangle inherits from Tool
   description:(*
      An rectangle is a square object.
   *);
end Rectangle;

object TextBox inherits from Tool
   components:string;
   description:(*
      A textbox is a rectangle with text in it.
   *);
end TextBox;

object Line inherits from Tool
   description:(*
      A line has a start and finish point.
   *);
end Line;

object Eraser inherits from Tool
   components:XCoordinate*, YCoordinate*;
   description:(*
      An eraser has a set of coordinates and a fixed radius.
   *);
end Eraser;

object Pencil inherits from Tool
   components:XCoordinate*, YCoordinate*;
   description:(*
      An eraser has a set of coordinates.
   *);
end Eraser;

object StudentStickyNote inherits from Tool
   components:TextBox;
   description:(*
      X1 and Y1 determine the placement of the textbox which is 
      expandable and colapsable.
   *);
end StudentStickyNote;

object Fill inherits from Tool
   description:(*
      X1 and Y1 determine the area that will be filled.
   *);
end Fill;

object Curve inherits from Tool
   components: X3, Y3;
   description:(*
      A curve has a start point, a finish point, and a curve point.
   *);
end Curve;

object X3 is 
   components:XCoordinate;
   description:(*
      X3 is an address on the x axis of a layer.
   *);
end X3;

object Y3 is 
   components:YCoordinate;
   description:(*
      Y3 is an address on the y axis of a layer.
   *);
end Y3;

operation Magnefy
   inputs:l:Layer;
   outputs:l':Layer;
   precondition:
      (*none*);
   postcondition:
      (*The Layer is magnefied.*);
   description:(*
      This operation zooms in on the given Layer.
   *);
end Magnefy;   

operation Draw is
   inputs:l:Layer, t:Tool;
   outputs:l':Layer;
   precondition:
      (*none*);
   postcondition:
      (*The tool is transfered onto the layer*);
   description:(*
      This operation places a tool on the current layer.
   *);
end Draw;

end Draw;