-- File:	Aspect_Grid.cdl
-- Created:	Thu Mar  2 14:23:42 1995
-- Author:	Jean-Louis Frenkel
--		<rmi@pernox>
-- Updated:	GG IMP230300 Add grid color parameters in constructor
--		and add new methods SetColors() & Colors()
---Copyright:	 Matra Datavision 1995

deferred class Grid from Aspect
inherits TShared from MMgt

uses
    PlaneAngle, Length from Quantity,
    GridDrawMode from Aspect,
    Color from Quantity
is 

    Initialize(anXOrigin: Length from Quantity = 0.0;
	       anYOrigin: Length from Quantity = 0.0;
               aRotationAngle: PlaneAngle from Quantity = 0;
	       aColor: Color from Quantity = Quantity_NOC_GRAY50;
	       aTenthColor: Color from Quantity = Quantity_NOC_GRAY70);
	       
    ---Purpose: creates a new grid. By default this grid is not
    --          active.
    
    ---Category: grid definition methods

    SetXOrigin(me: mutable; anOrigin: Length from Quantity) 
    is static;
    ---Level: Public
    ---Purpose: defines the x Origin of the grid.

    SetYOrigin(me: mutable; anOrigin: Length from Quantity) 
    is static;
    ---Level: Public
    ---Purpose: defines the y Origin of the grid.

    SetRotationAngle(me: mutable; anAngle: PlaneAngle from Quantity)
    is static;
    ---Level: Public
    ---Purpose: defines the orientation of the the grid.
    
    Rotate(me: mutable; anAngle: PlaneAngle from Quantity)
    is static;
    ---Level: Public
    ---Purpose: Rotate the grid from a relative angle.
    
    Translate(me: mutable; aDx, aDy: Length from Quantity)
    is static;
    ---Level: Public
    ---Purpose: Translate the grid from a relative distance.

    SetColors ( me  : mutable;
                    aColor     : Color from Quantity;
                    aTenthColor     : Color from Quantity )
    is virtual;
    ---Level: Public
    ---Purpose: Change the colors of the grid
    
---Category: Pick methods
--           
    Hit(me; X,Y: Length from Quantity; gridX, gridY : out Length from Quantity)
    is static;
    ---Level: Public
    ---Purpose: returns the point of the grid the closest to the point X,Y
    --          if the grid is active. If the grid is not active returns
    --          X,Y.
    
    Compute(me; X,Y: Length from Quantity; gridX, gridY : out Length from Quantity)
    is deferred;
    ---Level: Internal
    ---Purpose: returns the point of the grid the closest to the point X,Y
---Category: Managment methods.

    Activate(me: mutable)
    is static;
    ---Level: Public
    ---Purpose: activates the grid. The Hit method will return
    --          gridx and gridx computed according to the steps
    --          of the grid.
    
    Deactivate(me: mutable)
    is static;
    ---Level: Public
    ---Purpose: deactivates the grid. The hit method will return
    --          gridx and gridx as the enter value X & Y.
    
---Category: inquire methods

    XOrigin(me) returns Length from Quantity
    is static;
    ---Level: Public
    ---Purpose: returns the x Origin of the grid.
    
    YOrigin(me) returns Length from Quantity
    is static;
    ---Level: Public
    ---Purpose: returns the x Origin of the grid.
    
    
    RotationAngle(me) returns PlaneAngle from Quantity
    is static;
    ---Level: Public
    ---Purpose: returns the x Angle of the grid.
    
    
    IsActive(me) returns Boolean from Standard
    is static;
    ---Level: Public
    ---Purpose: Returns TRUE when the grid is active.

    Colors(me ; aColor,aTenthColor: out Color from Quantity)
    is static;
    ---Level: Public
    ---Purpose: Returns the colors of the grid.
    
---Category: display methods

    SetDrawMode(me: mutable; aDrawMode: GridDrawMode from Aspect)
    is static;
    ---Level: Public
    ---Purpose: Change the grid aspect.

    DrawMode(me) returns GridDrawMode from Aspect
    is static;
    ---Level: Public
    ---Purpose: Returns the grid aspect.
    
    Display(me: mutable)
    is virtual;
    ---Level: Public
    ---Purpose: Display the grid at screen.
    
    Erase(me)
    is virtual;
    ---Level: Public
    ---Purpose: Erase the grid from screen.
    
    IsDisplayed(me) 
    returns Boolean from Standard
    is virtual;
    ---Level: Public
    ---Purpose: Returns TRUE when the grid is displayed at screen.
    
    UpdateDisplay(me: mutable)
    is virtual protected;
    ---Level: Internal
    ---Purpose: Updates the grid parameters.
    
    Init(me: mutable)
    is deferred;
    ---Level: Internal
    
    
fields

    myRotationAngle: PlaneAngle from Quantity is protected;
    myXOrigin: Length from Quantity is protected;
    myYOrigin: Length from Quantity is protected;
    myColor: Color from Quantity is protected;
    myTenthColor: Color from Quantity is protected;
    myIsActive :Boolean from Standard;
    myIsDisplayed: Boolean from Standard;    
    myDrawMode: GridDrawMode from Aspect;

end Grid from Aspect;