package bluej.editor.stride;

import java.util.Collections;
import java.util.Map;

import bluej.stride.generic.Frame;
import bluej.stride.generic.FrameCanvas;
import bluej.stride.generic.FrameCursor;
import bluej.stride.generic.RecallableFocus;
import bluej.stride.slots.EditableSlot;
import bluej.utility.Utility;
import threadchecker.OnThread;
import threadchecker.Tag;




| A sum type that holds either an EditableSlot or a FrameCursor.
|
| Package-visible
|
class CursorOrSlot
{       

   private final EditableSlot slot;
   
   private final FrameCursor cursor;

   
   public CursorOrSlot(EditableSlot slot)
   {        
      if (slot == null) throw new NullPointerException();
       
      this.slot = slot;
       
      this.cursor = null;     
      }

   
   public CursorOrSlot(FrameCursor cursor)
   {        
      if (cursor == null) throw new NullPointerException();
       
      this.slot = null;
       
      this.cursor = cursor;     
      }

   
   


| Checks whether the frame cursor, or the frame that the slot belongs to,
| is directly inside the given canvas.
|
public boolean isInsideCanvas(FrameCanvas canvas)
   {        
      
      FrameCanvas ourCanvas;
      if (cursor != null)
      ourCanvas = cursor.getParentCanvas();
       
      else{ ourCanvas = Utility.orNull(slot.getParentFrame(), Frame::getParentCanvas);
         }

       
      return ourCanvas == canvas;     
      }

   
   


| Gets the frame that the slot belongs to, or the frame which the cursor's canvas is inside.
|
public Frame getParentFrame()
   {
      if (slot != null)
      return slot.getParentFrame();
       
      else{ return cursor.getParentCanvas().getParent().getFrame();
         }     
      }

   
   


| Gets the menu items for this slot/cursor (for window menu when focused, or right-click menu)
|
@OnThread(Tag.FXPlatform)
   
   public Map getMenuItems(boolean contextMenu)
   {
      return slot != null ? slot.getMenuItems(contextMenu) : Collections.singletonMap(EditableSlot.TopLevelMenu.EDIT, cursor.getMenuItems(false));     
      }

   
   


| Delegates to .equals on the cursor/slot
|
@Override
   
   public boolean equals(Object o)
   {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;

      CursorOrSlot that = (CursorOrSlot) o;

      if (cursor != null ? !cursor.equals(that.cursor) : that.cursor != null) return false;
      if (slot != null ? !slot.equals(that.slot) : that.slot != null) return false;

       
      return true;     
      }

   
   @Override
   
   public int hashCode()
   {
      int result = slot != null ? slot.hashCode() : 0;
      result = 31 * result + (cursor != null ? cursor.hashCode() : 0);
       
      return result;     
      }

   
   public boolean matchesSlot(EditableSlot s)
   {        
      return this.slot == s;     
      }

   
   
   public FrameCursor getCursor()
   {        
      return cursor;     
      }

   
   public RecallableFocus getRecallableFocus()
   {
      if (cursor != null)
           
      return cursor;
       
      return slot;     
      } 
   }