package bluej.pkgmgr;

import java.util.ArrayList;
import java.util.List;
import javafx.beans.binding.DoubleExpression;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.geometry.Point2D;
import javafx.scene.Node;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;

import bluej.utility.javafx.JavaFXUtil;
import threadchecker.OnThread;
import threadchecker.Tag;




| An overlay pane which can display nodes at arbitrary positions,
| with some additional support for tracking the current mouse position.
|
| It should be added to the front of a StackPane in front of whatever
| you want the overlays to appear in front of.
|
@OnThread(Tag.FXPlatform)
public class MouseTrackingOverlayPane
extends Pane{    
   
   private final DoubleProperty mouseX = new SimpleDoubleProperty(0.0);
   
   private final DoubleProperty mouseY = new SimpleDoubleProperty(0.0);
   
   
   private final BooleanProperty mouseInsideProperty = new SimpleBooleanProperty(false);
   
   private final List<MousePositionListener> listeners = new ArrayList<>();
    
   
   public MouseTrackingOverlayPane()
   {        
      
      
      
      
      setMouseTransparent(true);
      JavaFXUtil.onceNotNull(parentProperty(), parent ->
       {
         parent.addEventFilter(MouseEvent.MOUSE_MOVED, e ->
           {
            Point2D p = MouseTrackingOverlayPane.this.sceneToLocal(e.getSceneX(), e.getSceneY());
            mouseX.set(p.getX());
            mouseY.set(p.getY());
               
            for (MousePositionListener l : listeners)
            l.mouseMoved(e.getSceneX(), e.getSceneY());             
            });
         parent.addEventFilter(MouseEvent.MOUSE_ENTERED, e -> mouseInsideProperty.set(true));
         parent.addEventFilter(MouseEvent.MOUSE_EXITED, e -> mouseInsideProperty.set(false));         
         });
      }

   
   


| Adds a node to this pane.  The node's position will be set to be the current mouse
| position plus the given offsets.
|
| If showWhenMouseLeft is true, the node will be shown at the last mouse position when
| the mouse was inside the (parent's; see constructor) node.  If it's false, it will
| be hidden once the mouse exits.
|
public void addMouseTrackingOverlay(Node info, boolean showWhenMouseLeft, DoubleExpression xOffset, DoubleExpression yOffset)
   {
      getChildren().add(info);
      info.layoutXProperty().bind(mouseX.add(xOffset));
      info.layoutYProperty().bind(mouseY.add(yOffset));
      if (!showWhenMouseLeft)
      info.visibleProperty().bind(mouseInsideProperty);     
      }
    
   
   public void addMouseListener(MousePositionListener mouseListener)
   {
      listeners.add(mouseListener);     
      }

   
   


| Removes the node from the pane.
|
public void remove(Node node)
   {
      getChildren().remove(node);     
      }
    
   
   public void removeMouseListener(MousePositionListener mousePositionListener)
   {
      listeners.add(mousePositionListener);     
      }
    
    
   @OnThread(Tag.FXPlatform)
   
   @FunctionalInterface
   
   public static interface MousePositionListener
{              

      
      public void mouseMoved(double sceneX, double sceneY);     
      } 
   }