package greenfoot.guifx.export;

import bluej.Config;
import bluej.utility.javafx.JavaFXUtil;

import javafx.geometry.Orientation;
import javafx.scene.Cursor;
import javafx.scene.control.Slider;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;




| Panel that lets you manipulate an image by zooming (with slider or
| mouse wheel) and moving (by dragging with the mouse).
|
| @author Poul Henriksen
| @author Amjad Altadmri
|
public class ImageEditPane
extends HBox{    
   

| Canvas for the image we are controlling.
|
private ImageEditCanvas imageCanvas;
   
   

| Last position where mouse was dragged.
|
private double lastX;
   
   

| Last position where mouse was dragged.
|
private double lastY;

   
   

| Slider for zooming
|
private Slider zoomSlider;

   
   

| Width of the image view
|
private int width;
   
   

| Height of the image view
|
private int height;
    
   
   

| Label used for the slider.
|
private ImageView bigLabel;
   
   

| Label used for the slider.
|
private ImageView smallLabel;
    
   
   

| Whether to enable dragging / zooming, when we have an image
|
private boolean enableImageControls = true;
   
   

| Whether we actually have an image in the edit canvas
|
private boolean haveImage;
    
   
   


| Construct a new image edit panel for an image with the specified height and width.
|
| @param width The width of the image pane.
| @param height The height of the image pane.
|
public ImageEditPane(int width, int height)
   {        
      this.width = width;
       
      this.height = height;
      setPrefSize(width + 2, height + 2);
      getStyleClass().add("image-edit-pane");
      buildUI();     
      }
    
   
   


| Set the image to be manipulated.
|
| @param snapShot The image to be edited. It could be null.
|
public void setImage(Image snapShot)
   {
      double oldMinScale = imageCanvas.getMinimumScale();
      imageCanvas.setImage(snapShot); 
      double newMinScale = imageCanvas.getMinimumScale();            
      if (!haveImage || Math.abs(newMinScale - oldMinScale) > .0000001)
       {            
         
         imageCanvas.fit();
         zoomSlider.setValue(imageCanvas.getScale());         
         }
      if (!haveImage)
       {            
         haveImage = true;
         enableImageEditPanel(enableImageControls);         
         }     
      }
    
   
   


| Compose the user interface components.
|
private void buildUI()
   {        
      imageCanvas = new ImageEditCanvas(width, height, null);
      imageCanvas.setCursor(Cursor.HAND);
      imageCanvas.setOnMouseDragged(this::mouseDragged);
      imageCanvas.setOnMousePressed(this::mousePressed);
      imageCanvas.setOnMouseReleased(this::mouseReleased);
      imageCanvas.setOnScroll(this::mouseScroll);

      Pane sliderPane = createSliderPane();

       
      
      
      
      
      
      BorderPane border = new BorderPane(imageCanvas);
      border.getStyleClass().add("image-canvas");

      getChildren().addAll(border, sliderPane);     
      }

   
   


| Create a slider attaching two icons to it, a big one and a small one.
| It also sets it min/max values and link it to the image canvas scale.
|
| @return A pane containing the slider and its icons.
|
private Pane createSliderPane()
   {        
      zoomSlider = new Slider();
      zoomSlider.setOrientation(Orientation.VERTICAL);
      zoomSlider.setPrefHeight(imageCanvas.getHeight());
      zoomSlider.setMin(imageCanvas.getMinimumScale());
      zoomSlider.setMax(1);
      JavaFXUtil.addChangeListener(zoomSlider.valueProperty(),
      scale -> imageCanvas.setScale(scale.doubleValue()));

       
      
      Image image = JavaFXUtil.loadImage(Config.getGreenfootLibDir().getAbsolutePath()                
      + "/imagelib/other/greenfoot.png");
       
      bigLabel = new ImageView(image);
      bigLabel.setScaleX(1.2);
      bigLabel.setScaleY(1.2);
       
      smallLabel = new ImageView(image);
      smallLabel.setScaleX(.8);
      smallLabel.setScaleY(.8);

       
      AnchorPane anchorPane  = new AnchorPane(zoomSlider, bigLabel, smallLabel);
      AnchorPane.setLeftAnchor(zoomSlider, 0.0);
      AnchorPane.setTopAnchor(bigLabel, 0.0);
      AnchorPane.setLeftAnchor(bigLabel, 20.0);
      AnchorPane.setBottomAnchor(smallLabel, 0.0);
      AnchorPane.setLeftAnchor(smallLabel, 20.0);

       
      return anchorPane;     
      }

   
   


| The event to move the image in response to mouse drag.
|
| @param e The mouse event information
|
public void mouseDragged(MouseEvent e)
   {
      if (imageCanvas.isDisabled())
       {            
         return;         
         }
      if (e.getButton().equals(MouseButton.PRIMARY))
       {
         imageCanvas.setCursor(Cursor.MOVE);
         double dx = e.getX() - lastX;
         double dy = e.getY() - lastY;
         imageCanvas.move(dx, dy);
         lastX = e.getX();
         lastY = e.getY();         
         }     
      }

   
   


| The event to store the coordinates of a mouse press.
| It may be a start of a drag operation.
|
| @param e The mouse event information
|
public void mousePressed(MouseEvent e)
   {
      if (imageCanvas.isDisabled())
       {            
         return;         
         }
      if (e.getButton().equals(MouseButton.PRIMARY))
       {
         lastX = e.getX();
         lastY = e.getY();         
         }     
      }

   
   


| The event in response to mouse release.
| It may be an end to a drag operation.
|
| @param e The mouse event information
|
public void mouseReleased(MouseEvent e)
   {
      if (imageCanvas.isDisabled())
       {            
         return;         
         }
      if (e.getButton().equals(MouseButton.PRIMARY))
       {
         imageCanvas.setCursor(Cursor.HAND);         
         }     
      }

   
   


| The event to zoom the image in response to a mouse scroll.
|
| @param e The scroll event information
|
public void mouseScroll(ScrollEvent e)
   {
      if (imageCanvas.isDisabled())
       {            
         return;         
         }
      double scroll = e.getDeltaY() / 100;
      zoomSlider.setValue(zoomSlider.getValue() - scroll);     
      }

   
   


| Get the image created by this image panel or null if none exists.
|
public Image getImage()
   {
      if (!haveImage)
       {            
         return null;         
         }
      return JavaFXUtil.createImage(width, height, graphicsContext -> imageCanvas.paintImage(graphicsContext));     
      }
    
   
   


| Sets the slider and the image canvas to be enabled/disabled
|
| @param enabled If true, the controls, the zoom slider and image's canvas
|                will be enabled. Otherwise, they will be disabled.
|
public void enableImageEditPanel(boolean enabled)
   {        
      enableImageControls = enabled;
      if (!enabled || haveImage)
       {
         zoomSlider.setDisable(!enabled);
         imageCanvas.setDisable(!enabled);         
         }     
      } 
   }