tmf/org.lttng.scope.tmf2.views.ui/src/org/lttng/scope/tmf2/views/ui/jfx/examples/ZoomExample.java

   1 package org.lttng.scope.tmf2.views.ui.jfx.examples;
   2
   3 import java.net.MalformedURLException;
   4
   5 import org.eclipse.jdt.annotation.NonNullByDefault;
   6
   7 import javafx.application.Application;
   8 import javafx.geometry.Bounds;
   9 import javafx.geometry.Point2D;
  10 import javafx.geometry.Pos;
  11 import javafx.scene.Group;
  12 import javafx.scene.Node;
  13 import javafx.scene.Scene;
  14 import javafx.scene.canvas.Canvas;
  15 import javafx.scene.canvas.GraphicsContext;
  16 import javafx.scene.control.Label;
  17 import javafx.scene.control.ScrollPane;
  18 import javafx.scene.control.SplitPane;
  19 import javafx.scene.layout.Pane;
  20 import javafx.scene.layout.Region;
  21 import javafx.scene.layout.StackPane;
  22 import javafx.scene.paint.Color;
  23 import javafx.scene.shape.Circle;
  24 import javafx.stage.Stage;
  25
  26 @NonNullByDefault({})
  27 public class ZoomExample extends Application {
  28
  29     public static Region createContent() {
  30         double width = 1000;
  31         double height = 1000;
  32
  33         Canvas canvas = new Canvas(width, height);
  34         GraphicsContext gc = canvas.getGraphicsContext2D();
  35
  36         gc.setFill(Color.LIGHTGREY);
  37         gc.fillRect(0, 0, width, height);
  38
  39         gc.setStroke(Color.BLUE);
  40         gc.beginPath();
  41
  42         for (int i = 50; i < width; i += 50) {
  43             gc.moveTo(i, 0);
  44             gc.lineTo(i, height);
  45         }
  46
  47         for (int i = 50; i < height; i += 50) {
  48             gc.moveTo(0, i);
  49             gc.lineTo(width, i);
  50         }
  51         gc.stroke();
  52
  53         Pane content = new Pane(
  54                 new Circle(50, 50, 20),
  55                 new Circle(120, 90, 20, Color.RED),
  56                 new Circle(200, 70, 20, Color.GREEN)
  57         );
  58
  59         StackPane result = new StackPane(canvas, content);
  60         result.setAlignment(Pos.TOP_LEFT);
  61
  62         class DragData {
  63
  64             double startX;
  65             double startY;
  66             double startLayoutX;
  67             double startLayoutY;
  68             Node dragTarget;
  69         }
  70
  71         DragData dragData = new DragData();
  72
  73         content.setOnMousePressed(evt -> {
  74             if (evt.getTarget() != content) {
  75                 // initiate drag gesture, if a child of content receives the
  76                 // event to prevent ScrollPane from panning.
  77                 evt.consume();
  78                 evt.setDragDetect(true);
  79             }
  80         });
  81
  82         content.setOnDragDetected(evt -> {
  83             Node n = (Node) evt.getTarget();
  84             if (n != content) {
  85                 // set start paremeters
  86                 while (n.getParent() != content) {
  87                     n = n.getParent();
  88                 }
  89                 dragData.startX = evt.getX();
  90                 dragData.startY = evt.getY();
  91                 dragData.startLayoutX = n.getLayoutX();
  92                 dragData.startLayoutY = n.getLayoutY();
  93                 dragData.dragTarget = n;
  94                 n.startFullDrag();
  95                 evt.consume();
  96             }
  97         });
  98
  99         // stop dragging when mouse is released
 100         content.setOnMouseReleased(evt -> dragData.dragTarget = null);
 101
 102         content.setOnMouseDragged(evt -> {
 103             if (dragData.dragTarget != null) {
 104                 // move dragged node
 105                 dragData.dragTarget.setLayoutX(evt.getX() + dragData.startLayoutX - dragData.startX);
 106                 dragData.dragTarget.setLayoutY(evt.getY() + dragData.startLayoutY - dragData.startY);
 107 //                Point2D p = new Point2D(evt.getX(), evt.getY());
 108                 evt.consume();
 109             }
 110         });
 111
 112         return result;
 113     }
 114
 115     @Override
 116     public void start(Stage primaryStage) throws MalformedURLException {
 117         Region zoomTarget = createContent();
 118         zoomTarget.setPrefSize(1000, 1000);
 119         zoomTarget.setOnDragDetected(evt -> {
 120             Node target = (Node) evt.getTarget();
 121             while (target != zoomTarget && target != null) {
 122                 target = target.getParent();
 123             }
 124             if (target != null) {
 125                 target.startFullDrag();
 126             }
 127         });
 128
 129         Group group = new Group(zoomTarget);
 130
 131         // stackpane for centering the content, in case the ScrollPane viewport
 132         // is larget than zoomTarget
 133         StackPane content = new StackPane(group);
 134         group.layoutBoundsProperty().addListener((observable, oldBounds, newBounds) -> {
 135             // keep it at least as large as the content
 136             content.setMinWidth(newBounds.getWidth());
 137             content.setMinHeight(newBounds.getHeight());
 138         });
 139
 140         ScrollPane scrollPane = new ScrollPane(content);
 141         scrollPane.setPannable(true);
 142         scrollPane.viewportBoundsProperty().addListener((observable, oldBounds, newBounds) -> {
 143             // use vieport size, if not too small for zoomTarget
 144             content.setPrefSize(newBounds.getWidth(), newBounds.getHeight());
 145         });
 146
 147         content.setOnScroll(evt -> {
 148             if (evt.isControlDown()) {
 149                 evt.consume();
 150
 151                 final double zoomFactor = evt.getDeltaY() > 0 ? 1.2 : 1 / 1.2;
 152
 153                 Bounds groupBounds = group.getLayoutBounds();
 154                 final Bounds viewportBounds = scrollPane.getViewportBounds();
 155
 156                 // calculate pixel offsets from [0, 1] range
 157                 double valX = scrollPane.getHvalue() * (groupBounds.getWidth() - viewportBounds.getWidth());
 158                 double valY = scrollPane.getVvalue() * (groupBounds.getHeight() - viewportBounds.getHeight());
 159
 160                 // convert content coordinates to zoomTarget coordinates
 161                 Point2D posInZoomTarget = zoomTarget.parentToLocal(group.parentToLocal(new Point2D(evt.getX(), evt.getY())));
 162
 163                 // calculate adjustment of scroll position (pixels)
 164                 Point2D adjustment = zoomTarget.getLocalToParentTransform().deltaTransform(posInZoomTarget.multiply(zoomFactor - 1));
 165
 166                 // do the resizing
 167                 zoomTarget.setScaleX(zoomFactor * zoomTarget.getScaleX());
 168                 zoomTarget.setScaleY(zoomFactor * zoomTarget.getScaleY());
 169
 170                 // refresh ScrollPane scroll positions & content bounds
 171                 scrollPane.layout();
 172
 173                 // convert back to [0, 1] range
 174                 // (too large/small values are automatically corrected by ScrollPane)
 175                 groupBounds = group.getLayoutBounds();
 176                 scrollPane.setHvalue((valX + adjustment.getX()) / (groupBounds.getWidth() - viewportBounds.getWidth()));
 177                 scrollPane.setVvalue((valY + adjustment.getY()) / (groupBounds.getHeight() - viewportBounds.getHeight()));
 178             }
 179         });
 180
 181         StackPane left = new StackPane(new Label("Left Menu"));
 182         SplitPane root = new SplitPane(left, scrollPane);
 183
 184         Scene scene = new Scene(root, 800, 600);
 185
 186         primaryStage.setScene(scene);
 187         primaryStage.show();
 188     }
 189
 190     public static void main(String[] args) {
 191         launch(args);
 192     }
 193
 194 }