非常奇怪的问题,我最终成功将其浓缩成一个小代码片段来演示这个问题。我有一个包含1个组的窗格,该组包含一个包含一些椭圆的组。顶部组应用了旋转变换。椭圆可以被拖动。
请尝试下面的示例,向下拖动一些椭圆(超出组的边界),您将看到它们消失了。如果您最大化窗口,它们会再次出现,但您无法再拖动它们,它们不再接收任何事件。
现在是真正奇怪的部分,有三种方法可以解决这个问题:
代码(JavaFX 2.2.3和java 1.7.0_09 64位Windows 7):
请尝试下面的示例,向下拖动一些椭圆(超出组的边界),您将看到它们消失了。如果您最大化窗口,它们会再次出现,但您无法再拖动它们,它们不再接收任何事件。
现在是真正奇怪的部分,有三种方法可以解决这个问题:
- 不要应用变换
- 删除一个椭圆(!?) (我进行了实验以得出这个数字,11)
- 同时启动ScenicView并选择包含椭圆的组,以便您可以看到组的边界
代码(JavaFX 2.2.3和java 1.7.0_09 64位Windows 7):
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Point2D;
import javafx.scene.Group;
import javafx.scene.GroupBuilder;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.SceneBuilder;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Ellipse;
import javafx.scene.shape.EllipseBuilder;
import javafx.scene.transform.Rotate;
import javafx.scene.transform.RotateBuilder;
import javafx.stage.Stage;
public class DragProblem extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) {
DrawingPane drawingPane = new DrawingPane();
drawingPane.setStyle("-fx-background-color: darkgrey;");
Scene scene = SceneBuilder.create().root(drawingPane).width(1280d).height(1024d).build();
primaryStage.setScene(scene);
primaryStage.show();
}
public class DrawingPane extends Pane {
private Group transformedGroup;
private Group splinePoints;
public DrawingPane() {
transformedGroup = GroupBuilder.create().id("transformedGroup").build();
getChildren().add(transformedGroup);
addPoints();
makePointsDraggable();
}
public void addPoints() {
double[] coords = new double[] {
// comment any one the below x,y coordinates and the problem doesn't occur..
239.28353881835938, 488.2192687988281,
245.04466247558594, 505.30169677734375,
258.56671142578125, 539.49462890625,
267.2294006347656, 563.618408203125,
282.89141845703125, 587.84033203125,
309.6925048828125, 602.2174072265625,
327.4945068359375, 616.4683227539062,
345.25445556640625, 633.718994140625,
371.0416259765625, 649.0819702148438,
393.78704833984375, 667.402587890625,
442.67010498046875, 676.0886840820312 };
splinePoints = GroupBuilder.create().build();
for (int i = 0; i < coords.length; i += 2) {
Ellipse ellipse = EllipseBuilder.create().radiusX(3).radiusY(3).centerX(coords[i]).centerY(coords[i + 1]).build();
splinePoints.getChildren().add(ellipse);
}
transformedGroup.getChildren().add(splinePoints);
Rotate rotateTransform = RotateBuilder.create().build();
rotateTransform.setPivotX(224);
rotateTransform.setPivotY(437);
rotateTransform.setAngle(15);
// ..or comment this line to prevent the problem occuring
transformedGroup.getTransforms().add(rotateTransform);
}
public void makePointsDraggable() {
for (final Node n : splinePoints.getChildren()) {
Ellipse e = (Ellipse) n;
final NodeDragHandler ellipseDragHandler = new NodeDragHandler(e, transformedGroup);
e.setOnMousePressed(ellipseDragHandler);
e.setOnMouseDragged(ellipseDragHandler);
}
}
}
public class NodeDragHandler implements EventHandler<MouseEvent> {
protected final Ellipse node;
private final Node transformedGroup;
private double initialX;
private double initialY;
private Point2D initial;
private boolean dragStarted = false;
public NodeDragHandler(Ellipse node, Group transformedGroup) {
this.node = node;
this.transformedGroup = transformedGroup;
}
@Override
public void handle(MouseEvent event) {
if (!dragStarted) {
initialX = event.getScreenX();
initialY = event.getScreenY();
initial = transformedGroup.localToParent(new Point2D(node.getCenterX(), node.getCenterY()));
dragStarted = true;
} else {
double xDragged = event.getScreenX() - initialX;
double yDragged = event.getScreenY() - initialY;
Point2D newPos = new Point2D(initial.getX() + xDragged, initial.getY() + yDragged);
Point2D p = transformedGroup.parentToLocal(newPos.getX(), newPos.getY());
node.setCenterX(p.getX());
node.setCenterY(p.getY());
}
}
}
}