JavaFX 8动态节点缩放 [英] JavaFX 8 Dynamic Node scaling
本文介绍了JavaFX 8动态节点缩放的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试使用ScrollPane实现一个场景，用户可以在其中拖动节点并对其进行动态缩放.我可以使用鼠标滚轮进行拖动和缩放，也可以进行重置缩放，但是在使节点适合父级宽度的计算中遇到了麻烦.
I'm trying to implement a scene with a ScrollPane in which the user can drag a node around and scale it dynamically. I have the dragging and scaling with the mouse wheel working as well as a reset zoom, but I'm having trouble with the calculations to fit the node to the width of the parent.
这是我作为 sscce 的代码.
- (有效)鼠标滚轮将围绕鼠标指针放大和缩小
- (有效)左右键拖动矩形
- (有效)左键双击以重置缩放
- (无效)右键单击以适合宽度
如果我放大或缩小或更改窗口大小，则无法适应宽度.
If I zoom in or out or change the window size, the fit to width does not work.
如果有人可以帮助我进行计算，以使节点适合父级的宽度，我将非常感激.
If anyone can help me with the calculations to fit the node to the width of the parent, I would very much appreciate it.
已
EDITED:
- 我标记了无法正常工作的方法.它是
fitWidth()，双击鼠标右键即可调用. - 为了清晰和重点突出，我编辑了问题的文本
- I marked the method that is not working correctly. It is
fitWidth(), which is invoked by right mouse button double-clicking. - I edited the text of the question for clarity and focus
希望这现在更加清楚了.
Hopefully this is more clear now.
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.ScrollPane.ScrollBarPolicy;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.ScrollEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.shape.StrokeType;
import javafx.stage.Stage;
import javafx.util.Duration;
public class ZoomAndPanExample extends Application {
private ScrollPane scrollPane = new ScrollPane();
private final DoubleProperty zoomProperty = new SimpleDoubleProperty(1.0d);
private final DoubleProperty deltaY = new SimpleDoubleProperty(0.0d);
private final Group group = new Group();
public static void main(String[] args) {
Application.launch(args);
}
@Override
public void start(Stage primaryStage) {
scrollPane.setPannable(true);
scrollPane.setHbarPolicy(ScrollBarPolicy.NEVER);
scrollPane.setVbarPolicy(ScrollBarPolicy.NEVER);
AnchorPane.setTopAnchor(scrollPane, 10.0d);
AnchorPane.setRightAnchor(scrollPane, 10.0d);
AnchorPane.setBottomAnchor(scrollPane, 10.0d);
AnchorPane.setLeftAnchor(scrollPane, 10.0d);
AnchorPane root = new AnchorPane();
Rectangle rect = new Rectangle(80, 60);
rect.setStroke(Color.NAVY);
rect.setFill(Color.NAVY);
rect.setStrokeType(StrokeType.INSIDE);
group.getChildren().add(rect);
// create canvas
PanAndZoomPane panAndZoomPane = new PanAndZoomPane();
zoomProperty.bind(panAndZoomPane.myScale);
deltaY.bind(panAndZoomPane.deltaY);
panAndZoomPane.getChildren().add(group);
SceneGestures sceneGestures = new SceneGestures(panAndZoomPane);
scrollPane.setContent(panAndZoomPane);
panAndZoomPane.toBack();
scrollPane.addEventFilter( MouseEvent.MOUSE_CLICKED, sceneGestures.getOnMouseClickedEventHandler());
scrollPane.addEventFilter( MouseEvent.MOUSE_PRESSED, sceneGestures.getOnMousePressedEventHandler());
scrollPane.addEventFilter( MouseEvent.MOUSE_DRAGGED, sceneGestures.getOnMouseDraggedEventHandler());
scrollPane.addEventFilter( ScrollEvent.ANY, sceneGestures.getOnScrollEventHandler());
root.getChildren().add(scrollPane);
Scene scene = new Scene(root, 600, 400);
primaryStage.setScene(scene);
primaryStage.show();
}
class PanAndZoomPane extends Pane {
public static final double DEFAULT_DELTA = 1.3d;
DoubleProperty myScale = new SimpleDoubleProperty(1.0);
public DoubleProperty deltaY = new SimpleDoubleProperty(0.0);
private Timeline timeline;
public PanAndZoomPane() {
this.timeline = new Timeline(60);
// add scale transform
scaleXProperty().bind(myScale);
scaleYProperty().bind(myScale);
}
public double getScale() {
return myScale.get();
}
public void setScale( double scale) {
myScale.set(scale);
}
public void setPivot( double x, double y, double scale) {
// note: pivot value must be untransformed, i. e. without scaling
// timeline that scales and moves the node
timeline.getKeyFrames().clear();
timeline.getKeyFrames().addAll(
new KeyFrame(Duration.millis(200), new KeyValue(translateXProperty(), getTranslateX() - x)),
new KeyFrame(Duration.millis(200), new KeyValue(translateYProperty(), getTranslateY() - y)),
new KeyFrame(Duration.millis(200), new KeyValue(myScale, scale))
);
timeline.play();
}
/**
* !!!! The problem is in this method !!!!
*
* The calculations are incorrect, and result in unpredictable behavior
*
*/
public void fitWidth () {
double scale = getParent().getLayoutBounds().getMaxX()/getLayoutBounds().getMaxX();
double oldScale = getScale();
double f = (scale / oldScale)-1;
double dx = getTranslateX() - getBoundsInParent().getMinX() - getBoundsInParent().getWidth()/2;
double dy = getTranslateY() - getBoundsInParent().getMinY() - getBoundsInParent().getHeight()/2;
double newX = f*dx + getBoundsInParent().getMinX();
double newY = f*dy + getBoundsInParent().getMinY();
setPivot(newX, newY, scale);
}
public void resetZoom () {
double scale = 1.0d;
double x = getTranslateX();
double y = getTranslateY();
setPivot(x, y, scale);
}
public double getDeltaY() {
return deltaY.get();
}
public void setDeltaY( double dY) {
deltaY.set(dY);
}
}
/**
* Mouse drag context used for scene and nodes.
*/
class DragContext {
double mouseAnchorX;
double mouseAnchorY;
double translateAnchorX;
double translateAnchorY;
}
/**
* Listeners for making the scene's canvas draggable and zoomable
*/
public class SceneGestures {
private DragContext sceneDragContext = new DragContext();
PanAndZoomPane panAndZoomPane;
public SceneGestures( PanAndZoomPane canvas) {
this.panAndZoomPane = canvas;
}
public EventHandler<MouseEvent> getOnMouseClickedEventHandler() {
return onMouseClickedEventHandler;
}
public EventHandler<MouseEvent> getOnMousePressedEventHandler() {
return onMousePressedEventHandler;
}
public EventHandler<MouseEvent> getOnMouseDraggedEventHandler() {
return onMouseDraggedEventHandler;
}
public EventHandler<ScrollEvent> getOnScrollEventHandler() {
return onScrollEventHandler;
}
private EventHandler<MouseEvent> onMousePressedEventHandler = new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
sceneDragContext.mouseAnchorX = event.getX();
sceneDragContext.mouseAnchorY = event.getY();
sceneDragContext.translateAnchorX = panAndZoomPane.getTranslateX();
sceneDragContext.translateAnchorY = panAndZoomPane.getTranslateY();
}
};
private EventHandler<MouseEvent> onMouseDraggedEventHandler = new EventHandler<MouseEvent>() {
public void handle(MouseEvent event) {
panAndZoomPane.setTranslateX(sceneDragContext.translateAnchorX + event.getX() - sceneDragContext.mouseAnchorX);
panAndZoomPane.setTranslateY(sceneDragContext.translateAnchorY + event.getY() - sceneDragContext.mouseAnchorY);
event.consume();
}
};
/**
* Mouse wheel handler: zoom to pivot point
*/
private EventHandler<ScrollEvent> onScrollEventHandler = new EventHandler<ScrollEvent>() {
@Override
public void handle(ScrollEvent event) {
double delta = PanAndZoomPane.DEFAULT_DELTA;
double scale = panAndZoomPane.getScale(); // currently we only use Y, same value is used for X
double oldScale = scale;
panAndZoomPane.setDeltaY(event.getDeltaY());
if (panAndZoomPane.deltaY.get() < 0) {
scale /= delta;
} else {
scale *= delta;
}
double f = (scale / oldScale)-1;
double dx = (event.getX() - (panAndZoomPane.getBoundsInParent().getWidth()/2 + panAndZoomPane.getBoundsInParent().getMinX()));
double dy = (event.getY() - (panAndZoomPane.getBoundsInParent().getHeight()/2 + panAndZoomPane.getBoundsInParent().getMinY()));
panAndZoomPane.setPivot(f*dx, f*dy, scale);
event.consume();
}
};
/**
* Mouse click handler
*/
private EventHandler<MouseEvent> onMouseClickedEventHandler = new EventHandler<MouseEvent>() {
@Override
public void handle(MouseEvent event) {
if (event.getButton().equals(MouseButton.PRIMARY)) {
if (event.getClickCount() == 2) {
panAndZoomPane.resetZoom();
}
}
if (event.getButton().equals(MouseButton.SECONDARY)) {
if (event.getClickCount() == 2) {
panAndZoomPane.fitWidth();
}
}
}
};
}
}
推荐答案
我找到了答案.我正在查看错误的计算，并假定它与翻译有关.真正的罪魁祸首是规模差异的计算.我只是改变了这一点:
I found the answer. I was looking at the wrong calculations, assuming it to be related to the translations. The real culprit was the calculation for the difference in scale. I simply changed this:
double f = (scale / oldScale)-1;
对此:
double f = scale - oldScale;
这篇关于JavaFX 8动态节点缩放的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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