我正在使用UndoFX& ReactFX用于为我的2D形状应用程序实现撤消/重做功能。
问题是当我移动我的形状时,EventStream会记录每个X / Y运动像素。我只想记录最后一个位置(当用户释放拖动时)。
到目前为止我尝试了什么:
而不是使用changesOf(rect.xProperty()).map(c -> new xChange(c));
和
changesOf(rect.yProperty()).map(c -> new yChange(c));
我创建了一个DoubleProperty x,y
,并在释放用户鼠标时将形状x,y Property保存到这些变量中。
最后,我将更改更改为:changesOf(this.x).map(c -> new xChange(c));
和changesOf(this.y).map(c -> new yChange(c));
但这不起作用,它表现得像以前一样。
....
private class xChange extends RectangleChange<Double> {
public xChange(Double oldValue, Double newValue) {
super(oldValue, newValue);
}
public xChange(Change<Number> c) {
super(c.getOldValue().doubleValue(), c.getNewValue().doubleValue());
}
@Override void redo() { rect.setX(newValue); }
@Override xChange invert() { return new xChange(newValue, oldValue); }
@Override Optional<RectangleChange<?>> mergeWith(RectangleChange<?> other) {
if(other instanceof xChange) {
return Optional.of(new xChange(oldValue, ((xChange) other).newValue));
} else {
return Optional.empty();
}
}
@Override
public boolean equals(Object other) {
if(other instanceof xChange) {
xChange that = (xChange) other;
return Objects.equals(this.oldValue, that.oldValue)
&& Objects.equals(this.newValue, that.newValue);
} else {
return false;
}
}
}
...
EventStream<xChange> xChanges = changesOf(rect.xProperty()).map(c -> new xChange(c));
EventStream<yChange> yChanges = changesOf(rect.yProperty()).map(c -> new yChange(c));
changes = merge(widthChanges, heightChanges, xChanges, yChanges);
undoManager = UndoManagerFactory.unlimitedHistoryUndoManager(
changes, // stream of changes to observe
c -> c.invert(), // function to invert a change
c -> c.redo(), // function to undo a change
(c1, c2) -> c1.mergeWith(c2)); // function to merge two changes
答案 0 :(得分:2)
您需要将x中的更改与y中的更改合并。目前,x的变化后跟y的变化无法合并,因此如果移动形状使其交替x和y的变化(例如,沿对角线移动),则每个单独的变化将不会与前一个变化合并。
执行此操作的一种方法是生成其旧旧值为位置的更改,例如由Point2D
个对象表示。这是一个简单的例子:
import java.util.Objects;
import java.util.Optional;
import org.fxmisc.undo.UndoManager;
import org.fxmisc.undo.UndoManagerFactory;
import org.reactfx.EventStream;
import org.reactfx.EventStreams;
import org.reactfx.SuspendableEventStream;
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.geometry.Insets;
import javafx.geometry.Point2D;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
public class UndoRectangle extends Application {
@Override
public void start(Stage primaryStage) {
Rectangle rect = new Rectangle(50, 50, 150, 100);
rect.setFill(Color.CORNFLOWERBLUE);
EventStream<PositionChange> xChanges = EventStreams.changesOf(rect.xProperty()).map(c -> {
double oldX = c.getOldValue().doubleValue();
double newX = c.getNewValue().doubleValue();
double y = rect.getY();
return new PositionChange(new Point2D(oldX, y), new Point2D(newX, y));
});
EventStream<PositionChange> yChanges = EventStreams.changesOf(rect.yProperty()).map(c -> {
double oldY = c.getOldValue().doubleValue();
double newY = c.getNewValue().doubleValue();
double x = rect.getX();
return new PositionChange(new Point2D(x, oldY), new Point2D(x, newY));
});
SuspendableEventStream<PositionChange> posChanges = EventStreams.merge(xChanges, yChanges)
.reducible(PositionChange::merge);
UndoManager undoManager = UndoManagerFactory.unlimitedHistoryUndoManager(posChanges,
PositionChange::invert,
c -> posChanges.suspendWhile(() -> {
rect.setX(c.getNewPosition().getX());
rect.setY(c.getNewPosition().getY());
}),
(c1, c2) -> Optional.of(c1.merge(c2))
);
class MouseLoc { double x, y ; }
MouseLoc mouseLoc = new MouseLoc();
rect.setOnMousePressed(e -> {
mouseLoc.x = e.getSceneX();
mouseLoc.y = e.getSceneY();
});
rect.setOnMouseDragged(e -> {
rect.setX(rect.getX() + e.getSceneX() - mouseLoc.x);
rect.setY(rect.getY() + e.getSceneY() - mouseLoc.y);
mouseLoc.x = e.getSceneX();
mouseLoc.y = e.getSceneY();
});
rect.setOnMouseReleased(e -> undoManager.preventMerge());
Pane pane = new Pane(rect);
Button undo = new Button("Undo");
undo.disableProperty().bind(Bindings.not(undoManager.undoAvailableProperty()));
undo.setOnAction(e -> undoManager.undo());
Button redo = new Button("Redo");
redo.disableProperty().bind(Bindings.not(undoManager.redoAvailableProperty()));
redo.setOnAction(e -> undoManager.redo());
HBox buttons = new HBox(5, undo, redo);
buttons.setAlignment(Pos.CENTER);
BorderPane.setMargin(buttons, new Insets(5));
BorderPane root = new BorderPane(pane, null, null, buttons, null);
Scene scene = new Scene(root, 600, 600);
primaryStage.setScene(scene);
primaryStage.show();
}
public static class PositionChange {
private final Point2D oldPosition ;
private final Point2D newPosition ;
public PositionChange(Point2D oldPos, Point2D newPos) {
this.oldPosition = oldPos ;
this.newPosition = newPos ;
}
public Point2D getOldPosition() {
return oldPosition;
}
public Point2D getNewPosition() {
return newPosition;
}
public PositionChange merge(PositionChange other) {
return new PositionChange(oldPosition, other.newPosition);
}
public PositionChange invert() {
return new PositionChange(newPosition, oldPosition);
}
@Override
public boolean equals(Object o) {
if (o instanceof PositionChange) {
PositionChange other = (PositionChange) o ;
return Objects.equals(oldPosition, other.oldPosition)
&& Objects.equals(newPosition, other.newPosition);
} else return false ;
}
@Override
public int hashCode() {
return Objects.hash(oldPosition, newPosition);
}
}
public static void main(String[] args) {
launch(args);
}
}
请注意,重要的是&#34;撤消&#34;实现为&#34; atomic&#34;更改,因此撤消管理器在实现撤消时会看到(并忽略)单个更改。这可以通过在撤消期间暂停事件流来实现。