我正在扩展默认的Menu和MenuItem类，以便为其添加一些动画效果。
问题在于我需要知道Menu和MenuItem我正在处理的宽度和高度。这些课程不会延伸Node或Region，因此没有公开的方法可以获得它们的大小。大小由MenuItem内的文本大小加上相应的默认填充组成，我可以计算文本占用的空间，但我无法得到MenuItem的填充量。
有一个名为impl_styleableGetNode()的方法返回Node，但它总是为我返回null。
无论如何要获得尺寸？ MenuBar似乎也没有为此提供任何有用的方法。
修改
以下是我的课程，我试图在Menu课程中实施this素材设计按钮。基本上我使用setGraphic()方法渲染所有按钮。它工作得很好，但我使用的Pane宽度并未考虑Menu的填充，因此效果不完整。
public class MaterialDesignMenu extends Menu {
private Pane stackPane = new Pane();
private Label label = new Label();
private Circle circleRipple;
private Rectangle rippleClip = new Rectangle();
private Duration rippleDuration = Duration.millis(250);
private double lastRippleHeight = 0;
private double lastRippleWidth = 0;
private Color rippleColor = new Color(1, 0, 0, 0.3);
public MaterialDesignMenu() {
init("");
}
public MaterialDesignMenu(String text) {
init(text);
}
public MaterialDesignMenu(String text, Node graphic) {
init(text);
}
private void init(String text){
label.setText(text);
createRippleEffect();
stackPane.getChildren().addAll(circleRipple, label);
setGraphic(stackPane);
}
private void createRippleEffect() {
circleRipple = new Circle(0.1, rippleColor);
circleRipple.setOpacity(0.0);
// Optional box blur on ripple - smoother ripple effect
//circleRipple.setEffect(new BoxBlur(3, 3, 2));
// Fade effect bit longer to show edges on the end of animation
final FadeTransition fadeTransition = new FadeTransition(rippleDuration, circleRipple);
fadeTransition.setInterpolator(Interpolator.EASE_OUT);
fadeTransition.setFromValue(1.0);
fadeTransition.setToValue(0.0);
final Timeline scaleRippleTimeline = new Timeline();
final SequentialTransition parallelTransition = new SequentialTransition();
parallelTransition.getChildren().addAll(
scaleRippleTimeline,
fadeTransition
);
// When ripple transition is finished then reset circleRipple to starting point
parallelTransition.setOnFinished(event -> {
circleRipple.setOpacity(0.0);
circleRipple.setRadius(0.1);
});
stackPane.addEventHandler(MouseEvent.MOUSE_PRESSED, event -> {
parallelTransition.stop();
// Manually fire finish event
parallelTransition.getOnFinished().handle(null);
circleRipple.setCenterX(event.getX());
circleRipple.setCenterY(event.getY());
// Recalculate ripple size if size of button from last time was changed
if (stackPane.getWidth() != lastRippleWidth || stackPane.getHeight() != lastRippleHeight) {
lastRippleWidth = stackPane.getWidth();
lastRippleHeight = stackPane.getHeight();
rippleClip.setWidth(lastRippleWidth);
rippleClip.setHeight(lastRippleHeight);
/*
// try block because of possible null of Background, fills ...
try {
rippleClip.setArcHeight(stackPane.getBackground().getFills().get(0).getRadii().getTopLeftHorizontalRadius());
rippleClip.setArcWidth(stackPane.getBackground().getFills().get(0).getRadii().getTopLeftHorizontalRadius());
circleRipple.setClip(rippleClip);
} catch (Exception e) {
e.printStackTrace();
}*/
circleRipple.setClip(rippleClip);
// Getting 45% of longest button's length, because we want edge of ripple effect always visible
double circleRippleRadius = Math.max(stackPane.getHeight(), stackPane.getWidth()) * 0.45;
final KeyValue keyValue = new KeyValue(circleRipple.radiusProperty(), circleRippleRadius, Interpolator.EASE_OUT);
final KeyFrame keyFrame = new KeyFrame(rippleDuration, keyValue);
scaleRippleTimeline.getKeyFrames().clear();
scaleRippleTimeline.getKeyFrames().add(keyFrame);
}
parallelTransition.playFromStart();
});
}
public void setRippleColor(Color color) {
circleRipple.setFill(color);
}
}
答案 0 :(得分：1)
首先，您必须收听parentPopupProperty的{{1}}更改。当您获得父弹出窗口的实例而不是MenuItem skinProperty（parentPopup）的寄存器监听器时。获得皮肤后，您可以获得ContextMenu等同于MenuItemContainer的{{1}}，并且您可以收听Node或MenuItem widthProperty次更改}。
注意：heightProperty更改在屏幕上显示MenuItemContainer之前触发。
自定义类扩展skinProperty类：
ContextMenu自定义MenuItem侦听器类：
public class CstMenuItem extends MenuItem {
public CstMenuItem() {
// Create custom menu item listener.
new CstMenuItemListener(this);
}
/*
* Returns MenuItemContainer node associated with this menu item
* which can contain:
* 1. label node of type Label for displaying menu item text,
* 2. right node of type Label for displaying accelerator text,
* or an arrow if it's a Menu,
* 3. graphic node for displaying menu item icon, and
* 4. left node for displaying either radio button or check box.
*
* This is basically rewritten impl_styleableGetNode() which
* should not be used since it's marked as deprecated.
*/
public ContextMenuContent.MenuItemContainer getAssociatedNode() {
ContextMenu contextMenu = getParentPopup();
ContextMenuSkin skin = (ContextMenuSkin) contextMenu.getSkin();
ContextMenuContent content = (ContextMenuContent) skin.getNode();
// Items container contains MenuItemContainer nodes and Separator nodes.
Parent itemsContainer = content.getItemsContainer();
List<Node> children = itemsContainer.getChildrenUnmodifiable();
for (Node child : children) {
if (child instanceof ContextMenuContent.MenuItemContainer) {
ContextMenuContent.MenuItemContainer menuItemContainer =
(ContextMenuContent.MenuItemContainer) child;
if (menuItemContainer.getItem() == this) {
return menuItemContainer;
}
}
}
return null;
}
}