到目前为止,这是我能想到的解决方案:
public class PositionAdjuster {
public static void main(String[] args) { launch(args); }
private static final float SCALE = FXActivity.getInstance().getResources().getDisplayMetrics().density;
private Node nodeToAdjust;
private ObservableValue<Node> focusOwner;
private ViewGroup viewGroup;
private Rect currentBounds;
private DoubleProperty height;
private OnGlobalLayoutListener layoutListener;
public PositionAdjuster(Node nodeToAdjust, ObservableValue<Node> focusOwner) {
this.nodeToAdjust = nodeToAdjust;
this.focusOwner = focusOwner;
initLayoutListener();
}
private void initLayoutListener() {
double screenHeight = MobileApplication.getInstance().getScreenHeight();
height = new SimpleDoubleProperty(screenHeight);
height.addListener((ov, n, n1) -> onHeightChanged(n, n1));
layoutListener = () -> height.set(getCurrentHeigt());
viewGroup = FXActivity.getViewGroup();
viewGroup.getViewTreeObserver().addOnGlobalLayoutListener(layoutListener);
currentBounds = new Rect();
}
private float getCurrentHeigt() {
viewGroup.getRootView().getWindowVisibleDisplayFrame(currentBounds);
return currentBounds.height() / SCALE;
}
private void onHeightChanged(Number oldValue, Number newValue) {
double heightDelta = newValue.doubleValue() - oldValue.doubleValue();
if (heightDelta < 0) {
double maxY = getBoundsInScene(nodeToAdjust)).getMaxY();
double currentMaxY = heightDelta + maxY;
double result = currentMaxY- getBoundsInScene(focuseOwner.getValue()).getMaxY();
if (result < 0) {
nodeToAdjust.setTranslateY(result);
}
} else if (heightDelta > 0) {
nodeToAdjust.setTranslateY(0);
}
}
private Bounds getBoundsInScene(Node node) {
return node.localToScene(node.getBoundsInLocal());
}
public void removeListener() {
viewGroup.getViewTreeObserver().removeOnGlobalLayoutListener(layoutListener);
}
}
编辑:
我认为这是一种更直接的方法。以前的版本依赖于 maxYnoteToAdjust
等于屏幕的高度,而不考虑例如 bottomBar 的存在。现在,根据可见屏幕高度验证了 的 maxY 位置,focusedNode
差值用于重新定位其父级。
public AndroidPositionAdjuster(Node parent, ObservableValue<Node> focusOwner) {
this.parent = parent;
this.focusOwner = focusOwner;
initLayoutListener();
}
private void onHeightChanged(Number oldHeight, Number newHeight) {
double heightDelta = newHeight.doubleValue() - oldHeight.doubleValue();
if (heightDelta < 0) {
double maxY = newHeight.doubleValue();
double focusedNodeY = getBoundsInScene(focusOwner.getValue()).getMaxY();
double result = maxY - focusedNodeY;
if (result < 0) {
parent.setTranslateY(result);
}
} else if (heightDelta > 0) {
parent.setTranslateY(0);
}
}