getTargetRect method

RRect? getTargetRect({ bool rootOverlay = false, })

取得當下的index需要高亮的目標

Implementation

RRect? getTargetRect({
  bool rootOverlay = false,
}) {
  if (targetKey != null) {
    var key = targetKey!;

    final keyContext = key.currentContext;
    if (keyContext == null) {
      return null;
    }
    final renderBox = keyContext.findRenderObject() as RenderBox?;
    if (renderBox == null) {
      return null;
    }
    final size = renderBox.size;

    BuildContext? parentContext;
    if (rootOverlay) {
      parentContext =
          keyContext.findRootAncestorStateOfType<OverlayState>()?.context;
    } else {
      parentContext =
          keyContext.findAncestorStateOfType<NavigatorState>()?.context;
    }
    Offset offset;
    if (parentContext != null) {
      offset = renderBox.localToGlobal(
        Offset.zero,
        ancestor: parentContext.findRenderObject(),
      );
    } else {
      offset = renderBox.localToGlobal(Offset.zero);
    }

    final endOffset = offset.translate(size.width, size.height);
    Rect rect;
    if (targetPadding != null) {
      final paddingStartOffset = offset.translate(
        -targetPadding!.left,
        -targetPadding!.top,
      );
      final paddingEndOffset = endOffset.translate(
        targetPadding!.right,
        targetPadding!.bottom,
      );
      rect = Rect.fromPoints(paddingStartOffset, paddingEndOffset);
    } else {
      rect = Rect.fromPoints(offset, endOffset);
    }
    if (borderRadius != null) {
      return RRect.fromRectAndCorners(
        rect,
        topLeft: borderRadius!.topLeft,
        topRight: borderRadius!.topRight,
        bottomLeft: borderRadius!.bottomLeft,
        bottomRight: borderRadius!.bottomRight,
      );
    } else {
      return RRect.fromRectXY(rect, 0, 0);
    }
  } else {
    return targetRect;
  }
}