caculateBadgeParams method

void caculateBadgeParams(
  1. BadgeTab badgeTab,
  2. BoxConstraints constraints
)

Implementation

void caculateBadgeParams(BadgeTab badgeTab, BoxConstraints constraints) {
  _paddingTop = -5.0;

  if (badgeTab.badgeNum != null) {
    if (badgeTab.badgeNum! < 10) {
      _badgePadding = const EdgeInsets.only(left: 5.0, right: 5.0);
      _largeSize = 16.0;
      _badgeText = badgeTab.badgeNum?.toString() ?? "";
    } else if (badgeTab.badgeNum! > 99) {
      _badgePadding = const EdgeInsets.fromLTRB(4, 3, 4, 2);
      _largeSize = 16.0;
      _badgeText = "99+";
    } else {
      _badgePadding = const EdgeInsets.fromLTRB(4, 3, 4, 2);
      _largeSize = 16.0;
      _badgeText = badgeTab.badgeNum?.toString() ?? "";
    }
  } else {
    if (badgeTab.badgeText != null && badgeTab.badgeText!.isNotEmpty) {
      _badgePadding = const EdgeInsets.fromLTRB(6, 3, 6, 3);
      _largeSize = 16.0;
      _badgeText = badgeTab.badgeText?.toString() ?? "";
    } else {
      _badgePadding = const EdgeInsets.only(left: 4.0, right: 4.0);
      _largeSize = 8.0;
      _badgeText = "";
      _paddingTop = 1.0;
    }
  }

  // 获取 tabTextWidth
  TextStyle tabTextStyle =
      const TextStyle(overflow: TextOverflow.ellipsis, fontSize: 16);
  TextPainter tabTextPainter = TextPainter(
      locale: Localizations.localeOf(context), textAlign: TextAlign.center);
  tabTextPainter.textDirection = TextDirection.ltr;
  tabTextPainter.maxLines = 1;
  tabTextPainter.text = TextSpan(text: badgeTab.text, style: tabTextStyle);
  tabTextPainter.layout(maxWidth: constraints.maxWidth);
  double tabTextWidth = tabTextPainter.width;

  // 获取 badgeTextWidth
  TextStyle badgeTextStyle = const TextStyle(height: 1, fontSize: 10);
  TextPainter badgeTextPainter =
      TextPainter(textScaleFactor: MediaQuery.of(context).textScaleFactor);
  badgeTextPainter.textDirection = TextDirection.ltr;
  badgeTextPainter.maxLines = 1;
  badgeTextPainter.text = TextSpan(text: _badgeText, style: badgeTextStyle);
  badgeTextPainter.layout(maxWidth: constraints.maxWidth);
  // 红点内 text 的宽度
  double badgeTextWidth = badgeTextPainter.width;

  double badgeWidth = badgeTextWidth + _badgePadding.horizontal;

  // 获取外部传入的tab padding值
  EdgeInsets labelPadding = widget.labelPadding.resolve(TextDirection.ltr);

  if ((tabTextWidth + badgeWidth) >
      (constraints.maxWidth + labelPadding.right)) {
    // 如果tab文字宽度 + 红点宽度  > 约束宽度（父容器宽度）+ 设置tab 右padding  则将红点左移 红点宽度偏移量
    // if(_badgeWidth > (constraints.maxWidth + _labelPadding.right)){
    //   _paddingRight = 0.0;
    // }else{
    _paddingRight = constraints.maxWidth + labelPadding.right - badgeWidth;
    // }
  } else {
    _paddingRight = tabTextWidth;
  }
}