col static method

void col(List<GDisplayObject> items, { double gap = 0, double startX = 0, double startY = 0, double width = 0, double height = 0, MainAxisAlignment axisAlign = MainAxisAlignment.start, CrossAxisAlignment crossAlign = CrossAxisAlignment.start, bool mask = false, bool debug = false, })

Arranges the items vertically in a single column, similar to Flutter's Column, with optional gap between them. The column will start at the startX and startY position. The width and height of the column can be specified, but at least one of them must be greater than 0. The axisAlign parameter controls how the items are aligned along the vertical axis, while the crossAlign parameter controls how they are aligned along the horizontal axis. If mask is set to true, the parent container of the items will be clipped to the specified width and height. If debug is set to true, a red rectangle will be drawn around the column for debugging purposes.

Make sure all items belongs to the same parent.

Implementation

static void col(
  List<GDisplayObject> items, {
  double gap = 0,
  double startX = 0,
  double startY = 0,
  double width = 0,
  double height = 0,
  MainAxisAlignment axisAlign = MainAxisAlignment.start,
  CrossAxisAlignment crossAlign = CrossAxisAlignment.start,
  bool mask = false,
  bool debug = false,
}) {
  var currentY = .0, maxW = .0, maxH = .0, itemsH = .0;
  final numItems = items.length;
  if (numItems == 0) {
    return;
  }

  /// default to start.
  for (var i = 0; i < numItems; ++i) {
    var itm = items[i];
    itm.y = startY + currentY;
    itm.x = startX;
    maxW = Math.max(maxW, itm.width);
    var itmH = itm.height;
    itemsH += itmH;
    currentY += itmH + gap;
  }

  if (width <= 0) {
    width = maxW;
  }

  final parent = items.first.parent as GSprite?;
  final hasSize = width > 0 && height > 0;
  if (debug && parent != null && hasSize) {
    final g = parent.graphics;
    g.beginFill(debugColor).drawRect(startX, startY, width, height).endFill();
  }

  maxH = currentY - gap;
  currentY = 0;
  if (mask && parent != null && hasSize) {
    parent.maskRect = GRect(startX, startY, width, height);
  }
  if (crossAlign == CrossAxisAlignment.center) {
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.x = startX + (width - itm.width) / 2;
    }
  } else if (crossAlign == CrossAxisAlignment.end) {
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.x = startX + width - itm.width;
    }
  }

  if (axisAlign == MainAxisAlignment.center) {
    var centerY = (height - maxH) / 2;
    startY += centerY;
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.y = startY + currentY;
      currentY += itm.width + gap;
    }
  } else if (axisAlign == MainAxisAlignment.end) {
    startY += height - maxH;
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.y = startY + currentY;
      currentY += itm.height + gap;
    }
  } else if (axisAlign == MainAxisAlignment.spaceEvenly) {
    /// calculate gap.
    gap = (height - itemsH) / (numItems + 1);
    startY += gap;
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.y = startY + currentY;
      currentY += itm.height + gap;
    }
  } else if (axisAlign == MainAxisAlignment.spaceBetween) {
    gap = (height - itemsH) / (numItems - 1);
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.y = startY + currentY;
      currentY += itm.height + gap;
    }
  } else if (axisAlign == MainAxisAlignment.spaceAround) {
    gap = (height - itemsH) / (numItems);
    startY += gap / 2;
    for (var i = 0; i < numItems; ++i) {
      var itm = items[i];
      itm.y = startY + currentY;
      currentY += itm.height + gap;
    }
  }
}