resize method

void resize(int newWidth, int newHeight)

Resizes the buffer to the new dimensions, preserving existing content where it fits.

Implementation

void resize(int newWidth, int newHeight) {
  Tracer.record(_traceResizeId, Phase.begin, TraceCategory.layout);
  try {
    newWidth = max(0, newWidth);
    newHeight = max(0, newHeight);
    final newChars = List.filled(newWidth * newHeight, ' ');
    final newAttributes = Uint32List(newWidth * newHeight * 3);

    for (var i = 2; i < newAttributes.length; i += 3) {
      newAttributes[i] = Modifier.transparent;
    }

    final overlapWidth = min(width, newWidth);
    final overlapHeight = min(height, newHeight);

    if (overlapWidth > 0 && overlapHeight > 0) {
      for (var y = 0; y < overlapHeight; y++) {
        final targetCharStart = y * newWidth;
        final sourceCharStart = y * width;
        newChars.setRange(
          targetCharStart,
          targetCharStart + overlapWidth,
          characters,
          sourceCharStart,
        );

        final targetAttrStart = y * newWidth * 3;
        final sourceAttrStart = y * width * 3;
        newAttributes.setRange(
          targetAttrStart,
          targetAttrStart + overlapWidth * 3,
          attributes,
          sourceAttrStart,
        );
      }
    }

    width = newWidth;
    height = newHeight;
    characters = newChars;
    attributes = newAttributes;
  } finally {
    Tracer.record(_traceResizeId, Phase.end, TraceCategory.layout);
  }
}