cropBy method

Implementation

/// You can set the X-axis and Y-axis position of the
/// top left corner of the crop by
/// using the query ?crop={width_value},{height_value},x{value},y{value}.
/// This lets you define the starting point of the crop region.
/// The x-axis value and y-axis value can be defined in pixels or percentage.
///
/// An `example` of this would be
/// ?crop=300,400,x150,y75 or ?crop=300,400,x0.50,y0.60.
/// Compulsory parameters [width] and [height]
/// Optional parameters: [region]
/// Optional parameters: [offset]
/// For more details, Read documentation:
/// For more details read the doc: https://www.contentstack.com/docs/developers/apis/image-delivery-api/#crop-images
///
/// Example: With Aspect Ratio:
///
/// ```dart
/// final stack = contentstack.Stack(apiKey, deliveryToken, environment);
/// final imageTransformation = stack.imageTransform(imageUrl);
/// final response = await imageTransformation.
///                   cropBy(150, 100, cropRatio: '1:3').fetch();
/// log.fine(response);
/// ```
///
/// Example: Without aspect Ratio:
///
/// ```dart
/// final stack = contentstack.Stack(apiKey, deliveryToken, environment);
/// final imageTransformation = stack.imageTransform(imageUrl);
/// final response = await imageTransformation.cropBy(150, 100).fetch();
/// log.fine(response);
/// ```
void cropBy(int width, int height, {String region, String offset}) {
  /// checks if cropRatio is not null then takes height, width and
  /// cropRatio as prams else it takes crop params and comas
  /// separated width & height
  final cropLRBL = [];
  if (width != null) {
    cropLRBL.add(width);
  }
  if (height != null) {
    cropLRBL.add(height);
  }
  if (region != null) {
    cropLRBL.add(region);
  }
  if (offset != null) {
    cropLRBL.add(offset);
  }
  final commaSeparated = cropLRBL.join(', ');
  query.append('crop', commaSeparated);
}