MutableRectangle<T extends num>

class MutableRectangle<T extends num> extends _RectangleBase<T> implements Rectangle<T>

A class for representing two-dimensional axis-aligned rectangles with mutable properties.

Legacy: New usages of MutableRectangle are discouraged.

• If you are using the MutableRectangle class with dart:html, we recommend migrating to package:web. To learn how and why to migrate, check out the migration guide.
• If you want to store the boundaries of a rectangle in some coordinate system, consider using a record. Depending on how you will use it, this could look like var boundaries = (mixX: x1, maxX: x2, minY: y1, maxY: y2).
• If you need to perform intersection calculations or containment checks, consider using a dedicated library, such as package:vector_math.
• If you are developing a Flutter application or package, consider using the Rect type from dart:ui.

Implemented types

• Rectangle<T extends num>

Constructors

MutableRectangle()

MutableRectangle(T left, T top, T width, T height)

Create a mutable rectangle spanned by (left, top) and (left+width, top+height).

The rectangle contains the points with x-coordinate between left and left + width, and with y-coordinate between top and top + height, both inclusive.

The width and height should be non-negative. If width or height are negative, they are clamped to zero.

If width and height are zero, the "rectangle" comprises only the single point (left, top).

Example:

var rectangle = MutableRectangle(20, 50, 300, 600);
print(rectangle); // Rectangle (20, 50) 300 x 600
print(rectangle.left); // 20
print(rectangle.top); // 50
print(rectangle.right); // 320
print(rectangle.bottom); // 650

// Change rectangle width and height.
rectangle.width = 200;
rectangle.height = 100;

print(rectangle); // Rectangle (20, 50) 200 x 100
print(rectangle.left); // 20
print(rectangle.top); // 50
print(rectangle.right); // 220
print(rectangle.bottom); // 150

Legacy: New usages of MutableRectangle are discouraged. To learn more, check out the MutableRectangle class API docs.

Implementation

MutableRectangle(this.left, this.top, T width, T height)
  : this._width = (width < 0)
        ? _clampToZero<T>(width)
        : (width + 0 as dynamic),
    this._height = (height < 0)
        ? _clampToZero<T>(height)
        : (height + 0 as dynamic);

MutableRectangle.fromPoints() factory

factory MutableRectangle.fromPoints(Point<T> a, Point<T> b)

Create a mutable rectangle spanned by the points a and b;

The rectangle contains the points with x-coordinate between a.x and b.x, and with y-coordinate between a.y and b.y, both inclusive.

If the distance between a.x and b.x is not representable (which can happen if one or both is a double), the actual right edge might be slightly off from max(a.x, b.x). Similar for the y-coordinates and the bottom edge.

Example:

var leftTop = const Point(20, 50);
var rightBottom = const Point(300, 600);
var rectangle = MutableRectangle.fromPoints(leftTop, rightBottom);
print(rectangle); // Rectangle (20, 50) 280 x 550
print(rectangle.left); // 20
print(rectangle.top); // 50
print(rectangle.right); // 300
print(rectangle.bottom); // 600

Implementation

factory MutableRectangle.fromPoints(Point<T> a, Point<T> b) {
  T left = min(a.x, b.x);
  T width = (max(a.x, b.x) - left) as T;
  T top = min(a.y, b.y);
  T height = (max(a.y, b.y) - top) as T;
  return MutableRectangle<T>(left, top, width, height);
}

Properties

bottom no setter inherited

T get bottom

Inherited from _RectangleBase.

Implementation

T get bottom => (top + height) as T;

bottomLeft no setter inherited

Point<T> get bottomLeft

Inherited from _RectangleBase.

Implementation

Point<T> get bottomLeft => Point<T>(this.left, (this.top + this.height) as T);

bottomRight no setter inherited

Point<T> get bottomRight

Inherited from _RectangleBase.

Implementation

Point<T> get bottomRight =>
    Point<T>((this.left + this.width) as T, (this.top + this.height) as T);

hashCode no setter inherited

int get hashCode

Inherited from _RectangleBase.

Implementation

int get hashCode => SystemHash.hash4(
  left.hashCode,
  top.hashCode,
  right.hashCode,
  bottom.hashCode,
  0,
);

height read / write

T get height

getter:

The height of the rectangle.

setter:

Sets the height of the rectangle.

The height must be non-negative. If a negative height is supplied, it is clamped to zero.

Setting the value will change the bottom edge of the rectangle, but will not change top.

Implementation

T get height => _height;

set height(T height) {
  if (height < 0) height = _clampToZero<T>(height);
  _height = height;
}

left read / write

T left

getter:

The x-coordinate of the left edge.

Setting the value will move the rectangle without changing its width.

setter:

The x-coordinate of the left edge.

Setting the value will move the rectangle without changing its width.

Implementation

T left;

right no setter inherited

T get right

Inherited from _RectangleBase.

Implementation

T get right => (left + width) as T;

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation

external Type get runtimeType;

top read / write

T top

getter:

The y-coordinate of the left edge.

Setting the value will move the rectangle without changing its height.

setter:

The y-coordinate of the left edge.

Setting the value will move the rectangle without changing its height.

Implementation

T top;

topLeft no setter inherited

Point<T> get topLeft

Inherited from _RectangleBase.

Implementation

Point<T> get topLeft => Point<T>(this.left, this.top);

topRight no setter inherited

Point<T> get topRight

Inherited from _RectangleBase.

Implementation

Point<T> get topRight => Point<T>((this.left + this.width) as T, this.top);

width read / write

T get width

getter:

The width of the rectangle.

setter:

Sets the width of the rectangle.

The width must be non-negative. If a negative width is supplied, it is clamped to zero.

Setting the value will change the right edge of the rectangle, but will not change left.

Implementation

T get width => _width;

set width(T width) {
  if (width < 0) width = _clampToZero<T>(width);
  _width = width;
}

Methods

boundingBox() inherited

Rectangle<T> boundingBox(Rectangle<T> other)

Returns a new rectangle which completely contains this and other.

Inherited from _RectangleBase.

Implementation

Rectangle<T> boundingBox(Rectangle<T> other) {
  var right = max(this.left + this.width, other.left + other.width);
  var bottom = max(this.top + this.height, other.top + other.height);

  var left = min(this.left, other.left);
  var top = min(this.top, other.top);

  return Rectangle<T>(left, top, (right - left) as T, (bottom - top) as T);
}

containsPoint() inherited

bool containsPoint(Point<num> another)

Tests whether another is inside or along the edges of this.

Inherited from _RectangleBase.

Implementation

bool containsPoint(Point<num> another) {
  return another.x >= left &&
      another.x <= left + width &&
      another.y >= top &&
      another.y <= top + height;
}

containsRectangle() inherited

bool containsRectangle(Rectangle<num> another)

Tests whether this entirely contains another.

Inherited from _RectangleBase.

Implementation

bool containsRectangle(Rectangle<num> another) {
  return left <= another.left &&
      left + width >= another.left + another.width &&
      top <= another.top &&
      top + height >= another.top + another.height;
}

intersection() inherited

Rectangle<T>? intersection(Rectangle<T> other)

Computes the intersection of this and other.

The intersection of two axis-aligned rectangles, if any, is always another axis-aligned rectangle.

Returns the intersection of this and other, or null if they don't intersect.

Inherited from _RectangleBase.

Implementation

Rectangle<T>? intersection(Rectangle<T> other) {
  var x0 = max(left, other.left);
  var x1 = min(left + width, other.left + other.width);

  if (x0 <= x1) {
    var y0 = max(top, other.top);
    var y1 = min(top + height, other.top + other.height);

    if (y0 <= y1) {
      return Rectangle<T>(x0, y0, (x1 - x0) as T, (y1 - y0) as T);
    }
  }
  return null;
}

intersects() inherited

bool intersects(Rectangle<num> other)

Returns true if this intersects other.

Inherited from _RectangleBase.

Implementation

bool intersects(Rectangle<num> other) {
  return (left <= other.left + other.width &&
      other.left <= left + width &&
      top <= other.top + other.height &&
      other.top <= top + height);
}

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation

@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

toString() inherited

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from _RectangleBase.

Implementation

String toString() {
  return 'Rectangle ($left, $top) $width x $height';
}

Operators

operator ==() inherited

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.

• Reflexive: For all objects o, o == o must be true.

• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

• Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from _RectangleBase.

Implementation

bool operator ==(Object other) =>
    other is Rectangle &&
    left == other.left &&
    top == other.top &&
    right == other.right &&
    bottom == other.bottom;