SignatureController class
class for interaction with signature widget manages points representing signature on canvas provides signature manipulation functions (export, clear)
- Inheritance
-
- Object
- ChangeNotifier
- ValueNotifier<
List< Point> > - SignatureController
Constructors
-
SignatureController({List<
Point> ? points, Color penColor = Colors.black, double penStrokeWidth = 3.0, Color? exportBackgroundColor, VoidCallback? onDrawStart, VoidCallback? onDrawEnd}) - constructor
Properties
- exportBackgroundColor → Color?
-
background color to be used in exported png image
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- hasListeners → bool
-
Whether any listeners are currently registered.
no setterinherited
- isEmpty → bool
-
check if canvas is empty (opposite of isNotEmpty method for convenience)
no setter
- isNotEmpty → bool
-
check if canvas is not empty (opposite of isEmpty method for convenience)
no setter
- onDrawEnd ↔ VoidCallback?
-
callback to notify when drawing has stopped
getter/setter pair
- onDrawStart ↔ VoidCallback?
-
callback to notify when drawing has started
getter/setter pair
- penColor → Color
-
color of a signature line
final
- penStrokeWidth → double
-
boldness of a signature line
final
-
points
↔ List<
Point> -
getter for points representing signature on 2D canvas
getter/setter pair
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
-
value
↔ List<
Point> -
The current value stored in this notifier.
getter/setter pairinherited
Methods
-
addListener(
VoidCallback listener) → void -
Register a closure to be called when the object changes.
inherited
-
addPoint(
Point point) → void - add point to point collection
-
clear(
) → void - clear the canvas
-
dispose(
) → void -
Discards any resources used by the object. After this is called, the
object is not in a usable state and should be discarded (calls to
addListener will throw after the object is disposed).
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
notifyListeners(
) → void -
Call all the registered listeners.
inherited
-
removeListener(
VoidCallback listener) → void -
Remove a previously registered closure from the list of closures that are
notified when the object changes.
inherited
-
toImage(
) → Future< Image?> - convert to
-
toPngBytes(
) → Future< Uint8List?> - convert canvas to dart:ui Image and then to PNG represented in Uint8List
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited