Struct design_pattern_examples_rust::memento::memento_textobject::MementoTextObject

pub struct MementoTextObject {
    text: String,
}

Container for a string. Need to use a struct that allows the text to be changed while the container (this struct) remains constant. This way, operations can be applied to the text and the container’s contents change but not the container.

Fields

text: String

The text that can change in this MementoTextObject class.

Implementations

impl MementoTextObject

pub fn new(text: &str) -> MementoTextObject

Constructs a text object with an initial string.

Parameters

• text

  The text that will be managed by this MementoTextObject.

Returns

Returns a new instance of the MementoTextObject struct.

pub fn text(&self) -> &str

Gets the text in this MementoTextObject.

pub fn set_text(&mut self, text: &str)

Sets the text in this MementoTextObject.

pub fn get_memento(&self, operation_name: &str) -> Memento

Returns a Memento object containing a snapshot of the text stored in this instance.

Parameters

• operation_name

  The name of the memento to create. In this case, the name is the operation that is to be applied to the text object.

Returns

Returns an instance of the Memento struct, representing the snapshot of this MementoTextObject.

pub fn restore_memento(&mut self, memento: &Memento)

Sets the text in this MementoTextObject instance to the snapshot stored in the given Memento object (which is assumed to be from the MementoTextObject::get_memento() method).

Parameters

• memento

  A Memento object containing the text that will be copied over the text in this MementoTextObject.

Trait Implementations

impl Display for MementoTextObject

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Converts the MementoTextObject to a string (makes it easier to use the struct in string formatting).