77 lines
1.7 KiB
Rust
77 lines
1.7 KiB
Rust
//! This implements a "database" for our Todos app. It makes the assumption that we're only ever
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//! doing this stuff on the main thread; in a more complicated app, you'd probably make different
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//! choices.
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use std::cell::RefCell;
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use std::rc::Rc;
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/// The status of a Todo.
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#[derive(Debug)]
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pub enum TodoStatus {
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/// Yet to be completed.
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Incomplete,
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/// Completed. ;P
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Complete,
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}
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/// A Todo. Represents... something to do.
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#[derive(Debug)]
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pub struct Todo {
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/// The title of this todo.
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pub title: String,
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/// The status of this todo.
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pub status: TodoStatus,
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}
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/// A single-threaded Todos "database".
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#[derive(Debug, Default)]
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pub struct Todos(Rc<RefCell<Vec<Todo>>>);
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impl Todos {
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/// Insert a new Todo.
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pub fn insert(&self, title: String) {
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let mut stack = self.0.borrow_mut();
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let mut todos = vec![Todo {
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title: title,
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status: TodoStatus::Incomplete,
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}];
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todos.append(&mut stack);
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*stack = todos;
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}
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/// Edit a Todo at the row specified.
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pub fn with_mut<F>(&self, row: usize, handler: F)
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where
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F: Fn(&mut Todo),
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{
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let mut stack = self.0.borrow_mut();
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if let Some(todo) = stack.get_mut(row) {
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handler(todo);
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}
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}
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/// Run a block with the given Todo.
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pub fn with<F>(&self, row: usize, mut handler: F)
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where
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F: FnMut(&Todo),
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{
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let stack = self.0.borrow();
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if let Some(todo) = stack.get(row) {
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handler(todo);
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}
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}
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/// Returns the total number of Todos.
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pub fn len(&self) -> usize {
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let stack = self.0.borrow();
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stack.len()
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}
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}
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