make measurement cells disappear automatically

To avoid cluttering up the grid with green cells, measurement lines will
now disappear automatically after a while (currently, after you place
your third measurement line).

README.md

@@ -1,6 +1,6 @@
 # yayagram - Play nonograms/picross in your terminal
 
-**yayagram** is a puzzle game in which you fill out a grid with cells based on logic and number clues.
+**yayagram** is a puzzle game in which you fill out a grid with cells based on logic and number clues in your terminal.
 
 The game goes by many names: nonogram, picross, paint by numbers, griddlers, pic-a-pix, hanjie and others.
 
@@ -23,7 +23,7 @@ Binaries are also provided in the [Releases](https://github.com/r00ster91/yayagr
 
 * Runs in the terminal!
 * Cross-platform: runs on Linux and macOS.
-* Helpful features and tools like undo, redo and clear.
+* Helpful features and tools like undo, redo and, clear.
 * Random grids.
 * Custom grids: [create your own grids](#Editor) for others to play.
 * A new kind of cell: [maybed](#Maybed).

src/editor.rs

@@ -57,7 +57,7 @@ impl Editor {
                             help[2] = Some("?: maybed");
                             "????" // Represents unclearness.
                         }
-                        Cell::Measured(_) => {
+                        Cell::Measured(_, _) => {
                             help[3] = Some("R: measured");
                             "RRRR" // Resembles 尺 which is a unit of measure.
                         }
@@ -206,7 +206,7 @@ fn deserialize(str: &str) -> Result<(Size, Vec<Cell>), LoadError> {
                 '1' => Cell::Filled,
                 'X' => Cell::Crossed,
                 '?' => Cell::Maybed,
-                'R' => Cell::Measured(None),
+                'R' => Cell::Measured(None, None),
                 _ => {
                     return Err(LoadError {
                         message: "expected ' ', '1', 'X', '?' or 'R'",

src/grid.rs

@@ -23,6 +23,7 @@ pub struct Grid {
     pub vertical_clues_solutions: Vec<Clues>,
     pub max_clues_size: Size,
     pub undo_redo_buffer: UndoRedoBuffer,
+    pub measurement_counter: usize,
 }
 
 fn get_index(grid_width: u16, point: Point) -> usize {
@@ -90,13 +91,16 @@ impl Grid {
 
         let undo_redo_buffer = UndoRedoBuffer::default();
 
+        let measurement_counter = 0;
+
         Self {
             size,
             cells,
             horizontal_clues_solutions,
             vertical_clues_solutions,
             max_clues_size,
             undo_redo_buffer,
+            measurement_counter,
         }
     }
 

src/grid/cell.rs

@@ -16,9 +16,14 @@ pub enum Cell {
     /// Used to mark cells that are certainly empty.
     Crossed,
     /// Used for indicating cells that were measured using the measurement tool.
+    /// The first element of this tuple, the index, is a number shown on the cell.
     ///
-    /// When this cell is saved, the index is not preserved.
-    Measured(Option<usize>),
+    /// When this cell is saved, the index is not preserved and therefore the index can be null.
+    ///
+    /// The second element is a measurement counter. On each new measurement added, the counter is incremented.
+    /// We use the measurement counter to make measurement cells disappear after a while.
+    /// Use None for them to never disappear.
+    Measured(Option<usize>, Option<usize>),
 }
 
 impl Default for Cell {
@@ -40,7 +45,7 @@ impl Cell {
             Cell::Filled => Color::White,
             Cell::Maybed => Color::Blue,
             Cell::Crossed => Color::Red,
-            Cell::Measured(_) => Color::Green,
+            Cell::Measured(_, _) => Color::Green,
         }
     }
 
@@ -50,7 +55,7 @@ impl Cell {
             Cell::Filled => Color::Gray,
             Cell::Maybed => Color::DarkBlue,
             Cell::Crossed => Color::DarkRed,
-            Cell::Measured(_) => Color::DarkGreen,
+            Cell::Measured(_, _) => Color::DarkGreen,
         }
     }
 
@@ -95,7 +100,7 @@ impl Cell {
 
                 (None, background_color, "  ".into())
             }
-            Cell::Measured(index) => {
+            Cell::Measured(index, _) => {
                 let (foreground_color, content) = if let Some(index) = index {
                     (Some(Color::Black), format!("{:>2}", index).into())
                 } else {
@@ -130,13 +135,27 @@ pub const fn get_cell_point_from_cursor_point(cursor_point: Point, builder: &Bui
 }
 
 pub fn set_measured_cells(grid: &mut Grid, line_points: &[Point]) {
+    let measurement_counter = grid.measurement_counter;
     for (index, point) in line_points.iter().enumerate() {
         let cell = grid.get_mut_cell(*point);
+        if let Cell::Empty | Cell::Measured(_, _) = cell {
+            *cell = Cell::Measured(Some(index + 1), Some(measurement_counter));
+        }
+    }
 
-        if let Cell::Empty | Cell::Measured(_) = cell {
-            *cell = Cell::Measured(Some(index + 1));
+    // We want to clean up old measurement lines after a while to avoid cluttering up the grid with green cells,
+    // so we'll only allow a certain amount of lines at a time.
+    let allowed_count = 2;
+    for cell in &mut grid.cells {
+        if let Cell::Measured(_, Some(measurement_counter)) = *cell {
+            if grid.measurement_counter >= allowed_count
+                && measurement_counter == grid.measurement_counter - allowed_count
+            {
+                *cell = Cell::Empty;
+            }
         }
     }
+    grid.measurement_counter += 1;
 }
 
 pub fn draw_highlighted_cells(

src/grid/tools/fill.rs

@@ -6,7 +6,7 @@ pub fn fill(grid: &mut Grid, point: Point, first_cell: Cell, fill_cell: Cell) {
 
     // We want to fill multiple measured cells as one, regardless of the index
     let measured_cell =
-        matches!(*cell, Cell::Measured(_)) && matches!(first_cell, Cell::Measured(_));
+        matches!(*cell, Cell::Measured(_, _)) && matches!(first_cell, Cell::Measured(_, _));
 
     if *cell == first_cell || measured_cell {
         *cell = fill_cell;