Show error messages when settings boats disposition

rust/cli_player/src/ui_screens/set_boats_layout.rs

@@ -5,13 +5,15 @@ use std::time::{Duration, Instant};
 use crossterm::event;
 use crossterm::event::{Event, KeyCode, MouseButton, MouseEventKind};
 use tui::backend::Backend;
+use tui::layout::Rect;
 use tui::style::*;
+use tui::widgets::*;
 use tui::{Frame, Terminal};
 
 use sea_battle_backend::data::*;
 
 use crate::constants::*;
-use crate::ui_screens::utils::centered_rect_size;
+use crate::ui_screens::utils::{centered_rect_size, centered_text};
 use crate::ui_screens::ScreenResult;
 use crate::ui_widgets::game_map_widget::{ColoredCells, GameMapWidget};
 
@@ -129,6 +131,8 @@ fn ui<B: Backend>(
     model: &mut SetBotsLayoutScreen,
     rules: &GameRules,
 ) -> CoordinatesMapper {
+    let errors = model.layout.errors(rules);
+
     let current_boat = ColoredCells {
         color: Color::Green,
         cells: model.layout.0[model.curr_boat].all_coordinates(),
@@ -148,6 +152,14 @@ fn ui<B: Backend>(
 
     let mut coordinates_mapper = HashMap::new();
 
+    let mut legend = "n        next boat     \n\
+                     r        rotate boat    \n\n\
+                     ← ↓↑ →   move boat      \n\n"
+        .to_string();
+    if errors.is_empty() {
+        legend.push_str("Enter    confirm layout");
+    }
+
     let game_map_widget = GameMapWidget::new(rules)
         .set_default_empty_char(' ')
         .add_colored_cells(current_boat)
@@ -160,16 +172,25 @@ fn ui<B: Backend>(
                 }
             }
         })
-        .set_legend(
+        .set_legend(legend);
-            "n        next boat     \n\
-                     r        rotate boat    \n\n\
-                     ← ↓↑ →   move boat      \n\n\
-                     Enter    confirm layout",
-        );
 
     let (w, h) = game_map_widget.estimated_size();
     let area = centered_rect_size(w, h, &f.size());
     f.render_widget(game_map_widget, area);
 
+    if !errors.is_empty() {
+        let messages = ["INVALID_LAYOUT", errors[0]];
+        for (i, msg) in messages.iter().enumerate() {
+            let paragraph = Paragraph::new(*msg).style(Style::default().fg(Color::Red));
+            f.render_widget(
+                paragraph,
+                centered_text(
+                    msg,
+                    &Rect::new(f.size().x, area.bottom() + i as u16, f.size().width, 1),
+                ),
+            );
+        }
+    }
+
     coordinates_mapper
 }

rust/cli_player/src/ui_screens/utils.rs

@@ -45,3 +45,17 @@ pub fn centered_rect_size(width: u16, height: u16, parent: &Rect) -> Rect {
         height,
     }
 }
+
+/// Get coordinates to render centered text
+pub fn centered_text(text: &str, container: &Rect) -> Rect {
+    if text.len() > container.width as usize {
+        return *container;
+    }
+
+    Rect {
+        x: container.x + (container.width - text.len() as u16) / 2,
+        y: container.y,
+        height: 1,
+        width: text.len() as u16,
+    }
+}