Add bounds check for child_at

src/elements/grid.rs

@@ -3,11 +3,9 @@ use anyhow::Result;
 
 use crate::builder::validator::gridinfo::GridInfo;
 
-use std::{
-    sync::{
+use std::sync::{
     atomic::{AtomicBool, AtomicU32, Ordering::SeqCst},
     Arc, RwLock, RwLockReadGuard,
-    },
 };
 use std::{ops::Deref, sync::Weak};
 
@@ -68,7 +66,9 @@ impl ChildState {
     fn get(&self) -> Option<(Arc<dyn GuiElementTraits>, u32, u32)> {
         match self {
             ChildState::Some { child, x, y } => Some((child.clone(), *x, *y)),
-            ChildState::Extend { weak_child, x, y } => weak_child.upgrade().map(|child| (child, *x, *y)),
+            ChildState::Extend { weak_child, x, y } => {
+                weak_child.upgrade().map(|child| (child, *x, *y))
+            }
             ChildState::None => None,
         }
     }
@@ -177,6 +177,22 @@ impl Grid {
     }
 
     pub fn child_at(&self, x: usize, y: usize) -> Result<Option<Arc<dyn GuiElementTraits>>> {
+        if x >= self.dim_x {
+            return Err(anyhow::anyhow!(
+                "Tried to access Grid at {} while only being {} wide",
+                x,
+                self.dim_x
+            ));
+        }
+
+        if y >= self.dim_y {
+            return Err(anyhow::anyhow!(
+                "Tried to access Grid at {} while only being {} tall",
+                y,
+                self.dim_y
+            ));
+        }
+
         Ok(self.children.read().unwrap()[x][y].map(|c| c.clone()))
     }