Error to user when back mod x is positive

Resolves #1202

Signed-off-by: Jade Turner <[email protected]>

Author: spacey-sooty

src/components/config/robotconfig/SwerveConfigPanel.tsx

@@ -37,6 +37,7 @@ class SwerveConfigPanel extends Component<Props, State> {
           number={config.backLeft.x}
           maxWidthCharacters={8}
           titleTooltip="X coordinate of back modules (negative)"
+          valid={(number) => number.defaultUnitMagnitude <= 0}
         />
 
         <ExpressionInput

src/components/input/ExpressionInput.tsx

@@ -21,6 +21,8 @@ type Props = {
   titleTooltip?: string;
   /** Maximum width of the number input, in monospace characters */
   maxWidthCharacters?: number;
+  /** A function to verify the validity of an input. */
+  valid: ((thing: IExpressionStore) => boolean) | undefined;
 };
 
 type State = {
@@ -137,7 +139,11 @@ class Input extends Component<Props, State> {
           className={
             styles.Number +
             (showNumberWhenDisabled ? " " + styles.ShowWhenDisabled : "") +
-            (this.getValid() ? " " : " " + styles.Invalid)
+            (this.getValid() &&
+            (this.props.valid == undefined ||
+              this.props.valid(this.props.number))
+              ? " "
+              : " " + styles.Invalid)
           }
           style={{
             minWidth: `${characters}ch`,