Better decimal rounding in the NumberInput widget (#457)

* better decimal rounding in NumberInput

* - created function to reuse
- used math instead of string manipulation

* updated comment to be correct

* updated comment

* updated comment

Author: mfish33

frontend/src/components/widgets/inputs/NumberInput.vue

@@ -152,6 +152,8 @@
 <script lang="ts">
 import { defineComponent, PropType } from "vue";
 
+import { clamp } from "@/utilities/math";
+
 export type IncrementBehavior = "Add" | "Multiply" | "Callback" | "None";
 export type IncrementDirection = "Decrease" | "Increase";
 
@@ -240,13 +242,21 @@ export default defineComponent({
 			if (invalid) sanitized = this.value;
 
 			if (this.isInteger) sanitized = Math.round(sanitized);
-			if (typeof this.min === "number" && !Number.isNaN(this.min)) sanitized = Math.max(sanitized, this.min);
-			if (typeof this.max === "number" && !Number.isNaN(this.max)) sanitized = Math.min(sanitized, this.max);
+			sanitized = clamp(newValue, this.min, this.max);
 
 			if (!invalid) this.$emit("update:value", sanitized);
 
-			const roundingPower = 10 ** this.displayDecimalPlaces;
-			const displayValue = Math.round(sanitized * roundingPower) / roundingPower;
+			this.setText(sanitized);
+		},
+		setText(value: number) {
+			// Find the amount of digits on the left side of the Decimal
+			// 10.25 == 2
+			// 1.23 == 1
+			// 0.23 == 0 - Reason for the slightly more complicated code
+			const leftSideDigits = Math.max(Math.floor(value).toString().length, 0) * Math.sign(value);
+
+			const roundingPower = 10 ** Math.max(this.displayDecimalPlaces - leftSideDigits, 0);
+			const displayValue = Math.round(value * roundingPower) / roundingPower;
 			this.text = `${displayValue}${this.unit}`;
 		},
 	},
@@ -258,13 +268,9 @@ export default defineComponent({
 				return;
 			}
 
-			let sanitized = newValue;
-			if (typeof this.min === "number") sanitized = Math.max(sanitized, this.min);
-			if (typeof this.max === "number") sanitized = Math.min(sanitized, this.max);
+			const sanitized = clamp(newValue, this.min, this.max);
 
-			const roundingPower = 10 ** this.displayDecimalPlaces;
-			const displayValue = Math.round(sanitized * roundingPower) / roundingPower;
-			this.text = `${displayValue}${this.unit}`;
+			this.setText(sanitized);
 		},
 	},
 	mounted() {