[WIP] Increment and decrement buttons

docs/pages/base/api/number-input-unstyled.json

@@ -9,12 +9,15 @@
     "slotProps": {
       "type": {
         "name": "shape",
-        "description": "{ input?: func<br>&#124;&nbsp;object, root?: func<br>&#124;&nbsp;object }"
+        "description": "{ decrementButton?: func<br>&#124;&nbsp;object, incrementButton?: func<br>&#124;&nbsp;object, input?: func<br>&#124;&nbsp;object, root?: func<br>&#124;&nbsp;object }"
       },
       "default": "{}"
     },
     "slots": {
-      "type": { "name": "shape", "description": "{ input?: elementType, root?: elementType }" },
+      "type": {
+        "name": "shape",
+        "description": "{ decrementButton?: elementType, incrementButton?: elementType, input?: elementType, root?: elementType }"
+      },
       "default": "{}"
     }
   },

docs/pages/base/api/use-number-input.json

@@ -30,7 +30,10 @@
       "type": { "name": "React.FocusEventHandler", "description": "React.FocusEventHandler" }
     },
     "onValueChange": {
-      "type": { "name": "(value: number) =&gt void", "description": "(value: number) =&gt void" }
+      "type": {
+        "name": "(value: number | undefined) =&gt void",
+        "description": "(value: number | undefined) =&gt void"
+      }
     },
     "required": { "type": { "name": "boolean", "description": "boolean" } },
     "step": { "type": { "name": "number", "description": "number" } },
@@ -59,6 +62,20 @@
       },
       "required": true
     },
+    "getDecrementButtonProps": {
+      "type": {
+        "name": "<TOther extends Record<string, any&gt = {}&gt(externalProps?: TOther) =&gt UseNumberInputDecrementButtonSlotProps<TOther&gt",
+        "description": "<TOther extends Record<string, any&gt = {}&gt(externalProps?: TOther) =&gt UseNumberInputDecrementButtonSlotProps<TOther&gt"
+      },
+      "required": true
+    },
+    "getIncrementButtonProps": {
+      "type": {
+        "name": "<TOther extends Record<string, any&gt = {}&gt(externalProps?: TOther) =&gt UseNumberInputIncrementButtonSlotProps<TOther&gt",
+        "description": "<TOther extends Record<string, any&gt = {}&gt(externalProps?: TOther) =&gt UseNumberInputIncrementButtonSlotProps<TOther&gt"
+      },
+      "required": true
+    },
     "getInputProps": {
       "type": {
         "name": "<TOther extends Record<string, any&gt = {}&gt(externalProps?: TOther) =&gt UseNumberInputInputSlotProps<TOther&gt",
@@ -77,6 +94,16 @@
       "type": { "name": "string | undefined", "description": "string | undefined" },
       "required": true
     },
+    "isDecrementDisabled": {
+      "type": { "name": "boolean", "description": "boolean" },
+      "default": "false",
+      "required": true
+    },
+    "isIncrementDisabled": {
+      "type": { "name": "boolean", "description": "boolean" },
+      "default": "false",
+      "required": true
+    },
     "required": {
       "type": { "name": "boolean", "description": "boolean" },
       "default": "false",

docs/translations/api-docs/use-number-input/use-number-input.json

@@ -11,9 +11,13 @@
     "error": "If <code>true</code>, the <code>input</code> will indicate an error by setting the <code>aria-invalid</code> attribute.",
     "focused": "If <code>true</code>, the <code>input</code> will be focused.",
     "formControlContext": "Return value from the <code>useFormControlUnstyledContext</code> hook.",
+    "getDecrementButtonProps": "Resolver for the decrement button slot's props.",
+    "getIncrementButtonProps": "Resolver for the increment button slot's props.",
     "getInputProps": "Resolver for the input slot's props.",
     "getRootProps": "Resolver for the root slot's props.",
     "inputValue": "The dirty <code>value</code> of the <code>input</code> element when it is in focus.",
+    "isDecrementDisabled": "If <code>true</code>, the decrement button will be disabled.\ne.g. when the <code>value</code> is already at <code>min</code>",
+    "isIncrementDisabled": "If <code>true</code>, the increment button will be disabled.\ne.g. when the <code>value</code> is already at <code>max</code>",
     "required": "If <code>true</code>, the <code>input</code> will indicate that it's required.",
     "value": "The clamped <code>value</code> of the <code>input</code> element."
   }

packages/mui-base/src/NumberInputUnstyled/NumberInputUnstyled.tsx

@@ -8,6 +8,8 @@ import {
   NumberInputUnstyledProps,
   NumberInputUnstyledRootSlotProps,
   NumberInputUnstyledInputSlotProps,
+  NumberInputUnstyledIncrementButtonSlotProps,
+  NumberInputUnstyledDecrementButtonSlotProps,
   NumberInputUnstyledTypeMap,
 } from './NumberInputUnstyled.types';
 import { EventHandlers, useSlotProps, WithOptionalOwnerState } from '../utils';
@@ -50,10 +52,14 @@ const NumberInputUnstyled = React.forwardRef(function NumberInputUnstyled(
   const {
     getRootProps,
     getInputProps,
+    getIncrementButtonProps,
+    getDecrementButtonProps,
     focused,
     error: errorState,
     disabled: disabledState,
     formControlContext,
+    isIncrementDisabled,
+    isDecrementDisabled,
   } = useNumberInput({
     min,
     max,
@@ -88,6 +94,16 @@ const NumberInputUnstyled = React.forwardRef(function NumberInputUnstyled(
     [classes.disabled]: disabledState,
   };
 
+  const incrementButtonStateClasses = {
+    [classes.disabled]: isIncrementDisabled,
+    // TODO: focusable if input is readonly
+  };
+
+  const decrementButtonStateClasses = {
+    [classes.disabled]: isDecrementDisabled,
+    // TODO: focusable if input is readonly
+  };
+
   const propsForwardedToInputSlot = {
     id,
     placeholder,
@@ -107,20 +123,42 @@ const NumberInputUnstyled = React.forwardRef(function NumberInputUnstyled(
   });
 
   const Input = slots.input ?? 'input';
-
   const inputProps: WithOptionalOwnerState<NumberInputUnstyledInputSlotProps> = useSlotProps({
     elementType: Input,
     getSlotProps: (otherHandlers: EventHandlers) =>
       getInputProps({ ...otherHandlers, ...propsForwardedToInputSlot }),
     externalSlotProps: slotProps.input,
-    additionalProps: {},
+    // additionalProps: {},
     ownerState,
     className: [classes.input, inputStateClasses],
   });
 
+  const IncrementButton = slots.incrementButton ?? 'button';
+  const incrementButtonProps: WithOptionalOwnerState<NumberInputUnstyledIncrementButtonSlotProps> =
+    useSlotProps({
+      elementType: IncrementButton,
+      getSlotProps: getIncrementButtonProps,
+      externalSlotProps: slotProps.incrementButton,
+      ownerState,
+      className: [classes.incrementButton, incrementButtonStateClasses],
+    });
+
+  const DecrementButton = slots.decrementButton ?? 'button';
+  const decrementButtonProps: WithOptionalOwnerState<NumberInputUnstyledDecrementButtonSlotProps> =
+    useSlotProps({
+      elementType: DecrementButton,
+      getSlotProps: getDecrementButtonProps,
+      externalSlotProps: slotProps.decrementButton,
+      // additionalProps: {},
+      ownerState,
+      className: [classes.decrementButton, decrementButtonStateClasses],
+    });
+
   return (
     <Root {...rootProps}>
+      <DecrementButton {...decrementButtonProps} />
       <Input {...inputProps} />
+      <IncrementButton {...incrementButtonProps} />
     </Root>
   );
 }) as OverridableComponent<NumberInputUnstyledTypeMap>;
@@ -198,6 +236,8 @@ NumberInputUnstyled.propTypes /* remove-proptypes */ = {
    * @default {}
    */
   slotProps: PropTypes.shape({
+    decrementButton: PropTypes.oneOfType([PropTypes.func, PropTypes.object]),
+    incrementButton: PropTypes.oneOfType([PropTypes.func, PropTypes.object]),
     input: PropTypes.oneOfType([PropTypes.func, PropTypes.object]),
     root: PropTypes.oneOfType([PropTypes.func, PropTypes.object]),
   }),
@@ -207,6 +247,8 @@ NumberInputUnstyled.propTypes /* remove-proptypes */ = {
    * @default {}
    */
   slots: PropTypes.shape({
+    decrementButton: PropTypes.elementType,
+    incrementButton: PropTypes.elementType,
     input: PropTypes.elementType,
     root: PropTypes.elementType,
   }),

packages/mui-base/src/NumberInputUnstyled/NumberInputUnstyled.types.ts

@@ -1,10 +1,17 @@
 import { OverrideProps, Simplify } from '@mui/types';
 import { FormControlUnstyledState } from '../FormControlUnstyled';
-import { UseNumberInputParameters, UseNumberInputRootSlotProps } from './useNumberInput.types';
+import {
+  UseNumberInputParameters,
+  UseNumberInputRootSlotProps,
+  UseNumberInputIncrementButtonSlotProps,
+  UseNumberInputDecrementButtonSlotProps,
+} from './useNumberInput.types';
 import { SlotComponentProps } from '../utils';
 
 export interface NumberInputUnstyledRootSlotPropsOverrides {}
 export interface NumberInputUnstyledInputSlotPropsOverrides {}
+export interface NumberInputUnstyledIncrementButtonSlotPropsOverrides {}
+export interface NumberInputUnstyledDecrementButtonSlotPropsOverrides {}
 
 export type NumberInputUnstyledOwnProps = Omit<UseNumberInputParameters, 'error'> & {
   /**
@@ -30,6 +37,16 @@ export type NumberInputUnstyledOwnProps = Omit<UseNumberInputParameters, 'error'
       NumberInputUnstyledInputSlotPropsOverrides,
       NumberInputUnstyledOwnerState
     >;
+    incrementButton?: SlotComponentProps<
+      'button',
+      NumberInputUnstyledIncrementButtonSlotPropsOverrides,
+      NumberInputUnstyledOwnerState
+    >;
+    decrementButton?: SlotComponentProps<
+      'button',
+      NumberInputUnstyledDecrementButtonSlotPropsOverrides,
+      NumberInputUnstyledOwnerState
+    >;
   };
   /**
    * The components used for each slot inside the InputBase.
@@ -39,6 +56,8 @@ export type NumberInputUnstyledOwnProps = Omit<UseNumberInputParameters, 'error'
   slots?: {
     root?: React.ElementType;
     input?: React.ElementType;
+    incrementButton?: React.ElementType;
+    decrementButton?: React.ElementType;
   };
 };
 
@@ -78,3 +97,15 @@ export type NumberInputUnstyledInputSlotProps = Simplify<
     ref: React.Ref<HTMLInputElement>;
   }
 >;
+
+export type NumberInputUnstyledIncrementButtonSlotProps = Simplify<
+  UseNumberInputIncrementButtonSlotProps & {
+    ownerState: NumberInputUnstyledOwnerState;
+  }
+>;
+
+export type NumberInputUnstyledDecrementButtonSlotProps = Simplify<
+  UseNumberInputDecrementButtonSlotProps & {
+    ownerState: NumberInputUnstyledOwnerState;
+  }
+>;

packages/mui-base/src/NumberInputUnstyled/numberInputUnstyledClasses.ts

@@ -18,6 +18,10 @@ export interface NumberInputUnstyledClasses {
   error: string;
   /** Class name applied to the input element. */
   input: string;
+  /** Class name applied to the increment button element. */
+  incrementButton: string;
+  /** Class name applied to the decrement button element. */
+  decrementButton: string;
 }
 
 export type NumberInputUnstyledClassKey = keyof NumberInputUnstyledClasses;
@@ -35,6 +39,8 @@ const numberInputUnstyledClasses: NumberInputUnstyledClasses = generateUtilityCl
     'disabled',
     'error',
     'input',
+    'incrementButton',
+    'decrementButton',
     // 'adornedStart',
     // 'adornedEnd',
   ],

packages/mui-base/src/NumberInputUnstyled/useNumberInput.ts

@@ -9,6 +9,8 @@ import {
   UseNumberInputParameters,
   UseNumberInputRootSlotProps,
   UseNumberInputInputSlotProps,
+  UseNumberInputIncrementButtonSlotProps,
+  UseNumberInputDecrementButtonSlotProps,
   UseNumberInputReturnValue,
 } from './useNumberInput.types';
 import clamp from './clamp';
@@ -30,11 +32,9 @@ export default function useNumberInput(
   parameters: UseNumberInputParameters,
 ): UseNumberInputReturnValue {
   const {
-    // number
     min,
     max,
     step,
-    //
     defaultValue: defaultValueProp,
     disabled: disabledProp = false,
     error: errorProp = false,
@@ -108,7 +108,8 @@ export default function useNumberInput(
     };
 
   const handleValueChange =
-    () => (event: React.FocusEvent<HTMLInputElement>, val: number | undefined) => {
+    () =>
+    (event: React.FocusEvent<HTMLInputElement> | React.PointerEvent, val: number | undefined) => {
       // 1. clamp the number
       // 2. setInputValue(clamped_value)
       // 3. call onValueChange(newValue)
@@ -128,8 +129,10 @@ export default function useNumberInput(
       //       OR: (event, newValue) similar to SelectUnstyled
       // formControlContext?.onValueChange?.(newValue);
 
-      if (newValue) {
+      if (typeof newValue === 'number' && !Number.isNaN(newValue)) {
         onValueChange?.(newValue);
+      } else {
+        onValueChange?.(undefined);
       }
     };
 
@@ -197,6 +200,28 @@ export default function useNumberInput(
       otherHandlers.onClick?.(event);
     };
 
+  const handleStep =
+    (direction: 'up' | 'down') =>
+    (
+      event: React.PointerEvent, // TODO: this could also be a keyboard event: arrow up/down or enter on the button
+    ) => {
+      let newValue;
+
+      if (typeof value === 'number') {
+        newValue = {
+          up: value + (step ?? 1),
+          down: value - (step ?? 1),
+        }[direction];
+      } else {
+        // no value
+        newValue = {
+          up: min ?? 0,
+          down: max ?? 0,
+        }[direction];
+      }
+      handleValueChange()(event, newValue);
+    };
+
   const getRootProps = <TOther extends Record<string, any> = {}>(
     externalProps: TOther = {} as TOther,
   ): UseNumberInputRootSlotProps<TOther> => {
@@ -258,17 +283,51 @@ export default function useNumberInput(
     };
   };
 
+  const isIncrementDisabled =
+    typeof value === 'number' ? value >= (max ?? Number.MAX_SAFE_INTEGER) : false;
+
+  const getIncrementButtonProps = <TOther extends Record<string, any> = {}>(
+    externalProps: TOther = {} as TOther,
+  ): UseNumberInputIncrementButtonSlotProps<TOther> => {
+    return {
+      ...externalProps,
+      // the button should be tab-able if the input is readonly
+      tabIndex: -1,
+      disabled: isIncrementDisabled,
+      'aria-disabled': isIncrementDisabled,
+      onClick: handleStep('up'),
+    };
+  };
+
+  const isDecrementDisabled =
+    typeof value === 'number' ? value <= (min ?? Number.MIN_SAFE_INTEGER) : false;
+
+  const getDecrementButtonProps = <TOther extends Record<string, any> = {}>(
+    externalProps: TOther = {} as TOther,
+  ): UseNumberInputDecrementButtonSlotProps<TOther> => {
+    return {
+      ...externalProps,
+      // the button should be tab-able if the input is readonly
+      tabIndex: -1,
+      disabled: isDecrementDisabled,
+      'aria-disabled': isDecrementDisabled,
+      onClick: handleStep('down'),
+    };
+  };
+
   return {
     disabled: disabledProp,
     error: errorProp,
     focused,
     formControlContext,
     getInputProps,
-    // getIncrementButtonProps,
-    // getDecrementButtonProps,
+    getIncrementButtonProps,
+    getDecrementButtonProps,
     getRootProps,
     required: requiredProp,
     value: focused ? inputValue : value,
+    isIncrementDisabled,
+    isDecrementDisabled,
     // private and could be thrown out later
     inputValue,
   };