[new feature] Stepper: support long press gesture (#3711)

src/stepper/index.js

@@ -2,6 +2,9 @@ import { createNamespace, isDef, suffixPx } from '../utils';
 
 const [createComponent, bem] = createNamespace('stepper');
 
+const LONG_PRESS_START_TIME = 600;
+const LONG_PRESS_INTERVAL = 200;
+
 export default createComponent({
   props: {
     value: null,
@@ -78,19 +81,21 @@ export default createComponent({
       const { value } = event.target;
       const formatted = this.format(value);
 
-      if (!this.asyncChange) {
+      if (this.asyncChange) {
+        event.target.value = this.currentValue;
+        this.$emit('input', formatted);
+        this.$emit('change', formatted);
+      } else {
         if (+value !== formatted) {
           event.target.value = formatted;
         }
         this.currentValue = formatted;
-      } else {
-        event.target.value = this.currentValue;
-        this.$emit('input', formatted);
-        this.$emit('change', formatted);
       }
     },
 
-    onChange(type) {
+    onChange() {
+      const { type } = this;
+
       if (this[`${type}Disabled`]) {
         this.$emit('overlimit', type);
         return;
@@ -99,12 +104,13 @@ export default createComponent({
       const diff = type === 'minus' ? -this.step : +this.step;
       const value = Math.round((this.currentValue + diff) * 100) / 100;
 
-      if (!this.asyncChange) {
-        this.currentValue = this.range(value);
-      } else {
+      if (this.asyncChange) {
         this.$emit('input', value);
         this.$emit('change', value);
+      } else {
+        this.currentValue = this.range(value);
       }
+
       this.$emit(type);
     },
 
@@ -120,19 +126,56 @@ export default createComponent({
       if (this.currentValue === 0) {
         event.target.value = this.currentValue;
       }
+    },
+
+    longPressStep() {
+      this.longPressTimer = setTimeout(() => {
+        this.onChange(this.type);
+        this.longPressStep(this.type);
+      }, LONG_PRESS_INTERVAL);
+    },
+
+    onTouchStart(type) {
+      clearTimeout(this.longPressTimer);
+      this.isLongPress = false;
+
+      this.longPressTimer = setTimeout(() => {
+        this.isLongPress = true;
+        this.onChange();
+        this.longPressStep();
+      }, LONG_PRESS_START_TIME);
+    },
+
+    onTouchEnd(event) {
+      clearTimeout(this.longPressTimer);
+
+      if (this.isLongPress) {
+        event.preventDefault();
+      }
     }
   },
 
   render(h) {
-    const onChange = type => () => {
-      this.onChange(type);
-    };
+    const createListeners = type => ({
+      on: {
+        click: () => {
+          this.type = type;
+          this.onChange();
+        },
+        touchstart: () => {
+          this.type = type;
+          this.onTouchStart(type);
+        },
+        touchend: this.onTouchEnd,
+        touchcancel: this.onTouchEnd
+      }
+    });
 
     return (
       <div class={bem()}>
         <button
           class={bem('minus', { disabled: this.minusDisabled })}
-          onClick={onChange('minus')}
+          {...createListeners('minus')}
         />
         <input
           type="number"
@@ -150,7 +193,7 @@ export default createComponent({
         />
         <button
           class={bem('plus', { disabled: this.plusDisabled })}
-          onClick={onChange('plus')}
+          {...createListeners('plus')}
         />
       </div>
     );