From d929217752aac2dcfcd56852c7dbc3a834819de1 Mon Sep 17 00:00:00 2001
From: tangjinzhou <415800467@qq.com>
Date: Thu, 17 Mar 2022 10:19:18 +0800
Subject: [PATCH] Fix Input.TextArea cut text logic when maxLength configured.

---
 components/input/ClearableLabeledInput.tsx |  9 ++-
 components/input/TextArea.tsx              | 81 ++++++++++++++++++++--
 components/input/demo/textarea.vue         |  3 +
 components/input/inputProps.ts             |  1 +
 4 files changed, 86 insertions(+), 8 deletions(-)

diff --git a/components/input/ClearableLabeledInput.tsx b/components/input/ClearableLabeledInput.tsx
index 16724f679c..efcde5072b 100644
--- a/components/input/ClearableLabeledInput.tsx
+++ b/components/input/ClearableLabeledInput.tsx
@@ -33,6 +33,7 @@ export default defineComponent({
     focused: PropTypes.looseBool,
     bordered: PropTypes.looseBool.def(true),
     triggerFocus: { type: Function as PropType<() => void> },
+    hidden: Boolean,
   },
   setup(props, { slots, attrs }) {
     const containerRef = ref();
@@ -91,6 +92,7 @@ export default defineComponent({
         direction,
         readonly,
         bordered,
+        hidden,
         addonAfter = slots.addonAfter,
         addonBefore = slots.addonBefore,
       } = props;
@@ -121,6 +123,7 @@ export default defineComponent({
           class={affixWrapperCls}
           style={attrs.style}
           onMouseup={onInputMouseUp}
+          hidden={hidden}
         >
           {prefixNode}
           {cloneElement(element, {
@@ -139,6 +142,7 @@ export default defineComponent({
         addonAfter = slots.addonAfter?.(),
         size,
         direction,
+        hidden,
       } = props;
       // Not wrap when there is not addons
       if (!hasAddon({ addonBefore, addonAfter })) {
@@ -169,7 +173,7 @@ export default defineComponent({
       // Need another wrapper for changing display:table to display:inline-block
       // and put style prop in wrapper
       return (
-        <span class={mergedGroupClassName} style={attrs.style}>
+        <span class={mergedGroupClassName} style={attrs.style} hidden={hidden}>
           <span class={mergedWrapperClassName}>
             {addonBeforeNode}
             {cloneElement(labeledElement, { style: null })}
@@ -185,6 +189,7 @@ export default defineComponent({
         allowClear,
         direction,
         bordered,
+        hidden,
         addonAfter = slots.addonAfter,
         addonBefore = slots.addonBefore,
       } = props;
@@ -204,7 +209,7 @@ export default defineComponent({
         },
       );
       return (
-        <span class={affixWrapperCls} style={attrs.style}>
+        <span class={affixWrapperCls} style={attrs.style} hidden={hidden}>
           {cloneElement(element, {
             style: null,
             value,
diff --git a/components/input/TextArea.tsx b/components/input/TextArea.tsx
index bc887c316b..8e7b10ad5a 100644
--- a/components/input/TextArea.tsx
+++ b/components/input/TextArea.tsx
@@ -24,6 +24,26 @@ function fixEmojiLength(value: string, maxLength: number) {
   return [...(value || '')].slice(0, maxLength).join('');
 }
 
+function setTriggerValue(
+  isCursorInEnd: boolean,
+  preValue: string,
+  triggerValue: string,
+  maxLength: number,
+) {
+  let newTriggerValue = triggerValue;
+  if (isCursorInEnd) {
+    // 光标在尾部，直接截断
+    newTriggerValue = fixEmojiLength(triggerValue, maxLength!);
+  } else if (
+    [...(preValue || '')].length < triggerValue.length &&
+    [...(triggerValue || '')].length > maxLength!
+  ) {
+    // 光标在中间，如果最后的值超过最大值，则采用原先的值
+    newTriggerValue = preValue;
+  }
+  return newTriggerValue;
+}
+
 export default defineComponent({
   name: 'ATextarea',
   inheritAttrs: false,
@@ -40,6 +60,40 @@ export default defineComponent({
     // Max length value
     const hasMaxLength = computed(() => Number(props.maxlength) > 0);
     const compositing = ref(false);
+
+    const oldCompositionValueRef = ref<string>();
+    const oldSelectionStartRef = ref<number>(0);
+    const onInternalCompositionStart = (e: CompositionEvent) => {
+      compositing.value = true;
+      // 拼音输入前保存一份旧值
+      oldCompositionValueRef.value = mergedValue.value as string;
+      // 保存旧的光标位置
+      oldSelectionStartRef.value = (e.currentTarget as any).selectionStart;
+      emit('compositionstart', e);
+    };
+
+    const onInternalCompositionEnd = (e: CompositionEvent) => {
+      compositing.value = false;
+      let triggerValue = (e.currentTarget as any).value;
+      if (hasMaxLength.value) {
+        const isCursorInEnd =
+          oldSelectionStartRef.value >= props.maxlength + 1 ||
+          oldSelectionStartRef.value === oldCompositionValueRef.value?.length;
+        triggerValue = setTriggerValue(
+          isCursorInEnd,
+          oldCompositionValueRef.value as string,
+          triggerValue,
+          props.maxlength,
+        );
+      }
+      // Patch composition onChange when value changed
+      if (triggerValue !== mergedValue.value) {
+        setValue(triggerValue);
+        resolveOnChange(e.currentTarget as any, e, triggerChange, triggerValue);
+      }
+
+      emit('compositionend', e);
+    };
     const instance = getCurrentInstance();
     watch(
       () => props.value,
@@ -103,12 +157,24 @@ export default defineComponent({
     };
 
     const handleChange = (e: Event) => {
-      const { value, composing } = e.target as any;
-      compositing.value = (e as any).isComposing || composing;
-      if ((compositing.value && props.lazy) || stateValue.value === value) return;
-      let triggerValue = (e.currentTarget as any).value;
+      const { composing } = e.target as any;
+      let triggerValue = (e.target as any).value;
+      compositing.value = !!((e as any).isComposing || composing);
+      if ((compositing.value && props.lazy) || stateValue.value === triggerValue) return;
+
       if (hasMaxLength.value) {
-        triggerValue = fixEmojiLength(triggerValue, props.maxlength!);
+        // 1. 复制粘贴超过maxlength的情况 2.未超过maxlength的情况
+        const target = e.target as any;
+        const isCursorInEnd =
+          target.selectionStart >= props.maxlength! + 1 ||
+          target.selectionStart === triggerValue.length ||
+          !target.selectionStart;
+        triggerValue = setTriggerValue(
+          isCursorInEnd,
+          mergedValue.value as string,
+          triggerValue,
+          props.maxlength!,
+        );
       }
       resolveOnChange(e.currentTarget as any, e, triggerChange, triggerValue);
       setValue(triggerValue);
@@ -132,6 +198,8 @@ export default defineComponent({
         onChange: handleChange,
         onBlur,
         onKeydown: handleKeyDown,
+        onCompositionstart: onInternalCompositionStart,
+        onCompositionend: onInternalCompositionEnd,
       };
       if (props.valueModifiers?.lazy) {
         delete resizeProps.onInput;
@@ -172,7 +240,7 @@ export default defineComponent({
       mergedValue.value = val;
     });
     return () => {
-      const { maxlength, bordered = true } = props;
+      const { maxlength, bordered = true, hidden } = props;
       const { style, class: customClass } = attrs;
 
       const inputProps: any = {
@@ -204,6 +272,7 @@ export default defineComponent({
         }
         textareaNode = (
           <div
+            hidden={hidden}
             class={classNames(
               `${prefixCls.value}-textarea`,
               {
diff --git a/components/input/demo/textarea.vue b/components/input/demo/textarea.vue
index 0a9f5178ed..391c0ef000 100644
--- a/components/input/demo/textarea.vue
+++ b/components/input/demo/textarea.vue
@@ -17,6 +17,9 @@ For multi-line input.
 </docs>
 <template>
   <a-textarea v-model:value="value" placeholder="Basic usage" :rows="4" />
+  <br />
+  <br />
+  <a-textarea :rows="4" placeholder="maxLength is 6" :maxlength="6" />
 </template>
 <script lang="ts">
 import { defineComponent, ref } from 'vue';
diff --git a/components/input/inputProps.ts b/components/input/inputProps.ts
index 9ab449263e..c2f4250a8b 100644
--- a/components/input/inputProps.ts
+++ b/components/input/inputProps.ts
@@ -72,6 +72,7 @@ const inputProps = {
   onInput: PropTypes.func,
   'onUpdate:value': PropTypes.func,
   valueModifiers: Object,
+  hidden: Boolean,
 };
 export default inputProps;
 export type InputProps = Partial<ExtractPropTypes<typeof inputProps>>;