refactor: decoupling mListeners in PanguTextWatcher to TextViewDelegate

Author: fankes

pangutext-android/src/main/java/com/highcapable/pangutext/android/core/PanguTextWatcher.kt

@@ -26,9 +26,9 @@ import android.text.TextWatcher
 import android.widget.EditText
 import android.widget.TextView
 import com.highcapable.betterandroid.system.extension.tool.AndroidVersion
-import com.highcapable.kavaref.KavaRef.Companion.asResolver
 import com.highcapable.pangutext.android.PanguText
 import com.highcapable.pangutext.android.PanguTextConfig
+import com.highcapable.pangutext.android.core.TextViewDelegate.Companion.delegate
 import com.highcapable.pangutext.android.extension.injectRealTimePanguText
 
 /**
@@ -40,15 +40,7 @@ import com.highcapable.pangutext.android.extension.injectRealTimePanguText
  */
 class PanguTextWatcher internal constructor(private val base: TextView, private val config: PanguTextConfig) : TextWatcher {
 
-    /**
-     * The text watchers of the base [TextView].
-     * @return [ArrayList]<[TextWatcher]>.
-     */
-    private val textWatchers 
-        get() = base.asResolver().optional(silent = true).firstFieldOrNull {
-            name = "mListeners"
-            superclass()
-        }?.getQuietly<ArrayList<TextWatcher>>()
+    private val delegate = base.delegate
 
     /**
      * Whether to automatically re-measure the text width after processing.
@@ -62,20 +54,12 @@ class PanguTextWatcher internal constructor(private val base: TextView, private
         editable?.let { PanguText.format(base.resources, base.textSize, it, config) }
         if (!isAutoRemeasureText) return
 
-        val currentWatchers = mutableListOf<TextWatcher>()
-        textWatchers?.also {
-            currentWatchers.addAll(it)
-            // Avoid triggering events again during processing.
-            it.clear()
+        delegate.withoutTextWatchers {
+            // Reset the text to trigger remeasurement.
+            base.text = editable
         }
-
-        // Reset the text to trigger remeasurement.
-        base.text = editable
-        // Re-add to continue listening to text changes.
-        textWatchers?.addAll(currentWatchers)
-
-        currentWatchers.clear()
     }
+
     override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
     override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
 }

pangutext-android/src/main/java/com/highcapable/pangutext/android/core/TextViewDelegate.kt

@@ -0,0 +1,75 @@
+/*
+ * PanguText - A typographic solution for the optimal alignment of CJK characters, English words, and half-width digits.
+ * Copyright (C) 2019 HighCapable
+ * https://github.com/BetterAndroid/PanguText
+ *
+ * Apache License Version 2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is created by fankes on 2025/8/15.
+ */
+package com.highcapable.pangutext.android.core
+
+import android.text.TextWatcher
+import android.widget.TextView
+import com.highcapable.kavaref.KavaRef.Companion.resolve
+
+/**
+ * A delegate for [TextView] to manage its text watchers.
+ * @param instance the [TextView] instance.
+ */
+internal class TextViewDelegate private constructor(private val instance: TextView) {
+
+    companion object {
+
+        private val mListeners by lazy {
+            TextView::class.resolve()
+                .optional(silent = true)
+                .firstFieldOrNull { name = "mListeners" }
+        }
+
+        /**
+         * Create the [TextViewDelegate] for the given [TextView] instance.
+         * @return [TextViewDelegate]
+         */
+        val TextView.delegate get() = TextViewDelegate(this)
+    }
+
+    /**
+     * The text watchers of the [TextView].
+     * @return [ArrayList]<[TextWatcher]>.
+     */
+    private val textWatchers
+        get() = mListeners?.copy()?.of(instance)?.getQuietly<ArrayList<TextWatcher>>()
+
+    /**
+     * Execute the given action without triggering text watchers.
+     * @param action the action to execute without triggering text watchers.
+     */
+    inline fun withoutTextWatchers(action: () -> Unit) {
+        val currentWatchers = mutableListOf<TextWatcher>()
+        textWatchers?.also {
+            currentWatchers.addAll(it)
+            // Avoid triggering events again during processing.
+            it.clear()
+        }
+
+        // Run action.
+        action()
+        // Re-add to continue listening to text changes.
+        textWatchers?.addAll(currentWatchers)
+
+        currentWatchers.clear()
+    }
+}