Add view.*Position & holder extensions

drakeet · Jun 20, 2021 · 7dca987 · 7dca987
1 parent eefe2c2
commit 7dca987
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Showing 4 changed files with 33 additions and 2 deletions.
diff --git a/library/src/main/kotlin/com/drakeet/multitype/ViewDelegate.kt b/library/src/main/kotlin/com/drakeet/multitype/ViewDelegate.kt
@@ -12,6 +12,16 @@ import androidx.recyclerview.widget.RecyclerView
  */
 abstract class ViewDelegate<T, V : View> : ItemViewDelegate<T, ViewDelegate.Holder<V>>() {
 
+  protected val View.holder: Holder<V> get() {
+    return holder(this) ?: throw IllegalAccessException("The view holder property can only be called after onCreateView()!")
+  }
+
+  protected val View.layoutPosition: Int get() = holder.layoutPosition
+
+  protected val View.absoluteAdapterPosition: Int get() = holder.absoluteAdapterPosition
+
+  protected val View.bindingAdapterPosition: Int get() = holder.bindingAdapterPosition
+
   abstract fun onCreateView(context: Context): V
 
   abstract fun onBindView(view: V, item: T)
@@ -23,9 +33,19 @@ abstract class ViewDelegate<T, V : View> : ItemViewDelegate<T, ViewDelegate.Hold
 
   // Override this function if you need a ViewHolder or positions
   open fun onBindView(holder: Holder<V>, view: V, item: T) {
+    view.setTag(R.id.tagViewHolder, holder)
     onBindView(view, item)
   }
 
+  protected fun getRecyclerLayoutParams(view: View): RecyclerView.LayoutParams {
+    return (view.layoutParams as RecyclerView.LayoutParams)
+  }
+
+  private fun holder(view: View): Holder<V>? {
+    @Suppress("UNCHECKED_CAST")
+    return view.getTag(R.id.tagViewHolder) as? Holder<V>
+  }
+
   override fun onCreateViewHolder(context: Context, parent: ViewGroup): Holder<V> {
     return Holder(onCreateView(context, parent))
   }

diff --git a/library/src/main/res/values/ids.xml b/library/src/main/res/values/ids.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <item name="tagViewHolder" type="id" />
+</resources>
diff --git a/sample/src/main/kotlin/com/drakeet/multitype/sample/normal/RichView.kt b/sample/src/main/kotlin/com/drakeet/multitype/sample/normal/RichView.kt
@@ -20,6 +20,7 @@ class RichView(context: Context) : LinearLayout(context) {
   }
 
   val textView = AppCompatTextView(context).apply {
+    gravity = Gravity.CENTER
     setTextColor(Color.BLACK)
     addView(this, LayoutParams(WRAP_CONTENT, WRAP_CONTENT))
   }

diff --git a/sample/src/main/kotlin/com/drakeet/multitype/sample/normal/RichViewDelegate.kt b/sample/src/main/kotlin/com/drakeet/multitype/sample/normal/RichViewDelegate.kt
@@ -16,6 +16,7 @@
 
 package com.drakeet.multitype.sample.normal
 
+import android.annotation.SuppressLint
 import android.content.Context
 import android.view.Gravity
 import android.view.ViewGroup
@@ -35,9 +36,14 @@ class RichViewDelegate : ViewDelegate<RichItem, RichView>() {
     return RichView(context).apply { layoutParams = LayoutParams(MATCH_PARENT, WRAP_CONTENT) }
   }
 
+  @SuppressLint("SetTextI18n")
   override fun onBindView(view: RichView, item: RichItem) {
     view.imageView.setImageResource(item.imageResId)
-    view.textView.text = item.text
-    // Or bind the data in the RichView by calling view.setRichItem(item)
+    view.textView.text = """
+      |${item.text}
+      |layoutPosition: ${view.layoutPosition} 
+      |absoluteAdapterPosition: ${view.absoluteAdapterPosition} 
+      |bindingAdapterPosition: ${view.bindingAdapterPosition} 
+    """.trimMargin()
   }
 }