[Feature] Add a view parameter for getPopupText().

So that implementation can e.g. use the context from it.

Author: zhanghai

library/src/main/java/me/zhanghai/android/fastscroll/PopupTextProvider.java

@@ -16,10 +16,12 @@
 
 package me.zhanghai.android.fastscroll;
 
+import android.view.View;
+
 import androidx.annotation.NonNull;
 
 public interface PopupTextProvider {
 
     @NonNull
-    CharSequence getPopupText(int position);
+    CharSequence getPopupText(@NonNull View view, int position);
 }

library/src/main/java/me/zhanghai/android/fastscroll/RecyclerViewHelper.java

@@ -133,7 +133,7 @@ public CharSequence getPopupText() {
         if (position == RecyclerView.NO_POSITION) {
             return null;
         }
-        return popupTextProvider.getPopupText(position);
+        return popupTextProvider.getPopupText(mView, position);
     }
 
     private int getItemCount() {

sample/src/main/java/me/zhanghai/android/fastscroll/sample/LocaleListAdapter.java

@@ -18,6 +18,7 @@
 
 import android.text.TextUtils;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
 
 import androidx.annotation.NonNull;
@@ -80,7 +81,7 @@ public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
 
     @NonNull
     @Override
-    public CharSequence getPopupText(int position) {
+    public CharSequence getPopupText(@NonNull View view, int position) {
         Locale locale = getItem(position);
         return locale.toString().substring(0, 1).toUpperCase(Locale.getDefault());
     }