adding a fastscroller with letters at the contact list

app/build.gradle

@@ -40,4 +40,5 @@ dependencies {
     implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta4'
     implementation 'org.greenrobot:eventbus:3.2.0'
     implementation 'com.klinkerapps:android-smsmms:5.2.6'
+    implementation 'com.github.tibbi:IndicatorFastScroll:08f512858a'
 }

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/MainActivity.kt

@@ -212,7 +212,7 @@ class MainActivity : SimpleActivity() {
     }
 
     private fun launchAbout() {
-        val licenses = LICENSE_EVENT_BUS or LICENSE_SMS_MMS
+        val licenses = LICENSE_EVENT_BUS or LICENSE_SMS_MMS or LICENSE_INDICATOR_FAST_SCROLL
 
         val faqItems = arrayListOf(
             FAQItem(R.string.faq_1_title, R.string.faq_1_text),

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/NewConversationActivity.kt

@@ -1,9 +1,11 @@
 package com.simplemobiletools.smsmessenger.activities
 
 import android.content.Intent
+import android.content.res.ColorStateList
 import android.net.Uri
 import android.os.Bundle
 import android.view.WindowManager
+import com.reddit.indicatorfastscroll.FastScrollItemIndicator
 import com.simplemobiletools.commons.extensions.*
 import com.simplemobiletools.commons.helpers.PERMISSION_READ_CONTACTS
 import com.simplemobiletools.commons.helpers.ensureBackgroundThread
@@ -14,6 +16,8 @@ import com.simplemobiletools.smsmessenger.helpers.*
 import com.simplemobiletools.smsmessenger.models.Contact
 import kotlinx.android.synthetic.main.activity_conversation.*
 import kotlinx.android.synthetic.main.item_suggested_contact.view.*
+import java.util.*
+import kotlin.collections.ArrayList
 
 class NewConversationActivity : SimpleActivity() {
     private var allContacts = ArrayList<Contact>()
@@ -73,6 +77,18 @@ class NewConversationActivity : SimpleActivity() {
                 }
             }
         }
+
+        val states = arrayOf(intArrayOf(android.R.attr.state_enabled),
+            intArrayOf(-android.R.attr.state_enabled),
+            intArrayOf(-android.R.attr.state_checked),
+            intArrayOf(android.R.attr.state_pressed)
+        )
+        val textColor = config.textColor
+        val colors = intArrayOf(textColor, textColor, textColor, textColor)
+        val myList = ColorStateList(states, colors)
+        contacts_letter_fastscroller.textColor = myList
+        contacts_letter_fastscroller_thumb.setupWithFastScroller(contacts_letter_fastscroller)
+        contacts_letter_fastscroller_thumb.textColor = config.primaryColor.getContrastColor()
     }
 
     private fun isThirdPartyIntent(): Boolean {
@@ -88,6 +104,7 @@ class NewConversationActivity : SimpleActivity() {
         fillSuggestedContacts {
             getAvailableContacts {
                 allContacts = it
+
                 runOnUiThread {
                     setupAdapter(allContacts)
                 }
@@ -112,6 +129,8 @@ class NewConversationActivity : SimpleActivity() {
         }.apply {
             contacts_list.adapter = this
         }
+
+        setupLetterFastscroller(contacts)
     }
 
     private fun fillSuggestedContacts(callback: () -> Unit) {
@@ -142,6 +161,22 @@ class NewConversationActivity : SimpleActivity() {
         }
     }
 
+    private fun setupLetterFastscroller(contacts: ArrayList<Contact>) {
+        contacts_letter_fastscroller.setupWithRecyclerView(contacts_list, { position ->
+            try {
+                val name = contacts[position].name
+                var character = if (name.isNotEmpty()) name.substring(0, 1) else ""
+                if (!character.areLettersOnly()) {
+                    character = "#"
+                }
+
+                FastScrollItemIndicator.Text(character.toUpperCase(Locale.getDefault()))
+            } catch (e: Exception) {
+                FastScrollItemIndicator.Text("")
+            }
+        })
+    }
+
     private fun launchThreadActivity(phoneNumber: String, name: String) {
         val text = intent.getStringExtra(Intent.EXTRA_TEXT) ?: ""
         Intent(this, ThreadActivity::class.java).apply {

app/src/main/res/layout/activity_conversation.xml

@@ -105,4 +105,22 @@
         android:scrollbars="none"
         app:layoutManager="com.simplemobiletools.commons.views.MyLinearLayoutManager" />
 
+    <com.reddit.indicatorfastscroll.FastScrollerView
+        android:id="@+id/contacts_letter_fastscroller"
+        android:layout_width="32dp"
+        android:layout_height="wrap_content"
+        android:layout_alignTop="@+id/contacts_list"
+        android:layout_alignParentEnd="true"
+        android:paddingTop="@dimen/big_margin"
+        android:paddingBottom="@dimen/big_margin" />
+
+    <com.reddit.indicatorfastscroll.FastScrollerThumbView
+        android:id="@+id/contacts_letter_fastscroller_thumb"
+        android:layout_width="@dimen/fab_size"
+        android:layout_height="match_parent"
+        android:layout_alignTop="@+id/contacts_letter_fastscroller"
+        android:layout_alignBottom="@+id/contacts_letter_fastscroller"
+        android:layout_marginEnd="@dimen/activity_margin"
+        android:layout_toStartOf="@+id/contacts_letter_fastscroller" />
+
 </RelativeLayout>