Merge pull request #562 from Naveen3Singh/scrolling_improvements

Scrolling improvements

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

@@ -4,6 +4,7 @@ import android.annotation.SuppressLint
 import android.app.Activity
 import android.content.ActivityNotFoundException
 import android.content.Intent
+import android.content.res.ColorStateList
 import android.graphics.BitmapFactory
 import android.graphics.drawable.LayerDrawable
 import android.media.MediaMetadataRetriever
@@ -36,6 +37,8 @@ import androidx.annotation.StringRes
 import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.core.content.res.ResourcesCompat
 import androidx.core.view.*
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
 import com.simplemobiletools.commons.dialogs.ConfirmationDialog
@@ -79,6 +82,8 @@ class ThreadActivity : SimpleActivity() {
     private val TYPE_SEND = 15
     private val TYPE_DELETE = 16
 
+    private val SCROLL_TO_BOTTOM_FAB_LIMIT = 20
+
     private var threadId = 0L
     private var currentSIMCardIndex = 0
     private var isActivityVisible = false
@@ -142,6 +147,7 @@ class ThreadActivity : SimpleActivity() {
                     }
 
                     setupThread()
+                    setupScrollFab()
                 }
             } else {
                 finish()
@@ -173,12 +179,7 @@ class ThreadActivity : SimpleActivity() {
             }
         }
 
-        val bottomBarColor = if (baseConfig.isUsingSystemTheme) {
-            resources.getColor(R.color.you_bottom_bar_color)
-        } else {
-            getBottomNavigationBackgroundColor()
-        }
-
+        val bottomBarColor = getBottomBarColor()
         thread_send_message_holder.setBackgroundColor(bottomBarColor)
         reply_disabled_info_holder.setBackgroundColor(bottomBarColor)
         updateNavigationBarColor(bottomBarColor)
@@ -394,12 +395,11 @@ class ThreadActivity : SimpleActivity() {
         runOnUiThread {
             refreshMenuItems()
             getOrCreateThreadAdapter().apply {
-                val scrollPosition = if (currentList.lastOrNull() != threadItems.lastOrNull()) {
-                    threadItems.lastIndex
-                } else {
-                    -1
-                }
-                updateMessages(threadItems, scrollPosition)
+                val layoutManager = thread_messages_list.layoutManager as LinearLayoutManager
+                val lastPosition = itemCount - 1
+                val lastVisiblePosition = layoutManager.findLastVisibleItemPosition()
+                val shouldScrollToBottom = currentList.lastOrNull() != threadItems.lastOrNull() && lastPosition - lastVisiblePosition == 1
+                updateMessages(threadItems, if (shouldScrollToBottom) lastPosition else -1)
             }
         }
 
@@ -438,6 +438,22 @@ class ThreadActivity : SimpleActivity() {
         }
     }
 
+    private fun setupScrollFab() {
+        thread_messages_list.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                super.onScrolled(recyclerView, dx, dy)
+                val layoutManager = thread_messages_list.layoutManager as LinearLayoutManager
+                val lastVisibleItemPosition = layoutManager.findLastCompletelyVisibleItemPosition()
+                val isCloseToBottom = lastVisibleItemPosition >= getOrCreateThreadAdapter().itemCount - SCROLL_TO_BOTTOM_FAB_LIMIT
+                if (isCloseToBottom) {
+                    scroll_to_bottom_fab.hide()
+                } else {
+                    scroll_to_bottom_fab.show()
+                }
+            }
+        })
+    }
+
     private fun handleItemClick(any: Any) {
         when {
             any is Message && any.isScheduled -> showScheduledMessageInfo(any)
@@ -633,6 +649,11 @@ class ThreadActivity : SimpleActivity() {
                 addAttachment(it)
             }
         }
+        scroll_to_bottom_fab.setOnClickListener {
+            scrollToBottom()
+        }
+        scroll_to_bottom_fab.backgroundTintList = ColorStateList.valueOf(getBottomBarColor())
+        scroll_to_bottom_fab.applyColorFilter(textColor)
 
         setupScheduleSendUi()
     }
@@ -1235,7 +1256,7 @@ class ThreadActivity : SimpleActivity() {
 
         val newItems = getThreadItems()
         runOnUiThread {
-            getOrCreateThreadAdapter().updateMessages(newItems)
+            getOrCreateThreadAdapter().updateMessages(newItems, newItems.lastIndex)
             if (!refreshedSinceSent) {
                 refreshMessages()
             }
@@ -1661,4 +1682,10 @@ class ThreadActivity : SimpleActivity() {
             showAttachmentPicker()
         }
     }
+
+    private fun getBottomBarColor() = if (baseConfig.isUsingSystemTheme) {
+        resources.getColor(R.color.you_bottom_bar_color)
+    } else {
+        getBottomNavigationBackgroundColor()
+    }
 }

app/src/main/kotlin/com/simplemobiletools/smsmessenger/adapters/ThreadAdapter.kt

@@ -227,7 +227,7 @@ class ThreadAdapter(
 
     private fun isThreadDateTime(position: Int) = currentList.getOrNull(position) is ThreadDateTime
 
-    fun updateMessages(newMessages: ArrayList<ThreadItem>, scrollPosition: Int = newMessages.lastIndex) {
+    fun updateMessages(newMessages: ArrayList<ThreadItem>, scrollPosition: Int = -1) {
         val latestMessages = newMessages.toMutableList()
         submitList(latestMessages) {
             if (scrollPosition != -1) {

app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Constants.kt

@@ -70,7 +70,7 @@ const val FILE_SIZE_600_KB = 614_400L
 const val FILE_SIZE_1_MB = 1_048_576L
 const val FILE_SIZE_2_MB = 2_097_152L
 
-const val MESSAGES_LIMIT = 50
+const val MESSAGES_LIMIT = 75
 
 // intent launch request codes
 const val PICK_PHOTO_INTENT = 42

app/src/main/res/drawable/ic_arrow_down_vector.xml

@@ -0,0 +1,3 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="24" android:viewportHeight="24">
+    <path android:fillColor="@android:color/white" android:pathData="M11 5v11.17l-4.88-4.88c-0.39-0.39-1.03-0.39-1.42 0-0.39 0.39-0.39 1.02 0 1.41l6.59 6.59c0.39 0.39 1.02 0.39 1.41 0l6.59-6.59c0.39-0.39 0.39-1.02 0-1.41-0.39-0.39-1.02-0.39-1.41 0L13 16.17V5c0-0.55-0.45-1-1-1s-1 0.45-1 1z"/>
+</vector>

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

@@ -121,6 +121,18 @@
 
         </com.qtalk.recyclerviewfastscroller.RecyclerViewFastScroller>
 
+        <com.simplemobiletools.commons.views.MyFloatingActionButton
+            android:id="@+id/scroll_to_bottom_fab"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_margin="@dimen/activity_margin"
+            android:src="@drawable/ic_arrow_down_vector"
+            android:visibility="invisible"
+            app:fabSize="mini"
+            app:layout_constraintBottom_toBottomOf="@id/thread_messages_fastscroller"
+            app:layout_constraintEnd_toEndOf="@id/thread_messages_fastscroller"
+            tools:ignore="ContentDescription" />
+
         <include
             layout="@layout/layout_invalid_short_code_info"
             android:layout_width="match_parent"