Enhance user experience when home servers do not support threads.

changelog.d/5761.feature

@@ -0,0 +1 @@
+Improve user experience when home servers do not yet support threads

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/action/MessageActionsViewModel.kt

@@ -452,6 +452,10 @@ class MessageActionsViewModel @AssistedInject constructor(
                                  actionPermissions: ActionPermissions): Boolean {
         // We let reply in thread visible even if threads are not enabled, with an enhanced flow to attract users
 //        if (!vectorPreferences.areThreadMessagesEnabled()) return false
+        // Disable beta prompt if the homeserver do not support threads
+        if (!vectorPreferences.areThreadMessagesEnabled() &&
+                !session.getHomeServerCapabilities().canUseThreading) return false
+
         if (initialState.isFromThreadTimeline) return false
         if (event.root.isThread()) return false
         if (event.root.getClearType() != EventType.MESSAGE &&

vector/src/main/java/im/vector/app/features/home/room/threads/ThreadsManager.kt

@@ -18,6 +18,7 @@ package im.vector.app.features.home.room.threads
 
 import android.app.Activity
 import android.text.Spanned
+import androidx.annotation.StringRes
 import androidx.core.text.HtmlCompat
 import im.vector.app.R
 import im.vector.app.core.resources.StringProvider
@@ -49,11 +50,17 @@ class ThreadsManager @Inject constructor(
     /**
      * Generates and return an Html spanned string to be rendered especially in dialogs
      */
-    fun getBetaEnableThreadsMessage(): Spanned {
+    private fun generateLearnMoreHtmlString(@StringRes messageId: Int): Spanned {
         val learnMore = stringProvider.getString(R.string.action_learn_more)
         val learnMoreUrl = stringProvider.getString(R.string.threads_learn_more_url)
         val href = "<a href='$learnMoreUrl'>$learnMore</a>.<br><br>"
-        val message = stringProvider.getString(R.string.threads_beta_enable_notice_message, href)
+        val message = stringProvider.getString(messageId, href)
         return HtmlCompat.fromHtml(message, HtmlCompat.FROM_HTML_MODE_LEGACY)
     }
+
+    fun getBetaEnableThreadsMessage(): Spanned =
+            generateLearnMoreHtmlString(R.string.threads_beta_enable_notice_message)
+
+    fun getLabsEnableThreadsMessage(): Spanned =
+            generateLearnMoreHtmlString(R.string.threads_labs_enable_notice_message)
 }

vector/src/main/java/im/vector/app/features/settings/VectorSettingsLabsFragment.kt

@@ -17,18 +17,23 @@
 package im.vector.app.features.settings
 
 import android.os.Bundle
+import android.text.method.LinkMovementMethod
+import android.widget.TextView
 import androidx.preference.Preference
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import im.vector.app.R
 import im.vector.app.core.preference.VectorSwitchPreference
 import im.vector.app.features.MainActivity
 import im.vector.app.features.MainActivityArgs
 import im.vector.app.features.analytics.plan.MobileScreen
+import im.vector.app.features.home.room.threads.ThreadsManager
 import org.matrix.android.sdk.api.settings.LightweightSettingsStorage
 import javax.inject.Inject
 
 class VectorSettingsLabsFragment @Inject constructor(
         private val vectorPreferences: VectorPreferences,
-        private val lightweightSettingsStorage: LightweightSettingsStorage
+        private val lightweightSettingsStorage: LightweightSettingsStorage,
+        private val threadsManager: ThreadsManager
 ) : VectorSettingsBaseFragment() {
 
     override var titleRes = R.string.room_settings_labs_pref_title
@@ -46,15 +51,51 @@ class VectorSettingsLabsFragment @Inject constructor(
         }
 
         // clear cache
-        findPreference<VectorSwitchPreference>(VectorPreferences.SETTINGS_LABS_ENABLE_THREAD_MESSAGES)?.let {
-            it.onPreferenceClickListener = Preference.OnPreferenceClickListener {
-                // We should migrate threads only if threads are disabled
-                vectorPreferences.setShouldMigrateThreads(!vectorPreferences.areThreadMessagesEnabled())
-                lightweightSettingsStorage.setThreadMessagesEnabled(vectorPreferences.areThreadMessagesEnabled())
-                displayLoadingView()
-                MainActivity.restartApp(requireActivity(), MainActivityArgs(clearCache = true))
+        findPreference<VectorSwitchPreference>(VectorPreferences.SETTINGS_LABS_ENABLE_THREAD_MESSAGES)?.let { vectorPref ->
+            vectorPref.onPreferenceClickListener = Preference.OnPreferenceClickListener {
+                onThreadsPreferenceClickedInterceptor(vectorPref)
                 false
             }
         }
     }
+
+    /**
+     * Intercept the click to display a user friendly dialog when their homeserver do not support threads
+     */
+    private fun onThreadsPreferenceClickedInterceptor(vectorSwitchPreference: VectorSwitchPreference) {
+        val userEnabledThreads = vectorPreferences.areThreadMessagesEnabled()
+        if (!session.getHomeServerCapabilities().canUseThreading && userEnabledThreads) {
+            activity?.let {
+                MaterialAlertDialogBuilder(it)
+                        .setTitle(R.string.threads_labs_enable_notice_title)
+                        .setMessage(threadsManager.getLabsEnableThreadsMessage())
+                        .setCancelable(true)
+                        .setNegativeButton(R.string.action_not_now) { _, _ ->
+                            vectorSwitchPreference.isChecked = false
+                        }
+                        .setPositiveButton(R.string.action_try_it_out) { _, _ ->
+                            onThreadsPreferenceClicked()
+                        }
+                        .show()
+                        ?.findViewById<TextView>(android.R.id.message)
+                        ?.apply {
+                            linksClickable = true
+                            movementMethod = LinkMovementMethod.getInstance()
+                        }
+            }
+        } else {
+            onThreadsPreferenceClicked()
+        }
+    }
+
+    /**
+     * Action when threads preference switch is actually clicked
+     */
+    private fun onThreadsPreferenceClicked() {
+        // We should migrate threads only if threads are disabled
+        vectorPreferences.setShouldMigrateThreads(!vectorPreferences.areThreadMessagesEnabled())
+        lightweightSettingsStorage.setThreadMessagesEnabled(vectorPreferences.areThreadMessagesEnabled())
+        displayLoadingView()
+        MainActivity.restartApp(requireActivity(), MainActivityArgs(clearCache = true))
+    }
 }

vector/src/main/res/values/strings.xml

@@ -739,6 +739,9 @@
     <string name="threads_beta_enable_notice_title">Threads Beta</string>
     <!-- %s will be replaced with action_learn_more string resource that will be clickable(url redirection)  -->
     <string name="threads_beta_enable_notice_message">Threads help keep your conversations on-topic and easy to track. %sEnabling threads will refresh the app. This may take longer for some accounts.</string>
+    <string name="threads_labs_enable_notice_title">Threads Beta</string>
+    <string name="threads_labs_enable_notice_message">Your homeserver does not currently support threads, so this feature may be unreliable. Some threaded messages may not be reliably available. %sDo you want to enable threads anyway?</string>
+
 
     <!-- Search -->
     <string name="search_hint">Search</string>