Add support for following hashtags (#2642)

* Add support for following hashtags. Addresses #2637

* Update rxjava to coroutines

* Update new tag api to use suspend functions

* Update hashtag unfollow icon

* Set correct tint on hashtag follow/unfollow icons

* Translate hashtag follow/unfollow error messages

* Toast => Snackbar

* Remove unnecessary view lookup

app/src/main/java/com/keylesspalace/tusky/StatusListActivity.kt

@@ -18,12 +18,20 @@ package com.keylesspalace.tusky
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
+import android.util.Log
+import android.view.Menu
+import android.view.MenuItem
 import androidx.fragment.app.commit
+import androidx.lifecycle.lifecycleScope
+import at.connyduck.calladapter.networkresult.fold
+import com.google.android.material.snackbar.Snackbar
 import com.keylesspalace.tusky.components.timeline.TimelineFragment
 import com.keylesspalace.tusky.components.timeline.viewmodel.TimelineViewModel.Kind
 import com.keylesspalace.tusky.databinding.ActivityStatuslistBinding
+import com.keylesspalace.tusky.util.viewBinding
 import dagger.android.DispatchingAndroidInjector
 import dagger.android.HasAndroidInjector
+import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
@@ -31,16 +39,21 @@ class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
     @Inject
     lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
 
+    private val binding: ActivityStatuslistBinding by viewBinding(ActivityStatuslistBinding::inflate)
+    private lateinit var kind: Kind
+    private var hashtag: String? = null
+    private var followTagItem: MenuItem? = null
+    private var unfollowTagItem: MenuItem? = null
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        val binding = ActivityStatuslistBinding.inflate(layoutInflater)
         setContentView(binding.root)
 
         setSupportActionBar(binding.includedToolbar.toolbar)
 
-        val kind = Kind.valueOf(intent.getStringExtra(EXTRA_KIND)!!)
+        kind = Kind.valueOf(intent.getStringExtra(EXTRA_KIND)!!)
         val listId = intent.getStringExtra(EXTRA_LIST_ID)
-        val hashtag = intent.getStringExtra(EXTRA_HASHTAG)
+        hashtag = intent.getStringExtra(EXTRA_HASHTAG)
 
         val title = when (kind) {
             Kind.FAVOURITES -> getString(R.string.title_favourites)
@@ -67,6 +80,70 @@ class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
         }
     }
 
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        val tag = hashtag
+        if (kind == Kind.TAG && tag != null) {
+            lifecycleScope.launch {
+                mastodonApi.tag(tag).fold(
+                    { tagEntity ->
+                        menuInflater.inflate(R.menu.view_hashtag_toolbar, menu)
+                        followTagItem = menu.findItem(R.id.action_follow_hashtag)
+                        unfollowTagItem = menu.findItem(R.id.action_unfollow_hashtag)
+                        followTagItem?.isVisible = tagEntity.following == false
+                        unfollowTagItem?.isVisible = tagEntity.following == true
+                        followTagItem?.setOnMenuItemClickListener { followTag() }
+                        unfollowTagItem?.setOnMenuItemClickListener { unfollowTag() }
+                    },
+                    {
+                        Log.w(TAG, "Failed to query tag #$tag", it)
+                    }
+                )
+            }
+        }
+
+        return super.onCreateOptionsMenu(menu)
+    }
+
+    private fun followTag(): Boolean {
+        val tag = hashtag
+        if (tag != null) {
+            lifecycleScope.launch {
+                mastodonApi.followTag(tag).fold(
+                    {
+                        followTagItem?.isVisible = false
+                        unfollowTagItem?.isVisible = true
+                    },
+                    {
+                        Snackbar.make(binding.root, getString(R.string.error_following_hashtag_format, tag), Snackbar.LENGTH_SHORT).show()
+                        Log.e(TAG, "Failed to follow #$tag", it)
+                    }
+                )
+            }
+        }
+
+        return true
+    }
+
+    private fun unfollowTag(): Boolean {
+        val tag = hashtag
+        if (tag != null) {
+            lifecycleScope.launch {
+                mastodonApi.unfollowTag(tag).fold(
+                    {
+                        followTagItem?.isVisible = true
+                        unfollowTagItem?.isVisible = false
+                    },
+                    {
+                        Snackbar.make(binding.root, getString(R.string.error_unfollowing_hashtag_format, tag), Snackbar.LENGTH_SHORT).show()
+                        Log.e(TAG, "Failed to unfollow #$tag", it)
+                    }
+                )
+            }
+        }
+
+        return true
+    }
+
     override fun androidInjector() = dispatchingAndroidInjector
 
     companion object {
@@ -75,6 +152,7 @@ class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
         private const val EXTRA_LIST_ID = "id"
         private const val EXTRA_LIST_TITLE = "title"
         private const val EXTRA_HASHTAG = "tag"
+        const val TAG = "StatusListActivity"
 
         fun newFavouritesIntent(context: Context) =
             Intent(context, StatusListActivity::class.java).apply {

app/src/main/java/com/keylesspalace/tusky/entity/HashTag.kt

@@ -1,3 +1,3 @@
 package com.keylesspalace.tusky.entity
 
-data class HashTag(val name: String, val url: String)
+data class HashTag(val name: String, val url: String, val following: Boolean? = null)

app/src/main/java/com/keylesspalace/tusky/network/MastodonApi.kt

@@ -25,6 +25,7 @@ import com.keylesspalace.tusky.entity.Conversation
 import com.keylesspalace.tusky.entity.DeletedStatus
 import com.keylesspalace.tusky.entity.Emoji
 import com.keylesspalace.tusky.entity.Filter
+import com.keylesspalace.tusky.entity.HashTag
 import com.keylesspalace.tusky.entity.Instance
 import com.keylesspalace.tusky.entity.Marker
 import com.keylesspalace.tusky.entity.MastoList
@@ -656,4 +657,13 @@ interface MastodonApi {
         @Header("Authorization") auth: String,
         @Header(DOMAIN_HEADER) domain: String,
     ): NetworkResult<ResponseBody>
+
+    @GET("api/v1/tags/{name}")
+    suspend fun tag(@Path("name") name: String): NetworkResult<HashTag>
+
+    @POST("api/v1/tags/{name}/follow")
+    suspend fun followTag(@Path("name") name: String): NetworkResult<HashTag>
+
+    @POST("api/v1/tags/{name}/unfollow")
+    suspend fun unfollowTag(@Path("name") name: String): NetworkResult<HashTag>
 }

app/src/main/res/drawable/ic_person_remove_24dp.xml

@@ -0,0 +1,8 @@
+<!-- drawable/account_remove.xml -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:height="24dp"
+    android:width="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path android:fillColor="#000" android:pathData="M15,14C17.67,14 23,15.33 23,18V20H7V18C7,15.33 12.33,14 15,14M15,12A4,4 0 0,1 11,8A4,4 0 0,1 15,4A4,4 0 0,1 19,8A4,4 0 0,1 15,12M5,9.59L7.12,7.46L8.54,8.88L6.41,11L8.54,13.12L7.12,14.54L5,12.41L2.88,14.54L1.46,13.12L3.59,11L1.46,8.88L2.88,7.46L5,9.59Z" />
+</vector>

app/src/main/res/menu/view_hashtag_toolbar.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/action_follow_hashtag"
+        android:title="@string/action_follow"
+        app:showAsAction="ifRoom"
+        app:iconTint="?attr/colorOnSurface"
+        android:icon="@drawable/ic_person_add_24dp" />
+
+    <item
+        android:id="@+id/action_unfollow_hashtag"
+        android:title="@string/action_unfollow"
+        app:showAsAction="ifRoom"
+        app:iconTint="?attr/colorOnSurface"
+        android:icon="@drawable/ic_person_remove_24dp" />
+
+
+</menu>

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

@@ -22,6 +22,8 @@
     <string name="error_media_upload_image_or_video">Images and videos cannot both be attached to the same post.</string>
     <string name="error_media_upload_sending">The upload failed.</string>
     <string name="error_sender_account_gone">Error sending post.</string>
+    <string name="error_following_hashtag_format">Error following #%s</string>
+    <string name="error_unfollowing_hashtag_format">Error unfollowing #%s</string>
 
     <string name="title_login">Login</string>
     <string name="title_home">Home</string>