feat: Display compose button when viewing hashtags (#254)

Display the "compose" FAB when viewing a hashtag list. Tapping the
button will open `ComposeActivity` prepopulated with the hashtag at the
end of the post with the cursor at the start.

Fixes #228

app/src/main/java/app/pachli/StatusListActivity.kt

@@ -26,15 +26,19 @@ import androidx.fragment.app.commit
 import androidx.lifecycle.lifecycleScope
 import app.pachli.appstore.EventHub
 import app.pachli.appstore.FilterChangedEvent
+import app.pachli.components.compose.ComposeActivity
 import app.pachli.components.timeline.TimelineFragment
 import app.pachli.components.timeline.TimelineKind
 import app.pachli.databinding.ActivityStatuslistBinding
 import app.pachli.entity.Filter
 import app.pachli.entity.FilterV1
+import app.pachli.interfaces.ActionButtonActivity
 import app.pachli.interfaces.AppBarLayoutHost
+import app.pachli.util.unsafeLazy
 import app.pachli.util.viewBinding
 import at.connyduck.calladapter.networkresult.fold
 import com.google.android.material.appbar.AppBarLayout
+import com.google.android.material.floatingactionbutton.FloatingActionButton
 import com.google.android.material.snackbar.Snackbar
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
@@ -47,7 +51,7 @@ import javax.inject.Inject
  * the user's favourites, bookmarks, etc.
  */
 @AndroidEntryPoint
-class StatusListActivity : BottomSheetActivity(), AppBarLayoutHost {
+class StatusListActivity : BottomSheetActivity(), AppBarLayoutHost, ActionButtonActivity {
     @Inject
     lateinit var eventHub: EventHub
 
@@ -57,6 +61,8 @@ class StatusListActivity : BottomSheetActivity(), AppBarLayoutHost {
     override val appBarLayout: AppBarLayout
         get() = binding.includedToolbar.appbar
 
+    override val actionButton: FloatingActionButton? by unsafeLazy { binding.composeButton }
+
     /**
      * If showing statuses with a hashtag, the hashtag being used, without the
      * leading `#`.
@@ -103,6 +109,27 @@ class StatusListActivity : BottomSheetActivity(), AppBarLayoutHost {
                 replace(R.id.fragmentContainer, fragment)
             }
         }
+
+        val composeIntent = when (timelineKind) {
+            is TimelineKind.Tag -> {
+                val tag = (timelineKind as TimelineKind.Tag).tags.first()
+                ComposeActivity.startIntent(
+                    this,
+                    ComposeActivity.ComposeOptions(
+                        content = getString(R.string.title_tag_with_initial_position).format(tag),
+                        initialCursorPosition = ComposeActivity.InitialCursorPosition.START,
+                    ),
+                )
+            }
+            else -> null
+        }
+
+        if (composeIntent == null) {
+            binding.composeButton.hide()
+        } else {
+            binding.composeButton.setOnClickListener { startActivity(composeIntent) }
+            binding.composeButton.show()
+        }
     }
 
     override fun onCreateOptionsMenu(menu: Menu): Boolean {

app/src/main/java/app/pachli/components/compose/ComposeActivity.kt

@@ -260,7 +260,7 @@ class ComposeActivity :
         }
 
         setupLanguageSpinner(getInitialLanguages(composeOptions?.language, activeAccount))
-        setupComposeField(sharedPreferencesRepository, viewModel.startingText)
+        setupComposeField(sharedPreferencesRepository, viewModel.startingText, composeOptions)
         setupContentWarningField(composeOptions?.contentWarning)
         setupPollView()
         applyShareIntent(intent, savedInstanceState)
@@ -364,7 +364,11 @@ class ComposeActivity :
         binding.composeContentWarningField.doOnTextChanged { _, _, _, _ -> updateVisibleCharactersLeft() }
     }
 
-    private fun setupComposeField(preferences: SharedPreferencesRepository, startingText: String?) {
+    private fun setupComposeField(
+        preferences: SharedPreferencesRepository,
+        startingText: String?,
+        composeOptions: ComposeOptions?,
+    ) {
         binding.composeEditField.setOnReceiveContentListener(this)
 
         binding.composeEditField.setOnKeyListener { _, keyCode, event -> this.onKeyDown(keyCode, event) }
@@ -380,7 +384,13 @@ class ComposeActivity :
         binding.composeEditField.setTokenizer(ComposeTokenizer())
 
         binding.composeEditField.setText(startingText)
-        binding.composeEditField.setSelection(binding.composeEditField.length())
+
+        when (composeOptions?.initialCursorPosition ?: InitialCursorPosition.END) {
+            InitialCursorPosition.START -> binding.composeEditField.setSelection(0)
+            InitialCursorPosition.END -> binding.composeEditField.setSelection(
+                binding.composeEditField.length(),
+            )
+        }
 
         val mentionColour = binding.composeEditField.linkTextColors.defaultColor
         highlightSpans(binding.composeEditField.text, mentionColour)
@@ -1305,6 +1315,15 @@ class ComposeActivity :
         EDIT_SCHEDULED,
     }
 
+    /**
+     * Initial position of the cursor in EditText when the compose button is clicked
+     * in a hashtag timeline
+     */
+    enum class InitialCursorPosition {
+        START,
+        END,
+    }
+
     @Parcelize
     data class ComposeOptions(
         // Let's keep fields var until all consumers are Kotlin
@@ -1329,6 +1348,7 @@ class ComposeActivity :
         var language: String? = null,
         var statusId: String? = null,
         var kind: ComposeKind? = null,
+        var initialCursorPosition: InitialCursorPosition = InitialCursorPosition.END,
     ) : Parcelable
 
     companion object {

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

@@ -16,6 +16,15 @@
         android:layout_height="match_parent"
         app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/composeButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/fabMargin"
+        android:contentDescription="@string/action_compose"
+        app:layout_anchor="@id/fragmentContainer"
+        app:layout_anchorGravity="bottom|end"
+        app:srcCompat="@drawable/ic_create_24dp" />
     <include layout="@layout/item_status_bottom_sheet" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -9,6 +9,7 @@
     <string name="at_symbol" translatable="false">\@</string>
     <string name="hash_symbol" translatable="false">#</string>
     <string name="title_tag" translatable="false">#%s</string>
+    <string name="title_tag_with_initial_position" translatable="false">" #%s"</string>
 
     <string name="emoji_shortcode_format" translatable="false">:%s:</string>
     <string name="post_timestamp_with_edited_indicator" translatable="false">%s *</string>