chore(message-list): add legacy support for footer updates and trigger effects on footer click

core/ui/compose/common/src/main/kotlin/net/thunderbird/core/ui/compose/common/mvi/BaseStateMachineViewModel.kt

@@ -110,9 +110,22 @@ abstract class BaseStateMachineViewModel<TState : Any, TEvent : Any, TUiSideEffe
             val newState = stateMachine.process(event)
             if (newState != currentState) {
                 logger.verbose { "event(${event::class.simpleName}): state update." }
+            } else {
+                onEventWithoutStateModification(event, currentState)
             }
 
             sideEffectHandlers.forEach { it.handle(event, oldState = currentState, newState = newState) }
         }
     }
+
+    /**
+     * Processes an event without making changes to the state machine's state. Useful for
+     * events without state transition.
+     *
+     * @param event The [TEvent] to be processed.
+     * @param currentState The current state of the [StateMachine].
+     */
+    protected open fun onEventWithoutStateModification(event: TEvent, currentState: TState) {
+        // Override this method to handle events that doesn't trigger state changes.
+    }
 }

feature/mail/message/list/api/src/main/kotlin/net/thunderbird/feature/mail/message/list/ui/effect/MessageListEffect.kt

@@ -100,4 +100,8 @@ sealed interface MessageListEffect {
     data class ScrollToMessage(val message: MessageItemUi) : MessageListEffect
 
     data class OpenMessage(val message: MessageItemUi) : MessageListEffect
+
+    // region [ Legacy Support ]
+    data object TriggerOnFooterClicked : MessageListEffect
+    // endregion [ Legacy Support ]
 }

feature/mail/message/list/api/src/main/kotlin/net/thunderbird/feature/mail/message/list/ui/event/MessageListEvent.kt

@@ -112,4 +112,8 @@ sealed interface MessageListEvent {
      * @see MessageListEvent
      */
     data object LoadNextPage : UserEvent
+
+    // region [ Legacy Support events ]
+    data class UpdateFooter(val footer: String?) : SystemEvent
+    // endregion [ Legacy Support events ]
 }

feature/mail/message/list/internal/src/main/kotlin/net/thunderbird/feature/mail/message/list/internal/ui/MessageListViewModel.kt

@@ -53,4 +53,11 @@ internal class MessageListViewModel(
             }
             .launchIn(viewModelScope)
     }
+
+    override fun onEventWithoutStateModification(event: MessageListEvent, currentState: MessageListState) {
+        when (event) {
+            is MessageListEvent.OnFooterClick -> emitEffect(MessageListEffect.TriggerOnFooterClicked)
+            else -> Unit
+        }
+    }
 }

feature/mail/message/list/internal/src/main/kotlin/net/thunderbird/feature/mail/message/list/internal/ui/component/template/MessageList.kt

@@ -1,5 +1,7 @@
 package net.thunderbird.feature.mail.message.list.internal.ui.component.template
 
+import androidx.compose.animation.core.snap
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListState
@@ -20,6 +22,7 @@ import kotlinx.collections.immutable.ImmutableList
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.launch
 import net.thunderbird.core.ui.compose.common.modifier.testTagAsResourceId
+import net.thunderbird.core.ui.compose.theme2.MainTheme
 import net.thunderbird.feature.mail.message.list.internal.ui.component.MessageListItem
 import net.thunderbird.feature.mail.message.list.internal.ui.component.organism.MessageListFooter
 import net.thunderbird.feature.mail.message.list.internal.ui.component.organism.MessageListSwipeableItem
@@ -49,6 +52,7 @@ internal fun MessageListScope.MessageList(
     LazyColumn(
         modifier = modifier.testTagAsResourceId(TEST_TAG_MESSAGE_LIST_ROOT),
         state = listState,
+        contentPadding = PaddingValues(bottom = MainTheme.sizes.large),
     ) {
         items(
             items = state.messages,
@@ -81,8 +85,11 @@ internal fun MessageListScope.MessageList(
                 )
             }
         }
-        item {
-            MessageListFooter(state, dispatchEvent, Modifier.animateItem())
+
+        if (state.metadata.footer.text.isNotBlank()) {
+            item {
+                MessageListFooter(state, dispatchEvent, Modifier.animateItem(placementSpec = snap()))
+            }
         }
     }
 }

feature/mail/message/list/internal/src/main/kotlin/net/thunderbird/feature/mail/message/list/internal/ui/state/machine/SetupGlobalState.kt

@@ -58,5 +58,14 @@ internal fun StateMachineBuilder<MessageListState, MessageListEvent>.globalState
         transition<MessageItemEvent.OnFocusExit> { currentState, _ ->
             currentState.withMetadata { copy(focusedMessage = null) }
         }
+
+        // #region [ Legacy support ]
+        transition<MessageListEvent.UpdateFooter> { state, event ->
+            state.withMetadata {
+                val showFooter = event.footer?.isNotBlank() == true
+                copy(footer = footer.copy(showFooter = showFooter, text = event.footer.orEmpty()))
+            }
+        }
+        // #endregion [ Legacy support ]
     }
 }

legacy/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListFragment.kt

@@ -1303,7 +1303,7 @@ class MessageListFragment :
     }
 
     override fun updateFooterText(text: String?) {
-        // TODO(#10778): trigger update footer text event.
+        viewModel.event(MessageListEvent.UpdateFooter(text))
     }
 
     private fun selectAll() {
@@ -2452,6 +2452,7 @@ class MessageListFragment :
                 openMessage(messageReference)
             }
 
+            MessageListEffect.TriggerOnFooterClicked -> onFooterClicked()
             else -> Unit
         }
     }