long press the hero to delete a partially downloaded list

The hero's control now carries the whole rule: a tap does what the state offers
(Download, Cancel, Delete) and a long press asks to delete when there is anything
downloaded to delete, so a partially downloaded album can be emptied without
starting the rest first. Nothing downloaded means the long press does nothing.

The rule itself returns the actions rather than one of them, so a partially
downloaded list offers both Download and Delete; the tap takes the first. That
list is what the library tabs' context menus will read.

app/src/main/kotlin/com/subtracks/ui/components/HeroDetailScaffold.kt

@@ -2,6 +2,7 @@ package com.subtracks.ui.components
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -209,11 +210,21 @@ private fun HeroSubtitle(
     )
 }
 
-fun ListDownloadStatus.action(): BulkDownloadAction =
+fun ListDownloadStatus.actions(): List<BulkDownloadAction> =
     when {
-        complete -> BulkDownloadAction.Delete
-        downloading > 0 -> BulkDownloadAction.Cancel
-        else -> BulkDownloadAction.Download
+        complete -> listOf(BulkDownloadAction.Delete)
+        downloading > 0 -> listOf(BulkDownloadAction.Cancel)
+        downloaded > 0 -> listOf(BulkDownloadAction.Download, BulkDownloadAction.Delete)
+        else -> listOf(BulkDownloadAction.Download)
+    }
+
+fun ListDownloadStatus.action(): BulkDownloadAction = actions().first()
+
+private fun downloadActionLabel(action: BulkDownloadAction): String =
+    when (action) {
+        BulkDownloadAction.Download -> "Download"
+        BulkDownloadAction.Cancel -> "Cancel download"
+        BulkDownloadAction.Delete -> "Delete download"
     }
 
 @Composable
@@ -284,17 +295,29 @@ fun HeroHeader(
             modifier = controlsModifier.fillMaxWidth(),
             verticalAlignment = Alignment.CenterVertically,
         ) {
-            IconButton(
-                onClick = { onDownloadAction(downloadStatus.action()) },
+            Box(
+                modifier =
+                    Modifier
+                        .size(48.dp)
+                        .combinedClickable(
                             enabled = hasSongs,
-                modifier = Modifier.padding(horizontal = 8.dp),
+                            onClick = { onDownloadAction(downloadStatus.action()) },
+                            onClickLabel = downloadActionLabel(downloadStatus.action()),
+                            onLongClick = {
+                                if (BulkDownloadAction.Delete in downloadStatus.actions()) {
+                                    onDownloadAction(BulkDownloadAction.Delete)
+                                }
+                            },
+                            onLongClickLabel = "Delete download",
+                        ),
+                contentAlignment = Alignment.Center,
             ) {
                 when (downloadStatus.action()) {
                     BulkDownloadAction.Delete -> {
                         Icon(
                             imageVector = Icons.Rounded.DownloadDone,
                             contentDescription = "Delete download",
-                            modifier = Modifier.size(28.dp).offset(y = 1.5.dp),
+                            modifier = Modifier.size(28.dp),
                         )
                     }
 
@@ -310,7 +333,7 @@ fun HeroHeader(
                     }
 
                     BulkDownloadAction.Download -> {
-                        Icon(Icons.Rounded.Download, contentDescription = "Download", modifier = Modifier.offset(y = 1.5.dp))
+                        Icon(Icons.Rounded.Download, contentDescription = "Download", modifier = Modifier.size(24.dp))
                     }
                 }
             }

app/src/test/kotlin/com/subtracks/ui/components/BulkDownloadActionTest.kt

@@ -26,4 +26,26 @@ class BulkDownloadActionTest {
     fun aFullyDownloadedListOffersDelete() {
         assertEquals(BulkDownloadAction.Delete, ListDownloadStatus(total = 3, downloaded = 3).action())
     }
+
+    @Test
+    fun aPartiallyDownloadedListOffersBoth() {
+        assertEquals(
+            listOf(BulkDownloadAction.Download, BulkDownloadAction.Delete),
+            ListDownloadStatus(total = 3, downloaded = 1).actions(),
+        )
+    }
+
+    @Test
+    fun anInFlightListOffersOnlyCancel() {
+        assertEquals(
+            listOf(BulkDownloadAction.Cancel),
+            ListDownloadStatus(total = 3, downloaded = 1, downloading = 1).actions(),
+        )
+    }
+
+    @Test
+    fun anUndownloadedListOffersOnlyDownload() {
+        assertEquals(listOf(BulkDownloadAction.Download), ListDownloadStatus(total = 3).actions())
+        assertEquals(listOf(BulkDownloadAction.Download), ListDownloadStatus().actions())
+    }
 }

app/src/test/kotlin/com/subtracks/ui/components/HeroDownloadTest.kt

@@ -3,14 +3,17 @@ package com.subtracks.ui.components
 import androidx.activity.ComponentActivity
 import androidx.compose.ui.test.assertIsNotEnabled
 import androidx.compose.ui.test.junit4.v2.createAndroidComposeRule
+import androidx.compose.ui.test.longClick
 import androidx.compose.ui.test.onNodeWithContentDescription
 import androidx.compose.ui.test.performClick
+import androidx.compose.ui.test.performTouchInput
 import androidx.compose.ui.unit.dp
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.subtracks.data.model.BulkDownloadAction
 import com.subtracks.data.model.ListDownloadStatus
 import com.subtracks.ui.theme.SubtracksTheme
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -42,6 +45,26 @@ class HeroDownloadTest {
         assertEquals(listOf(BulkDownloadAction.Delete), actions)
     }
 
+    @Test
+    fun longPressingAPartiallyDownloadedListAsksToDelete() {
+        val actions = mutableListOf<BulkDownloadAction>()
+        render(ListDownloadStatus(total = 3, downloaded = 1)) { actions += it }
+
+        composeRule.onNodeWithContentDescription("Download").performTouchInput { longClick() }
+
+        assertEquals(listOf(BulkDownloadAction.Delete), actions)
+    }
+
+    @Test
+    fun longPressingAnUndownloadedListDoesNothing() {
+        val actions = mutableListOf<BulkDownloadAction>()
+        render(ListDownloadStatus(total = 3)) { actions += it }
+
+        composeRule.onNodeWithContentDescription("Download").performTouchInput { longClick() }
+
+        assertTrue(actions.isEmpty())
+    }
+
     @Test
     fun theButtonIsDisabledWithoutSongs() {
         render(ListDownloadStatus(), hasSongs = false) {}