Fix Android share completion and link intents

android/src/main/java/ShareIntentPayload.kt

@@ -0,0 +1,21 @@
+package plugin.vnidrop.share
+
+internal data class ShareIntentPayload(
+    val title: String?,
+    val body: String?,
+) {
+    companion object {
+        fun from(options: ShareOptions): ShareIntentPayload {
+            val text = options.text.nonEmptyOrNull()
+            val title = options.title.nonEmptyOrNull()
+            val url = options.url.nonEmptyOrNull()
+
+            return ShareIntentPayload(
+                title = title ?: text,
+                body = url ?: text,
+            )
+        }
+
+        private fun String?.nonEmptyOrNull(): String? = this?.takeIf { it.isNotEmpty() }
+    }
+}

android/src/main/java/SharePlugin.kt

@@ -9,7 +9,9 @@ import android.os.Looper
 import android.util.Base64
 import java.io.File
 import java.io.FileOutputStream
+import androidx.activity.result.ActivityResult
 import androidx.core.content.FileProvider
+import app.tauri.annotation.ActivityCallback
 import app.tauri.annotation.Command
 import app.tauri.annotation.InvokeArg
 import app.tauri.annotation.TauriPlugin
@@ -37,9 +39,8 @@ class ShareOptions {
 @TauriPlugin
 class SharePlugin(private val activity: Activity): Plugin(activity) {
     private var pendingShareInvoke: Invoke? = null
-    private var shareInProgress = false
-    private var awaitingShareResume = false
     private var pendingCleanupFiles: List<File> = emptyList()
+    private val shareSession = ShareSessionState()
     private val cleanupHandler = Handler(Looper.getMainLooper())
 
     companion object {
@@ -57,7 +58,7 @@ class SharePlugin(private val activity: Activity): Plugin(activity) {
 
     @Command
     fun share(invoke: Invoke) {
-        if (shareInProgress) {
+        if (shareSession.isInProgress) {
             invoke.reject("Share already in progress.")
             return
         }
@@ -111,22 +112,22 @@ class SharePlugin(private val activity: Activity): Plugin(activity) {
 
             shareIntent.type = determinedMimeType
 
-            val combinedText = combineTextAndUrl(args.text, args.url)
-            if (combinedText != null) {
-                shareIntent.putExtra(Intent.EXTRA_TEXT, combinedText)
+            val payload = ShareIntentPayload.from(args)
+            payload.body?.let {
+                shareIntent.putExtra(Intent.EXTRA_TEXT, it)
             }
-            if (args.title != null) {
-                shareIntent.putExtra(Intent.EXTRA_TITLE, args.title)
+            payload.title?.let {
+                shareIntent.putExtra(Intent.EXTRA_TITLE, it)
+                shareIntent.putExtra(Intent.EXTRA_SUBJECT, it)
             }
 
             shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
-            val chooser = Intent.createChooser(shareIntent, args.title)
+            val chooser = Intent.createChooser(shareIntent, payload.title)
 
             pendingShareInvoke = invoke
-            shareInProgress = true
-            awaitingShareResume = false
             pendingCleanupFiles = filesForShare
-            activity.startActivity(chooser)
+            shareSession.start()
+            startActivityForResult(invoke, chooser, "shareResult")
         } catch (e: Exception) {
             cleanupFiles(filesForShare)
             resetPendingShare()
@@ -136,19 +137,20 @@ class SharePlugin(private val activity: Activity): Plugin(activity) {
 
     override fun onPause() {
         super.onPause()
-        if (shareInProgress) {
-            awaitingShareResume = true
-        }
+        shareSession.markPaused()
     }
 
     override fun onResume() {
         super.onResume()
-        if (shareInProgress && awaitingShareResume) {
-            val invoke = pendingShareInvoke
-            val filesToClean = pendingCleanupFiles
-            resetPendingShare()
-            scheduleCleanup(filesToClean)
-            invoke?.resolve()
+        if (shareSession.completeFromResume()) {
+            resolvePendingShare()
+        }
+    }
+
+    @ActivityCallback
+    fun shareResult(invoke: Invoke, result: ActivityResult) {
+        if (shareSession.completeFromActivityResult()) {
+            resolvePendingShare(invoke)
         }
     }
 
@@ -194,23 +196,18 @@ class SharePlugin(private val activity: Activity): Plugin(activity) {
         return clipData
     }
 
-    private fun combineTextAndUrl(text: String?, url: String?): String? {
-        val hasText = !text.isNullOrEmpty()
-        val hasUrl = !url.isNullOrEmpty()
-
-        return when {
-            hasText && hasUrl -> "$text\n$url"
-            hasText -> text
-            hasUrl -> url
-            else -> null
-        }
+    private fun resolvePendingShare(invoke: Invoke? = pendingShareInvoke) {
+        val filesToClean = pendingCleanupFiles
+        pendingShareInvoke = null
+        pendingCleanupFiles = emptyList()
+        scheduleCleanup(filesToClean)
+        invoke?.resolve()
     }
 
     private fun resetPendingShare() {
         pendingShareInvoke = null
-        shareInProgress = false
-        awaitingShareResume = false
         pendingCleanupFiles = emptyList()
+        shareSession.reset()
     }
 
     private fun scheduleCleanup(files: List<File>) {

android/src/main/java/ShareSessionState.kt

@@ -0,0 +1,38 @@
+package plugin.vnidrop.share
+
+internal class ShareSessionState {
+    var isInProgress: Boolean = false
+        private set
+
+    private var awaitingResume: Boolean = false
+
+    fun start() {
+        check(!isInProgress) { "Share session already in progress." }
+        isInProgress = true
+        awaitingResume = false
+    }
+
+    fun markPaused() {
+        if (isInProgress) {
+            awaitingResume = true
+        }
+    }
+
+    fun completeFromActivityResult(): Boolean = completeIf(isInProgress)
+
+    fun completeFromResume(): Boolean = completeIf(isInProgress && awaitingResume)
+
+    fun reset() {
+        isInProgress = false
+        awaitingResume = false
+    }
+
+    private fun completeIf(shouldComplete: Boolean): Boolean {
+        if (!shouldComplete) {
+            return false
+        }
+
+        reset()
+        return true
+    }
+}

android/src/test/java/ShareIntentPayloadUnitTest.kt

@@ -0,0 +1,76 @@
+package plugin.vnidrop.share
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class ShareIntentPayloadUnitTest {
+    @Test
+    fun usesUrlAsBodyAndTextAsFallbackTitle() {
+        val payload = ShareIntentPayload.from(
+            options(
+                text = "Read this article",
+                url = "https://example.com/article",
+            )
+        )
+
+        assertEquals("Read this article", payload.title)
+        assertEquals("https://example.com/article", payload.body)
+    }
+
+    @Test
+    fun explicitTitleTakesPrecedenceOverText() {
+        val payload = ShareIntentPayload.from(
+            options(
+                text = "Description",
+                title = "Article title",
+                url = "https://example.com/article",
+            )
+        )
+
+        assertEquals("Article title", payload.title)
+        assertEquals("https://example.com/article", payload.body)
+    }
+
+    @Test
+    fun textOnlyPayloadUsesTextAsTitleAndBody() {
+        val payload = ShareIntentPayload.from(options(text = "Hello"))
+
+        assertEquals("Hello", payload.title)
+        assertEquals("Hello", payload.body)
+    }
+
+    @Test
+    fun emptyValuesDoNotHideShareableText() {
+        val payload = ShareIntentPayload.from(
+            options(
+                text = "Hello",
+                title = "",
+                url = "",
+            )
+        )
+
+        assertEquals("Hello", payload.title)
+        assertEquals("Hello", payload.body)
+    }
+
+    @Test
+    fun emptyPayloadHasNoTitleOrBody() {
+        val payload = ShareIntentPayload.from(options())
+
+        assertNull(payload.title)
+        assertNull(payload.body)
+    }
+
+    private fun options(
+        text: String? = null,
+        title: String? = null,
+        url: String? = null,
+    ): ShareOptions {
+        return ShareOptions().apply {
+            this.text = text
+            this.title = title
+            this.url = url
+        }
+    }
+}

android/src/test/java/ShareSessionStateUnitTest.kt

@@ -0,0 +1,43 @@
+package plugin.vnidrop.share
+
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class ShareSessionStateUnitTest {
+    @Test
+    fun activityResultCompletesSessionAndAllowsAnotherShare() {
+        val state = ShareSessionState()
+
+        state.start()
+        assertTrue(state.isInProgress)
+        assertTrue(state.completeFromActivityResult())
+        assertFalse(state.isInProgress)
+
+        state.start()
+        assertTrue(state.isInProgress)
+    }
+
+    @Test
+    fun resumeRemainsAFallbackAfterPause() {
+        val state = ShareSessionState()
+
+        state.start()
+        assertFalse(state.completeFromResume())
+
+        state.markPaused()
+        assertTrue(state.completeFromResume())
+        assertFalse(state.isInProgress)
+    }
+
+    @Test
+    fun completionOnlyHappensOnce() {
+        val state = ShareSessionState()
+
+        state.start()
+        state.markPaused()
+        assertTrue(state.completeFromActivityResult())
+        assertFalse(state.completeFromResume())
+        assertFalse(state.completeFromActivityResult())
+    }
+}

android/test-support/tauri-api/src/main/java/app/tauri/annotation/ActivityCallback.kt

@@ -0,0 +1,5 @@
+package app.tauri.annotation
+
+@Target(AnnotationTarget.FUNCTION)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class ActivityCallback

android/test-support/tauri-api/src/main/java/app/tauri/plugin/Plugin.kt

@@ -1,6 +1,7 @@
 package app.tauri.plugin
 
 import android.app.Activity
+import android.content.Intent
 
 open class Plugin(activity: Activity) {
     @Suppress("UNUSED_VARIABLE")
@@ -9,4 +10,13 @@ open class Plugin(activity: Activity) {
     open fun onPause() {}
 
     open fun onResume() {}
+
+    fun startActivityForResult(invoke: Invoke, intent: Intent, callback: String) {
+        @Suppress("UNUSED_VARIABLE")
+        val ignoredInvoke = invoke
+        @Suppress("UNUSED_VARIABLE")
+        val ignoredIntent = intent
+        @Suppress("UNUSED_VARIABLE")
+        val ignoredCallback = callback
+    }
 }