Bettering torrent support.

app/src/main/java/com/jerboa/Constants.kt

@@ -8,3 +8,5 @@ const val MAX_POST_TITLE_LENGTH = 200
  */
 const val SHOW_UPVOTE_PCT_THRESHOLD = 0.9F
 const val VIEW_VOTES_LIMIT = 40L
+
+val ALLOWED_SCHEMES = listOf("http", "https", "magnet")

app/src/main/java/com/jerboa/Utils.kt

@@ -45,7 +45,6 @@ import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.unit.dp
 import androidx.core.os.LocaleListCompat
-import androidx.core.util.PatternsCompat
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewmodel.CreationExtras
@@ -251,7 +250,7 @@ fun parseUrl(
     baseUrl: String,
     url: String,
 ): Pair<Boolean, String>? {
-    if (url.startsWith("https://") || url.startsWith("http://")) {
+    if (ALLOWED_SCHEMES.any { url.startsWith(it) }) {
         return Pair(false, url)
     } else if (url.startsWith("/c/")) {
         if (url.count { c -> c == '@' } == 1) {
@@ -648,7 +647,7 @@ fun validateUrl(
     url: String,
     label: String = ctx.getString(R.string.url),
 ): InputField =
-    if (url.isNotEmpty() && !PatternsCompat.WEB_URL.matcher(url).matches()) {
+    if (url.isNotEmpty() && !ALLOWED_SCHEMES.any { url.startsWith(it) }) {
         InputField(
             label = ctx.getString(R.string.url_invalid),
             hasError = true,

app/src/main/java/com/jerboa/ui/components/post/PostListing.kt

@@ -109,6 +109,7 @@ import com.jerboa.ui.components.community.CommunityLink
 import com.jerboa.ui.components.community.CommunityName
 import com.jerboa.ui.components.person.PersonProfileLink
 import com.jerboa.ui.components.post.composables.PostOptionsDropdown
+import com.jerboa.ui.components.settings.about.TORRENT_HELP_LINK
 import com.jerboa.ui.theme.ACTION_BAR_ICON_SIZE
 import com.jerboa.ui.theme.CARD_COLORS
 import com.jerboa.ui.theme.LARGER_ICON_THUMBNAIL_SIZE
@@ -483,6 +484,10 @@ fun PostBody(
         // The metadata card
         if (fullBody && showPostLinkPreview) {
             MetadataCard(post = post)
+
+            if (post.url?.startsWith("magnet") == true) {
+                TorrentHelpInfo()
+            }
         }
 
         // Check to make sure body isn't empty string
@@ -1762,7 +1767,7 @@ fun MetadataCard(post: Post) {
             shape = MaterialTheme.shapes.medium,
             modifier =
                 Modifier
-                    .padding(vertical = MEDIUM_PADDING, horizontal = MEDIUM_PADDING)
+                    .padding(MEDIUM_PADDING)
                     .fillMaxWidth(),
             content = {
                 Column(
@@ -1789,3 +1794,24 @@ fun MetadataCard(post: Post) {
         )
     }
 }
+
+@Composable
+fun TorrentHelpInfo() {
+    OutlinedCard(
+        shape = MaterialTheme.shapes.medium,
+        modifier =
+            Modifier
+                .padding(MEDIUM_PADDING)
+                .fillMaxWidth(),
+        content = {
+            Column(
+                modifier = Modifier.padding(MEDIUM_PADDING),
+            ) {
+                MyMarkdownText(
+                    markdown = stringResource(R.string.torrent_help, TORRENT_HELP_LINK),
+                    onClick = {},
+                )
+            }
+        },
+    )
+}

app/src/main/java/com/jerboa/ui/components/post/create/CreatePostScreen.kt

@@ -118,12 +118,25 @@ fun CreatePostScreen(
     }
 
     val (suggestedTitle, suggestedTitleLoading) =
-        when (val res = createPostViewModel.siteMetadataRes) {
-            ApiState.Empty -> MetaDataRes(null, false)
-            ApiState.Loading -> MetaDataRes(null, true)
-            is ApiState.Success ->
-                MetaDataRes(res.data.metadata.title, false)
-            else -> MetaDataRes(null, false)
+        // If its a torrent magnet link, use the dn param to extract the torrent title
+        if (url.startsWith("magnet")) {
+            val query = Uri.parse(url).query
+            // Unfortunately you have to use a fake http uri, otherwise getQueryParameter throws a non-hierarchical error.
+            val torrentDownloadName = Uri.parse("http://test.com?$query").getQueryParameter("dn")
+
+            if (torrentDownloadName !== null) {
+                MetaDataRes(torrentDownloadName, false)
+            } else {
+                MetaDataRes(null, false)
+            }
+        } else {
+            when (val res = createPostViewModel.siteMetadataRes) {
+                ApiState.Empty -> MetaDataRes(null, false)
+                ApiState.Loading -> MetaDataRes(null, true)
+                is ApiState.Success ->
+                    MetaDataRes(res.data.metadata.title, false)
+                else -> MetaDataRes(null, false)
+            }
         }
     Surface(color = MaterialTheme.colorScheme.background) {
         Scaffold(

app/src/main/java/com/jerboa/ui/components/settings/about/AboutScreen.kt

@@ -51,6 +51,7 @@ const val JERBOA_MATRIX_CHAT = "https://matrix.to/#/#jerboa-dev:matrix.org"
 const val DONATE_LINK = "https://join-lemmy.org/donate"
 const val JERBOA_LEMMY_ML_LINK = "https://lemmy.ml/c/jerboa"
 const val MASTODON_LINK = "https://mastodon.social/@LemmyDev"
+const val TORRENT_HELP_LINK = "https://join-lemmy.org/docs/users/02-media.html#torrents"
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable

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

@@ -493,4 +493,5 @@
     <string name="you_have_no_blocked_users">You have no blocked users</string>
     <string name="you_have_no_blocked_communities">You have no blocked communities</string>
     <string name="you_have_no_blocked_instances">You have no blocked instances</string>
+    <string name="torrent_help">Lemmy can use a technology called BitTorrent to view or stream media. [Click here](%1$s) to learn how.</string>
 </resources>