feat: channel links, link info on long-tap

Signed-off-by: Infi <infi@infi.sh>

app/src/main/java/chat/revolt/callbacks/ActionChannel.kt

@@ -4,6 +4,8 @@ import kotlinx.coroutines.channels.Channel
 
 sealed class Action {
     data class OpenUserSheet(val userId: String, val serverId: String?) : Action()
+    data class SwitchChannel(val channelId: String) : Action()
+    data class LinkInfo(val url: String) : Action()
 }
 
 val ActionChannel = Channel<Action>(

app/src/main/java/chat/revolt/components/chat/Message.kt

@@ -6,7 +6,6 @@ import android.net.Uri
 import android.text.SpannableStringBuilder
 import android.text.TextUtils
 import android.text.format.DateUtils
-import android.text.method.LinkMovementMethod
 import android.widget.Toast
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
@@ -59,6 +58,7 @@ import chat.revolt.api.schemas.AutumnResource
 import chat.revolt.api.schemas.User
 import chat.revolt.components.generic.UserAvatar
 import chat.revolt.components.generic.UserAvatarWidthPlaceholder
+import chat.revolt.internals.markdown.LongClickLinkMovementMethod
 import chat.revolt.api.schemas.Message as MessageSchema
 
 @Composable
@@ -294,7 +294,7 @@ fun Message(
                                     textSize = 16f
                                     typeface = ResourcesCompat.getFont(ctx, R.font.inter)
 
-                                    movementMethod = LinkMovementMethod.getInstance()
+                                    movementMethod = LongClickLinkMovementMethod.instance
 
                                     setTextColor(contentColor.toArgb())
                                 }

app/src/main/java/chat/revolt/components/generic/Markdown.kt

@@ -2,7 +2,6 @@ package chat.revolt.components.generic
 
 import android.text.SpannableStringBuilder
 import android.text.TextUtils
-import android.text.method.LinkMovementMethod
 import android.util.Log
 import android.util.TypedValue
 import android.view.ViewGroup
@@ -25,6 +24,7 @@ import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.res.ResourcesCompat
 import chat.revolt.R
 import chat.revolt.api.RevoltAPI
+import chat.revolt.internals.markdown.LongClickLinkMovementMethod
 import chat.revolt.internals.markdown.MarkdownContext
 import chat.revolt.internals.markdown.MarkdownParser
 import chat.revolt.internals.markdown.MarkdownState
@@ -97,7 +97,7 @@ fun UIMarkdown(
                 setMaxLines(maxLines)
                 setTextSize(TypedValue.COMPLEX_UNIT_SP, fontSize.value)
 
-                movementMethod = LinkMovementMethod.getInstance()
+                movementMethod = LongClickLinkMovementMethod.instance
 
                 layoutParams = ViewGroup.LayoutParams(
                     ViewGroup.LayoutParams.WRAP_CONTENT,

app/src/main/java/chat/revolt/internals/Platform.kt

@@ -0,0 +1,9 @@
+package chat.revolt.internals
+
+import android.os.Build
+
+object Platform {
+    fun needsShowClipboardNotification(): Boolean {
+        return Build.VERSION.SDK_INT < Build.VERSION_CODES.S
+    }
+}

app/src/main/java/chat/revolt/internals/markdown/LinkSpan.kt

@@ -3,7 +3,6 @@ package chat.revolt.internals.markdown
 import android.content.Intent
 import android.net.Uri
 import android.text.TextPaint
-import android.text.style.ClickableSpan
 import android.view.View
 import androidx.browser.customtabs.CustomTabsIntent
 import chat.revolt.activities.InviteActivity
@@ -15,7 +14,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.runBlocking
 
 class LinkSpan(private val url: String, private val drawBackground: Boolean = false) :
-    ClickableSpan() {
+    LongClickableSpan() {
     override fun onClick(widget: View) {
         val uri = Uri.parse(url)
 
@@ -49,6 +48,14 @@ class LinkSpan(private val url: String, private val drawBackground: Boolean = fa
                         ActionChannel.send(Action.OpenUserSheet(userId!!, serverId))
                     }
                 }
+
+                "channel" -> {
+                    val channelId = uri.getQueryParameter("channel")
+
+                    runBlocking(Dispatchers.IO) {
+                        ActionChannel.send(Action.SwitchChannel(channelId!!))
+                    }
+                }
             }
 
             return
@@ -61,6 +68,12 @@ class LinkSpan(private val url: String, private val drawBackground: Boolean = fa
         customTab.launchUrl(widget.context, Uri.parse(url))
     }
 
+    override fun onLongClick(view: View?) {
+        runBlocking(Dispatchers.IO) {
+            ActionChannel.send(Action.LinkInfo(url))
+        }
+    }
+
     override fun updateDrawState(ds: TextPaint) {
         ds.color = ds.linkColor
         ds.isUnderlineText = false

app/src/main/java/chat/revolt/internals/markdown/LongClickLinkMovementMethod.kt

@@ -0,0 +1,84 @@
+package chat.revolt.internals.markdown
+
+import android.os.Handler
+import android.os.Looper
+import android.text.Selection
+import android.text.Spannable
+import android.text.method.LinkMovementMethod
+import android.text.method.MovementMethod
+import android.text.style.ClickableSpan
+import android.view.MotionEvent
+import android.view.View
+import android.widget.TextView
+
+abstract class LongClickableSpan : ClickableSpan() {
+    abstract fun onLongClick(view: View?)
+}
+
+// https://stackoverflow.com/a/63398843
+class LongClickLinkMovementMethod : LinkMovementMethod() {
+    private var longClickHandler: Handler? = null
+    private var isLongPressed = false
+    override fun onTouchEvent(
+        widget: TextView, buffer: Spannable,
+        event: MotionEvent
+    ): Boolean {
+        val action = event.action
+        if (action == MotionEvent.ACTION_CANCEL) {
+            longClickHandler?.removeCallbacksAndMessages(null)
+        }
+        if (action == MotionEvent.ACTION_UP ||
+            action == MotionEvent.ACTION_DOWN
+        ) {
+            var x = event.x.toInt()
+            var y = event.y.toInt()
+            x -= widget.totalPaddingLeft
+            y -= widget.totalPaddingTop
+            x += widget.scrollX
+            y += widget.scrollY
+            val layout = widget.layout
+            val line = layout.getLineForVertical(y)
+            val off = layout.getOffsetForHorizontal(line, x.toFloat())
+            val link = buffer.getSpans(
+                off, off,
+                LongClickableSpan::class.java
+            )
+            if (link.isNotEmpty()) {
+                if (action == MotionEvent.ACTION_UP) {
+                    longClickHandler?.removeCallbacksAndMessages(null)
+                    if (!isLongPressed) {
+                        link[0].onClick(widget)
+                    }
+                    isLongPressed = false
+                } else {
+                    Selection.setSelection(
+                        buffer,
+                        buffer.getSpanStart(link[0]),
+                        buffer.getSpanEnd(link[0])
+                    )
+                    longClickHandler?.postDelayed({
+                        link[0].onLongClick(widget)
+                        isLongPressed = true
+                    }, LONG_CLICK_TIME)
+                }
+                return true
+            }
+        }
+        return super.onTouchEvent(widget, buffer, event)
+    }
+
+    companion object {
+        private const val LONG_CLICK_TIME = 500L
+        val instance: MovementMethod?
+            get() {
+                if (sInstance == null) {
+                    sInstance = LongClickLinkMovementMethod()
+                    // Handler deprecated https://stackoverflow.com/a/62477706/4116924
+                    sInstance!!.longClickHandler = Handler(Looper.getMainLooper())
+                }
+                return sInstance
+            }
+
+        private var sInstance: LongClickLinkMovementMethod? = null
+    }
+}

app/src/main/java/chat/revolt/internals/markdown/MarkdownNodes.kt

@@ -37,9 +37,18 @@ class UserMentionNode(private val userId: String) : Node<MarkdownContext>() {
 
 class ChannelMentionNode(private val channelId: String) : Node<MarkdownContext>() {
     override fun render(builder: SpannableStringBuilder, renderContext: MarkdownContext) {
-        builder.append(
+        val content = renderContext.channelMap[channelId]?.let { "#$it" }
-            renderContext.channelMap[channelId]?.let { "#$it" }
+            ?: "<#$channelId>"
-                ?: "<#${channelId}>"
+
+        builder.append(content)
+        builder.setSpan(
+            LinkSpan(
+                "revolt-android://link-action/channel?channel=$channelId",
+                drawBackground = true
+            ),
+            builder.length - content.length,
+            builder.length,
+            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
         )
     }
 }

app/src/main/java/chat/revolt/screens/chat/ChatRouterScreen.kt

@@ -28,6 +28,7 @@ import androidx.compose.material3.DrawerState
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
@@ -49,7 +50,9 @@ import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalSoftwareKeyboardController
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.ViewModel
@@ -91,6 +94,7 @@ import chat.revolt.screens.chat.views.NoCurrentChannelScreen
 import chat.revolt.screens.chat.views.channel.ChannelScreen
 import chat.revolt.sheets.AddServerSheet
 import chat.revolt.sheets.ChangelogSheet
+import chat.revolt.sheets.LinkInfoSheet
 import chat.revolt.sheets.ServerContextSheet
 import chat.revolt.sheets.StatusSheet
 import chat.revolt.sheets.UserContextSheet
@@ -275,6 +279,11 @@ fun ChatRouterScreen(
     var userContextSheetTarget by remember { mutableStateOf("") }
     var userContextSheetServer by remember { mutableStateOf<String?>(null) }
 
+    var showChannelUnavailableAlert by remember { mutableStateOf(false) }
+
+    var showLinkInfoSheet by remember { mutableStateOf(false) }
+    var linkInfoSheetUrl by remember { mutableStateOf("") }
+
     var useTabletAwareUI by remember { mutableStateOf(false) }
 
     val drawerBackHandler = remember {
@@ -359,6 +368,27 @@ fun ChatRouterScreen(
                         userContextSheetServer = action.serverId
                         showUserContextSheet = true
                     }
+
+                    is Action.SwitchChannel -> {
+                        val resolvedChannel = RevoltAPI.channelCache[action.channelId]
+
+                        if (resolvedChannel == null) {
+                            showChannelUnavailableAlert = true
+                            return@let
+                        }
+
+                        viewModel.navigateToChannel(action.channelId, navController)
+                        if (resolvedChannel.server != null) {
+                            viewModel.navigateToServer(resolvedChannel.server, navController)
+                        } else {
+                            viewModel.navigateToServer("home", navController)
+                        }
+                    }
+
+                    is Action.LinkInfo -> {
+                        linkInfoSheetUrl = action.url
+                        showLinkInfoSheet = true
+                    }
                 }
             }
         }
@@ -508,6 +538,60 @@ fun ChatRouterScreen(
         }
     }
 
+    if (showChannelUnavailableAlert) {
+        AlertDialog(
+            onDismissRequest = {
+                showChannelUnavailableAlert = false
+            },
+            icon = {
+                Icon(
+                    painter = painterResource(R.drawable.ic_lock_alert_24dp),
+                    contentDescription = null, // decorative
+                    tint = MaterialTheme.colorScheme.primary
+                )
+            },
+            title = {
+                Text(
+                    text = stringResource(id = R.string.channel_link_invalid),
+                    textAlign = TextAlign.Center,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            },
+            text = {
+                Text(
+                    text = stringResource(id = R.string.channel_link_invalid_description),
+                    textAlign = TextAlign.Center,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            },
+            confirmButton = {
+                TextButton(onClick = {
+                    showChannelUnavailableAlert = false
+                }) {
+                    Text(text = stringResource(id = R.string.ok))
+                }
+            }
+        )
+    }
+
+    if (showLinkInfoSheet) {
+        val linkInfoSheetState = rememberModalBottomSheetState()
+
+        ModalBottomSheet(
+            sheetState = linkInfoSheetState,
+            onDismissRequest = {
+                showLinkInfoSheet = false
+            },
+        ) {
+            LinkInfoSheet(
+                url = linkInfoSheetUrl,
+                onDismiss = {
+                    showLinkInfoSheet = false
+                }
+            )
+        }
+    }
+
     Column(
         modifier = Modifier
             .fillMaxWidth()

app/src/main/java/chat/revolt/sheets/LinkInfoSheet.kt

@@ -0,0 +1,97 @@
+package chat.revolt.sheets
+
+import android.net.Uri
+import android.widget.Toast
+import androidx.browser.customtabs.CustomTabsIntent
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.surfaceColorAtElevation
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalClipboardManager
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.unit.dp
+import chat.revolt.R
+import chat.revolt.components.generic.SheetClickable
+import chat.revolt.internals.Platform
+import kotlinx.coroutines.launch
+
+@Composable
+fun LinkInfoSheet(url: String, onDismiss: () -> Unit) {
+    val clipboardManager = LocalClipboardManager.current
+    val context = LocalContext.current
+    val coroutineScope = rememberCoroutineScope()
+
+    Column(
+        modifier = Modifier
+            .padding(horizontal = 16.dp, vertical = 8.dp)
+            .verticalScroll(rememberScrollState()),
+    ) {
+        Box(
+            modifier = Modifier
+                .clip(MaterialTheme.shapes.medium)
+                .background(MaterialTheme.colorScheme.surfaceColorAtElevation(0.dp))
+                .clickable(onClick = {
+                    if (url.startsWith("revolt-android://")) return@clickable
+
+                    val customTab = CustomTabsIntent
+                        .Builder()
+                        .setShowTitle(true)
+                        .build()
+
+                    customTab.launchUrl(context, Uri.parse(url))
+                })
+        ) {
+            Text(
+                text = url,
+                color = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.padding(16.dp)
+            )
+        }
+
+        Spacer(modifier = Modifier.height(8.dp))
+
+        SheetClickable(
+            icon = { modifier ->
+                Icon(
+                    painter = painterResource(id = R.drawable.ic_content_copy_24dp),
+                    contentDescription = null,
+                    modifier = modifier
+                )
+            },
+            label = { style ->
+                Text(
+                    text = stringResource(id = R.string.copy),
+                    style = style
+                )
+            },
+        ) {
+            coroutineScope.launch {
+                clipboardManager.setText(AnnotatedString(url))
+                if (Platform.needsShowClipboardNotification()) {
+                    Toast.makeText(
+                        context,
+                        context.getString(R.string.copied),
+                        Toast.LENGTH_SHORT
+                    ).show()
+                }
+            }
+            onDismiss()
+        }
+    }
+}

app/src/main/res/drawable/ic_lock_alert_24dp.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:height="24dp"
+    android:width="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#ffffff"
+        android:pathData="M10 17C11.1 17 12 16.1 12 15C12 13.9 11.1 13 10 13C8.9 13 8 13.9 8 15S8.9 17 10 17M16 8C17.1 8 18 8.9 18 10V20C18 21.1 17.1 22 16 22H4C2.9 22 2 21.1 2 20V10C2 8.9 2.9 8 4 8H5V6C5 3.2 7.2 1 10 1S15 3.2 15 6V8H16M10 3C8.3 3 7 4.3 7 6V8H13V6C13 4.3 11.7 3 10 3M22 13H20V7H22V13M22 17H20V15H22V17Z" />
+</vector>

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

@@ -184,6 +184,9 @@
     <string name="copy">Copy</string>
     <string name="copied">Copied to clipboard</string>
 
+    <string name="channel_link_invalid">You can\'t view this channel</string>
+    <string name="channel_link_invalid_description">This channel may have been deleted or you may not have permission to view it.</string>
+
     <string name="channel_info_sheet_description">Channel description</string>
     <string name="channel_info_sheet_description_empty">There hasn\'t been a description set for this channel yet.</string>
     <string name="channel_info_sheet_options">Options</string>