Support for NIP-94

app/build.gradle

@@ -146,6 +146,9 @@ dependencies {
     // view svgs
     implementation "io.coil-kt:coil-svg:$coil_version"
 
+    // create blurhash
+    implementation group: 'io.trbl', name: 'blurhash', version: '1.0.0'
+
     // Rendering clickable text
     implementation "com.google.accompanist:accompanist-flowlayout:$accompanist_version"
     // Permission to upload pictures:

app/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -3,6 +3,7 @@ package com.vitorpamplona.amethyst.model
 import android.content.res.Resources
 import androidx.core.os.ConfigurationCompat
 import androidx.lifecycle.LiveData
+import com.vitorpamplona.amethyst.service.FileHeader
 import com.vitorpamplona.amethyst.service.model.*
 import com.vitorpamplona.amethyst.service.relays.Client
 import com.vitorpamplona.amethyst.service.relays.Constants
@@ -357,6 +358,25 @@ class Account(
         }
     }
 
+    fun sendHeader(headerInfo: FileHeader): Note? {
+        if (!isWriteable()) return null
+
+        val signedEvent = FileHeaderEvent.create(
+            url = headerInfo.url,
+            mimeType = headerInfo.mimeType,
+            hash = headerInfo.hash,
+            size = headerInfo.size.toString(),
+            blurhash = headerInfo.blurHash,
+            description = headerInfo.description,
+            privateKey = loggedIn.privKey!!
+        )
+
+        Client.send(signedEvent)
+        LocalCache.consume(signedEvent)
+
+        return LocalCache.notes[signedEvent.id]
+    }
+
     fun sendPost(message: String, replyTo: List<Note>?, mentions: List<User>?, tags: List<String>? = null) {
         if (!isWriteable()) return
 

app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -651,6 +651,19 @@ object LocalCache {
         refreshObservers(note)
     }
 
+    fun consume(event: FileHeaderEvent) {
+        val note = getOrCreateNote(event.id)
+
+        // Already processed this event.
+        if (note.event != null) return
+
+        val author = getOrCreateUser(event.pubKey)
+
+        note.loadEvent(event, author, emptyList())
+
+        refreshObservers(note)
+    }
+
     fun findUsersStartingWith(username: String): List<User> {
         return users.values.filter {
             (it.anyNameStartsWith(username)) ||

app/src/main/java/com/vitorpamplona/amethyst/service/BlurHashDecoder.kt

@@ -0,0 +1,203 @@
+package com.vitorpamplona.amethyst.service
+
+import android.graphics.Bitmap
+import android.graphics.Color
+import kotlin.math.cos
+import kotlin.math.pow
+import kotlin.math.withSign
+
+object BlurHashDecoder {
+
+    // cache Math.cos() calculations to improve performance.
+    // The number of calculations can be huge for many bitmaps: width * height * numCompX * numCompY * 2 * nBitmaps
+    // the cache is enabled by default, it is recommended to disable it only when just a few images are displayed
+    private val cacheCosinesX = HashMap<Int, DoubleArray>()
+    private val cacheCosinesY = HashMap<Int, DoubleArray>()
+
+    /**
+     * Clear calculations stored in memory cache.
+     * The cache is not big, but will increase when many image sizes are used,
+     * if the app needs memory it is recommended to clear it.
+     */
+    fun clearCache() {
+        cacheCosinesX.clear()
+        cacheCosinesY.clear()
+    }
+
+    /**
+     * Returns width/height
+     */
+    fun aspectRatio(blurHash: String?): Float? {
+        if (blurHash == null || blurHash.length < 6) {
+            return null
+        }
+        val numCompEnc = decode83(blurHash, 0, 1)
+        val numCompX = (numCompEnc % 9) + 1
+        val numCompY = (numCompEnc / 9) + 1
+        if (blurHash.length != 4 + 2 * numCompX * numCompY) {
+            return null
+        }
+
+        return numCompX.toFloat() / numCompY.toFloat()
+    }
+
+    /**
+     * Decode a blur hash into a new bitmap.
+     *
+     * @param useCache use in memory cache for the calculated math, reused by images with same size.
+     *                 if the cache does not exist yet it will be created and populated with new calculations.
+     *                 By default it is true.
+     */
+    fun decode(blurHash: String?, width: Int, height: Int, punch: Float = 1f, useCache: Boolean = true): Bitmap? {
+        if (blurHash == null || blurHash.length < 6) {
+            return null
+        }
+        val numCompEnc = decode83(blurHash, 0, 1)
+        val numCompX = (numCompEnc % 9) + 1
+        val numCompY = (numCompEnc / 9) + 1
+        if (blurHash.length != 4 + 2 * numCompX * numCompY) {
+            return null
+        }
+        val maxAcEnc = decode83(blurHash, 1, 2)
+        val maxAc = (maxAcEnc + 1) / 166f
+        val colors = Array(numCompX * numCompY) { i ->
+            if (i == 0) {
+                val colorEnc = decode83(blurHash, 2, 6)
+                decodeDc(colorEnc)
+            } else {
+                val from = 4 + i * 2
+                val colorEnc = decode83(blurHash, from, from + 2)
+                decodeAc(colorEnc, maxAc * punch)
+            }
+        }
+        return composeBitmap(width, height, numCompX, numCompY, colors, useCache)
+    }
+
+    private fun decode83(str: String, from: Int = 0, to: Int = str.length): Int {
+        var result = 0
+        for (i in from until to) {
+            val index = charMap[str[i]] ?: -1
+            if (index != -1) {
+                result = result * 83 + index
+            }
+        }
+        return result
+    }
+
+    private fun decodeDc(colorEnc: Int): FloatArray {
+        val r = colorEnc shr 16
+        val g = (colorEnc shr 8) and 255
+        val b = colorEnc and 255
+        return floatArrayOf(srgbToLinear(r), srgbToLinear(g), srgbToLinear(b))
+    }
+
+    private fun srgbToLinear(colorEnc: Int): Float {
+        val v = colorEnc / 255f
+        return if (v <= 0.04045f) {
+            (v / 12.92f)
+        } else {
+            ((v + 0.055f) / 1.055f).pow(2.4f)
+        }
+    }
+
+    private fun decodeAc(value: Int, maxAc: Float): FloatArray {
+        val r = value / (19 * 19)
+        val g = (value / 19) % 19
+        val b = value % 19
+        return floatArrayOf(
+            signedPow2((r - 9) / 9.0f) * maxAc,
+            signedPow2((g - 9) / 9.0f) * maxAc,
+            signedPow2((b - 9) / 9.0f) * maxAc
+        )
+    }
+
+    private fun signedPow2(value: Float) = value.pow(2f).withSign(value)
+
+    private fun composeBitmap(
+        width: Int,
+        height: Int,
+        numCompX: Int,
+        numCompY: Int,
+        colors: Array<FloatArray>,
+        useCache: Boolean
+    ): Bitmap {
+        // use an array for better performance when writing pixel colors
+        val imageArray = IntArray(width * height)
+        val calculateCosX = !useCache || !cacheCosinesX.containsKey(width * numCompX)
+        val cosinesX = getArrayForCosinesX(calculateCosX, width, numCompX)
+        val calculateCosY = !useCache || !cacheCosinesY.containsKey(height * numCompY)
+        val cosinesY = getArrayForCosinesY(calculateCosY, height, numCompY)
+        for (y in 0 until height) {
+            for (x in 0 until width) {
+                var r = 0f
+                var g = 0f
+                var b = 0f
+                for (j in 0 until numCompY) {
+                    for (i in 0 until numCompX) {
+                        val cosX = cosinesX.getCos(calculateCosX, i, numCompX, x, width)
+                        val cosY = cosinesY.getCos(calculateCosY, j, numCompY, y, height)
+                        val basis = (cosX * cosY).toFloat()
+                        val color = colors[j * numCompX + i]
+                        r += color[0] * basis
+                        g += color[1] * basis
+                        b += color[2] * basis
+                    }
+                }
+                imageArray[x + width * y] = Color.rgb(linearToSrgb(r), linearToSrgb(g), linearToSrgb(b))
+            }
+        }
+        return Bitmap.createBitmap(imageArray, width, height, Bitmap.Config.ARGB_8888)
+    }
+
+    private fun getArrayForCosinesY(calculate: Boolean, height: Int, numCompY: Int) = when {
+        calculate -> {
+            DoubleArray(height * numCompY).also {
+                cacheCosinesY[height * numCompY] = it
+            }
+        }
+        else -> {
+            cacheCosinesY[height * numCompY]!!
+        }
+    }
+
+    private fun getArrayForCosinesX(calculate: Boolean, width: Int, numCompX: Int) = when {
+        calculate -> {
+            DoubleArray(width * numCompX).also {
+                cacheCosinesX[width * numCompX] = it
+            }
+        }
+        else -> cacheCosinesX[width * numCompX]!!
+    }
+
+    private fun DoubleArray.getCos(
+        calculate: Boolean,
+        x: Int,
+        numComp: Int,
+        y: Int,
+        size: Int
+    ): Double {
+        if (calculate) {
+            this[x + numComp * y] = cos(Math.PI * y * x / size)
+        }
+        return this[x + numComp * y]
+    }
+
+    private fun linearToSrgb(value: Float): Int {
+        val v = value.coerceIn(0f, 1f)
+        return if (v <= 0.0031308f) {
+            (v * 12.92f * 255f + 0.5f).toInt()
+        } else {
+            ((1.055f * v.pow(1 / 2.4f) - 0.055f) * 255 + 0.5f).toInt()
+        }
+    }
+
+    private val charMap = listOf(
+        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
+        'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+        'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
+        'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '#', '$', '%', '*', '+', ',',
+        '-', '.', ':', ';', '=', '?', '@', '[', ']', '^', '_', '{', '|', '}', '~'
+    )
+        .mapIndexed { i, c -> c to i }
+        .toMap()
+}

app/src/main/java/com/vitorpamplona/amethyst/service/BlurHashImage.kt

@@ -0,0 +1,65 @@
+package com.vitorpamplona.amethyst.service
+
+import android.content.Context
+import android.net.Uri
+import androidx.core.graphics.drawable.toDrawable
+import coil.ImageLoader
+import coil.decode.DataSource
+import coil.fetch.DrawableResult
+import coil.fetch.FetchResult
+import coil.fetch.Fetcher
+import coil.request.ImageRequest
+import coil.request.Options
+import java.net.URLDecoder
+import java.net.URLEncoder
+import kotlin.math.roundToInt
+
+class BlurHashFetcher(
+    private val options: Options,
+    private val data: Uri
+) : Fetcher {
+
+    override suspend fun fetch(): FetchResult {
+        val encodedHash = data.toString().removePrefix("bluehash:")
+        val hash = URLDecoder.decode(encodedHash, "utf-8")
+
+        val aspectRatio = BlurHashDecoder.aspectRatio(hash) ?: 1.0f
+
+        val preferredWidth = 100
+
+        val bitmap = BlurHashDecoder.decode(
+            hash,
+            preferredWidth,
+            (preferredWidth * (1 / aspectRatio)).roundToInt()
+        )
+
+        if (bitmap == null) {
+            throw Exception("Unable to convert Bluehash $hash")
+        }
+
+        return DrawableResult(
+            drawable = bitmap.toDrawable(options.context.resources),
+            isSampled = false,
+            dataSource = DataSource.MEMORY
+        )
+    }
+
+    object Factory : Fetcher.Factory<Uri> {
+        override fun create(data: Uri, options: Options, imageLoader: ImageLoader): Fetcher {
+            return BlurHashFetcher(options, data)
+        }
+    }
+}
+
+object BlurHashRequester {
+    fun imageRequest(context: Context, message: String): ImageRequest {
+        val encodedMessage = URLEncoder.encode(message, "utf-8")
+
+        return ImageRequest
+            .Builder(context)
+            .data("bluehash:$encodedMessage")
+            .fetcherFactory(BlurHashFetcher.Factory)
+            .crossfade(100)
+            .build()
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/service/FileHeader.kt

@@ -0,0 +1,65 @@
+package com.vitorpamplona.amethyst.service
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.util.Log
+import com.vitorpamplona.amethyst.model.toHexKey
+import io.trbl.blurhash.BlurHash
+import java.net.URL
+import java.security.MessageDigest
+import kotlin.math.roundToInt
+
+class FileHeader(
+    val url: String,
+    val mimeType: String?,
+    val hash: String,
+    val size: Int,
+    val blurHash: String?,
+    val description: String? = null
+) {
+    companion object {
+        fun prepare(fileUrl: String, mimeType: String?, onReady: (FileHeader) -> Unit, onError: () -> Unit) {
+            try {
+                val imageData = URL(fileUrl).readBytes()
+                val sha256 = MessageDigest.getInstance("SHA-256")
+
+                val hash = sha256.digest(imageData).toHexKey()
+                val size = imageData.size
+
+                val blurHash = if (mimeType?.startsWith("image/") == true) {
+                    val opt = BitmapFactory.Options()
+                    opt.inPreferredConfig = Bitmap.Config.ARGB_8888
+                    val mBitmap = BitmapFactory.decodeByteArray(imageData, 0, imageData.size, opt)
+
+                    val intArray = IntArray(mBitmap.width * mBitmap.height)
+                    mBitmap.getPixels(
+                        intArray,
+                        0,
+                        mBitmap.width,
+                        0,
+                        0,
+                        mBitmap.width,
+                        mBitmap.height
+                    )
+
+                    val aspectRatio = (mBitmap.width).toFloat() / (mBitmap.height).toFloat()
+
+                    if (aspectRatio > 1) {
+                        BlurHash.encode(intArray, mBitmap.width, mBitmap.height, 9, (9 * (1 / aspectRatio)).roundToInt())
+                    } else if (aspectRatio < 1) {
+                        BlurHash.encode(intArray, mBitmap.width, mBitmap.height, (9 * aspectRatio).roundToInt(), 9)
+                    } else {
+                        BlurHash.encode(intArray, mBitmap.width, mBitmap.height, 4, 4)
+                    }
+                } else {
+                    null
+                }
+
+                onReady(FileHeader(fileUrl, mimeType, hash, size, blurHash, ""))
+            } catch (e: Exception) {
+                Log.e("ImageDownload", "Couldn't convert image in to File Header: ${e.message}")
+                onError()
+            }
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/service/NostrDataSource.kt

@@ -75,6 +75,7 @@ abstract class NostrDataSource(val debugName: String) {
                         is ContactListEvent -> LocalCache.consume(event)
                         is DeletionEvent -> LocalCache.consume(event)
 
+                        is FileHeaderEvent -> LocalCache.consume(event)
                         is LnZapEvent -> {
                             event.zapRequest?.let { onEvent(it, subscriptionId, relay) }
                             LocalCache.consume(event)

app/src/main/java/com/vitorpamplona/amethyst/service/NostrSingleEventDataSource.kt

@@ -111,9 +111,12 @@ object NostrSingleEventDataSource : NostrDataSource("SingleEventFeed") {
                 types = FeedType.values().toSet(),
                 filter = JsonFilter(
                     kinds = listOf(
-                        TextNoteEvent.kind, LongTextNoteEvent.kind, ReactionEvent.kind, RepostEvent.kind, LnZapEvent.kind, LnZapRequestEvent.kind,
-                        ChannelMessageEvent.kind, ChannelCreateEvent.kind, ChannelMetadataEvent.kind, BadgeDefinitionEvent.kind, BadgeAwardEvent.kind, BadgeProfilesEvent.kind,
-                        PollNoteEvent.kind, PrivateDmEvent.kind
+                        TextNoteEvent.kind, LongTextNoteEvent.kind, PollNoteEvent.kind,
+                        ReactionEvent.kind, RepostEvent.kind,
+                        LnZapEvent.kind, LnZapRequestEvent.kind,
+                        ChannelMessageEvent.kind, ChannelCreateEvent.kind, ChannelMetadataEvent.kind,
+                        BadgeDefinitionEvent.kind, BadgeAwardEvent.kind, BadgeProfilesEvent.kind,
+                        PrivateDmEvent.kind, FileHeaderEvent.kind
                     ),
                     ids = interestedEvents.toList()
                 )

app/src/main/java/com/vitorpamplona/amethyst/service/model/Event.kt

@@ -222,6 +222,7 @@ open class Event(
             ContactListEvent.kind -> ContactListEvent(id, pubKey, createdAt, tags, content, sig)
             DeletionEvent.kind -> DeletionEvent(id, pubKey, createdAt, tags, content, sig)
 
+            FileHeaderEvent.kind -> FileHeaderEvent(id, pubKey, createdAt, tags, content, sig)
             LnZapEvent.kind -> LnZapEvent(id, pubKey, createdAt, tags, content, sig)
             LnZapPaymentRequestEvent.kind -> LnZapPaymentRequestEvent(id, pubKey, createdAt, tags, content, sig)
             LnZapRequestEvent.kind -> LnZapRequestEvent(id, pubKey, createdAt, tags, content, sig)

app/src/main/java/com/vitorpamplona/amethyst/service/model/FileHeaderEvent.kt

@@ -0,0 +1,71 @@
+package com.vitorpamplona.amethyst.service.model
+
+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.toHexKey
+import nostr.postr.Utils
+import java.util.Date
+
+class FileHeaderEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: List<List<String>>,
+    content: String,
+    sig: HexKey
+) : Event(id, pubKey, createdAt, kind, tags, content, sig) {
+
+    fun url() = tags.firstOrNull { it.size > 1 && it[0] == URL }?.get(1)
+    fun encryptionKey() = tags.firstOrNull { it.size > 2 && it[0] == ENCRYPTION_KEY }?.let { AESGCM(it[1], it[2]) }
+    fun mimeType() = tags.firstOrNull { it.size > 1 && it[0] == MIME_TYPE }?.get(1)
+    fun hash() = tags.firstOrNull { it.size > 1 && it[0] == HASH }?.get(1)
+    fun size() = tags.firstOrNull { it.size > 1 && it[0] == FILE_SIZE }?.get(1)
+    fun magnetURI() = tags.firstOrNull { it.size > 1 && it[0] == MAGNET_URI }?.get(1)
+    fun torrentInfoHash() = tags.firstOrNull { it.size > 1 && it[0] == TORRENT_INFOHASH }?.get(1)
+    fun blurhash() = tags.firstOrNull { it.size > 1 && it[0] == BLUR_HASH }?.get(1)
+
+    companion object {
+        const val kind = 1063
+
+        private const val URL = "url"
+        private const val ENCRYPTION_KEY = "aes-256-gcm"
+        private const val MIME_TYPE = "m"
+        private const val FILE_SIZE = "size"
+        private const val HASH = "x"
+        private const val MAGNET_URI = "magnet"
+        private const val TORRENT_INFOHASH = "i"
+        private const val BLUR_HASH = "blurhash"
+
+        fun create(
+            url: String,
+            mimeType: String? = null,
+            description: String? = null,
+            hash: String? = null,
+            size: String? = null,
+            blurhash: String? = null,
+            magnetURI: String? = null,
+            torrentInfoHash: String? = null,
+            encryptionKey: AESGCM? = null,
+            privateKey: ByteArray,
+            createdAt: Long = Date().time / 1000
+        ): FileHeaderEvent {
+            var tags = listOfNotNull(
+                listOf(URL, url),
+                mimeType?.let { listOf(MIME_TYPE, mimeType) },
+                hash?.let { listOf(HASH, it) },
+                size?.let { listOf(FILE_SIZE, it) },
+                blurhash?.let { listOf(BLUR_HASH, it) },
+                magnetURI?.let { listOf(MAGNET_URI, it) },
+                torrentInfoHash?.let { listOf(TORRENT_INFOHASH, it) },
+                encryptionKey?.let { listOf(ENCRYPTION_KEY, it.key, it.nonce) }
+            )
+
+            val content = description ?: ""
+            val pubKey = Utils.pubkeyCreate(privateKey).toHexKey()
+            val id = generateId(pubKey, createdAt, kind, tags, content)
+            val sig = Utils.sign(id, privateKey)
+            return FileHeaderEvent(id.toHexKey(), pubKey, createdAt, tags, content, sig.toHexKey())
+        }
+    }
+}
+
+data class AESGCM(val key: String, val nonce: String)

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/ImageUploader.kt

@@ -15,7 +15,7 @@ object ImageUploader {
     fun uploadImage(
         uri: Uri,
         contentResolver: ContentResolver,
-        onSuccess: (String) -> Unit,
+        onSuccess: (String, String?) -> Unit,
         onError: (Throwable) -> Unit
     ) {
         val contentType = contentResolver.getType(uri)
@@ -64,7 +64,7 @@ object ImageUploader {
                             "There must be an uploaded image URL in the response"
                         }
 
-                        onSuccess(url)
+                        onSuccess(url, contentType)
                     }
                 } catch (e: Exception) {
                     e.printStackTrace()

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/NewPostViewModel.kt

@@ -13,6 +13,7 @@ import androidx.compose.ui.text.input.TextFieldValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.vitorpamplona.amethyst.model.*
+import com.vitorpamplona.amethyst.service.FileHeader
 import com.vitorpamplona.amethyst.service.model.PrivateDmEvent
 import com.vitorpamplona.amethyst.service.model.TextNoteEvent
 import com.vitorpamplona.amethyst.ui.components.isValidURL
@@ -110,13 +111,39 @@ open class NewPostViewModel : ViewModel() {
         ImageUploader.uploadImage(
             uri = it,
             contentResolver = context.contentResolver,
-            onSuccess = { imageUrl ->
-                isUploadingImage = false
-                message = TextFieldValue(message.text + "\n\n" + imageUrl)
-
+            onSuccess = { imageUrl, mimeType ->
                 viewModelScope.launch(Dispatchers.IO) {
-                    delay(2000)
-                    urlPreview = findUrlInMessage()
+                    // Images don't seem to be ready immediately after upload
+
+                    if (mimeType?.startsWith("image/") == true) {
+                        delay(2000)
+                    } else {
+                        delay(5000)
+                    }
+
+                    FileHeader.prepare(
+                        imageUrl,
+                        mimeType,
+                        onReady = {
+                            val note = account?.sendHeader(it)
+
+                            isUploadingImage = false
+
+                            if (note == null) {
+                                message = TextFieldValue(message.text + "\n\n" + imageUrl)
+                            } else {
+                                message = TextFieldValue(message.text + "\n\nnostr:" + note.idNote())
+                            }
+
+                            urlPreview = findUrlInMessage()
+                        },
+                        onError = {
+                            isUploadingImage = false
+                            viewModelScope.launch {
+                                imageUploadingError.emit("Failed to upload the image / video")
+                            }
+                        }
+                    )
                 }
             },
             onError = {

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/NewUserMetadataViewModel.kt

@@ -171,7 +171,7 @@ class NewUserMetadataViewModel : ViewModel() {
         ImageUploader.uploadImage(
             uri = it,
             contentResolver = context.contentResolver,
-            onSuccess = { imageUrl ->
+            onSuccess = { imageUrl, mimeType ->
                 onUploading(false)
                 onUploaded(imageUrl)
             },

app/src/main/java/com/vitorpamplona/amethyst/ui/components/RichTextViewer.kt

@@ -139,11 +139,17 @@ fun RichTextViewer(
         } else {
             val urls = UrlDetector(content, UrlDetectorOptions.Default).detect()
             val urlSet = urls.mapTo(LinkedHashSet(urls.size)) { it.originalUrl }
-            val imagesForPager = urlSet.filter { fullUrl ->
+            val imagesForPager = urlSet.mapNotNull { fullUrl ->
                 val removedParamsFromUrl = fullUrl.split("?")[0].lowercase()
-                imageExtensions.any { removedParamsFromUrl.endsWith(it) } || videoExtensions.any { removedParamsFromUrl.endsWith(it) }
-            }
-            val imagesForPagerSet = imagesForPager.toSet()
+                if (imageExtensions.any { removedParamsFromUrl.endsWith(it) }) {
+                    ZoomableImage(fullUrl)
+                } else if (videoExtensions.any { removedParamsFromUrl.endsWith(it) }) {
+                    ZoomableVideo(fullUrl)
+                } else {
+                    null
+                }
+            }.associateBy { it.url }
+            val imageList = imagesForPager.values.toList()
 
             // FlowRow doesn't work well with paragraphs. So we need to split them
             content.split('\n').forEach { paragraph ->
@@ -152,8 +158,9 @@ fun RichTextViewer(
                     s.forEach { word: String ->
                         if (canPreview) {
                             // Explicit URL
-                            if (imagesForPagerSet.contains(word)) {
-                                ZoomableImageView(word, imagesForPager)
+                            val img = imagesForPager[word]
+                            if (img != null) {
+                                ZoomableContentView(img, imageList)
                             } else if (urlSet.contains(word)) {
                                 UrlPreview(word, "$word ")
                             } else if (word.startsWith("lnbc", true)) {

app/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableContentView.kt

@@ -0,0 +1,408 @@
+package com.vitorpamplona.amethyst.ui.components
+
+import android.content.Context
+import android.util.Log
+import android.widget.Toast
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.combinedClickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.pager.PagerState
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.InlineTextContent
+import androidx.compose.foundation.text.appendInlineContent
+import androidx.compose.material.Icon
+import androidx.compose.material.IconButton
+import androidx.compose.material.LocalTextStyle
+import androidx.compose.material.MaterialTheme
+import androidx.compose.material.Surface
+import androidx.compose.material.Text
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Report
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.compositeOver
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalClipboardManager
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.Placeholder
+import androidx.compose.ui.text.PlaceholderVerticalAlign
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.compose.ui.window.Dialog
+import androidx.compose.ui.window.DialogProperties
+import coil.annotation.ExperimentalCoilApi
+import coil.compose.AsyncImage
+import coil.compose.AsyncImagePainter
+import coil.imageLoader
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.model.toHexKey
+import com.vitorpamplona.amethyst.service.BlurHashRequester
+import com.vitorpamplona.amethyst.ui.actions.CloseButton
+import com.vitorpamplona.amethyst.ui.actions.LoadingAnimation
+import com.vitorpamplona.amethyst.ui.actions.SaveToGallery
+import com.vitorpamplona.amethyst.ui.theme.Nip05
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import net.engawapg.lib.zoomable.rememberZoomState
+import net.engawapg.lib.zoomable.zoomable
+import java.security.MessageDigest
+
+abstract class ZoomableContent(
+    val url: String,
+    val description: String? = null,
+    val hash: String? = null
+)
+
+class ZoomableImage(
+    url: String,
+    description: String? = null,
+    hash: String? = null,
+    val bluehash: String? = null
+) : ZoomableContent(url, description, hash)
+
+class ZoomableVideo(
+    url: String,
+    description: String? = null,
+    hash: String? = null
+) : ZoomableContent(url, description, hash)
+
+fun figureOutMimeType(fullUrl: String): ZoomableContent {
+    val removedParamsFromUrl = fullUrl.split("?")[0].lowercase()
+    val isImage = imageExtensions.any { removedParamsFromUrl.endsWith(it) }
+    val isVideo = videoExtensions.any { removedParamsFromUrl.endsWith(it) }
+
+    return if (isImage) {
+        ZoomableImage(fullUrl)
+    } else if (isVideo) {
+        ZoomableVideo(fullUrl)
+    } else {
+        ZoomableImage(fullUrl)
+    }
+}
+
+@Composable
+@OptIn(ExperimentalFoundationApi::class)
+fun ZoomableContentView(content: ZoomableContent, images: List<ZoomableContent> = listOf(content)) {
+    val clipboardManager = LocalClipboardManager.current
+    val scope = rememberCoroutineScope()
+    val context = LocalContext.current
+
+    // store the dialog open or close state
+    var dialogOpen by remember {
+        mutableStateOf(false)
+    }
+
+    // store the dialog open or close state
+    var imageState by remember {
+        mutableStateOf<AsyncImagePainter.State?>(null)
+    }
+
+    var verifiedHash by remember {
+        mutableStateOf<Boolean?>(null)
+    }
+
+    LaunchedEffect(key1 = content.url, key2 = imageState) {
+        if (imageState is AsyncImagePainter.State.Success) {
+            scope.launch(Dispatchers.IO) {
+                verifiedHash = verifyHash(content, context)
+            }
+        }
+    }
+
+    val mainImageModifier = Modifier
+        .fillMaxWidth()
+        .clip(shape = RoundedCornerShape(15.dp))
+        .border(
+            1.dp,
+            MaterialTheme.colors.onSurface.copy(alpha = 0.12f),
+            RoundedCornerShape(15.dp)
+        )
+        .combinedClickable(
+            onClick = { dialogOpen = true },
+            onLongClick = { clipboardManager.setText(AnnotatedString(content.url)) }
+        )
+
+    if (content is ZoomableImage) {
+        Box() {
+            AsyncImage(
+                model = content.url,
+                contentDescription = content.description,
+                contentScale = ContentScale.FillWidth,
+                modifier = mainImageModifier,
+                onLoading = {
+                    imageState = it
+                },
+                onSuccess = {
+                    imageState = it
+                }
+            )
+
+            if (imageState !is AsyncImagePainter.State.Success) {
+                if (content.bluehash != null) {
+                    DisplayBlueHash(content, mainImageModifier)
+                } else {
+                    DisplayUrlWithLoadingSymbol(content)
+                }
+            } else {
+                HashVerificationSymbol(verifiedHash, Modifier.align(Alignment.TopEnd))
+            }
+        }
+    } else {
+        VideoView(content.url) { dialogOpen = true }
+    }
+
+    if (dialogOpen) {
+        ZoomableImageDialog(content, images, onDismiss = { dialogOpen = false })
+    }
+}
+
+@Composable
+private fun DisplayUrlWithLoadingSymbol(content: ZoomableContent) {
+    ClickableUrl(urlText = "$content ", url = content.url)
+
+    val myId = "inlineContent"
+    val emptytext = buildAnnotatedString {
+        withStyle(
+            LocalTextStyle.current.copy(color = MaterialTheme.colors.primary).toSpanStyle()
+        ) {
+            append("")
+            appendInlineContent(myId, "[icon]")
+        }
+    }
+    val inlineContent = mapOf(
+        Pair(
+            myId,
+            InlineTextContent(
+                Placeholder(
+                    width = 17.sp,
+                    height = 17.sp,
+                    placeholderVerticalAlign = PlaceholderVerticalAlign.Center
+                )
+            ) {
+                LoadingAnimation()
+            }
+        )
+    )
+
+    // Empty Text for Size of Icon
+    Text(
+        text = emptytext,
+        inlineContent = inlineContent
+    )
+}
+
+@Composable
+private fun DisplayBlueHash(
+    content: ZoomableImage,
+    modifier: Modifier
+) {
+    if (content.bluehash == null) return
+
+    val context = LocalContext.current
+    AsyncImage(
+        model = BlurHashRequester.imageRequest(
+            context,
+            content.bluehash
+        ),
+        contentDescription = content.description,
+        contentScale = ContentScale.FillWidth,
+        modifier = modifier
+    )
+}
+
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+fun ZoomableImageDialog(imageUrl: ZoomableContent, allImages: List<ZoomableContent> = listOf(imageUrl), onDismiss: () -> Unit) {
+    Dialog(
+        onDismissRequest = onDismiss,
+        properties = DialogProperties(usePlatformDefaultWidth = false)
+    ) {
+        Surface(modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background) {
+            Column() {
+                val pagerState: PagerState = remember { PagerState() }
+
+                Row(
+                    modifier = Modifier
+                        .padding(10.dp)
+                        .fillMaxWidth(),
+                    horizontalArrangement = Arrangement.SpaceBetween,
+                    verticalAlignment = Alignment.CenterVertically
+                ) {
+                    CloseButton(onCancel = onDismiss)
+
+                    SaveToGallery(url = allImages[pagerState.currentPage].url)
+                }
+
+                if (allImages.size > 1) {
+                    SlidingCarousel(
+                        pagerState = pagerState,
+                        itemsCount = allImages.size,
+                        itemContent = { index ->
+                            RenderImageOrVideo(allImages[index])
+                        }
+                    )
+                } else {
+                    RenderImageOrVideo(imageUrl)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun RenderImageOrVideo(content: ZoomableContent) {
+    val scope = rememberCoroutineScope()
+    val context = LocalContext.current
+
+    // store the dialog open or close state
+    var imageState by remember {
+        mutableStateOf<AsyncImagePainter.State?>(null)
+    }
+
+    var verifiedHash by remember {
+        mutableStateOf<Boolean?>(null)
+    }
+
+    LaunchedEffect(key1 = content.url, key2 = imageState) {
+        if (imageState is AsyncImagePainter.State.Success) {
+            scope.launch(Dispatchers.IO) {
+                verifiedHash = verifyHash(content, context)
+            }
+        }
+    }
+
+    if (content is ZoomableImage) {
+        Box() {
+            AsyncImage(
+                model = content.url,
+                contentDescription = content.description,
+                contentScale = ContentScale.FillWidth,
+                modifier = Modifier
+                    .fillMaxSize()
+                    .zoomable(rememberZoomState()),
+                onLoading = {
+                    imageState = it
+                },
+                onSuccess = {
+                    imageState = it
+                }
+            )
+            if (imageState !is AsyncImagePainter.State.Success) {
+                DisplayBlueHash(content = content, modifier = Modifier.fillMaxWidth())
+            } else {
+                HashVerificationSymbol(verifiedHash, Modifier.align(Alignment.TopEnd))
+            }
+        }
+    } else {
+        Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxSize(1f)) {
+            VideoView(content.url)
+        }
+    }
+}
+
+@OptIn(ExperimentalCoilApi::class)
+private suspend fun verifyHash(content: ZoomableContent, context: Context): Boolean? {
+    if (content.hash == null) return null
+
+    context.imageLoader.diskCache?.get(content.url)?.use { snapshot ->
+        val imageFile = snapshot.data.toFile()
+        val bytes = imageFile.readBytes()
+        val sha256 = MessageDigest.getInstance("SHA-256")
+
+        val hash = sha256.digest(bytes).toHexKey()
+
+        Log.d("Image Hash Verification", "$hash == ${content.hash}")
+
+        return hash == content.hash
+    }
+
+    return null
+}
+
+@Composable
+private fun HashVerificationSymbol(verifiedHash: Boolean?, modifier: Modifier) {
+    if (verifiedHash == null) return
+
+    val localContext = LocalContext.current
+    val scope = rememberCoroutineScope()
+
+    Box(
+        modifier
+            .width(40.dp)
+            .height(40.dp)
+            .padding(10.dp)
+    ) {
+        Box(
+            Modifier
+                .clip(CircleShape)
+                .fillMaxSize(0.6f)
+                .align(Alignment.Center)
+                .background(MaterialTheme.colors.background)
+        )
+
+        if (verifiedHash == true) {
+            IconButton(
+                onClick = {
+                    scope.launch {
+                        Toast.makeText(
+                            localContext,
+                            localContext.getString(R.string.hash_verification_passed),
+                            Toast.LENGTH_LONG
+                        ).show()
+                    }
+                }
+            ) {
+                Icon(
+                    painter = painterResource(R.drawable.ic_verified),
+                    "Hash Verified",
+                    tint = Nip05.copy(0.52f).compositeOver(MaterialTheme.colors.background),
+                    modifier = Modifier.size(30.dp)
+                )
+            }
+        } else if (verifiedHash == false) {
+            IconButton(
+                onClick = {
+                    scope.launch {
+                        Toast.makeText(
+                            localContext,
+                            localContext.getString(R.string.hash_verification_failed),
+                            Toast.LENGTH_LONG
+                        ).show()
+                    }
+                }
+            ) {
+                Icon(
+                    tint = Color.Red,
+                    imageVector = Icons.Default.Report,
+                    contentDescription = "Invalid Hash",
+                    modifier = Modifier.size(30.dp)
+                )
+            }
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableImageView.kt

@@ -1,188 +0,0 @@
-package com.vitorpamplona.amethyst.ui.components
-
-import androidx.compose.foundation.ExperimentalFoundationApi
-import androidx.compose.foundation.border
-import androidx.compose.foundation.combinedClickable
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.pager.PagerState
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.text.InlineTextContent
-import androidx.compose.foundation.text.appendInlineContent
-import androidx.compose.material.LocalTextStyle
-import androidx.compose.material.MaterialTheme
-import androidx.compose.material.Surface
-import androidx.compose.material.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.layout.ContentScale
-import androidx.compose.ui.platform.LocalClipboardManager
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.AnnotatedString
-import androidx.compose.ui.text.Placeholder
-import androidx.compose.ui.text.PlaceholderVerticalAlign
-import androidx.compose.ui.text.buildAnnotatedString
-import androidx.compose.ui.text.withStyle
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import androidx.compose.ui.window.Dialog
-import androidx.compose.ui.window.DialogProperties
-import coil.compose.AsyncImage
-import coil.compose.AsyncImagePainter
-import com.vitorpamplona.amethyst.R
-import com.vitorpamplona.amethyst.ui.actions.CloseButton
-import com.vitorpamplona.amethyst.ui.actions.LoadingAnimation
-import com.vitorpamplona.amethyst.ui.actions.SaveToGallery
-import net.engawapg.lib.zoomable.rememberZoomState
-import net.engawapg.lib.zoomable.zoomable
-
-@Composable
-@OptIn(ExperimentalFoundationApi::class)
-fun ZoomableImageView(word: String, images: List<String> = listOf(word)) {
-    val clipboardManager = LocalClipboardManager.current
-
-    // store the dialog open or close state
-    var dialogOpen by remember {
-        mutableStateOf(false)
-    }
-
-    // store the dialog open or close state
-    var imageState by remember {
-        mutableStateOf<AsyncImagePainter.State?>(null)
-    }
-
-    val removedParamsFromUrl = word.split("?")[0].lowercase()
-    if (imageExtensions.any { removedParamsFromUrl.endsWith(it) }) {
-        AsyncImage(
-            model = word,
-            contentDescription = word,
-            contentScale = ContentScale.FillWidth,
-            modifier = Modifier
-                .fillMaxWidth()
-                .clip(shape = RoundedCornerShape(15.dp))
-                .border(
-                    1.dp,
-                    MaterialTheme.colors.onSurface.copy(alpha = 0.12f),
-                    RoundedCornerShape(15.dp)
-                )
-                .combinedClickable(
-                    onClick = { dialogOpen = true },
-                    onLongClick = { clipboardManager.setText(AnnotatedString(word)) }
-                ),
-            onLoading = {
-                imageState = it
-            },
-            onSuccess = {
-                imageState = it
-            }
-        )
-
-        if (imageState !is AsyncImagePainter.State.Success) {
-            ClickableUrl(urlText = "$word ", url = word)
-
-            val myId = "inlineContent"
-            val emptytext = buildAnnotatedString {
-                withStyle(
-                    LocalTextStyle.current.copy(color = MaterialTheme.colors.primary).toSpanStyle()
-                ) {
-                    append("")
-                    appendInlineContent(myId, "[icon]")
-                }
-            }
-            val inlineContent = mapOf(
-                Pair(
-                    myId,
-                    InlineTextContent(
-                        Placeholder(
-                            width = 17.sp,
-                            height = 17.sp,
-                            placeholderVerticalAlign = PlaceholderVerticalAlign.Center
-                        )
-                    ) {
-                        LoadingAnimation()
-                    }
-                )
-            )
-
-            // Empty Text for Size of Icon
-            Text(
-                text = emptytext,
-                inlineContent = inlineContent
-            )
-        }
-    } else {
-        VideoView(word) { dialogOpen = true }
-    }
-
-    if (dialogOpen) {
-        ZoomableImageDialog(word, images, onDismiss = { dialogOpen = false })
-    }
-}
-
-@OptIn(ExperimentalFoundationApi::class)
-@Composable
-fun ZoomableImageDialog(imageUrl: String, allImages: List<String> = listOf(imageUrl), onDismiss: () -> Unit) {
-    Dialog(
-        onDismissRequest = onDismiss,
-        properties = DialogProperties(usePlatformDefaultWidth = false)
-    ) {
-        Surface(modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background) {
-            Column() {
-                var pagerState: PagerState = remember { PagerState() }
-
-                Row(
-                    modifier = Modifier
-                        .padding(10.dp)
-                        .fillMaxWidth(),
-                    horizontalArrangement = Arrangement.SpaceBetween,
-                    verticalAlignment = Alignment.CenterVertically
-                ) {
-                    CloseButton(onCancel = onDismiss)
-
-                    SaveToGallery(url = allImages[pagerState.currentPage])
-                }
-
-                if (allImages.size > 1) {
-                    SlidingCarousel(
-                        pagerState = pagerState,
-                        itemsCount = allImages.size,
-                        itemContent = { index ->
-                            RenderImageOrVideo(allImages[index])
-                        }
-                    )
-                } else {
-                    RenderImageOrVideo(imageUrl)
-                }
-            }
-        }
-    }
-}
-
-@Composable
-private fun RenderImageOrVideo(imageUrl: String) {
-    val removedParamsFromUrl = imageUrl.split("?")[0].lowercase()
-    if (imageExtensions.any { removedParamsFromUrl.endsWith(it) }) {
-        AsyncImage(
-            model = imageUrl,
-            contentDescription = stringResource(id = R.string.profile_image),
-            contentScale = ContentScale.FillWidth,
-            modifier = Modifier
-                .fillMaxSize()
-                .zoomable(rememberZoomState())
-        )
-    } else {
-        Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxSize(1f)) {
-            VideoView(imageUrl)
-        }
-    }
-}

app/src/main/java/com/vitorpamplona/amethyst/ui/note/NoteCompose.kt

@@ -167,6 +167,8 @@ fun NoteComposeInner(
         ChannelHeader(baseChannel = baseChannel, account = account, navController = navController)
     } else if (noteEvent is BadgeDefinitionEvent) {
         BadgeDisplay(baseNote = note)
+    } else if (noteEvent is FileHeaderEvent) {
+        FileHeaderDisplay(note)
     } else {
         var isNew by remember { mutableStateOf<Boolean>(false) }
 
@@ -776,6 +778,30 @@ fun BadgeDisplay(baseNote: Note) {
     }
 }
 
+@Composable
+fun FileHeaderDisplay(note: Note) {
+    val event = (note.event as? FileHeaderEvent) ?: return
+
+    val fullUrl = event.url() ?: return
+    val blurHash = event.blurhash()
+    val hash = event.hash()
+    val description = event.content
+    val removedParamsFromUrl = fullUrl.split("?")[0].lowercase()
+    val isImage = imageExtensions.any { removedParamsFromUrl.endsWith(it) }
+    val isVideo = videoExtensions.any { removedParamsFromUrl.endsWith(it) }
+
+    if (isImage || isVideo) {
+        val content = if (isImage) {
+            ZoomableImage(fullUrl, description, hash, blurHash)
+        } else {
+            ZoomableVideo(fullUrl, description, hash)
+        }
+        ZoomableContentView(content = content, listOf(content))
+    } else {
+        UrlPreview(fullUrl, "$fullUrl ")
+    }
+}
+
 @Composable
 private fun LongFormHeader(noteEvent: LongTextNoteEvent, note: Note, loggedIn: User) {
     Row(

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/ChannelScreen.kt

@@ -89,6 +89,8 @@ fun ChannelScreen(
     val context = LocalContext.current
     val channelScreenModel: NewPostViewModel = viewModel()
 
+    channelScreenModel.account = account
+
     if (account != null && channelId != null) {
         val replyTo = remember { mutableStateOf<Note?>(null) }
 

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/ChatroomScreen.kt

@@ -67,6 +67,8 @@ fun ChatroomScreen(userId: String?, accountViewModel: AccountViewModel, navContr
     val context = LocalContext.current
     val chatRoomScreenModel: NewPostViewModel = viewModel()
 
+    chatRoomScreenModel.account = account
+
     if (account != null && userId != null) {
         val replyTo = remember { mutableStateOf<Note?>(null) }
 

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/ProfileScreen.kt

@@ -68,6 +68,7 @@ import com.vitorpamplona.amethyst.ui.components.RobohashAsyncImage
 import com.vitorpamplona.amethyst.ui.components.RobohashFallbackAsyncImage
 import com.vitorpamplona.amethyst.ui.components.TranslatableRichTextViewer
 import com.vitorpamplona.amethyst.ui.components.ZoomableImageDialog
+import com.vitorpamplona.amethyst.ui.components.figureOutMimeType
 import com.vitorpamplona.amethyst.ui.dal.UserProfileBookmarksFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.UserProfileConversationsFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.UserProfileFollowersFeedFilter
@@ -401,8 +402,9 @@ private fun ProfileHeader(
         }
     }
 
-    if (zoomImageDialogOpen) {
-        ZoomableImageDialog(baseUser.profilePicture()!!, onDismiss = { zoomImageDialogOpen = false })
+    val profilePic = baseUser.profilePicture()
+    if (zoomImageDialogOpen && profilePic != null) {
+        ZoomableImageDialog(figureOutMimeType(profilePic), onDismiss = { zoomImageDialogOpen = false })
     }
 }
 
@@ -706,7 +708,7 @@ private fun DrawBanner(baseUser: User) {
         )
 
         if (zoomImageDialogOpen) {
-            ZoomableImageDialog(imageUrl = banner, onDismiss = { zoomImageDialogOpen = false })
+            ZoomableImageDialog(imageUrl = figureOutMimeType(banner), onDismiss = { zoomImageDialogOpen = false })
         }
     } else {
         Image(

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

@@ -292,4 +292,9 @@
     <string name="lightning_create_and_add_invoice">Create and Add</string>
     <string name="poll_author_no_vote">Poll authors can\'t vote in their own polls.</string>
     <string name="poll_hashtag" translatable="false">#zappoll</string>
+
+
+    <string name="hash_verification_passed">Image is the same since the post</string>
+    <string name="hash_verification_failed">Image has changed. The author might not have seen the change</string>
+
 </resources>