Merge pull request #1350 from davotoula/share-media-to-other-apps

Share images to other apps

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/ShareHelper.kt

@@ -0,0 +1,135 @@
+/**
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.components
+
+import android.content.Context
+import android.net.Uri
+import android.util.Log
+import androidx.core.content.FileProvider
+import com.vitorpamplona.amethyst.Amethyst
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.File
+import java.io.FileInputStream
+import java.io.IOException
+
+object ShareHelper {
+    private const val TAG = "ShareHelper"
+    private const val DEFAULT_EXTENSION = "jpg"
+    private const val SHARED_FILE_PREFIX = "shared_media"
+
+    // Media type magic numbers
+    private val JPEG_MAGIC = byteArrayOf(0xFF.toByte(), 0xD8.toByte())
+    private val PNG_MAGIC = byteArrayOf(0x89.toByte(), 0x50.toByte(), 0x4E.toByte(), 0x47.toByte())
+    private val WEBP_HEADER_START = "RIFF".toByteArray()
+    private val WEBP_HEADER_END = "WEBP".toByteArray()
+    private val GIF_MAGIC = "GIF8".toByteArray()
+
+    suspend fun getSharableUriFromUrl(
+        context: Context,
+        imageUrl: String,
+    ): Pair<Uri, String> =
+        withContext(Dispatchers.IO) {
+            // Safely get snapshot and file
+            Amethyst.instance.diskCache.openSnapshot(imageUrl)?.use { snapshot ->
+                val file = snapshot.data.toFile()
+
+                // Determine file extension and prepare sharable file
+                val fileExtension = getImageExtension(file)
+                val fileCopy = prepareSharableFile(context, file, fileExtension)
+
+                // Return sharable uri
+                return@use Pair(
+                    FileProvider.getUriForFile(context, "${context.packageName}.provider", fileCopy),
+                    fileExtension,
+                )
+            } ?: throw IOException("Unable to open snapshot for: $imageUrl")
+        }
+
+    private fun getImageExtension(file: File): String =
+        try {
+            FileInputStream(file).use { inputStream ->
+                val header = ByteArray(12)
+                val bytesRead = inputStream.read(header)
+
+                if (bytesRead < 4) {
+                    // If we couldn't read at least 4 bytes, default to jpg
+                    return DEFAULT_EXTENSION
+                }
+
+                when {
+                    // JPEG: Check first 2 bytes
+                    matchesMagicNumbers(header, 0, JPEG_MAGIC) -> "jpg"
+
+                    // PNG: Check first 4 bytes
+                    matchesMagicNumbers(header, 0, PNG_MAGIC) -> "png"
+
+                    // GIF: Check first 4 bytes for "GIF8"
+                    matchesMagicNumbers(header, 0, GIF_MAGIC) -> "gif"
+
+                    // WEBP: Check "RIFF" (bytes 0-3) and "WEBP" (bytes 8-11)
+                    matchesMagicNumbers(header, 0, WEBP_HEADER_START) &&
+                        bytesRead >= 12 &&
+                        matchesMagicNumbers(header, 8, WEBP_HEADER_END) -> "webp"
+
+                    else -> DEFAULT_EXTENSION
+                }
+            }
+        } catch (e: IOException) {
+            Log.w(TAG, "Could not determine image type for ${file.name}, defaulting to $DEFAULT_EXTENSION", e)
+            DEFAULT_EXTENSION
+        }
+
+    private fun matchesMagicNumbers(
+        data: ByteArray,
+        offset: Int,
+        magicBytes: ByteArray,
+    ): Boolean {
+        if (offset + magicBytes.size > data.size) {
+            return false
+        }
+
+        for (i in magicBytes.indices) {
+            if (data[offset + i] != magicBytes[i]) {
+                return false
+            }
+        }
+        return true
+    }
+
+    private fun prepareSharableFile(
+        context: Context,
+        originalFile: File,
+        extension: String,
+    ): File {
+        val timestamp = System.currentTimeMillis()
+        val sharableFile = File(context.cacheDir, "${SHARED_FILE_PREFIX}_$timestamp.$extension")
+
+        try {
+            originalFile.copyTo(sharableFile, overwrite = true)
+        } catch (e: IOException) {
+            Log.e(TAG, "Failed to copy file for sharing", e)
+            throw e
+        }
+
+        return sharableFile
+    }
+}

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

@@ -20,6 +20,8 @@
  */
 package com.vitorpamplona.amethyst.ui.components
 
+import android.content.Context
+import android.content.Intent
 import android.util.Log
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.AnimatedVisibilityScope
@@ -47,6 +49,7 @@ import androidx.compose.runtime.collectAsState
 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
@@ -104,6 +107,7 @@ import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.persistentListOf
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlin.time.Duration.Companion.seconds
 
@@ -680,6 +684,7 @@ fun ShareImageAction(
             hash = content.hash,
             mimeType = content.mimeType,
             onDismiss = onDismiss,
+            content = content,
         )
     } else if (content is MediaPreloadedContent) {
         ShareImageAction(
@@ -692,6 +697,7 @@ fun ShareImageAction(
             hash = null,
             mimeType = content.mimeType,
             onDismiss = onDismiss,
+            content = content,
         )
     }
 }
@@ -708,7 +714,10 @@ fun ShareImageAction(
     hash: String?,
     mimeType: String?,
     onDismiss: () -> Unit,
+    content: BaseMediaContent? = null,
 ) {
+    val scope = rememberCoroutineScope()
+
     DropdownMenu(
         expanded = popupExpanded.value,
         onDismissRequest = onDismiss,
@@ -751,10 +760,49 @@ fun ShareImageAction(
                 },
             )
         }
+
+        content?.let {
+            if (content is MediaUrlImage) {
+                val context = LocalContext.current
+                videoUri?.let {
+                    if (videoUri.isNotEmpty()) {
+                        DropdownMenuItem(
+                            text = { Text(stringRes(R.string.share_image)) },
+                            onClick = {
+                                scope.launch { shareImageFile(context, videoUri, mimeType) }
+                                onDismiss()
+                            },
+                        )
+                    }
+                }
+            }
+        }
     }
 }
 
-private suspend fun verifyHash(content: MediaUrlContent): Boolean? {
+private suspend fun shareImageFile(
+    context: Context,
+    videoUri: String,
+    mimeType: String?,
+) {
+    // Get sharable URI and file extension
+    val (uri, fileExtension) = ShareHelper.getSharableUriFromUrl(context, videoUri)
+
+    // Determine mime type, use provided or derive from extension
+    val determinedMimeType = mimeType ?: "image/$fileExtension"
+
+    // Create share intent
+    val shareIntent =
+        Intent(Intent.ACTION_SEND).apply {
+            type = determinedMimeType
+            putExtra(Intent.EXTRA_STREAM, uri)
+            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+        }
+
+    context.startActivity(Intent.createChooser(shareIntent, null))
+}
+
+private fun verifyHash(content: MediaUrlContent): Boolean? {
     if (content.hash == null) return null
 
     Amethyst.instance.diskCache.openSnapshot(content.url)?.use { snapshot ->

amethyst/src/main/res/values-cs/strings.xml

@@ -936,4 +936,5 @@
     <string name="torrent_no_apps">Pro otevření a stažení souboru nejsou nainstalovány žádné torrent aplikace.</string>
     <string name="select_list_to_filter">Vyberte seznam pro filtrování kanálu</string>
     <string name="temporary_account">Odhlásit se na zámek zařízení</string>
+    <string name="share_image">Sdílet obrázek…</string>
 </resources>

amethyst/src/main/res/values-de/strings.xml

@@ -941,4 +941,5 @@ anz der Bedingungen ist erforderlich</string>
     <string name="torrent_no_apps">Keine Torrent-Apps installiert, um die Datei zu öffnen und herunterzuladen.</string>
     <string name="select_list_to_filter">Liste zum Filtern des Feeds auswählen</string>
     <string name="temporary_account">Beim Sperren des Geräts abmelden</string>
+    <string name="share_image">Bild teilen…</string>
 </resources>

amethyst/src/main/res/values-pt-rBR/strings.xml

@@ -958,4 +958,5 @@
     <string name="private_message">Mensagem Privada</string>
     <string name="group_relay">Relé de chat</string>
     <string name="group_relay_explanation">O relé a qual todos os usuários deste chat se conectam</string>
+    <string name="share_image">Compartilhar imagem…</string>
 </resources>

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

@@ -1170,4 +1170,5 @@
 
     <string name="group_relay">Chat Relay</string>
     <string name="group_relay_explanation">The relay that all users of this chat connect to</string>
+    <string name="share_image">Share image…</string>
 </resources>

amethyst/src/main/res/xml/file_paths.xml

@@ -3,4 +3,6 @@
     <external-path
         name="external_files"
         path="." />
+
+    <cache-path name="cache" path="." />
 </paths>