Add media send feature module.

core/util/src/main/java/org/signal/core/util/ContentTypeUtil.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.core.util;
+
+import android.provider.MediaStore;
+import android.text.TextUtils;
+
+import androidx.annotation.Nullable;
+
+/**
+ * Utility methods for working with media content types.
+ *
+ * Intended to live in core util so feature modules can reuse common
+ * MIME/type predicates without depending on app-layer utilities.
+ */
+public final class ContentTypeUtil {
+
+  private ContentTypeUtil() {}
+
+  public static final String IMAGE_PNG         = "image/png";
+  public static final String IMAGE_JPEG        = "image/jpeg";
+  public static final String IMAGE_HEIC        = "image/heic";
+  public static final String IMAGE_HEIF        = "image/heif";
+  public static final String IMAGE_AVIF        = "image/avif";
+  public static final String IMAGE_WEBP        = "image/webp";
+  public static final String IMAGE_GIF         = "image/gif";
+  public static final String AUDIO_AAC         = "audio/aac";
+  public static final String AUDIO_MP4         = "audio/mp4";
+  public static final String AUDIO_UNSPECIFIED = "audio/*";
+  public static final String VIDEO_MP4         = "video/mp4";
+  public static final String VIDEO_UNSPECIFIED = "video/*";
+  public static final String VCARD             = "text/x-vcard";
+  public static final String LONG_TEXT         = "text/x-signal-plain";
+  public static final String VIEW_ONCE         = "application/x-signal-view-once";
+  public static final String UNKNOWN           = "*/*";
+  public static final String OCTET             = "application/octet-stream";
+
+  public static boolean isMms(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals("application/mms");
+  }
+
+  public static boolean isVideo(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().startsWith("video/");
+  }
+
+  public static boolean isVcard(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(VCARD);
+  }
+
+  public static boolean isGif(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_GIF);
+  }
+
+  public static boolean isJpegType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_JPEG);
+  }
+
+  public static boolean isHeicType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_HEIC);
+  }
+
+  public static boolean isHeifType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_HEIF);
+  }
+
+  public static boolean isAvifType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_AVIF);
+  }
+
+  public static boolean isWebpType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_WEBP);
+  }
+
+  public static boolean isPngType(@Nullable String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_PNG);
+  }
+
+  public static boolean isTextType(@Nullable String contentType) {
+    return contentType != null && contentType.startsWith("text/");
+  }
+
+  public static boolean isImageType(@Nullable String contentType) {
+    if (contentType == null) {
+      return false;
+    }
+
+    return (contentType.startsWith("image/") && !contentType.equals("image/svg+xml")) ||
+           contentType.equals(MediaStore.Images.Media.CONTENT_TYPE);
+  }
+
+  public static boolean isAudioType(@Nullable String contentType) {
+    if (contentType == null) {
+      return false;
+    }
+
+    return contentType.startsWith("audio/") ||
+           contentType.equals(MediaStore.Audio.Media.CONTENT_TYPE);
+  }
+
+  public static boolean isVideoType(@Nullable String contentType) {
+    if (contentType == null) {
+      return false;
+    }
+
+    return contentType.startsWith("video/") ||
+           contentType.equals(MediaStore.Video.Media.CONTENT_TYPE);
+  }
+
+  public static boolean isImageOrVideoType(@Nullable String contentType) {
+    return isImageType(contentType) || isVideoType(contentType);
+  }
+
+  public static boolean isStorySupportedType(@Nullable String contentType) {
+    return isImageOrVideoType(contentType) && !isGif(contentType);
+  }
+
+  public static boolean isImageVideoOrAudioType(@Nullable String contentType) {
+    return isImageOrVideoType(contentType) || isAudioType(contentType);
+  }
+
+  public static boolean isImageAndNotGif(@Nullable String contentType) {
+    return isImageType(contentType) && !isGif(contentType);
+  }
+
+  public static boolean isLongTextType(@Nullable String contentType) {
+    return contentType != null && contentType.equals(LONG_TEXT);
+  }
+
+  public static boolean isViewOnceType(@Nullable String contentType) {
+    return contentType != null && contentType.equals(VIEW_ONCE);
+  }
+
+  public static boolean isOctetStream(@Nullable String contentType) {
+    return OCTET.equals(contentType);
+  }
+
+  public static boolean isDocumentType(@Nullable String contentType) {
+    return !isImageOrVideoType(contentType) && !isGif(contentType) && !isLongTextType(contentType) && !isViewOnceType(contentType);
+  }
+}