From cc61e93c742d5e883daccbb680b0c6c8cef9015c Mon Sep 17 00:00:00 2001
From: Thibault Deckers <thibault.deckers@gmail.com>
Date: Thu, 18 Mar 2021 12:05:16 +0900
Subject: [PATCH] info: show GeoTiff tags in their own section

---
 .../aves/channel/calls/MetadataHandler.kt     | 21 +++++++++++++++----
 .../thibault/aves/metadata/TiffTags.kt        | 11 ++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MetadataHandler.kt b/android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MetadataHandler.kt
index 1dbcdc345..5b8c69cd7 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MetadataHandler.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MetadataHandler.kt
@@ -18,6 +18,7 @@ import com.adobe.internal.xmp.properties.XMPPropertyInfo
 import com.bumptech.glide.load.resource.bitmap.TransformationUtils
 import com.drew.imaging.ImageMetadataReader
 import com.drew.lang.Rational
+import com.drew.metadata.Tag
 import com.drew.metadata.exif.*
 import com.drew.metadata.file.FileTypeDirectory
 import com.drew.metadata.gif.GifAnimationDirectory
@@ -125,17 +126,29 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
                         metadataMap[dirName] = dirMap
 
                         // tags
+                        val tags = dir.tags
                         if (mimeType == MimeTypes.TIFF && (dir is ExifIFD0Directory || dir is ExifThumbnailDirectory)) {
-                            dirMap.putAll(dir.tags.map {
+                            fun tagMapper(it: Tag): Pair<String, String> {
                                 val name = if (it.hasTagName()) {
                                     it.tagName
                                 } else {
                                     TiffTags.getTagName(it.tagType) ?: it.tagName
                                 }
-                                Pair(name, it.description)
-                            })
+                                return Pair(name, it.description)
+                            }
+
+                            if (dir is ExifIFD0Directory && dir.isGeoTiff()) {
+                                // split GeoTIFF tags in their own directory
+                                val byGeoTiff = tags.groupBy { TiffTags.isGeoTiffTag(it.tagType) }
+                                metadataMap["GeoTIFF"] = HashMap<String, String>().apply {
+                                    byGeoTiff[true]?.map { tagMapper(it) }?.let { putAll(it) }
+                                }
+                                byGeoTiff[false]?.map { tagMapper(it) }?.let { dirMap.putAll(it) }
+                            } else {
+                                dirMap.putAll(tags.map { tagMapper(it) })
+                            }
                         } else {
-                            dirMap.putAll(dir.tags.map { Pair(it.tagName, it.description) })
+                            dirMap.putAll(tags.map { Pair(it.tagName, it.description) })
                         }
                         if (dir is XmpDirectory) {
                             try {
diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/TiffTags.kt b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/TiffTags.kt
index 6fd91d5e1..230c1e630 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/TiffTags.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/TiffTags.kt
@@ -110,6 +110,15 @@ object TiffTags {
     // Count = variable
     const val TAG_ORIGINAL_RAW_FILE_NAME = 0xc68b
 
+    private val geotiffTags = listOf(
+        TAG_GEO_ASCII_PARAMS,
+        TAG_GEO_DOUBLE_PARAMS,
+        TAG_GEO_KEY_DIRECTORY,
+        TAG_MODEL_PIXEL_SCALE,
+        TAG_MODEL_TIEPOINT,
+        TAG_MODEL_TRANSFORMATION,
+    )
+
     private val tagNameMap = hashMapOf(
         TAG_X_POSITION to "X Position",
         TAG_Y_POSITION to "Y Position",
@@ -132,6 +141,8 @@ object TiffTags {
         TAG_ORIGINAL_RAW_FILE_NAME to "Original Raw File Name",
     )
 
+    fun isGeoTiffTag(tag: Int) = geotiffTags.contains(tag)
+
     fun getTagName(tag: Int): String? {
         return tagNameMap[tag]
     }