From 86bb3423f4722569ccb9aafb937cfac8159b65d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6ren=20Brunk?= <soeren@brunk.io>
Date: Sun, 5 Jan 2025 18:47:07 +0100
Subject: [PATCH] Take into account exif rotation information when scaling
 images. Fixes #877

---
 app/build.gradle                              |  2 ++
 .../patrick/grocy/util/PictureUtil.java       | 20 ++++++++++++++++++-
 gradle/libs.versions.toml                     |  2 ++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/app/build.gradle b/app/build.gradle
index a9c34125a..a648a65e3 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -127,6 +127,8 @@ dependencies {
     // ZXing for barcode scanning
     implementation libs.zxing.core
     implementation libs.zxing.android.embedded
+    // For image rotation
+    implementation libs.exifinterface
     // https://github.com/journeyapps/zxing-android-embedded#option-2-desugaring-advanced
     // prevents bug https://github.com/patzly/grocy-android/issues/425
     coreLibraryDesugaring libs.desugar
diff --git a/app/src/main/java/xyz/zedler/patrick/grocy/util/PictureUtil.java b/app/src/main/java/xyz/zedler/patrick/grocy/util/PictureUtil.java
index 9390b18a9..bb5f79e4e 100644
--- a/app/src/main/java/xyz/zedler/patrick/grocy/util/PictureUtil.java
+++ b/app/src/main/java/xyz/zedler/patrick/grocy/util/PictureUtil.java
@@ -22,11 +22,14 @@
 
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.Matrix;
 import android.graphics.drawable.Drawable;
+import android.util.Log;
 import android.view.View;
 import android.widget.ImageView;
 import androidx.annotation.Nullable;
 import androidx.cardview.widget.CardView;
+import androidx.exifinterface.media.ExifInterface;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.RequestBuilder;
 import com.bumptech.glide.load.DataSource;
@@ -44,6 +47,8 @@
 
 public class PictureUtil {
 
+  private static final String TAG = PictureUtil.class.getSimpleName();
+
   public static void loadPicture(ImageView imageView, @Nullable CardView frame, String pictureUrl) {
     Glide.with(imageView.getContext())
         .load(new GlideUrl(
@@ -117,7 +122,20 @@ public static Bitmap scaleBitmap(String imagePath) {
     int scaleFactor = Math.min(imageWidth / maxWidth, imageHeight / maxHeight);
     options.inJustDecodeBounds = false;
     options.inSampleSize = scaleFactor;
-    return BitmapFactory.decodeFile(imagePath, options);
+    int rotation = 0;
+    try {
+      var exif = new ExifInterface(imagePath);
+      rotation = exif.getRotationDegrees();
+    } catch (IOException e) {
+      Log.w(TAG, "Reading exif data failed, ignoring possible rotation: " + e);
+    }
+    var bitmap = BitmapFactory.decodeFile(imagePath, options);
+    if (rotation == 0) return bitmap;
+    else {
+      var matrix = new Matrix();
+      matrix.postRotate(rotation);
+      return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
+    }
   }
 
   public static Bitmap scaleBitmap(Bitmap bitmap) {
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c37dc16f8..ae9cd8184 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -25,6 +25,7 @@ work = "2.10.0"
 zxing-core = "3.3.0"
 zxing-android-embedded = "4.3.0"
 desugar = "2.1.4"
+exifinterface = "1.3.7"
 
 [libraries]
 appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
@@ -67,6 +68,7 @@ zxing-android-embedded = { module = "com.journeyapps:zxing-android-embedded", ve
 # https://github.com/journeyapps/zxing-android-embedded#option-2-desugaring-advanced
 # prevents bug https://github.com/patzly/grocy-android/issues/425
 desugar = { module = "com.android.tools:desugar_jdk_libs", version.ref = "desugar" }
+exifinterface = { module = "androidx.exifinterface:exifinterface", version.ref = "exifinterface" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }