fix: parse image orientation from exif data (closes #497)

Author: Bnyro

app/build.gradle.kts

@@ -67,6 +67,7 @@ dependencies {
     implementation("androidx.core:core-ktx:1.16.0")
     implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.9.1")
     implementation("androidx.activity:activity-compose:1.10.1")
+    implementation("androidx.exifinterface:exifinterface:1.4.1")
     testImplementation("junit:junit:4.13.2")
     androidTestImplementation("androidx.test.ext:junit:1.2.1")
     androidTestImplementation("androidx.test.espresso:espresso-core:3.6.1")

app/src/main/java/com/bnyro/translate/ui/components/ImageCropDialog.kt

@@ -17,12 +17,14 @@
 
 package com.bnyro.translate.ui.components
 
+import android.annotation.SuppressLint
 import android.graphics.Bitmap
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.gestures.detectDragGestures
 import androidx.compose.foundation.layout.BoxWithConstraints
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.ArrowBack
 import androidx.compose.material.icons.filled.Done
 import androidx.compose.material3.CenterAlignedTopAppBar
@@ -88,7 +90,7 @@ fun ImageCropDialog(
                 title = { Text(stringResource(R.string.image_translation)) },
                 navigationIcon = {
                     StyledIconButton(
-                        imageVector = Icons.Default.ArrowBack,
+                        imageVector = Icons.AutoMirrored.Filled.ArrowBack,
                         onClick = { onDismissRequest() }
                     )
                 },
@@ -123,6 +125,7 @@ fun ImageCropDialog(
     }
 }
 
+@SuppressLint("UnusedBoxWithConstraintsScope")
 @Composable
 fun CropImageView(
     modifier: Modifier = Modifier,

app/src/main/java/com/bnyro/translate/util/ImageHelper.kt

@@ -21,8 +21,12 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.graphics.Canvas
+import android.graphics.Matrix
 import android.graphics.Paint
+import androidx.exifinterface.media.ExifInterface
 import android.net.Uri
+import android.os.Build
+import androidx.core.graphics.createBitmap
 
 data class ImageTransform(
     val width: Int,
@@ -33,17 +37,68 @@ data class ImageTransform(
 
 object ImageHelper {
     fun getImage(context: Context, uri: Uri): Bitmap? {
-        return context.contentResolver.openInputStream(uri)?.use {
+        val bitmap = context.contentResolver.openInputStream(uri)?.use {
             BitmapFactory.decodeStream(it)
+        } ?: return null
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            val `is` = context.contentResolver.openInputStream(uri) ?: return bitmap
+            val exifMetadata =
+                ExifInterface(`is`).getAttributeInt(
+                    ExifInterface.TAG_ORIENTATION,
+                    ExifInterface.ORIENTATION_NORMAL
+                )
+            return rotateBitmap(bitmap, exifMetadata) ?: bitmap
+        }
+
+        return bitmap
+    }
+
+    fun rotateBitmap(bitmap: Bitmap, orientation: Int): Bitmap? {
+        val matrix: Matrix = Matrix()
+        when (orientation) {
+            ExifInterface.ORIENTATION_NORMAL -> return bitmap
+            ExifInterface.ORIENTATION_FLIP_HORIZONTAL -> matrix.setScale(-1F, 1F)
+            ExifInterface.ORIENTATION_ROTATE_180 -> matrix.setRotate(180F)
+            ExifInterface.ORIENTATION_FLIP_VERTICAL -> {
+                matrix.setRotate(180F)
+                matrix.postScale(-1F, 1F)
+            }
+
+            ExifInterface.ORIENTATION_TRANSPOSE -> {
+                matrix.setRotate(90F)
+                matrix.postScale(-1F, 1F)
+            }
+
+            ExifInterface.ORIENTATION_ROTATE_90 -> matrix.setRotate(90F)
+            ExifInterface.ORIENTATION_TRANSVERSE -> {
+                matrix.setRotate(-90F)
+                matrix.postScale(-1F, 1F)
+            }
+
+            ExifInterface.ORIENTATION_ROTATE_270 -> matrix.setRotate(-90F)
+            else -> return bitmap
+        }
+        try {
+            val bmRotated = Bitmap.createBitmap(
+                bitmap,
+                0,
+                0,
+                bitmap.width,
+                bitmap.height,
+                matrix,
+                true
+            )
+            bitmap.recycle()
+            return bmRotated
+        } catch (e: OutOfMemoryError) {
+            e.printStackTrace()
+            return null
         }
     }
 
     fun setAlpha(originalBitmap: Bitmap, alpha: Int): Bitmap {
-        val newBitmap = Bitmap.createBitmap(
-            originalBitmap.getWidth(),
-            originalBitmap.getHeight(),
-            Bitmap.Config.ARGB_8888
-        )
+        val newBitmap = createBitmap(originalBitmap.width, originalBitmap.height)
         val canvas = Canvas(newBitmap)
         val paint = Paint().apply { this.alpha = alpha }
         canvas.drawBitmap(originalBitmap, 0f, 0f, paint)