android: Properly adjust emulation surface aspect ratio

Previously the emulation surface wouldn't respond properly to orientation changes. This would result in the screen appearing stretched when starting in one orientation and switching to another.

The code for calculating the bounds of the view have been changed to match the expected behavior now. Before the view would just match parent in height and width. Now instead of using setLeftTopRightBottom (which is intended to be used for animations) we pass newly calculated bounds for the view into super. Now the view bounds match the emulation output.

This also means that we don't need the overload for the SettingsActivity to launch it using an ActivityResultLauncher. We can just update the view in onResume.

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/ui/SettingsActivity.kt

@@ -11,7 +11,6 @@ import android.view.View
 import android.view.ViewGroup.MarginLayoutParams
 import android.widget.Toast
 import androidx.activity.OnBackPressedCallback
-import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.view.ViewCompat
@@ -246,17 +245,5 @@ class SettingsActivity : AppCompatActivity(), SettingsActivityView {
             settings.putExtra(ARG_GAME_ID, gameId)
             context.startActivity(settings)
         }
-
-        fun launch(
-            context: Context,
-            launcher: ActivityResultLauncher<Intent>,
-            menuTag: String?,
-            gameId: String?
-        ) {
-            val settings = Intent(context, SettingsActivity::class.java)
-            settings.putExtra(ARG_MENU_TAG, menuTag)
-            settings.putExtra(ARG_GAME_ID, gameId)
-            launcher.launch(settings)
-        }
     }
 }

src/android/app/src/main/java/org/yuzu/yuzu_emu/fragments/EmulationFragment.kt

@@ -7,7 +7,6 @@ import android.annotation.SuppressLint
 import android.app.AlertDialog
 import android.content.Context
 import android.content.DialogInterface
-import android.content.Intent
 import android.content.SharedPreferences
 import android.content.pm.ActivityInfo
 import android.content.res.Configuration
@@ -19,8 +18,6 @@ import android.util.Rational
 import android.view.*
 import android.widget.TextView
 import androidx.activity.OnBackPressedCallback
-import androidx.activity.result.ActivityResultLauncher
-import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.widget.PopupMenu
 import androidx.core.content.res.ResourcesCompat
 import androidx.core.graphics.Insets
@@ -66,8 +63,6 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
 
     private var isInFoldableLayout = false
 
-    private lateinit var onReturnFromSettings: ActivityResultLauncher<Intent>
-
     override fun onAttach(context: Context) {
         super.onAttach(context)
         if (context is EmulationActivity) {
@@ -81,11 +76,6 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
                         .collect { updateFoldableLayout(context, it) }
                 }
             }
-
-            onReturnFromSettings = context.activityResultRegistry.register(
-                "SettingsResult",
-                ActivityResultContracts.StartActivityForResult()
-            ) { updateScreenLayout() }
         } else {
             throw IllegalStateException("EmulationFragment must have EmulationActivity parent")
         }
@@ -149,12 +139,7 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
                 }
 
                 R.id.menu_settings -> {
-                    SettingsActivity.launch(
-                        requireContext(),
-                        onReturnFromSettings,
-                        SettingsFile.FILE_NAME_CONFIG,
-                        ""
-                    )
+                    SettingsActivity.launch(requireContext(), SettingsFile.FILE_NAME_CONFIG, "")
                     true
                 }
 

src/android/app/src/main/java/org/yuzu/yuzu_emu/views/FixedRatioSurfaceView.kt

@@ -7,7 +7,6 @@ import android.content.Context
 import android.util.AttributeSet
 import android.util.Rational
 import android.view.SurfaceView
-import kotlin.math.roundToInt
 
 class FixedRatioSurfaceView @JvmOverloads constructor(
     context: Context,
@@ -22,27 +21,44 @@ class FixedRatioSurfaceView @JvmOverloads constructor(
      */
     fun setAspectRatio(ratio: Rational?) {
         aspectRatio = ratio?.toFloat() ?: 0f
+        requestLayout()
     }
 
     override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
-        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
-        val width = MeasureSpec.getSize(widthMeasureSpec)
-        val height = MeasureSpec.getSize(heightMeasureSpec)
+        val displayWidth: Float = MeasureSpec.getSize(widthMeasureSpec).toFloat()
+        val displayHeight: Float = MeasureSpec.getSize(heightMeasureSpec).toFloat()
         if (aspectRatio != 0f) {
-            val newWidth: Int
-            val newHeight: Int
-            if (height * aspectRatio < width) {
-                newWidth = (height * aspectRatio).roundToInt()
-                newHeight = height
+            val displayAspect = displayWidth / displayHeight
+            if (displayAspect < aspectRatio) {
+                // Max out width
+                val halfHeight = displayHeight / 2
+                val surfaceHeight = displayWidth / aspectRatio
+                val newTop: Float = halfHeight - (surfaceHeight / 2)
+                val newBottom: Float = halfHeight + (surfaceHeight / 2)
+                super.onMeasure(
+                    widthMeasureSpec,
+                    MeasureSpec.makeMeasureSpec(
+                        newBottom.toInt() - newTop.toInt(),
+                        MeasureSpec.EXACTLY
+                    )
+                )
+                return
             } else {
-                newWidth = width
-                newHeight = (width / aspectRatio).roundToInt()
+                // Max out height
+                val halfWidth = displayWidth / 2
+                val surfaceWidth = displayHeight * aspectRatio
+                val newLeft: Float = halfWidth - (surfaceWidth / 2)
+                val newRight: Float = halfWidth + (surfaceWidth / 2)
+                super.onMeasure(
+                    MeasureSpec.makeMeasureSpec(
+                        newRight.toInt() - newLeft.toInt(),
+                        MeasureSpec.EXACTLY
+                    ),
+                    heightMeasureSpec
+                )
+                return
             }
-            val left = (width - newWidth) / 2
-            val top = (height - newHeight) / 2
-            setLeftTopRightBottom(left, top, left + newWidth, top + newHeight)
-        } else {
-            setLeftTopRightBottom(0, 0, width, height)
         }
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
     }
 }