Add button to flip to rear camera, still in mirror mode.

app/build.gradle

@@ -34,15 +34,15 @@ android {
 }
 
 dependencies {
-    implementation 'androidx.camera:camera-view:1.3.1'
-    implementation 'androidx.appcompat:appcompat:1.6.1'
-    implementation 'com.google.android.material:material:1.11.0'
-    implementation 'androidx.camera:camera-lifecycle:1.3.1'
-    implementation "androidx.camera:camera-camera2:1.3.1"
-    implementation 'com.google.android.material:material:1.11.0'
-    implementation 'androidx.compose.material3:material3:1.1.2'
-    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    implementation 'androidx.camera:camera-view:1.4.1'
+    implementation 'androidx.appcompat:appcompat:1.7.0'
+    implementation 'com.google.android.material:material:1.12.0'
+    implementation 'androidx.camera:camera-lifecycle:1.4.1'
+    implementation 'androidx.camera:camera-camera2:1.4.1'
+    implementation 'com.google.android.material:material:1.12.0'
+    implementation 'androidx.compose.material3:material3:1.3.1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.2.0'
     testImplementation 'junit:junit:4.13.2'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.2.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.6.1'
 }

app/src/main/java/com/polar/mirror/FreezeController.java

@@ -38,6 +38,7 @@ public class FreezeController {
     private final Context mContext;
     private boolean mCameraFrozen = false;
     private final FloatingActionButton mFreezeButton;
+    private int selectedCamera = CameraSelector.LENS_FACING_FRONT;
 
     FreezeController(Context context, FloatingActionButton freezeButton, PreviewView cameraView,
                      ImageView freezeView){
@@ -57,25 +58,27 @@ public class FreezeController {
      */
     public void onCameraInitialized(@NonNull ProcessCameraProvider provider, LifecycleOwner lcOwner){
         CameraSelector cameraSelector = new CameraSelector.Builder()
-                .requireLensFacing(CameraSelector.LENS_FACING_FRONT)
+                .requireLensFacing(selectedCamera)
                 .build();
         provider.bindToLifecycle(lcOwner, cameraSelector, mImageCapture);
         Log.d(TAG, "completed onCameraInitialized");
     }
 
     private int getRotationAngleFromOrientation(int orientation){
-        int angle = 270;
+        int angle;
+        boolean rearCamera = getSelectedCamera() == CameraSelector.LENS_FACING_BACK;
         switch (orientation) {
             case Surface.ROTATION_90:
                 angle = 0;
                 break;
             case Surface.ROTATION_180:
-                angle = 90;
+                angle = rearCamera ? 270 : 90;
                 break;
             case Surface.ROTATION_270:
                 angle = 180;
                 break;
             default:
+                angle = rearCamera ? 90 : 270;
                 break;
         }
         return angle;
@@ -151,4 +154,17 @@ public void toggleFreeze(){
             mCameraFrozen = true;
         }
     }
+
+    public void toggleSelectedCamera() {
+        if (selectedCamera == CameraSelector.LENS_FACING_FRONT) {
+            selectedCamera = CameraSelector.LENS_FACING_BACK;
+        } else {
+            selectedCamera = CameraSelector.LENS_FACING_FRONT;
+        }
+    }
+
+    public int getSelectedCamera() {
+        return selectedCamera;
+    }
+
 }

app/src/main/java/com/polar/mirror/MainActivity.java

@@ -4,6 +4,7 @@
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.camera.core.CameraSelector;
+import androidx.camera.core.MirrorMode;
 import androidx.camera.core.Preview;
 import androidx.camera.view.PreviewView;
 import androidx.camera.lifecycle.ProcessCameraProvider;
@@ -14,6 +15,7 @@
 import android.os.Build;
 import android.os.Bundle;
 import android.util.Log;
+import android.view.Surface;
 import android.view.View;
 import android.widget.ImageView;
 import android.widget.Toast;
@@ -33,6 +35,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
     private final static String TAG = "MainActivity";
     private Preview mPreview = null;
     private static final int CAMERA_PERMISSION_CODE = 858;
+    private ProcessCameraProvider mCameraProvider = null;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -125,12 +128,15 @@ private void setupFloatingButtons(){
         FloatingActionButton exitButton = findViewById(R.id.exit_button);
         FloatingActionButton freezeButton = findViewById(R.id.freeze_button);
         FloatingActionButton lowLightButton = findViewById(R.id.low_light_button);
+        FloatingActionButton cameraChooserButton = findViewById(R.id.camera_chooser_button);
         exitButton.setClickable(true);
         exitButton.setOnClickListener(this);
         freezeButton.setClickable(true);
         freezeButton.setOnClickListener(this);
         lowLightButton.setClickable(true);
         lowLightButton.setOnClickListener(this);
+        cameraChooserButton.setClickable(true);
+        cameraChooserButton.setOnClickListener(this);
     }
 
     /**
@@ -147,17 +153,22 @@ private void hideSystemUi(){
      * @throws ExecutionException in case of task errors
      * @throws InterruptedException in case of thread interruption
      */
+    @androidx.annotation.OptIn(markerClass = androidx.camera.core.ExperimentalMirrorMode.class)
     private void startCamera() throws ExecutionException, InterruptedException {
-        mPreview = new Preview.Builder().build();
+        mCameraView.setImplementationMode(PreviewView.ImplementationMode.COMPATIBLE);
+        mCameraView.addOnLayoutChangeListener(this::onLayoutChange);
+        mPreview = new Preview.Builder()
+                .setMirrorMode(MirrorMode.MIRROR_MODE_ON)
+                .build();
         mPreview.setSurfaceProvider(mCameraView.getSurfaceProvider());
-        ProcessCameraProvider cameraProvider = ProcessCameraProvider.getInstance(this).get();
+        mCameraProvider = ProcessCameraProvider.getInstance(this).get();
         try {
             CameraSelector cameraSelector = new CameraSelector.Builder()
-                    .requireLensFacing(CameraSelector.LENS_FACING_FRONT)
+                    .requireLensFacing(mFreezeController.getSelectedCamera())
                     .build();
-            cameraProvider.unbindAll();
-            cameraProvider.bindToLifecycle(this, cameraSelector, mPreview);
-            mFreezeController.onCameraInitialized(cameraProvider, this);
+            mCameraProvider.unbindAll();
+            mCameraProvider.bindToLifecycle(this, cameraSelector, mPreview);
+            mFreezeController.onCameraInitialized(mCameraProvider, this);
         } catch (Exception e) {
             e.printStackTrace();
         }
@@ -178,6 +189,19 @@ private void toggleLowLightMode(){
         mLowLightController.toggleLowLightMode();
     }
 
+    /**
+     * Toggles front/rear camera
+     */
+    private void toggleSelectedCamera(){
+        mFreezeController.toggleSelectedCamera();
+        CameraSelector cameraSelector = new CameraSelector.Builder()
+                .requireLensFacing(mFreezeController.getSelectedCamera())
+                .build();
+        mCameraProvider.unbindAll();
+        mCameraProvider.bindToLifecycle(this, cameraSelector, mPreview);
+        mFreezeController.onCameraInitialized(mCameraProvider, this);
+    }
+
     @Override
     public void onClick(@NonNull View v) {
         int viewId = v.getId();
@@ -188,6 +212,8 @@ public void onClick(@NonNull View v) {
             toggleCameraFreeze();
         } else if(viewId == R.id.low_light_button){
             toggleLowLightMode();
+        } else if(viewId == R.id.camera_chooser_button){
+            toggleSelectedCamera();
         } else {
             Log.w(TAG, "Unknown id of view: " + viewId);
         }
@@ -218,5 +244,28 @@ public void onRequestPermissionsResult(int requestCode, @NonNull String[] permis
             }
         }
     }
-}
 
+    private void onLayoutChange(View view, int i, int i1, int i2, int i3, int i4, int i5, int i6, int i7) {
+        int orientation = mCameraView.getDisplay().getRotation();
+        if (mFreezeController.getSelectedCamera() == CameraSelector.LENS_FACING_BACK) {
+            int o;
+            switch (orientation) {
+                case Surface.ROTATION_0:
+                    o = Surface.ROTATION_0;
+                    break;
+                case Surface.ROTATION_90:
+                    o = Surface.ROTATION_270;
+                    break;
+                case Surface.ROTATION_180:
+                    o = Surface.ROTATION_180;
+                    break;
+                default: // Surface.ROTATION_270:
+                    o = Surface.ROTATION_90;
+                    break;
+            }
+            mPreview.setTargetRotation(o);
+        } else {
+            mPreview.setTargetRotation(orientation);
+        }
+    }
+}

app/src/main/res/layout/action_panel.xml

@@ -85,6 +85,30 @@
 
         </LinearLayout>
 
+        <!-- Wrapper for Low-level light Button and Label -->
+        <LinearLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:orientation="vertical"
+            android:layout_margin="16dp">
+
+            <com.google.android.material.floatingactionbutton.FloatingActionButton
+                android:id="@+id/camera_chooser_button"
+                style="@style/Widget.Mirror.FloatingActionButton"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:contentDescription="@string/flip_camera"
+                android:src="@android:drawable/ic_menu_rotate" />
+
+            <TextView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="center"
+                android:text="@string/flip_camera"
+                android:textColor="@color/white" />
+
+        </LinearLayout>
+
     </LinearLayout>
 
 </RelativeLayout>

app/src/main/res/values-pl/strings.xml

@@ -9,4 +9,5 @@
     <string name="no_camera_permissions">Dostęp do kamery nie został przyznany. Użyj aplikacji Ustawienia, aby pryznać dostęp</string>
     <string name="low_light">Tryb ciemności</string>
     <string name="low_light_mode_overlay">Overlay trybu ciemności</string>
+    <string name="flip_camera">Obrót</string>
 </resources>

app/src/main/res/values-uk/strings.xml

@@ -8,4 +8,5 @@
     <string name="no_camera_permissions">Доступ до камери не надано. Скористуйтесь застосунком Налаштування, аби надати доступ вручну</string>
     <string name="low_light">Режим пітьми</string>
     <string name="low_light_mode_overlay">Оверлей режим пітьми</string>
+    <string name="flip_camera">Фліп</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -8,4 +8,5 @@
     <string name="no_camera_permissions">Camera permissions was not granted. Use Settings app to grant it.</string>
     <string name="low_light">Dark mode</string>
     <string name="low_light_mode_overlay">Low light mode overlay</string>
+    <string name="flip_camera">Flip</string>
 </resources>

build.gradle

@@ -1,4 +1,4 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
-id 'com.android.application' version '8.3.1' apply false
+id 'com.android.application' version '8.7.3' apply false
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,11 @@
 #Tue Oct 24 12:02:08 CEST 2023
+# suppress inspection "Annotator"
 distributionBase=GRADLE_USER_HOME
+# suppress inspection "Annotator"
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+# suppress inspection "Annotator"
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
+# suppress inspection "Annotator"
 zipStoreBase=GRADLE_USER_HOME
+# suppress inspection "Annotator"
 zipStorePath=wrapper/dists