[Flashlight] Added On-Screen Flashlight support

Added support for an on-screen flashlight, which is basically
a fragment showing a pre-defined color on a full screen canvas
with the option to adjust the brightness of the screen.

app/src/main/AndroidManifest.xml

@@ -72,6 +72,8 @@
             android:exported="true">
             <intent-filter>
                 <action android:name="androidx.car.app.action.SERVICE" />
+                <action android:name="androidx.car.app.CarAppService"/>
+                <category android:name="androidx.car.app.category.MESSAGING"/>
             </intent-filter>
         </service>
 

app/src/main/java/com/aldo/apps/familyhelpers/FlashlightActivity.java

@@ -1,7 +1,13 @@
 package com.aldo.apps.familyhelpers;
 
+import androidx.annotation.ColorRes;
+import androidx.annotation.IdRes;
+import androidx.annotation.LayoutRes;
 import androidx.annotation.RequiresApi;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.view.WindowCompat;
+import androidx.core.view.WindowInsetsCompat;
+import androidx.core.view.WindowInsetsControllerCompat;
 
 import android.graphics.PorterDuff;
 import android.os.Build;
@@ -11,6 +17,7 @@ import android.view.View;
 import android.widget.ImageView;
 
 import com.aldo.apps.familyhelpers.ui.FlashLightLevelShifter;
+import com.aldo.apps.familyhelpers.utils.DisplayBrightnessController;
 import com.aldo.apps.familyhelpers.utils.FlashlightHelper;
 import com.google.android.material.button.MaterialButton;
 
@@ -40,13 +47,34 @@ public class FlashlightActivity extends AppCompatActivity {
      */
     private FlashlightHelper mFlashlightHelper;
 
+    /**
+     * The fullscreen view that acts as the on-screen flashlight.
+     */
+    private View mOnScreenFlashlight;
+
+    /**
+     * The {@link WindowInsetsControllerCompat} to control fullscreen mode.
+     */
+    private WindowInsetsControllerCompat mFullscreenController;
+
+    private DisplayBrightnessController mBrightnessController;
+
     @RequiresApi(api = Build.VERSION_CODES.TIRAMISU)
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_flashlight);
+        mFullscreenController = WindowCompat.getInsetsController(getWindow(),
+                getWindow().getDecorView());
+        mBrightnessController = new DisplayBrightnessController(findViewById(R.id.tv_current_brightness), this);
 
         initButtons();
+        mOnScreenFlashlight = findViewById(R.id.on_screen_flashlight_view);
+        mOnScreenFlashlight.setOnClickListener(v -> {
+            mOnScreenFlashlight.setVisibility(View.GONE);
+            mFullscreenController.hide(WindowInsetsCompat.Type.systemBars());
+        });
+        mBrightnessController.setupSwipeGesture(mOnScreenFlashlight);
         mLightOnIndicator = findViewById(R.id.flashlight_status_indicator);
         mFlashlightLevelShifter = findViewById(R.id.flashlight_level_shifter);
         mFlashlightHelper = new FlashlightHelper(this);
@@ -81,6 +109,13 @@ public class FlashlightActivity extends AppCompatActivity {
             mFlashlightLevelShifter.setProgress(maxBrightness);
             mFlashlightHelper.setFlashlightBrightness(maxBrightness);
         });
+        initializeColorButton(R.id.btn_onscreen_flashlight_red, R.color.flashlight_onscreen_red, false);
+        initializeColorButton(R.id.btn_onscreen_flashlight_orange, R.color.flashlight_onscreen_orange, false);
+        initializeColorButton(R.id.btn_onscreen_flashlight_blue, R.color.flashlight_onscreen_blue, false);
+        initializeColorButton(R.id.btn_onscreen_flashlight_green, R.color.flashlight_onscreen_green, false);
+        initializeColorButton(R.id.btn_onscreen_flashlight_gray, R.color.flashlight_onscreen_gray, false);
+        initializeColorButton(R.id.btn_onscreen_flashlight_white, R.color.flashlight_onscreen_white, true);
+        initializeColorButton(R.id.btn_onscreen_flashlight_yellow, R.color.flashlight_onscreen_yellow, true);
     }
 
     @Override
@@ -106,6 +141,25 @@ public class FlashlightActivity extends AppCompatActivity {
         }
     }
 
+    /**
+     * Helper method to initialize a color button by applying the proper color to the surface and
+     * the textview.
+     *
+     * @param btnId   The ID of the button to initialize.
+     * @param colorId The id of the color top apply.
+     * @param isLight True if it is a light color, false otherwise.
+     */
+    private void initializeColorButton(@IdRes final int btnId,
+                                       @ColorRes final int colorId,
+                                       final boolean isLight) {
+        findViewById(btnId).setOnClickListener(v -> {
+            mOnScreenFlashlight.setBackgroundColor(getColor(colorId));
+            mOnScreenFlashlight.setVisibility(View.VISIBLE);
+            mFullscreenController.hide(WindowInsetsCompat.Type.systemBars());
+            mBrightnessController.setLightModeColor(isLight);
+        });
+    }
+
     /**
      * Helper method to print any potential errors while subscribing to the current status observable.
      *

app/src/main/java/com/aldo/apps/familyhelpers/utils/DisplayBrightnessController.java

@@ -0,0 +1,277 @@
+package com.aldo.apps.familyhelpers.utils;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.util.Log;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.WindowManager;
+import android.widget.TextView;
+
+import androidx.annotation.ColorRes;
+import androidx.annotation.IntegerRes;
+import androidx.annotation.NonNull;
+import androidx.annotation.StringRes;
+import androidx.preference.PreferenceManager;
+
+import com.aldo.apps.familyhelpers.R;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Utility class to control the display brightness of an Android activity using swipe gestures.
+ * <p>
+ * This class allows users to adjust the screen brightness by swiping up or down on a specified view.
+ * It also displays the current brightness level in a TextView.  The brightness adjustment
+ * is controlled by user preferences for sensitivity and step size.
+ */
+public class DisplayBrightnessController {
+
+    /**
+     * Tag for debugging purposes.
+     */
+    private static final String TAG = "DisplayBrightnessController";
+
+    /**
+     * Maximum allowed display brightness value.
+     */
+    private static final int DISPLAY_BRIGHTNESS_MAX_VALUE = 255;
+
+    /**
+     * Minimum allowed display brightness value.
+     */
+    private static final int DISPLAY_BRIGHTNESS_MIN_VALUE = 1;
+
+    /**
+     * Base value for swipe sensitivity calculation.
+     */
+    private static final int SWIPE_SENSITIVITY_BASE = 10;
+
+    /**
+     * TextView to display the current brightness level.
+     */
+    private final TextView mCurrentBrightnessText;
+
+    /**
+     * {@link WeakReference} to the {@link Context} of the application.
+     */
+    private final WeakReference<Context> mContextRef;
+
+    /**
+     * {@link WeakReference} to the {@link Activity} whose screen brightness is being controlled.
+     */
+    private final WeakReference<Activity> mActivityRef;
+
+    /**
+     * SharedPreferences instance for accessing user preferences.
+     */
+    private final SharedPreferences mPreferences;
+
+    /**
+     * Current brightness level.
+     */
+    private int mCurrentBrightness = 125;
+
+    /**
+     * Initial Y coordinate of the touch event for swipe detection.
+     */
+    private float mInitialY;
+
+    /**
+     * Constructor for DisplayBrightnessController.
+     *
+     * @param textView The TextView used to display the current brightness level.
+     * @param activity The Activity whose screen brightness will be controlled.
+     * The Activity's application context is used for SharedPreferences.
+     */
+    public DisplayBrightnessController(final TextView textView, final Activity activity) {
+        mCurrentBrightnessText = textView;
+        mActivityRef = new WeakReference<>(activity);
+        mContextRef = new WeakReference<>(activity.getApplicationContext());
+        mPreferences = PreferenceManager.getDefaultSharedPreferences(activity.getApplicationContext());
+    }
+
+    /**
+     * Sets up a swipe gesture listener on the provided view to control screen brightness.
+     * <p>
+     * The gesture listener detects vertical swipes.  Swiping up increases brightness, and swiping
+     * down decreases it.  The sensitivity of the swipe and the amount of brightness change
+     * per swipe are determined by user preferences.  A single tap hides or shows the brightness text.
+     *
+     * @param view The view on which the swipe gesture should be detected.
+     */
+    public void setupSwipeGesture(final View view) {
+        final Context context = mContextRef.get();
+        if (context == null) {
+            Log.e(TAG, "setupSwipeGesture: Context null, cannot continue");
+            return;
+        }
+        final GestureDetector gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
+            @Override
+            public boolean onDown(@NonNull final MotionEvent e) {
+                mInitialY = e.getY();
+                return true;
+            }
+
+            @Override
+            public boolean onScroll(final MotionEvent e1,
+                                    @NonNull final MotionEvent e2,
+                                    final float distanceX,
+                                    final float distanceY) {
+                final float diffY = e2.getY() - mInitialY;
+                mInitialY = e2.getY();
+
+                // Get sensitivity from preferences.  Fall back to default if not found.
+                final float sensitivityValue = (float) SWIPE_SENSITIVITY_BASE / mPreferences.getInt(
+                        getString(R.string.pref_key_on_screen_flashlight_sensitivity),
+                        getInt(R.integer.pref_on_screen_flashlight_sensitivity_def));
+
+                Log.d(TAG, "onScroll: Started with Sensitivity = [" + sensitivityValue + "]");
+                if (Math.abs(diffY) > sensitivityValue) {
+                    Log.d(TAG, "onScroll: Relevant swipe detected");
+                    mCurrentBrightnessText.setVisibility(View.VISIBLE);
+                    adjustBrightness(diffY < 0);
+                }
+                return true;
+            }
+
+            @Override
+            public boolean onSingleTapUp(@NonNull final MotionEvent e) {
+                Log.d(TAG, "onSingleTapUp: Tap detected, set visibility to GONE");
+                // Toggle visibility of the brightness text on single tap
+                if (View.VISIBLE == mCurrentBrightnessText.getVisibility()) {
+                    mCurrentBrightnessText.setVisibility(View.GONE);
+                } else {
+                    view.setVisibility(View.GONE); // added to hide view.
+                }
+                return true; // Indicate that this tap is handled
+            }
+        });
+
+        // Set the touch listener on the view to use the gesture detector
+        view.setOnTouchListener((v, event) -> gestureDetector.onTouchEvent(event));
+    }
+
+    /**
+     * Adjusts the screen brightness based on the swipe direction.
+     * <p>
+     * This method reads the brightness step size from preferences and changes the brightness
+     * by that amount.  It also updates the brightness TextView.
+     *
+     * @param increase True to increase brightness, false to decrease.
+     */
+    private void adjustBrightness(final boolean increase) {
+        Log.d(TAG, "adjustBrightness() called with: increase = [" + increase + "]");
+        // Get step size from preferences.  Fall back to default if not found.
+        final int stepSize = mPreferences.getInt(
+                getString(R.string.pref_key_on_screen_flashlight_step_size),
+                getInt(R.integer.pref_on_screen_flashlight_step_size_def));
+
+        Log.d(TAG, "adjustBrightness: Called with StepSize = [" + stepSize
+                + "] and current brightness = [" + mCurrentBrightness + "]");
+        // Check if current brightness is within valid bounds
+        if (DISPLAY_BRIGHTNESS_MIN_VALUE <= mCurrentBrightness
+                && mCurrentBrightness <= DISPLAY_BRIGHTNESS_MAX_VALUE) {
+            Log.d(TAG, "adjustBrightness: Called within valid range");
+            final int newBrightness;
+            if (increase) {
+                newBrightness = Math.min(DISPLAY_BRIGHTNESS_MAX_VALUE, mCurrentBrightness + stepSize);
+            } else {
+                newBrightness = Math.max(DISPLAY_BRIGHTNESS_MIN_VALUE, mCurrentBrightness - stepSize);
+            }
+            setBrightness(newBrightness);
+            updateBrightnessText(newBrightness);
+            mCurrentBrightness = newBrightness;
+        }
+    }
+
+    /**
+     * Sets the screen brightness of the activity.
+     *
+     * @param brightness The new brightness value (0-255).
+     */
+    private void setBrightness(final int brightness) {
+        final Activity activity = mActivityRef.get();
+        if (activity == null) {
+            Log.e(TAG, "setBrightness: Activity is null, cannot continue");
+            return;
+        }
+        Log.d(TAG, "setBrightness: Setting the screen brightness to [" + brightness + "]");
+        final WindowManager.LayoutParams layout = activity.getWindow().getAttributes();
+        layout.screenBrightness = brightness / (float) DISPLAY_BRIGHTNESS_MAX_VALUE;
+        activity.getWindow().setAttributes(layout);
+    }
+
+    /**
+     * Updates the brightness TextView with the current brightness value.
+     *
+     * @param brightnessValue The current brightness value.
+     */
+    private void updateBrightnessText(final int brightnessValue) {
+        Log.d(TAG, "updateBrightnessText() called with: brightnessValue = [" + brightnessValue + "]");
+        mCurrentBrightnessText.setText(String.format(
+                getString(R.string.flashlight_on_screen_brightness_base_text) ,brightnessValue));
+    }
+
+    /**
+     * Helper method to set the text color adjustable to either light of dark colors to be visible
+     * on either surface.
+     *
+     * @param isLightModeColor true if the color is a light color, false otherwise.
+     */
+    public void setLightModeColor(final boolean isLightModeColor) {
+        Log.d(TAG, "setLightModeColor() called with: isLightModeColor = [" + isLightModeColor + "]");
+        if (isLightModeColor) {
+            mCurrentBrightnessText.setTextColor(getColor(R.color.black));
+        } else {
+            mCurrentBrightnessText.setTextColor(getColor(R.color.white));
+        }
+    }
+
+    /**
+     * Helper method to get a string resource from the activity.
+     *
+     * @param textId The resource ID of the string.
+     * @return The string value.
+     */
+    private String getString(@StringRes final int textId) {
+        final Activity activity = mActivityRef.get();
+        if (activity == null) {
+            Log.e(TAG, "getString: Activity is null, cannot continue");
+            return "";
+        }
+        return activity.getString(textId);
+    }
+
+    /**
+     * Helper method to get a color resource from the activity.
+     *
+     * @param colorId The resource ID of the color.
+     * @return The color value.
+     */
+    private int getColor(@ColorRes final int colorId) {
+        final Activity activity = mActivityRef.get();
+        if (activity == null) {
+            Log.e(TAG, "getInt: Activity is null, cannot continue");
+            return 0;
+        }
+        return activity.getColor(colorId);
+    }
+
+    /**
+     * Helper method to get an integer resource from the activity.
+     *
+     * @param intId The resource ID of the integer.
+     * @return The integer value.
+     */
+    private int getInt(@IntegerRes final int intId) {
+        final Activity activity = mActivityRef.get();
+        if (activity == null) {
+            Log.e(TAG, "getInt: Activity is null, cannot continue");
+            return 0;
+        }
+        return activity.getResources().getInteger(intId);
+    }
+}

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

@@ -6,6 +6,115 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     tools:context=".FlashlightActivity">
 
+    <TextView
+        android:id="@+id/tv_onscreen_flashlight"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        android:text="@string/flashlight_on_screen_title"
+        android:textSize="@dimen/flashlight_category_header_text_size"
+        android:layout_marginStart="@dimen/flashlight_category_header_margin_start"
+        android:layout_marginTop="@dimen/flashlight_category_header_margin_top"
+        android:layout_marginBottom="@dimen/flashlight_category_header_margin_bottom"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_red"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:backgroundTint="@color/flashlight_onscreen_red"
+        android:textColor="@color/white"
+        android:text="@string/flashlight_on_screen_color_red"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/tv_onscreen_flashlight"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_blue"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:text="@string/flashlight_on_screen_color_blue"
+        android:backgroundTint="@color/flashlight_onscreen_blue"
+        android:textColor="@color/white"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_red"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_green"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:text="@string/flashlight_on_screen_color_green"
+        android:backgroundTint="@color/flashlight_onscreen_green"
+        android:textColor="@color/white"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_blue"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_orange"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:backgroundTint="@color/flashlight_onscreen_orange"
+        android:textColor="@color/white"
+        android:text="@string/flashlight_on_screen_color_orange"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_green"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_yellow"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:backgroundTint="@color/flashlight_onscreen_yellow"
+        android:textColor="@color/black"
+        android:text="@string/flashlight_on_screen_color_yellow"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_orange"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_gray"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:backgroundTint="@color/flashlight_onscreen_gray"
+        android:textColor="@color/white"
+        android:text="@string/flashlight_on_screen_color_gray"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_yellow"/>
+
+    <Button
+        android:id="@+id/btn_onscreen_flashlight_white"
+        android:layout_width="0dp"
+        android:layout_height="@dimen/flashlight_onscreen_button_layout_height"
+        app:layout_constrainedWidth="true"
+        app:layout_constraintStart_toStartOf="parent"
+        android:backgroundTint="@color/flashlight_onscreen_white"
+        android:textColor="@color/black"
+        android:text="@string/flashlight_on_screen_color_white"
+        android:layout_marginHorizontal="@dimen/flashlight_onscreen_button_margin_horizontal"
+        android:layout_marginTop="@dimen/flashlight_onscreen_button_margin_top"
+        app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
+        app:layout_constraintTop_toBottomOf="@id/btn_onscreen_flashlight_gray"/>
+
     <ImageView
         android:id="@+id/flashlight_status_indicator"
         android:src="@drawable/ic_flashlight_off"
@@ -71,4 +180,30 @@
         app:layout_constraintEnd_toStartOf="@id/flashlight_level_shifter"
         android:text="@string/flashlight_set_max_level"/>
 
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/flashlight_camera_title"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintBottom_toTopOf="@id/btn_flashlight_maximum"
+        android:textSize="@dimen/flashlight_category_header_text_size"
+        android:layout_marginStart="@dimen/flashlight_category_header_margin_start"
+        android:layout_marginTop="@dimen/flashlight_category_header_margin_top"
+        android:layout_marginBottom="@dimen/flashlight_category_header_margin_bottom"/>
+
+    <View
+        android:id="@+id/on_screen_flashlight_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:visibility="gone"/>
+
+    <TextView
+        android:id="@+id/tv_current_brightness"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        android:layout_margin="45dp"
+        android:textSize="45sp"/>
+
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -24,10 +24,19 @@
     <string name="share_location_background_permission_rationale">Um deinen Standort auch zu teilen, während die App im Hintergrund ist, bitte wähle die \"Immer\" Option.</string>
     <string name="title_activity_settings">Einstellungen</string>
     <string name="title_flashlight">Taschenlampe</string>
+    <string name="flashlight_camera_title">Taschenlampe Rückseite</string>
     <string name="flashlight_camera_rationale">Um auf die Taschenlampe zugreifen zu können, wird die Kamera Berechtigung gebraucht.</string>
     <string name="flashlight_set_min_level">Aktiviere die Taschenlampe auf minimaler Helligkeit</string>
     <string name="flashlight_set_med_level">Aktiviere die Taschenlampe auf mittlerer Helligkeit</string>
     <string name="flashlight_set_max_level">Aktiviere die Taschenlampe auf maximaler Helligkeit</string>
+    <string name="flashlight_on_screen_color_red">Roter Bildschirm</string>
+    <string name="flashlight_on_screen_color_blue">Blauer Bildschirm</string>
+    <string name="flashlight_on_screen_color_green">Grüner Bildschirm</string>
+    <string name="flashlight_on_screen_color_orange">Orangener Bildschirm</string>
+    <string name="flashlight_on_screen_color_yellow">Gelber Bildschirm</string>
+    <string name="flashlight_on_screen_color_white">Weißer Bildschirm</string>
+    <string name="flashlight_on_screen_color_gray">Grauer Bildschirm</string>
+    <string name="flashlight_on_screen_brightness_base_text">Helligkeit: %d</string>
     <string name="title_settings">Einstellungen</string>
     <string name="pref_share_location_header">Standort teilen</string>
     <string name="pref_share_location_freq_title">Standort Update Frequenz</string>
@@ -43,4 +52,16 @@
     <string name="pref_flashlight_store_brightness_title">Helligkeit speichern</string>
     <string name="pref_flashlight_store_brightness_summary_off">Wenn die Taschenlampe gestartet wird, wird die unten gesetzte Standard Helligkeit genommen.</string>
     <string name="pref_flashlight_store_brightness_summary_on">Die zuletzt gewählte Helligkeit wird gespeichert und beim neustart angewandt</string>
+    <string name="pref_on_screen_flashlight_sensitivity_title">Empfindlichkeit Swipe</string>
+    <string name="pref_on_screen_flashlight_sensitivity_summary">Die Empfindlichkeit mit der auf Swipe Gesten reagiert wird</string>
+    <string name="pref_on_screen_flashlight_step_size_title">Schrittgröße</string>
+    <string name="pref_on_screen_flashlight_step_size_summary">Die Größe der Schritte mit der die Helligkeit verändert werden soll</string>
+    <string name="android_auto_message_currently_sharing">Du teilst bereits deinen Standort mit der Familie, willst du aufhören?</string>
+    <string name="android_auto_message_not_sharing">Android Auto wurde gestartet, willst du deinen Standort teilen?</string>
+    <string name="android_auto_actions_start_sharing">Ja, fang an zu teilen</string>
+    <string name="android_auto_actions_stop_sharing">Ja, hör auf zu teilen</string>
+    <string name="android_auto_share_location_start">Start</string>
+    <string name="android_auto_share_location_start_desc">Anfangen den Standort zu teilen</string>
+    <string name="android_auto_share_location_stop">Stop</string>
+    <string name="android_auto_share_location_stop_desc">Aufhören den Standort zu teilen</string>
 </resources>

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

@@ -24,10 +24,19 @@
     <string name="share_location_background_permission_rationale">In order to share your position also while in the background, please grant the always permission</string>
     <string name="title_activity_settings">Settings</string>
     <string name="title_flashlight">Flashlight</string>
+    <string name="flashlight_camera_title">Camera Flashlight</string>
     <string name="flashlight_camera_rationale">In order to have access to the flashlight, you need to grant the Camera permission.</string>
     <string name="flashlight_set_min_level">Activate flashlight on minimum brightness</string>
     <string name="flashlight_set_med_level">Activate flashlight on medium brightness</string>
     <string name="flashlight_set_max_level">Activate flashlight on maximum brightness</string>
+    <string name="flashlight_on_screen_color_red">Red On-Screen</string>
+    <string name="flashlight_on_screen_color_blue">Blue On-Screen</string>
+    <string name="flashlight_on_screen_color_green">Green On-Screen</string>
+    <string name="flashlight_on_screen_color_orange">Orange On-Screen</string>
+    <string name="flashlight_on_screen_color_yellow">Yellow On-Screen</string>
+    <string name="flashlight_on_screen_color_white">White On-Screen</string>
+    <string name="flashlight_on_screen_color_gray">Gray On-Screen</string>
+    <string name="flashlight_on_screen_brightness_base_text">Brightness: %d</string>
     <string name="title_settings">Settings</string>
     <string name="pref_share_location_header">Share Location</string>
     <string name="pref_share_location_freq_title">Location Update frequency</string>
@@ -43,4 +52,16 @@
     <string name="pref_flashlight_store_brightness_title">Remember Brightness</string>
     <string name="pref_flashlight_store_brightness_summary_off">The default brightness selected below, will be selected every time you start the flashlight</string>
     <string name="pref_flashlight_store_brightness_summary_on">The last selected brightness will be remembered when starting the flashlight again</string>
+    <string name="pref_on_screen_flashlight_sensitivity_title">Swipe Sensitivity</string>
+    <string name="pref_on_screen_flashlight_sensitivity_summary">The sensitivity of the swipe gesture on the on-screen flashlight</string>
+    <string name="pref_on_screen_flashlight_step_size_title">Swipe Step Size</string>
+    <string name="pref_on_screen_flashlight_step_size_summary">The change step size of the on-screen swipe gesture</string>
+    <string name="android_auto_message_currently_sharing">You are already sharing your location with your family, do you wanna stop?</string>
+    <string name="android_auto_message_not_sharing">Android Auto start has been detected, do you wanna share your location?</string>
+    <string name="android_auto_actions_start_sharing">Yes, start to share</string>
+    <string name="android_auto_actions_stop_sharing">Yes, stop sharing</string>
+    <string name="android_auto_share_location_start">Start</string>
+    <string name="android_auto_share_location_start_desc">Start to share location</string>
+    <string name="android_auto_share_location_stop">Stop</string>
+    <string name="android_auto_share_location_stop_desc">Stop to share the location</string>
 </resources>

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

@@ -9,9 +9,17 @@
     <color name="helperGroupTileBorder_NightMode">#00796B</color>
     <color name="light_blue_400">#FF29B6F6</color>
     <color name="light_blue_600">#FF039BE5</color>
-    <color name="gray_400">#FFBDBDBD</color>
+    <color name="gray_400">#EFE7E7</color>
     <color name="gray_600">#FF757575</color>
 
+    <color name="flashlight_onscreen_red">#C62828</color>
+    <color name="flashlight_onscreen_blue">#283593</color>
+    <color name="flashlight_onscreen_green">#00695C</color>
+    <color name="flashlight_onscreen_orange">#D84315</color>
+    <color name="flashlight_onscreen_yellow">#FF8F00</color>
+    <color name="flashlight_onscreen_white">#D3C5C5</color>
+    <color name="flashlight_onscreen_gray">#616161</color>
+
     <!-- Auto-Generated Colors -->
     <color name="md_theme_primary">#904A44</color>
     <color name="md_theme_onPrimary">#FFFFFF</color>

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

@@ -33,6 +33,13 @@
     <dimen name="flashlight_activity_margin_bottom">25dp</dimen>
     <dimen name="flashlight_material_button_margin_start">20dp</dimen>
     <dimen name="flashlight_material_button_margin_end">30dp</dimen>
+    <dimen name="flashlight_onscreen_button_layout_height">50dp</dimen>
+    <dimen name="flashlight_onscreen_button_margin_top">10dp</dimen>
+    <dimen name="flashlight_onscreen_button_margin_horizontal">35dp</dimen>
+    <dimen name="flashlight_category_header_text_size">20sp</dimen>
+    <dimen name="flashlight_category_header_margin_start">10dp</dimen>
+    <dimen name="flashlight_category_header_margin_top">25dp</dimen>
+    <dimen name="flashlight_category_header_margin_bottom">15dp</dimen>
     <integer name="flashlight_material_button_lines">3</integer>
     <integer name="flashlight_material_button_max_lines">3</integer>
 
@@ -45,4 +52,12 @@
     <integer name="pref_flashlight_def_brightness_max">100</integer>
     <integer name="pref_flashlight_def_brightness_default">75</integer>
     <integer name="pref_flashlight_def_brightness_increment">1</integer>
+    <integer name="pref_on_screen_flashlight_sensitivity_min">1</integer>
+    <integer name="pref_on_screen_flashlight_sensitivity_max">100</integer>
+    <integer name="pref_on_screen_flashlight_sensitivity_def">50</integer>
+    <integer name="pref_on_screen_flashlight_sensitivity_increment">10</integer>
+    <integer name="pref_on_screen_flashlight_step_size_min">1</integer>
+    <integer name="pref_on_screen_flashlight_step_size_max">25</integer>
+    <integer name="pref_on_screen_flashlight_step_size_def">1</integer>
+    <integer name="pref_on_screen_flashlight_step_size_increment">1</integer>
 </resources>

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

@@ -35,10 +35,20 @@
 
     <!-- Flashlight Functionality Strings -->
     <string name="title_flashlight">Flashlight</string>
+    <string name="flashlight_camera_title">Camera Flashlight</string>
     <string name="flashlight_camera_rationale">In order to have access to the flashlight, you need to grant the Camera permission.</string>
     <string name="flashlight_set_min_level">Activate flashlight on minimum brightness</string>
     <string name="flashlight_set_med_level">Activate flashlight on medium brightness</string>
     <string name="flashlight_set_max_level">Activate flashlight on maximum brightness</string>
+    <string name="flashlight_on_screen_title">On-Screen Flashlight</string>
+    <string name="flashlight_on_screen_color_red">Red On-Screen</string>
+    <string name="flashlight_on_screen_color_blue">Blue On-Screen</string>
+    <string name="flashlight_on_screen_color_green">Green On-Screen</string>
+    <string name="flashlight_on_screen_color_orange">Orange On-Screen</string>
+    <string name="flashlight_on_screen_color_yellow">Yellow On-Screen</string>
+    <string name="flashlight_on_screen_color_white">White On-Screen</string>
+    <string name="flashlight_on_screen_color_gray">Gray On-Screen</string>
+    <string name="flashlight_on_screen_brightness_base_text">Brightness: %d</string>
 
     <!-- Settings -->
     <string name="title_settings">Settings</string>
@@ -60,6 +70,10 @@
     <string name="pref_flashlight_store_brightness_summary_on">The last selected brightness will be remembered when starting the flashlight again</string>
     <string name="pref_flashlight_default_brightness_title">Default Brightness</string>
     <string name="pref_flashlight_default_brightness_summary">The default brightness to be set when starting the activity in \%</string>
+    <string name="pref_on_screen_flashlight_sensitivity_title">Swipe Sensitivity</string>
+    <string name="pref_on_screen_flashlight_sensitivity_summary">The sensitivity of the swipe gesture on the on-screen flashlight</string>
+    <string name="pref_on_screen_flashlight_step_size_title">Swipe Step Size</string>
+    <string name="pref_on_screen_flashlight_step_size_summary">The change step size of the on-screen swipe gesture</string>
 
     <!-- Preference Keys -->
     <string name="pref_key_share_location_freq" translatable="false">location_update_freq</string>
@@ -67,15 +81,17 @@
     <string name="pref_key_share_location_man_acc" translatable="false">manual_accuracy</string>
     <string name="pref_key_flashlight_store_brightness" translatable="false">store_last_brightness</string>
     <string name="pref_key_flashlight_default_brightness" translatable="false">flashlight_default_brightness</string>
+    <string name="pref_key_on_screen_flashlight_sensitivity" translatable="false">on_screen_flash_sensititvity</string>
+    <string name="pref_key_on_screen_flashlight_step_size" translatable="false">on_screen_flash_step_size</string>
 
     <!-- Android Auto related Strings -->
-    <string name="android_auto_message_currently_sharing" translatable="false">You are already sharing your location with your family, do you wanna stop?</string>
+    <string name="android_auto_message_currently_sharing">You are already sharing your location with your family, do you wanna stop?</string>
-    <string name="android_auto_message_not_sharing" translatable="false">Android Auto start has been detected, do you wanna share your location?</string>
+    <string name="android_auto_message_not_sharing">Android Auto start has been detected, do you wanna share your location?</string>
-    <string name="android_auto_actions_start_sharing" translatable="false">Yes, start to share</string>
+    <string name="android_auto_actions_start_sharing">Yes, start to share</string>
-    <string name="android_auto_actions_stop_sharing" translatable="false">Yes, stop sharing</string>
+    <string name="android_auto_actions_stop_sharing">Yes, stop sharing</string>
-    <string name="android_auto_share_location_start" translatable="false">Start</string>
+    <string name="android_auto_share_location_start">Start</string>
-    <string name="android_auto_share_location_start_desc" translatable="false">Start to share location</string>
+    <string name="android_auto_share_location_start_desc">Start to share location</string>
-    <string name="android_auto_share_location_stop" translatable="false">Stop</string>
+    <string name="android_auto_share_location_stop">Stop</string>
-    <string name="android_auto_share_location_stop_desc" translatable="false">Stop to share the location</string>
+    <string name="android_auto_share_location_stop_desc">Stop to share the location</string>
 
 </resources>

app/src/main/res/xml/root_preferences.xml

@@ -51,6 +51,30 @@
             app:seekBarIncrement="@integer/pref_flashlight_def_brightness_increment"
             app:showSeekBarValue="true"/>
 
+        <PreferenceCategory app:title="On-Screen Flashlight">
+
+            <SeekBarPreference
+                app:key="@string/pref_key_on_screen_flashlight_sensitivity"
+                app:title="@string/pref_on_screen_flashlight_sensitivity_title"
+                app:min="@integer/pref_on_screen_flashlight_sensitivity_min"
+                android:max="@integer/pref_on_screen_flashlight_sensitivity_max"
+                app:seekBarIncrement="@integer/pref_on_screen_flashlight_sensitivity_increment"
+                app:showSeekBarValue="true"
+                app:defaultValue="@integer/pref_on_screen_flashlight_sensitivity_def"
+                app:summary="@string/pref_on_screen_flashlight_sensitivity_summary"/>
+
+            <SeekBarPreference
+                app:key="@string/pref_key_on_screen_flashlight_step_size"
+                app:title="@string/pref_on_screen_flashlight_step_size_title"
+                app:min="@integer/pref_on_screen_flashlight_step_size_min"
+                android:max="@integer/pref_on_screen_flashlight_step_size_max"
+                app:seekBarIncrement="@integer/pref_on_screen_flashlight_step_size_increment"
+                app:showSeekBarValue="true"
+                app:defaultValue="@integer/pref_on_screen_flashlight_step_size_def"
+                app:summary="@string/pref_on_screen_flashlight_step_size_summary"/>
+
+        </PreferenceCategory>
+
     </PreferenceCategory>
 
 </PreferenceScreen>