change imageview visuals from src to background

app/src/main/java/com/simplemobiletools/flashlight/MyCameraImpl.java

@@ -9,6 +9,7 @@ import com.squareup.otto.Bus;
 
 public class MyCameraImpl {
     private static final String TAG = MyCameraImpl.class.getSimpleName();
+
     private static Camera mCamera;
     private static Camera.Parameters mParams;
     private static Bus mBus;
@@ -20,10 +21,12 @@ public class MyCameraImpl {
     private static boolean mIsFlashlightOn;
     private static boolean mIsMarshmallow;
     private static boolean mShouldEnableFlashlight;
+    private static int mStroboFrequency;
 
     public MyCameraImpl(Context cxt) {
         mContext = cxt;
         mIsMarshmallow = isMarshmallow();
+        mStroboFrequency = 1000;
 
         if (mBus == null) {
             mBus = BusProvider.getInstance();
@@ -39,6 +42,10 @@ public class MyCameraImpl {
         handleCameraSetup();
     }
 
+    public void setStroboFrequency(int frequency) {
+        mStroboFrequency = frequency;
+    }
+
     public boolean toggleStroboscope() {
         if (!mIsStroboscopeRunning)
             disableFlashlight();
@@ -202,9 +209,9 @@ public class MyCameraImpl {
             while (!mShouldStroboscopeStop) {
                 try {
                     mCamera.setParameters(torchOn);
-                    Thread.sleep(500);
+                    Thread.sleep(mStroboFrequency);
                     mCamera.setParameters(torchOff);
-                    Thread.sleep(500);
+                    Thread.sleep(mStroboFrequency);
                 } catch (InterruptedException ignored) {
                     mShouldStroboscopeStop = true;
                 } catch (RuntimeException ignored) {

app/src/main/java/com/simplemobiletools/flashlight/activities/MainActivity.java

@@ -29,6 +29,8 @@ import butterknife.OnClick;
 
 public class MainActivity extends SimpleActivity {
     private static final int CAMERA_PERMISSION = 1;
+    private static final int MAX_STROBO_DELAY = 2000;
+    private static final int MIN_STROBO_DELAY = 30;
 
     @BindView(R.id.toggle_btn) ImageView mToggleBtn;
     @BindView(R.id.bright_display_btn) ImageView mBrightDisplayBtn;
@@ -47,6 +49,27 @@ public class MainActivity extends SimpleActivity {
         mBus = BusProvider.getInstance();
         changeIconColor(R.color.translucent_white, mBrightDisplayBtn);
         changeIconColor(R.color.translucent_white, mStroboscopeBtn);
+        mStroboscopeBar.setMax(MAX_STROBO_DELAY - MIN_STROBO_DELAY);
+        mStroboscopeBar.setProgress(mStroboscopeBar.getMax() / 2);
+
+        mStroboscopeBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
+            @Override
+            public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
+                final int frequency = mStroboscopeBar.getMax() - progress + MIN_STROBO_DELAY;
+                if (mCameraImpl != null)
+                    mCameraImpl.setStroboFrequency(frequency);
+            }
+
+            @Override
+            public void onStartTrackingTouch(SeekBar seekBar) {
+
+            }
+
+            @Override
+            public void onStopTrackingTouch(SeekBar seekBar) {
+
+            }
+        });
     }
 
     @Override
@@ -180,7 +203,7 @@ public class MainActivity extends SimpleActivity {
 
     private void changeIconColor(int colorId, ImageView imageView) {
         final int appColor = getResources().getColor(colorId);
-        imageView.getDrawable().mutate().setColorFilter(appColor, PorterDuff.Mode.SRC_IN);
+        imageView.getBackground().mutate().setColorFilter(appColor, PorterDuff.Mode.SRC_IN);
     }
 
     @Subscribe

app/src/main/res/drawable/circles_big.xml

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item
-        android:width="60dp"
-        android:height="60dp"
+        android:bottom="60dp"
         android:left="60dp"
+        android:right="60dp"
         android:top="60dp">
         <shape
             android:shape="oval">
@@ -15,9 +15,9 @@
     </item>
 
     <item
-        android:width="120dp"
-        android:height="120dp"
+        android:bottom="30dp"
         android:left="30dp"
+        android:right="30dp"
         android:top="30dp">
         <shape
             android:shape="oval">
@@ -28,9 +28,7 @@
         </shape>
     </item>
 
-    <item
-        android:width="180dp"
-        android:height="180dp">
+    <item>
         <shape
             android:shape="oval">
             <stroke

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

@@ -13,23 +13,25 @@
         android:id="@+id/toggle_btn"
         android:layout_width="@dimen/main_button_size"
         android:layout_height="@dimen/main_button_size"
-        android:src="@drawable/circles_big"/>
+        android:layout_marginBottom="@dimen/activity_margin"
+        android:background="@drawable/circles_big"/>
 
     <ImageView
         android:id="@+id/bright_display_btn"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:layout_marginBottom="@dimen/activity_margin"
         android:layout_marginTop="@dimen/buttons_margin"
-        android:padding="@dimen/activity_margin"
-        android:src="@mipmap/bright_display"/>
+        android:background="@mipmap/bright_display"
+        android:padding="@dimen/activity_margin"/>
 
     <ImageView
         android:id="@+id/stroboscope_btn"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="@dimen/buttons_margin"
-        android:padding="@dimen/activity_margin"
-        android:src="@mipmap/bright_display"/>
+        android:background="@mipmap/bright_display"
+        android:padding="@dimen/activity_margin"/>
 
     <SeekBar
         android:id="@+id/stroboscope_bar"