Simplify conditions that check for lollipop, api 21, version (#2023)

Lollipop, API 21, has been the min sdk version for over a year in this
project.
There were still some conditions in the code, which checked for api 21,
that can be removed or simplified.

app/src/main/java/com/nutomic/syncthingandroid/activities/FolderActivity.java

@@ -81,7 +81,6 @@ public class FolderActivity extends SyncthingActivity
     private static final String IGNORE_FILE_NAME = ".stignore";
 
     private Folder mFolder;
-    // Contains SAF readwrite access URI on API level >= Build.VERSION_CODES.LOLLIPOP (21)
     private Uri mFolderUri = null;
     // Indicates the result of the write test to mFolder.path on dialog init or after a path change.
     Boolean mCanWriteToPath = false;
@@ -216,12 +215,6 @@ public class FolderActivity extends SyncthingActivity
      */
     @SuppressLint("InlinedAPI")
     private void onPathViewClick() {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            startActivityForResult(FolderPickerActivity.createIntent(this, mFolder.path, null),
-                FolderPickerActivity.DIRECTORY_REQUEST_CODE);
-            return;
-        }
-
         // This has to be android.net.Uri as it implements a Parcelable.
         android.net.Uri externalFilesDirUri = FileUtils.getExternalFilesDirUri(FolderActivity.this);
 
@@ -460,8 +453,7 @@ public class FolderActivity extends SyncthingActivity
                             .show();
                     return true;
                 }
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP &&
+                if (mFolderUri != null) {
-                    mFolderUri != null) {
                     /**
                      * Normally, syncthing takes care of creating the ".stfolder" marker.
                      * This fails on newer android versions if the syncthing binary only has
@@ -516,7 +508,6 @@ public class FolderActivity extends SyncthingActivity
         super.onActivityResult(requestCode, resultCode, data);
 
         if (resultCode == Activity.RESULT_OK && requestCode == CHOOSE_FOLDER_REQUEST) {
-            // This result case only occurs on API level >= Build.VERSION_CODES.LOLLIPOP (21)
             mFolderUri = data.getData();
             if (mFolderUri == null) {
                 return;

app/src/main/java/com/nutomic/syncthingandroid/service/Constants.java

@@ -139,11 +139,6 @@ public class Constants {
      * to syncthing core v0.14.53+.
      */
     public static Boolean osSupportsTLS12() {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            // Pre-Lollipop devices don't support TLS 1.2
-            return false;
-        }
-
         if (Build.VERSION.SDK_INT == Build.VERSION_CODES.N) {
             /**
              * SSLProtocolException: SSL handshake failed on Android N/7.0,

app/src/main/java/com/nutomic/syncthingandroid/service/NotificationHandler.java

@@ -299,9 +299,7 @@ public class NotificationHandler {
                         Constants.FLAG_IMMUTABLE | PendingIntent.FLAG_UPDATE_CURRENT));
 
 
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
         nb.setCategory(Notification.CATEGORY_ERROR);
-        }
         mNotificationManager.notify(ID_STOP_BACKGROUND_WARNING, nb.build());
     }
 }

app/src/main/java/com/nutomic/syncthingandroid/service/RunConditionMonitor.java

@@ -91,11 +91,9 @@ public class RunConditionMonitor {
         ReceiverManager.registerReceiver(mContext, new BatteryReceiver(), filter);
 
         // PowerSaveModeChangedReceiver
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
         ReceiverManager.registerReceiver(mContext,
                 new PowerSaveModeChangedReceiver(),
                 new IntentFilter(PowerManager.ACTION_POWER_SAVE_MODE_CHANGED));
-        }
 
         // SyncStatusObserver to monitor android's "AutoSync" quick toggle.
         mSyncStatusObserverHandle = ContentResolver.addStatusChangeListener(
@@ -207,12 +205,10 @@ public class RunConditionMonitor {
         }
 
         // Power saving
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
         if (prefRespectPowerSaving && isPowerSaving()) {
             Log.v(TAG, "decideShouldRun: prefRespectPowerSaving && isPowerSaving");
             blockerReasons.add(POWERSAVING_ENABLED);
         }
-        }
 
         // Android global AutoSync setting.
         if (prefRespectMasterSync && !ContentResolver.getMasterSyncAutomatically()) {
@@ -298,25 +294,6 @@ public class RunConditionMonitor {
      * Functions for run condition information retrieval.
      */
     private boolean isCharging() {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            // API level < 21
-            return isCharging_API16();
-        } else {
-            // API level >= 21
-            return isCharging_API17();
-        }
-    }
-
-    @TargetApi(16)
-    private boolean isCharging_API16() {
-        Intent batteryIntent = mContext.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
-        int status = batteryIntent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
-        return status == BatteryManager.BATTERY_STATUS_CHARGING ||
-            status == BatteryManager.BATTERY_STATUS_FULL;
-    }
-
-    @TargetApi(17)
-    private boolean isCharging_API17() {
         Intent intent = mContext.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
         int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
         return plugged == BatteryManager.BATTERY_PLUGGED_AC ||
@@ -324,12 +301,7 @@ public class RunConditionMonitor {
                 plugged == BatteryManager.BATTERY_PLUGGED_WIRELESS;
     }
 
-    @TargetApi(21)
     private boolean isPowerSaving() {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            Log.e(TAG, "isPowerSaving may not be called on pre-lollipop android versions.");
-            return false;
-        }
         PowerManager powerManager = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
         if (powerManager == null) {
             Log.e(TAG, "getSystemService(POWER_SERVICE) unexpectedly returned NULL.");

app/src/main/java/com/nutomic/syncthingandroid/util/FileUtils.java

@@ -24,9 +24,6 @@ public class FileUtils {
 
     private static final String TAG = "FileUtils";
 
-    // TargetApi(21)
-    private static final Boolean isCompatible = (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
-
     private FileUtils() {
         // Private constructor to enforce Singleton pattern.
     }
@@ -36,7 +33,6 @@ public class FileUtils {
     private static final String HOME_VOLUME_NAME = "home";
 
     @Nullable
-    @TargetApi(21)
     public static String getAbsolutePathFromSAFUri(Context context, @Nullable final Uri safResultUri) {
         Uri treeUri = DocumentsContract.buildDocumentUriUsingTree(safResultUri,
             DocumentsContract.getTreeDocumentId(safResultUri));
@@ -45,10 +41,6 @@ public class FileUtils {
 
     @Nullable
     public static String getAbsolutePathFromTreeUri(Context context, @Nullable final Uri treeUri) {
-        if (!isCompatible) {
-            Log.e(TAG, "getAbsolutePathFromTreeUri: called on unsupported API level");
-            return null;
-        }
         if (treeUri == null) {
             Log.w(TAG, "getAbsolutePathFromTreeUri: called with treeUri == null");
             return null;
@@ -83,13 +75,7 @@ public class FileUtils {
         }
     }
 
-    @SuppressLint("ObsoleteSdkInt")
-    @TargetApi(21)
     private static String getVolumePath(final String volumeId, Context context) {
-        if (!isCompatible) {
-            Log.e(TAG, "getVolumePath called on unsupported API level");
-            return null;
-        }
         try {
             if (HOME_VOLUME_NAME.equals(volumeId)) {
                 Log.v(TAG, "getVolumePath: isHomeVolume");
@@ -136,8 +122,6 @@ public class FileUtils {
         return null;
     }
 
-    @SuppressLint("ObsoleteSdkInt")
-    @TargetApi(21)
     private static String volumeToPath(Object storageVolumeElement, Class<?> storageVolumeClazz) throws Exception {
         try {
             // >= API level 30
@@ -159,7 +143,6 @@ public class FileUtils {
      * This is crucial to assist the user finding a writeable folder
      * to use syncthing's two way sync feature.
      */
-    @TargetApi(19)
     public static android.net.Uri getExternalFilesDirUri(Context context) {
         try {
             /**
@@ -192,7 +175,6 @@ public class FileUtils {
         return null;
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     private static String getVolumeIdFromTreeUri(final Uri treeUri) {
         final String docId = DocumentsContract.getTreeDocumentId(treeUri);
         final String[] split = docId.split(":");
@@ -203,7 +185,6 @@ public class FileUtils {
         }
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     private static String getDocumentPathFromTreeUri(final Uri treeUri) {
         final String docId = DocumentsContract.getTreeDocumentId(treeUri);
         final String[] split = docId.split(":");

app/src/main/java/com/nutomic/syncthingandroid/util/Languages.java

@@ -66,7 +66,6 @@ public final class Languages {
      * or different than the current system-wide locale.  The preference is cleared
      * if the language matches the system-wide locale or "System Default" is chosen.
      */
-    @TargetApi(17)
     public void setLanguage(Context context) {
         String language = mPreferences.getString(PREFERENCE_LANGUAGE, null);
         Locale locale;
@@ -89,11 +88,7 @@ public final class Languages {
 
         final Resources resources = context.getResources();
         Configuration config = resources.getConfiguration();
-        if (Build.VERSION.SDK_INT >= 17) {
         config.setLocale(locale);
-        } else {
-            config.locale = locale;
-        }
         resources.updateConfiguration(config, resources.getDisplayMetrics());
     }