Remove code smell

Author: samtstern

easypermissions/src/main/java/pub/devrel/easypermissions/EasyPermissions.java

@@ -21,10 +21,8 @@
 import android.content.pm.PackageManager;
 import android.os.Build;
 import android.support.annotation.NonNull;
-import android.support.annotation.RequiresApi;
 import android.support.annotation.StringRes;
 import android.support.v4.app.ActivityCompat;
-import android.support.v4.app.Fragment;
 import android.support.v4.content.ContextCompat;
 import android.util.Log;
 
@@ -63,7 +61,7 @@ public interface PermissionCallbacks extends ActivityCompat.OnRequestPermissions
      * yet granted.
      * @see Manifest.permission
      */
-    public static boolean hasPermissions(@NonNull Context context, @NonNull String... perms) {
+    public static boolean hasPermissions(Context context, @NonNull String... perms) {
         // Always return true for SDK < M, let the system deal with the permissions
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
             Log.w(TAG, "hasPermissions: API version < M, returning true by default");
@@ -72,6 +70,12 @@ public static boolean hasPermissions(@NonNull Context context, @NonNull String..
             return true;
         }
 
+        // Null context may be passed if we have detected Low API (less than M) so getting
+        // to this point with a null context should not be possible.
+        if (context == null) {
+            throw new IllegalArgumentException("Can't check permissions for null context");
+        }
+
         for (String perm : perms) {
             if (ContextCompat.checkSelfPermission(context, perm)
                     != PackageManager.PERMISSION_GRANTED) {
@@ -91,7 +95,14 @@ public static void requestPermissions(@NonNull Object host,
                                           @NonNull String rationale,
                                           int requestCode,
                                           @NonNull String... perms) {
-        PermissionHelper.getInstance(host).requestPermissions(rationale, requestCode, perms);
+
+        // Use default Android 'OK' and 'Cancel' buttons
+        requestPermissions(host,
+                rationale,
+                android.R.string.ok,
+                android.R.string.cancel,
+                requestCode,
+                perms);
     }
 
     /**
@@ -106,21 +117,24 @@ public static void requestPermissions(@NonNull Object host,
      * @param perms          a set of permissions to be requested.
      * @see Manifest.permission
      */
-    @RequiresApi(api = Build.VERSION_CODES.HONEYCOMB)
     public static void requestPermissions(@NonNull Object host,
                                           @NonNull String rationale,
                                           @StringRes int positiveButton,
                                           @StringRes int negativeButton,
                                           int requestCode,
                                           @NonNull String... perms) {
 
-        // Check for permissions before dispatching
-        if (hasPermissions(getContext(host), perms)) {
+        // Get a permission helper for the calling object
+        PermissionHelper helper = PermissionHelper.getInstance(host);
+
+        // Check for permissions before dispatching the request
+        if (hasPermissions(helper.getContext(), perms)) {
             notifyAlreadyHasPermissions(host, requestCode, perms);
             return;
         }
 
-        PermissionHelper.getInstance(host).requestPermissions(rationale, positiveButton,
+        // Request permissions
+        helper.requestPermissions(rationale, positiveButton,
                 negativeButton, requestCode, perms);
     }
 
@@ -225,26 +239,6 @@ public static boolean somePermissionDenied(@NonNull Object host, @NonNull String
         return PermissionHelper.getInstance(host).somePermissionDenied(perms);
     }
 
-    /**
-     * Get an {@link Context} from an object that could be an Activity or Fragment.
-     */
-    @NonNull
-    @RequiresApi(api = Build.VERSION_CODES.HONEYCOMB)
-    private static Context getContext(@NonNull Object object) {
-        // TODO(samstern): I'd really like to remove this method so that there is no
-        //                 type-checking in this class but LowApiPermissionHelper stops me
-        //                 since it can't provide a Context for its host.
-        if (object instanceof Activity) {
-            return ((Activity) object);
-        } else if (object instanceof Fragment) {
-            return ((Fragment) object).getActivity();
-        } else if (object instanceof android.app.Fragment) {
-            return ((android.app.Fragment) object).getActivity();
-        } else {
-            throw new IllegalArgumentException("Cannot get context from object: " + object);
-        }
-    }
-
     /**
      * Run permission callbacks on an object that requested permissions but already has them
      * by simulating {@link PackageManager#PERMISSION_GRANTED}.

easypermissions/src/main/java/pub/devrel/easypermissions/helper/ActivityPermissionHelper.java

@@ -2,6 +2,7 @@
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
+import android.content.Context;
 import android.support.annotation.NonNull;
 import android.support.annotation.StringRes;
 import android.support.v4.app.ActivityCompat;
@@ -40,4 +41,9 @@ public void requestPermissions(@NonNull String rationale,
     public boolean shouldShowRequestPermissionRationale(@NonNull String perm) {
         return ActivityCompat.shouldShowRequestPermissionRationale(getHost(), perm);
     }
+
+    @Override
+    public Context getContext() {
+        return getHost();
+    }
 }

easypermissions/src/main/java/pub/devrel/easypermissions/helper/FrameworkFragmentPermissionHelper.java

@@ -2,6 +2,7 @@
 
 import android.annotation.SuppressLint;
 import android.app.Fragment;
+import android.content.Context;
 import android.support.annotation.NonNull;
 import android.support.annotation.StringRes;
 
@@ -39,4 +40,10 @@ public void requestPermissions(@NonNull String rationale,
     public boolean shouldShowRequestPermissionRationale(@NonNull String perm) {
         return getHost().shouldShowRequestPermissionRationale(perm);
     }
+
+    @Override
+    @SuppressLint("NewApi")
+    public Context getContext() {
+        return getHost().getActivity();
+    }
 }

easypermissions/src/main/java/pub/devrel/easypermissions/helper/LowApiPermissionsHelper.java

@@ -27,4 +27,9 @@ public void requestPermissions(@NonNull String rationale,
     public boolean shouldShowRequestPermissionRationale(@NonNull String perm) {
         return false;
     }
+
+    @Override
+    public Context getContext() {
+        return null;
+    }
 }

easypermissions/src/main/java/pub/devrel/easypermissions/helper/PermissionHelper.java

@@ -1,6 +1,7 @@
 package pub.devrel.easypermissions.helper;
 
 import android.app.Activity;
+import android.content.Context;
 import android.os.Build;
 import android.support.annotation.NonNull;
 import android.support.annotation.RequiresApi;
@@ -48,17 +49,6 @@ public PermissionHelper(@NonNull T host) {
         this.mHost = host;
     }
 
-    public void requestPermissions(@NonNull String rationale,
-                                   int requestCode,
-                                   @NonNull String... perms) {
-        // Use default Android OK and Cancel strings
-        requestPermissions(rationale,
-                android.R.string.ok,
-                android.R.string.cancel,
-                requestCode,
-                perms);
-    }
-
     public boolean shouldShowRationale(@NonNull String[] perms) {
         for (String perm : perms) {
             if (shouldShowRequestPermissionRationale(perm)) {
@@ -98,6 +88,8 @@ public abstract void requestPermissions(@NonNull String rationale,
 
     public abstract boolean shouldShowRequestPermissionRationale(@NonNull String perm);
 
+    public abstract Context getContext();
+
     // ============================================================================
     // Protected methods
     // ============================================================================

easypermissions/src/main/java/pub/devrel/easypermissions/helper/SupportFragmentPermissionHelper.java

@@ -1,6 +1,7 @@
 package pub.devrel.easypermissions.helper;
 
 import android.annotation.SuppressLint;
+import android.content.Context;
 import android.support.annotation.NonNull;
 import android.support.annotation.StringRes;
 import android.support.v4.app.Fragment;
@@ -37,4 +38,9 @@ public void requestPermissions(@NonNull String rationale,
     public boolean shouldShowRequestPermissionRationale(@NonNull String perm) {
         return getHost().shouldShowRequestPermissionRationale(perm);
     }
+
+    @Override
+    public Context getContext() {
+        return getHost().getActivity();
+    }
 }