Add setting to show/hide pictures in device gallery

Fix gsantner#55

Author: jeffsieu

app/src/main/java/io/github/gsantner/memetastic/activity/SettingsActivity.java

@@ -2,17 +2,23 @@
 
 import android.annotation.SuppressLint;
 import android.app.FragmentTransaction;
+import android.content.ContentResolver;
 import android.content.Context;
+import android.content.Intent;
 import android.content.SharedPreferences;
+import android.net.Uri;
 import android.os.Bundle;
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
+import android.provider.MediaStore;
 import android.support.design.widget.AppBarLayout;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.View;
 
+import java.io.File;
+import java.io.IOException;
 import java.util.Date;
 
 import butterknife.BindView;
@@ -140,8 +146,48 @@ public boolean onPreferenceTreeClick(PreferenceScreen screen, Preference prefere
                         getActivity().finish();
                     }
                 }
+                if (key.equals(getString(R.string.pref_key__is_show_in_gallery))) {
+                    boolean showInGallery = settings.getDefaultPreferences().getBoolean(key, true);
+                    File memeDirectory = AssetUpdater.getMemesDir(AppSettings.get());
+                    File noMediaFile = new File(memeDirectory, ".nomedia");
+                    if (showInGallery) {
+                        noMediaFile.delete();
+                        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(memeDirectory, ".nomedia"))));
+                        File[] files = memeDirectory.listFiles();
+                        for (int i = 0; i < files.length; i++) {
+                            deleteFileFromMediaStore(context.getContentResolver(), files[i]);
+                            context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(files[i])));
+                        }
+                    } else {
+                        try {
+                            noMediaFile.createNewFile();
+                            context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(noMediaFile)));
+                        } catch (IOException e) {
+                            e.printStackTrace();
+                        }
+                    }
+                }
             }
             return super.onPreferenceTreeClick(screen, preference);
         }
     }
+
+    public static void deleteFileFromMediaStore(final ContentResolver contentResolver, final File file) {
+        String canonicalPath;
+        try {
+            canonicalPath = file.getCanonicalPath();
+        } catch (IOException e) {
+            canonicalPath = file.getAbsolutePath();
+        }
+        final Uri uri = MediaStore.Files.getContentUri("external");
+        final int result = contentResolver.delete(uri,
+                MediaStore.Files.FileColumns.DATA + "=?", new String[]{canonicalPath});
+        if (result == 0) {
+            final String absolutePath = file.getAbsolutePath();
+            if (!absolutePath.equals(canonicalPath)) {
+                contentResolver.delete(uri,
+                        MediaStore.Files.FileColumns.DATA + "=?", new String[]{absolutePath});
+            }
+        }
+    }
 }

app/src/main/res/drawable/ic_photo_library_black_24dp.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M22,16L22,4c0,-1.1 -0.9,-2 -2,-2L8,2c-1.1,0 -2,0.9 -2,2v12c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2zM11,12l2.03,2.71L16,11l4,5L8,16l3,-4zM2,6v14c0,1.1 0.9,2 2,2h14v-2L4,20L4,6L2,6z"/>
+</vector>

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

@@ -70,5 +70,6 @@
     <string name="pref_key__is_migrated" translatable="false">pref_key__is_migrated</string>
     <string name="pref_key__download_assets_try" translatable="false">pref_key__download_assets_try</string>
     <string name="pref_key__memelist_view_type" translatable="false">pref_key__memelist_view_type</string>
+    <string name="pref_key__is_show_in_gallery" translatable="false">pref_key__is_show_in_gallery</string>
 
 </resources>

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

@@ -96,6 +96,7 @@
     <string name="pref_title__thumbnail_quality__percent">Thumbnail quality</string>
     <string name="pref_summary__memelist_view_type">Set view type (Picture grid, Rows with title)</string>
     <string name="pref_title__memelist_view_type">View Type</string>
+    <string name="pref_title__is_show_in_gallery">Show in device gallery</string>
 
     <!-- Language -->
     <string name="pref_title__language">Language</string>

app/src/main/res/xml/preferences_master.xml

@@ -92,6 +92,12 @@
 
     <PreferenceCategory android:title="@string/miscellaneous">
 
+        <CheckBoxPreference
+            android:defaultValue="true"
+            android:icon="@drawable/ic_photo_library_black_24dp"
+            android:key="@string/pref_key__is_show_in_gallery"
+            android:title="@string/pref_title__is_show_in_gallery"/>
+
         <!--suppress AndroidDomInspection -->
         <net.gsantner.opoc.ui.LanguagePreference
             android:defaultValue=""