[GB Mobile] Apply OS font size changes to the editor

WordPress/src/main/AndroidManifest.xml

@@ -205,6 +205,7 @@
             android:windowSoftInputMode="stateVisible" />
         <activity
             android:name=".ui.posts.EditPostActivity"
+            android:configChanges="fontScale"
             android:theme="@style/Calypso.ActionMode.Dark"
             android:windowSoftInputMode="stateHidden|adjustResize">
             <meta-data

WordPress/src/main/java/org/wordpress/android/ui/posts/EditPostActivity.java

@@ -342,6 +342,8 @@ enum RestartEditorOptions {
     // for keeping the media uri while asking for permissions
     private ArrayList<Uri> mDroppedMediaUris;
 
+    private float mConfigurationFontSize;
+
     private boolean isModernEditor() {
         return mShowNewEditor || mShowAztecEditor || mShowGutenbergEditor;
     }
@@ -587,6 +589,8 @@ public void run() {
             }
         });
 
+        mConfigurationFontSize = getResources().getConfiguration().fontScale;
+
         ActivityId.trackLastActivity(ActivityId.POST_EDITOR);
     }
 
@@ -801,6 +805,7 @@ protected void onSaveInstanceState(Bundle outState) {
         outState.putBoolean(STATE_KEY_HTML_MODE_ON, mHtmlModeMenuStateOn);
         outState.putSerializable(WordPress.SITE, mSite);
         outState.putParcelable(STATE_KEY_REVISION, mRevision);
+        outState.putFloat("mConfigurationFontSize", mConfigurationFontSize);
 
         outState.putSerializable(STATE_KEY_EDITOR_SESSION_DATA, mPostEditorAnalyticsSession);
         mIsConfigChange = true; // don't call sessionData.end() in onDestroy() if this is an Android config change
@@ -822,12 +827,33 @@ protected void onRestoreInstanceState(Bundle savedInstanceState) {
         if (savedInstanceState.getBoolean(STATE_KEY_IS_PHOTO_PICKER_VISIBLE, false)) {
             showPhotoPicker();
         }
+
+        mConfigurationFontSize = savedInstanceState.getFloat("mConfigurationFontSize", 0f);
     }
 
     @Override
     public void onConfigurationChanged(Configuration newConfig) {
         super.onConfigurationChanged(newConfig);
 
+
+        if (newConfig.fontScale != mConfigurationFontSize && (mEditorFragment instanceof GutenbergEditorFragment)) {
+            // Configuration has changed: Save the new fontScale and update the GB editor fragment(s).
+            // We can't rely on the Android and RN font scaling system, since we're using GB mobile
+            // in a retained fragment, and the configuration changed code is not called automatically.
+            // `setRetainInstance(true)` was set here
+            // https://github.com/wordpress-mobile/WordPress-Android/pull/9030
+            // in order to fix a couple of issues: history lost, and device rotation issues.
+            GutenbergEditorFragment gbFragment = (GutenbergEditorFragment) mEditorFragment;
+            try {
+                updatePostObject(true);
+            } catch (EditorFragmentNotAddedException e) {
+                AppLog.e(T.EDITOR, "Impossible to save the post, we weren't able to update it.");
+                return;
+            }
+            mConfigurationFontSize = newConfig.fontScale;
+            gbFragment.updateEditorContentAndReload(mPost.getTitle(), mPost.getContent());
+        }
+
         // resize the photo picker if the user rotated the device
         int orientation = newConfig.orientation;
         if (orientation != mPhotoPickerOrientation) {

libs/editor/WordPressEditor/src/main/java/org/wordpress/android/editor/GutenbergContainerFragment.java

@@ -18,6 +18,8 @@ public class GutenbergContainerFragment extends Fragment {
     private static final String ARG_LOCALE = "param_locale";
     private static final String ARG_TRANSLATIONS = "param_translations";
 
+    private static final String KEY_HTML_MODE_ENABLED = "KEY_HTML_MODE_ENABLED";
+
     private boolean mHtmlModeEnabled;
     private boolean mHasReceivedAnyContent;
 
@@ -53,6 +55,10 @@ public void onCreate(Bundle savedInstanceState) {
         String localeString = getArguments().getString(ARG_LOCALE);
         Bundle translations = getArguments().getBundle(ARG_TRANSLATIONS);
 
+        if (savedInstanceState != null) {
+            mHtmlModeEnabled = savedInstanceState.getBoolean(KEY_HTML_MODE_ENABLED);
+        }
+
         mWPAndroidGlueCode = new WPAndroidGlueCode();
         mWPAndroidGlueCode.onCreate(getContext());
         mWPAndroidGlueCode.onCreateView(
@@ -90,6 +96,11 @@ public void onDestroy() {
         mWPAndroidGlueCode.onDestroy(getActivity());
     }
 
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        outState.putBoolean(KEY_HTML_MODE_ENABLED, mHtmlModeEnabled);
+    }
+
     public void setTitle(String title) {
         mWPAndroidGlueCode.setTitle(title);
         mHasReceivedAnyContent = mWPAndroidGlueCode.hasReceivedInitialTitleAndContent();
@@ -145,4 +156,13 @@ public void mediaFileUploadSucceeded(final int mediaId, final String mediaUrl, f
     public void clearMediaFileURL(final int mediaId) {
         mWPAndroidGlueCode.clearMediaFileURL(mediaId);
     }
+
+    /**
+     * Recreate the react application and context.
+     * See: https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/
+     * react/ReactInstanceManager.java#L350
+     */
+    public void recreateReactContextInBackground() {
+        mWPAndroidGlueCode.recreateReactContextInBackground();
+    }
 }

libs/editor/WordPressEditor/src/main/java/org/wordpress/android/editor/GutenbergEditorFragment.java

@@ -59,6 +59,8 @@ public class GutenbergEditorFragment extends EditorFragmentAbstract implements
         IHistoryListener {
     private static final String KEY_HTML_MODE_ENABLED = "KEY_HTML_MODE_ENABLED";
     private static final String KEY_EDITOR_DID_MOUNT = "KEY_EDITOR_DID_MOUNT";
+    private static final String KEY_TITLE_BEFORE_CONFIG_CHANGES = "KEY_TITLE_BEFORE_CONFIG_CHANGES";
+    private static final String KEY_CONTENT_BEFORE_CONFIG_CHANGES = "KEY_CONTENT_BEFORE_CONFIG_CHANGES";
     private static final String ARG_IS_NEW_POST = "param_is_new_post";
     private static final String ARG_LOCALE_SLUG = "param_locale_slug";
 
@@ -85,6 +87,9 @@ public class GutenbergEditorFragment extends EditorFragmentAbstract implements
 
     private ProgressDialog mSavingContentProgressDialog;
 
+    private String mTitleBeforeConfigChanged = null;
+    private String mContentBeforeConfigChanged = null;
+
     public static GutenbergEditorFragment newInstance(String title,
                                                       String content,
                                                       boolean isNewPost,
@@ -202,6 +207,8 @@ public void onCreate(Bundle savedInstanceState) {
         if (savedInstanceState != null) {
             mHtmlModeEnabled = savedInstanceState.getBoolean(KEY_HTML_MODE_ENABLED);
             mEditorDidMount = savedInstanceState.getBoolean(KEY_EDITOR_DID_MOUNT);
+            mTitleBeforeConfigChanged = savedInstanceState.getString(KEY_TITLE_BEFORE_CONFIG_CHANGES, null);
+            mContentBeforeConfigChanged = savedInstanceState.getString(KEY_CONTENT_BEFORE_CONFIG_CHANGES, null);
         }
     }
 
@@ -260,6 +267,14 @@ public void onEditorDidMount(boolean hasUnsupportedBlocks) {
                             @Override
                             public void run() {
                                 setEditorProgressBarVisibility(!mEditorDidMount);
+                                if (mTitleBeforeConfigChanged != null) {
+                                    setTitle(mTitleBeforeConfigChanged);
+                                    mTitleBeforeConfigChanged = null;
+                                }
+                                if (mContentBeforeConfigChanged != null) {
+                                    setContent(mContentBeforeConfigChanged);
+                                    mContentBeforeConfigChanged = null;
+                                }
                             }
                         });
                     }
@@ -452,6 +467,8 @@ public void onAttach(Activity activity) {
     public void onSaveInstanceState(Bundle outState) {
         outState.putBoolean(KEY_HTML_MODE_ENABLED, mHtmlModeEnabled);
         outState.putBoolean(KEY_EDITOR_DID_MOUNT, mEditorDidMount);
+        outState.putString(KEY_TITLE_BEFORE_CONFIG_CHANGES, mTitleBeforeConfigChanged);
+        outState.putString(KEY_CONTENT_BEFORE_CONFIG_CHANGES, mContentBeforeConfigChanged);
     }
 
     @Override
@@ -774,4 +791,15 @@ public void run() {
 
         return true;
     }
+
+    // Save a temporary copy of the content in GB mobile, and restore it when the editor is refreshed
+    // Note: History, block focused, scroll and caret position are lost after this call!
+    public void updateEditorContentAndReload(String title, String content) {
+        mContentBeforeConfigChanged = content;
+        mTitleBeforeConfigChanged = title;
+        // set this to false otherwise the spinning dialog is not shown
+        mEditorDidMount = false;
+        setEditorProgressBarVisibility(mEditorDidMount);
+        mRetainedGutenbergContainerFragment.recreateReactContextInBackground();
+    }
 }