Refactor theme changing to avoid code repetition

1 files changed, 60 insertions, 0 deletions

diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/ThemeChanger.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/ThemeChanger.java
new file mode 100644
index 000000000..4878271a2
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/ThemeChanger.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2015 Thialfihar <thi@thialfihar.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.ui.util;
+
+import android.content.Context;
+import android.view.ContextThemeWrapper;
+
+import org.sufficientlysecure.keychain.Constants;
+import org.sufficientlysecure.keychain.R;
+import org.sufficientlysecure.keychain.util.Preferences;
+
+public class ThemeChanger {
+    private Context mContext;
+    private Preferences mPreferences;
+    private String mCurrentTheme = null;
+
+    public ThemeChanger(Context context) {
+        mContext = context;
+        mPreferences = Preferences.getPreferences(mContext);
+    }
+
+    /**
+     * Apply the theme set in preferences if it isn't equal to mCurrentTheme
+     * anymore or mCurrentTheme hasn't been set yet.
+     * If a new theme is applied in this method, then return true, so
+     * the caller can re-create the activity, if need be.
+     */
+    public boolean changeTheme() {
+        String newTheme = mPreferences.getTheme();
+        if (mCurrentTheme != null && mCurrentTheme.equals(newTheme)) {
+            return false;
+        }
+
+        int themeId = R.style.LightTheme;
+        if (Constants.Pref.Theme.DARK.equals(newTheme)) {
+            themeId = R.style.DarkTheme;
+        }
+
+        ContextThemeWrapper w = new ContextThemeWrapper(mContext, themeId);
+        mContext.getTheme().setTo(w.getTheme());
+        mCurrentTheme = newTheme;
+
+        return true;
+    }
+}