diff --git a/app/build.gradle b/app/build.gradle
index 06cfb995..9a1bbe4e 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -82,8 +82,6 @@ dependencies {
     compile 'com.google.android.gms:play-services-base:8.4.0'
     compile 'com.google.android.gms:play-services-analytics:8.4.0'
     compile(name: 'plotter', ext: 'aar')
-    compile 'org.solovyev:common-text:1.0.7'
-    compile 'org.solovyev:common-listeners:1.0.7'
     compile('com.google.guava:guava:11.0.2') {
         exclude(module: 'jsr305')
     }
diff --git a/app/src/main/java/org/solovyev/android/prefs/CollectionToStringPreference.java b/app/src/main/java/org/solovyev/android/prefs/CollectionToStringPreference.java
deleted file mode 100644
index 0088d12a..00000000
--- a/app/src/main/java/org/solovyev/android/prefs/CollectionToStringPreference.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2013 serso aka se.solovyev
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- * Contact details
- *
- * Email: se.solovyev@gmail.com
- * Site:  http://se.solovyev.org
- */
-
-package org.solovyev.android.prefs;
-
-import android.content.SharedPreferences;
-import org.solovyev.common.text.ListMapper;
-import org.solovyev.common.text.Mapper;
-import org.solovyev.common.text.StringMapper;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.util.Collection;
-import java.util.List;
-
-public class CollectionToStringPreference<C extends Collection<T>, T> extends AbstractPreference<C> {
-
-    @Nonnull
-    private final Mapper<C> mapper;
-
-    private CollectionToStringPreference(@Nonnull String key, @Nullable C defaultValue, @Nonnull Mapper<C> mapper) {
-        super(key, defaultValue);
-        this.mapper = mapper;
-    }
-
-    @Nonnull
-    public static <T> CollectionToStringPreference<List<T>, T> forList(@Nonnull String key, @Nullable List<T> defaultValue, @Nonnull Mapper<List<T>> mapper) {
-        return new CollectionToStringPreference<List<T>, T>(key, defaultValue, mapper);
-    }
-
-    @Nonnull
-    public static <T> CollectionToStringPreference<List<T>, T> forTypedList(@Nonnull String key, @Nullable List<T> defaultValue, @Nonnull Mapper<T> mapper) {
-        return new CollectionToStringPreference<List<T>, T>(key, defaultValue, ListMapper.newInstance(mapper));
-    }
-
-    @Nonnull
-    public static CollectionToStringPreference<List<String>, String> forStringList(@Nonnull String key, @Nullable List<String> defaultValue) {
-        return new CollectionToStringPreference<List<String>, String>(key, defaultValue, ListMapper.newInstance(StringMapper.getInstance()));
-    }
-
-   @Override
-    protected C getPersistedValue(@Nonnull SharedPreferences preferences) {
-        return mapper.parseValue(preferences.getString(getKey(), null));
-    }
-
-    @Override
-    protected void putPersistedValue(@Nonnull SharedPreferences.Editor editor, @Nonnull C values) {
-        editor.putString(getKey(), mapper.formatValue(values));
-    }
-}
diff --git a/app/src/main/java/org/solovyev/android/prefs/NumberIntervalPreference.java b/app/src/main/java/org/solovyev/android/prefs/NumberIntervalPreference.java
deleted file mode 100644
index 0dabe873..00000000
--- a/app/src/main/java/org/solovyev/android/prefs/NumberIntervalPreference.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2013 serso aka se.solovyev
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- * Contact details
- *
- * Email: se.solovyev@gmail.com
- * Site:  http://se.solovyev.org
- */
-
-package org.solovyev.android.prefs;
-
-import android.content.SharedPreferences;
-import org.solovyev.common.interval.Interval;
-import org.solovyev.common.text.Mapper;
-import org.solovyev.common.text.NumberIntervalMapper;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-public final class NumberIntervalPreference<N extends Number & Comparable<N>> extends AbstractPreference<Interval<N>> {
-
-    @Nonnull
-    private final Mapper<Interval<N>> mapper;
-
-    private NumberIntervalPreference(@Nonnull String key, @Nullable Interval<N> defaultValue, @Nonnull Class<N> clazz) {
-        super(key, defaultValue);
-        this.mapper = NumberIntervalMapper.of(clazz);
-
-    }
-
-    @Nonnull
-    public static <N extends Number & Comparable<N>> NumberIntervalPreference<N> of(@Nonnull String key, @Nullable Interval<N> defaultValue, @Nonnull Class<N> clazz) {
-        return new NumberIntervalPreference<N>(key, defaultValue, clazz);
-    }
-
-    @Override
-    protected Interval<N> getPersistedValue(@Nonnull SharedPreferences preferences) {
-        final String result = preferences.getString(getKey(), null);
-        if (result == null) {
-            return null;
-        } else {
-            return mapper.parseValue(result);
-        }
-    }
-
-    @Override
-    protected void putPersistedValue(@Nonnull SharedPreferences.Editor editor, @Nonnull Interval<N> value) {
-        editor.putString(getKey(), mapper.formatValue(value));
-    }
-
-}
diff --git a/app/src/main/java/org/solovyev/common/text/EnumMapper.java b/app/src/main/java/org/solovyev/common/text/EnumMapper.java
new file mode 100644
index 00000000..594aa101
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/EnumMapper.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.HashMap;
+import java.util.Map;
+
+public class EnumMapper<T extends Enum> implements Mapper<T> {
+
+    @Nonnull
+    private final static Map<Class<? extends Enum>, Mapper<?>> cachedMappers = new HashMap<Class<? extends Enum>, Mapper<?>>();
+
+    private final Class<T> enumClass;
+
+    private EnumMapper(@Nonnull Class<T> enumClass) {
+        this.enumClass = enumClass;
+    }
+
+    @Nonnull
+    public static <T extends Enum> Mapper<T> of(@Nonnull Class<T> enumClass) {
+        Mapper<T> result = (Mapper<T>) cachedMappers.get(enumClass);
+        if (result == null) {
+            // do not care about synchronization
+            result = new EnumMapper<T>(enumClass);
+            cachedMappers.put(enumClass, result);
+        }
+
+        return result;
+    }
+
+    @Override
+    public String formatValue(@Nullable T value) throws IllegalArgumentException {
+        return value == null ? null : value.name();
+    }
+
+    @Override
+    public T parseValue(@Nullable String value) throws IllegalArgumentException {
+        return value == null ? null : (T) Enum.valueOf(enumClass, value);
+    }
+}
diff --git a/app/src/main/java/org/solovyev/common/text/Formatter.java b/app/src/main/java/org/solovyev/common/text/Formatter.java
new file mode 100644
index 00000000..d83f6c39
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/Formatter.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nullable;
+
+public interface Formatter<T> {
+    /**
+     * Method formats string value of specified object
+     *
+     * @param value object to be converted to string
+     * @return string representation of current object
+     * @throws IllegalArgumentException illegal argument exception in case of any error (AND ONLY ONE EXCEPTION, I.E. NO NUMBER FORMAT EXCEPTIONS AND SO ON)
+     */
+    @Nullable
+    String formatValue(@Nullable T value) throws IllegalArgumentException;
+}
diff --git a/app/src/main/java/org/solovyev/common/text/Mapper.java b/app/src/main/java/org/solovyev/common/text/Mapper.java
new file mode 100644
index 00000000..aa69b6c0
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/Mapper.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+/**
+ * Class represents an interface for mapping string value to the typed object.
+ *
+ * @param <T>
+ * @see Formatter
+ * @see Parser
+ */
+public interface Mapper<T> extends Formatter<T>, Parser<T> {
+}
diff --git a/app/src/main/java/org/solovyev/common/text/NumberMapper.java b/app/src/main/java/org/solovyev/common/text/NumberMapper.java
new file mode 100644
index 00000000..b82f5c29
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/NumberMapper.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class NumberMapper<N extends Number> implements Mapper<N> {
+
+    private static final List<Class<? extends Number>> supportedClasses = NumberParser.supportedClasses;
+
+    private static final Map<Class<?>, Mapper<?>> mappers = new HashMap<>(supportedClasses.size());
+
+    static {
+        for (Class<? extends Number> supportedClass : supportedClasses) {
+            mappers.put(supportedClass, newInstance(supportedClass));
+        }
+    }
+
+    @Nonnull
+    private final Formatter<N> formatter;
+
+    @Nonnull
+    private final Parser<? extends N> parser;
+
+    /**
+     * Use org.solovyev.common.text.NumberMapper#getMapper(java.lang.Class<N>) instead
+     *
+     * @param clazz class representing parsed object
+     */
+    private NumberMapper(@Nonnull Class<? extends N> clazz) {
+        this(NumberParser.of(clazz), ValueOfFormatter.<N>getNotNullFormatter());
+    }
+
+    private NumberMapper(@Nonnull Parser<? extends N> parser,
+                         @Nonnull Formatter<N> formatter) {
+        this.parser = parser;
+        this.formatter = formatter;
+    }
+
+    @Nonnull
+    public static <N extends Number> Mapper<N> newInstance(@Nonnull Parser<? extends N> parser,
+                                                           @Nonnull Formatter<N> formatter) {
+        return new NumberMapper<>(parser, formatter);
+    }
+
+    @Nonnull
+    private static <N extends Number> Mapper<N> newInstance(@Nonnull Class<? extends N> clazz) {
+        return new NumberMapper<>(clazz);
+    }
+
+    @Nonnull
+    public static <N extends Number> Mapper<N> of(@Nonnull Class<? extends N> clazz) {
+        assert supportedClasses.contains(clazz) : "Class " + clazz + " is not supported by " + NumberMapper.class;
+        return (Mapper<N>) mappers.get(clazz);
+    }
+
+    @Override
+    public String formatValue(@Nullable N value) throws IllegalArgumentException {
+        return formatter.formatValue(value);
+    }
+
+    @Override
+    public N parseValue(@Nullable String value) throws IllegalArgumentException {
+        return this.parser.parseValue(value);
+    }
+}
diff --git a/app/src/main/java/org/solovyev/common/text/NumberParser.java b/app/src/main/java/org/solovyev/common/text/NumberParser.java
new file mode 100644
index 00000000..232cbbc9
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/NumberParser.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class NumberParser<N extends Number> implements Parser<N> {
+
+    static final List<Class<? extends Number>> supportedClasses = Arrays.<Class<? extends Number>>asList(Integer.class, Float.class, Long.class, Double.class);
+
+    private static final Map<Class<?>, Parser<?>> parsers = new HashMap<>(supportedClasses.size());
+
+    static {
+        for (Class<? extends Number> supportedClass : supportedClasses) {
+            parsers.put(supportedClass, new NumberParser<>(supportedClass));
+        }
+    }
+
+    @Nonnull
+    private final Class<? extends N> clazz;
+
+    private NumberParser(@Nonnull Class<? extends N> clazz) {
+        this.clazz = clazz;
+    }
+
+    @Nonnull
+    public static <N extends Number> Parser<N> of(@Nonnull Class<N> clazz) {
+        assert supportedClasses.contains(clazz) : "Class " + clazz + " is not supported by " + NumberParser.class;
+        return (Parser<N>) parsers.get(clazz);
+    }
+
+    @Override
+    public N parseValue(@Nullable String value) throws IllegalArgumentException {
+        N result;
+
+        if (value != null) {
+            if (this.clazz.equals(Integer.class)) {
+                result = (N) Integer.valueOf(value);
+            } else if (this.clazz.equals(Float.class)) {
+                result = (N) Float.valueOf(value);
+            } else if (this.clazz.equals(Long.class)) {
+                result = (N) Long.valueOf(value);
+            } else if (this.clazz.equals(Double.class)) {
+                result = (N) Double.valueOf(value);
+            } else {
+                throw new UnsupportedOperationException(this.clazz + " is not supported!");
+            }
+        } else {
+            result = null;
+        }
+
+        return result;
+    }
+}
diff --git a/app/src/main/java/org/solovyev/common/text/Parser.java b/app/src/main/java/org/solovyev/common/text/Parser.java
new file mode 100644
index 00000000..ce0b36c8
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/Parser.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nullable;
+
+public interface Parser<T> {
+    /**
+     * Method parses specified value and returns converted object
+     *
+     * @param value string to be parsed
+     * @return parsed object
+     * @throws IllegalArgumentException illegal argument exception in case of any error (AND ONLY ONE EXCEPTION, I.E. NO NUMBER FORMAT EXCEPTIONS AND SO ON)
+     */
+    @Nullable
+    T parseValue(@Nullable String value) throws IllegalArgumentException;
+}
diff --git a/app/src/main/java/org/solovyev/common/text/StringMapper.java b/app/src/main/java/org/solovyev/common/text/StringMapper.java
new file mode 100644
index 00000000..a81b0921
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/StringMapper.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public class StringMapper implements Mapper<String> {
+
+    @Nonnull
+    private static final Mapper<String> instance = new StringMapper();
+
+    private StringMapper() {
+    }
+
+    @Nonnull
+    public static Mapper<String> getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String formatValue(@Nullable String value) {
+        return value;
+    }
+
+    @Override
+    public String parseValue(@Nullable String value) {
+        return value;
+    }
+}
diff --git a/app/src/main/java/org/solovyev/common/text/ValueOfFormatter.java b/app/src/main/java/org/solovyev/common/text/ValueOfFormatter.java
new file mode 100644
index 00000000..dc965c9c
--- /dev/null
+++ b/app/src/main/java/org/solovyev/common/text/ValueOfFormatter.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ---------------------------------------------------------------------
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.common.text;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public class ValueOfFormatter<T> implements Formatter<T> {
+
+    @Nonnull
+    private static final ValueOfFormatter<Object> notNullFormatter = new ValueOfFormatter<Object>(false);
+
+    @Nonnull
+    private static final ValueOfFormatter<Object> nullableFormatter = new ValueOfFormatter<Object>(true);
+    private final boolean processNulls;
+
+    private ValueOfFormatter() {
+        this(false);
+    }
+
+    private ValueOfFormatter(boolean processNulls) {
+        this.processNulls = processNulls;
+    }
+
+    @Nonnull
+    public static <T> ValueOfFormatter<T> getNotNullFormatter() {
+        return (ValueOfFormatter<T>) notNullFormatter;
+    }
+
+    @Nonnull
+    public static <T> ValueOfFormatter<T> getNullableFormatter() {
+        return (ValueOfFormatter<T>) nullableFormatter;
+    }
+
+    @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = {"NP_LOAD_OF_KNOWN_NULL_VALUE"}, justification = "If 'processNulls' is true => must result 'null'")
+    @Override
+    public String formatValue(@Nullable T t) throws IllegalArgumentException {
+        if (t == null) {
+            if (processNulls) {
+                return String.valueOf(t);
+            } else {
+                return null;
+            }
+        } else {
+            return String.valueOf(t);
+        }
+    }
+}