Logger -> ErrorReporter

app/src/main/java/org/solovyev/android/calculator/AbstractCalculatorMathRegistry.java

@@ -89,7 +89,7 @@ public abstract class AbstractCalculatorMathRegistry<T extends MathEntity, P ext
                         final JBuilder<? extends T> builder = createBuilder(entity);
                         add(builder);
                     } catch (RuntimeException e) {
-                        Locator.getInstance().getLogger().error(null, e.getLocalizedMessage(), e);
+                        Locator.getInstance().getErrorReporter().onException(e);
                         notCreatedEntities.add(entity);
                     }
                 }
@@ -107,7 +107,7 @@ public abstract class AbstractCalculatorMathRegistry<T extends MathEntity, P ext
             }
         } catch (RuntimeException e) {
             // just in case
-            Locator.getInstance().getLogger().error(null, e.getLocalizedMessage(), e);
+            Locator.getInstance().getErrorReporter().onException(e);
         }
     }
 

app/src/main/java/org/solovyev/android/calculator/AcraErrorReporter.java

@@ -0,0 +1,40 @@
+/*
+ * 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.calculator;
+
+import org.acra.ACRA;
+
+import javax.annotation.Nonnull;
+
+public class AcraErrorReporter implements ErrorReporter {
+
+    @Override
+    public void onException(@Nonnull Throwable e) {
+        ACRA.getErrorReporter().reportBuilder().forceSilent().exception(e).send();
+    }
+
+    @Override
+    public void onError(@Nonnull String message) {
+        ACRA.getErrorReporter().reportBuilder().forceSilent().exception(new Throwable(message)).send();
+    }
+}

app/src/main/java/org/solovyev/android/calculator/AndroidCalculatorLogger.java

@@ -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.calculator;
-
-import android.util.Log;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * User: serso
- * Date: 10/11/12
- * Time: 12:15 AM
- */
-public class AndroidCalculatorLogger implements CalculatorLogger {
-
-    @Nonnull
-    private static final String TAG = "Calculatorpp";
-
-    @Override
-    public void debug(@Nullable String tag, @Nonnull String message) {
-        Log.d(getTag(tag), message);
-    }
-
-    @Nonnull
-    private String getTag(@Nullable String tag) {
-        return tag != null ? TAG + "/" + tag : TAG;
-    }
-
-    @Override
-    public void debug(@Nullable String tag, @Nullable String message, @Nonnull Throwable e) {
-        Log.d(getTag(tag), message, e);
-    }
-
-    @Override
-    public void error(@Nullable String tag, @Nullable String message, @Nonnull Throwable e) {
-        Log.e(getTag(tag), message, e);
-    }
-
-    @Override
-    public void error(@Nullable String tag, @Nullable String message) {
-        Log.e(getTag(tag), message);
-    }
-}

app/src/main/java/org/solovyev/android/calculator/App.java

@@ -220,11 +220,6 @@ public final class App {
         return Preferences.Widget.getTheme(getPreferences());
     }
 
-    @Nonnull
-    public static Executor getBackground() {
-        return background;
-    }
-
     @Nonnull
     public static Preferences.Gui.Theme getThemeFor(@Nonnull Context context) {
         if (context instanceof CalculatorOnscreenService) {

app/src/main/java/org/solovyev/android/calculator/AppModule.java

@@ -6,25 +6,32 @@ import android.os.Handler;
 import android.os.Looper;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
+
 import com.squareup.otto.Bus;
-import dagger.Module;
+
-import dagger.Provides;
 import org.solovyev.android.UiThreadExecutor;
 
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import javax.annotation.Nonnull;
 import javax.inject.Named;
 import javax.inject.Singleton;
-import java.util.concurrent.Executor;
+
-import java.util.concurrent.Executors;
+import dagger.Module;
-import java.util.concurrent.ThreadFactory;
+import dagger.Provides;
 
 @Module
 public class AppModule {
 
-    @NonNull
+    // single thread, should be used during the startup
     public static final String THREAD_INIT = "thread-init";
-    @NonNull
+    // UI application thread
     public static final String THREAD_UI = "thread-ui";
+    // multiple threads
+    public static final String THREAD_BACKGROUND = "thread-background";
 
     @NonNull
     private final Application application;
@@ -75,6 +82,26 @@ public class AppModule {
         });
     }
 
+    @Provides
+    @Singleton
+    @Named(THREAD_BACKGROUND)
+    Executor provideBackgroundThread() {
+        return Executors.newFixedThreadPool(5, new ThreadFactory() {
+            @NonNull
+            private final AtomicInteger counter = new AtomicInteger();
+            @Override
+            public Thread newThread(@Nonnull Runnable r) {
+                return new Thread(r, "Background #" + counter.getAndIncrement());
+            }
+        });
+    }
+
+    @Provides
+    @Singleton
+    ErrorReporter provideErrorReporter() {
+        return new AcraErrorReporter();
+    }
+
     @Provides
     @Singleton
     @Named(THREAD_UI)

app/src/main/java/org/solovyev/android/calculator/CalculatorApplication.java

@@ -58,6 +58,10 @@ public class CalculatorApplication extends android.app.Application implements Sh
     @Named(AppModule.THREAD_INIT)
     Executor initThread;
 
+    @Inject
+    @Named(AppModule.THREAD_UI)
+    Executor uiThread;
+
     @Inject
     Handler handler;
 
@@ -81,28 +85,29 @@ public class CalculatorApplication extends android.app.Application implements Sh
     @Inject
     Keyboard keyboard;
 
-    @Inject
-    @Named(AppModule.THREAD_UI)
-    Executor uiThread;
-
     @Inject
     History history;
 
     @Inject
     Broadcaster broadcaster;
 
+    @Inject
+    ErrorReporter errorReporter;
+
     @Override
     public void onCreate() {
         final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
         final Languages languages = new Languages(preferences);
 
         onPreCreate(preferences, languages);
+        super.onCreate();
+
         component = DaggerAppComponent.builder()
                 .appModule(new AppModule(this))
                 .build();
         component.inject(this);
+        history.init(initThread);
 
-        super.onCreate();
         onPostCreate(preferences, languages);
     }
 
@@ -117,7 +122,7 @@ public class CalculatorApplication extends android.app.Application implements Sh
                 new AndroidCalculatorEngine(this),
                 new AndroidCalculatorClipboard(this),
                 new AndroidCalculatorNotifier(this),
-                new AndroidCalculatorLogger(),
+                errorReporter,
                 new AndroidCalculatorPreferenceService(this),
                 keyboard,
                 new AndroidCalculatorPlotter(this, new CalculatorPlotterImpl(calculator))

app/src/main/java/org/solovyev/android/calculator/CalculatorDialogActivity.java

@@ -91,7 +91,7 @@ public class CalculatorDialogActivity extends ActionBarActivity {
 
         final DialogData dialogData = readDialogData(getIntent());
         if (dialogData == null) {
-            Locator.getInstance().getLogger().error(TAG, "Dialog data is null!");
+            Locator.getInstance().getErrorReporter().onError("Dialog data is null!");
             this.finish();
         } else {
             setContentView(R.layout.cpp_dialog);

app/src/main/java/org/solovyev/android/calculator/CalculatorEngineImpl.java

@@ -185,8 +185,8 @@ public class CalculatorEngineImpl implements CalculatorEngine {
     }
 
     private void logException(@Nonnull Exception e) {
-        final CalculatorLogger logger = Locator.getInstance().getLogger();
+        final ErrorReporter errorReporter = Locator.getInstance().getErrorReporter();
-        logger.error("Engine", e.getMessage(), e);
+        errorReporter.onException(e);
     }
 
     @Override

app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java

@@ -268,7 +268,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
                     result.toString();
 
                     if (messageRegistry.hasMessage()) {
-                        final CalculatorLogger logger = Locator.getInstance().getLogger();
+                        final ErrorReporter errorReporter = Locator.getInstance().getErrorReporter();
                         try {
                             final List<Message> messages = new ArrayList<Message>();
                             while (messageRegistry.hasMessage()) {
@@ -279,7 +279,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
                             }
                         } catch (Throwable e) {
                             // todo serso: not good but we need proper synchronization
-                            logger.error("Calculator", e.getMessage(), e);
+                            errorReporter.onException(e);
                         }
                     }
 

app/src/main/java/org/solovyev/android/calculator/CalculatorLocator.java

@@ -32,7 +32,7 @@ public interface CalculatorLocator {
               @Nonnull CalculatorEngine engine,
               @Nonnull CalculatorClipboard clipboard,
               @Nonnull CalculatorNotifier notifier,
-              @Nonnull CalculatorLogger logger,
+              @Nonnull ErrorReporter errorReporter,
               @Nonnull CalculatorPreferenceService preferenceService,
               @Nonnull Keyboard keyboard,
               @Nonnull CalculatorPlotter plotter);
@@ -53,7 +53,7 @@ public interface CalculatorLocator {
     CalculatorNotifier getNotifier();
 
     @Nonnull
-    CalculatorLogger getLogger();
+    ErrorReporter getErrorReporter();
 
     @Nonnull
     CalculatorPlotter getPlotter();

app/src/main/java/org/solovyev/android/calculator/Display.java

@@ -66,7 +66,7 @@ public class Display implements CalculatorEventListener {
 
     @Inject
     public Display(@Nonnull Calculator calculator) {
-        this.lastEvent = new CalculatorEventHolder(CalculatorUtils.createFirstEventDataId());
+        lastEvent = new CalculatorEventHolder(CalculatorUtils.createFirstEventDataId());
         calculator.addCalculatorEventListener(this);
     }
 

app/src/main/java/org/solovyev/android/calculator/Editor.java

@@ -27,7 +27,6 @@ import android.content.SharedPreferences;
 import com.squareup.otto.Bus;
 
 import org.solovyev.android.Check;
-import org.solovyev.android.calculator.text.TextProcessor;
 import org.solovyev.android.calculator.text.TextProcessorEditorResult;
 import org.solovyev.android.calculator.view.EditorTextProcessor;
 
@@ -43,7 +42,7 @@ public class Editor {
 
     private static final String TAG = App.subTag("Editor");
     @Nullable
-    private final TextProcessor<TextProcessorEditorResult, String> textProcessor;
+    private final EditorTextProcessor textProcessor;
     @Nullable
     private EditorView view;
     @Nonnull
@@ -53,11 +52,7 @@ public class Editor {
 
     @Inject
     public Editor(@Nonnull SharedPreferences preferences) {
-        this(new EditorTextProcessor(preferences));
+        textProcessor = new EditorTextProcessor(preferences);
-    }
-
-    public Editor(@Nullable TextProcessor<TextProcessorEditorResult, String> textProcessor) {
-        this.textProcessor = textProcessor;
     }
 
     public static int clamp(int selection, @Nonnull CharSequence text) {
@@ -92,12 +87,8 @@ public class Editor {
     public EditorState onTextChanged(@Nonnull EditorState newState) {
         Check.isMainThread();
         if (textProcessor != null) {
-            try {
             final TextProcessorEditorResult result = textProcessor.process(newState.getTextString());
             newState = EditorState.create(result.getCharSequence(), newState.selection + result.getOffset());
-            } catch (CalculatorParseException e) {
-                Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
-            }
         }
         final EditorState oldState = state;
         state = newState;

app/src/main/java/org/solovyev/android/calculator/ErrorReporter.java

@@ -0,0 +1,30 @@
+/*
+ * 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.calculator;
+
+import javax.annotation.Nonnull;
+
+public interface ErrorReporter {
+    void onException(@Nonnull Throwable e);
+    void onError(@Nonnull String message);
+}

app/src/main/java/org/solovyev/android/calculator/Locator.java

@@ -39,7 +39,7 @@ public class Locator implements CalculatorLocator {
     @Nonnull
     private CalculatorNotifier calculatorNotifier = new DummyCalculatorNotifier();
     @Nonnull
-    private CalculatorLogger calculatorLogger = new SystemOutCalculatorLogger();
+    private ErrorReporter errorReporter = new SystemErrorReporter();
     @Nonnull
     private CalculatorClipboard calculatorClipboard = new DummyCalculatorClipboard();
     @Nonnull
@@ -61,7 +61,7 @@ public class Locator implements CalculatorLocator {
                      @Nonnull CalculatorEngine engine,
                      @Nonnull CalculatorClipboard clipboard,
                      @Nonnull CalculatorNotifier notifier,
-                     @Nonnull CalculatorLogger logger,
+                     @Nonnull ErrorReporter errorReporter,
                      @Nonnull CalculatorPreferenceService preferenceService,
                      @Nonnull Keyboard keyboard,
                      @Nonnull CalculatorPlotter plotter) {
@@ -70,7 +70,7 @@ public class Locator implements CalculatorLocator {
         this.calculatorEngine = engine;
         this.calculatorClipboard = clipboard;
         this.calculatorNotifier = notifier;
-        this.calculatorLogger = logger;
+        this.errorReporter = errorReporter;
         this.calculatorPreferenceService = preferenceService;
         this.calculatorPlotter = plotter;
 
@@ -113,8 +113,8 @@ public class Locator implements CalculatorLocator {
 
     @Override
     @Nonnull
-    public CalculatorLogger getLogger() {
+    public ErrorReporter getErrorReporter() {
-        return calculatorLogger;
+        return errorReporter;
     }
 
     @Nonnull

app/src/main/java/org/solovyev/android/calculator/SystemErrorReporter.java

@@ -25,19 +25,15 @@ package org.solovyev.android.calculator;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
-/**
+public class SystemErrorReporter implements ErrorReporter {
- * User: serso
- * Date: 10/11/12
- * Time: 12:11 AM
- */
-public interface CalculatorLogger {
 
-    void debug(@Nullable String tag, @Nonnull String message);
+    @Override
-
+    public void onException(@Nonnull Throwable e) {
-    void debug(@Nullable String tag, @Nullable String message, @Nonnull Throwable e);
+        e.printStackTrace(System.out);
-
+    }
-    void error(@Nullable String tag, @Nullable String message, @Nonnull Throwable e);
-
-    void error(@Nullable String tag, @Nullable String message);
 
+    @Override
+    public void onError(@Nullable String message) {
+        System.out.println(message);
+    }
 }

app/src/main/java/org/solovyev/android/calculator/SystemOutCalculatorLogger.java

@@ -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.calculator;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * User: serso
- * Date: 10/11/12
- * Time: 12:12 AM
- */
-public class SystemOutCalculatorLogger implements CalculatorLogger {
-
-    @Nonnull
-    private static final String TAG = SystemOutCalculatorLogger.class.getSimpleName();
-
-    @Override
-    public void debug(@Nullable String tag, @Nullable String message) {
-        System.out.println(getTag(tag) + ": " + message);
-    }
-
-    @Nonnull
-    private String getTag(@Nullable String tag) {
-        return tag != null ? tag : TAG;
-    }
-
-    @Override
-    public void debug(@Nullable String tag, @Nullable String message, @Nonnull Throwable e) {
-        debug(tag, message);
-        e.printStackTrace(System.out);
-    }
-
-    @Override
-    public void error(@Nullable String tag, @Nullable String message, @Nonnull Throwable e) {
-        System.out.println(getTag(tag) + ": " + message);
-        e.printStackTrace(System.out);
-    }
-
-    @Override
-    public void error(@Nullable String tag, @Nullable String message) {
-        System.out.println(getTag(tag) + ": " + message);
-    }
-}

app/src/main/java/org/solovyev/android/calculator/history/History.java

@@ -41,12 +41,13 @@ import org.solovyev.android.calculator.Display;
 import org.solovyev.android.calculator.DisplayState;
 import org.solovyev.android.calculator.Editor;
 import org.solovyev.android.calculator.EditorState;
-import org.solovyev.android.calculator.Locator;
+import org.solovyev.android.calculator.ErrorReporter;
 import org.solovyev.android.calculator.model.AndroidCalculatorEngine.Preferences;
 import org.solovyev.android.io.FileLoader;
 import org.solovyev.android.io.FileSaver;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedList;
@@ -65,6 +66,7 @@ import static android.text.TextUtils.isEmpty;
 public class History {
 
     public static final String TAG = App.subTag("History");
+    public static final String OLD_HISTORY_PREFS_KEY = "org.solovyev.android.calculator.CalculatorModel_history";
     private static final ChangedEvent CHANGED_EVENT_RECENT = new ChangedEvent(true);
     private static final ChangedEvent CHANGED_EVENT_SAVED = new ChangedEvent(false);
     private static final int MAX_INTERMEDIATE_STREAK = 5;
@@ -76,29 +78,23 @@ public class History {
     private final RecentHistory recent = new RecentHistory();
     @Nonnull
     private final List<HistoryState> saved = new ArrayList<>();
-    @Nonnull
+    @Inject
-    private final Application application;
+    Application application;
-    @Nonnull
+    @Inject
-    private final Bus bus;
+    Bus bus;
     @Inject
     Handler handler;
     @Inject
     SharedPreferences preferences;
     @Inject
     Editor editor;
-
     @Inject
-    public History(@NonNull Application application, @NonNull Bus bus, @Nonnull @Named(AppModule.THREAD_INIT) Executor initThread) {
+    Display display;
-        this.application = application;
+    @Inject
-        this.bus = bus;
+    ErrorReporter errorReporter;
-        this.bus.register(this);
+    @Inject
-        initThread.execute(new Runnable() {
+    @Named(AppModule.THREAD_BACKGROUND)
-            @Override
+    Executor backgroundThread;
-            public void run() {
-                init();
-            }
-        });
-    }
 
     @Nullable
     static List<HistoryState> convertOldHistory(@NonNull String xml) {
@@ -120,7 +116,7 @@ public class History {
     }
 
     @Nonnull
-    static List<HistoryState> loadStates(@Nonnull File file) {
+    static List<HistoryState> loadStates(@Nonnull File file) throws IOException, JSONException {
         if (!file.exists()) {
             return Collections.emptyList();
         }
@@ -128,12 +124,7 @@ public class History {
         if (isEmpty(json)) {
             return Collections.emptyList();
         }
-        try {
         return RecentHistory.fromJson(new JSONArray(json.toString()));
-        } catch (JSONException e) {
-            Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
-        }
-        return Collections.emptyList();
     }
 
     private static boolean isIntermediate(@Nonnull String olderText,
@@ -183,6 +174,21 @@ public class History {
         return sb.toString();
     }
 
+    @Inject
+    public History() {
+    }
+
+    public void init(@NonNull Executor initThread) {
+        Check.isMainThread();
+        bus.register(this);
+        initThread.execute(new Runnable() {
+            @Override
+            public void run() {
+                initAsync();
+            }
+        });
+    }
+
     @NonNull
     private File getSavedHistoryFile() {
         return new File(application.getFilesDir(), "history-saved.json");
@@ -195,7 +201,7 @@ public class History {
 
     private void migrateOldHistory() {
         try {
-            final String xml = preferences.getString("org.solovyev.android.calculator.CalculatorModel_history", null);
+            final String xml = preferences.getString(OLD_HISTORY_PREFS_KEY, null);
             if (isEmpty(xml)) {
                 return;
             }
@@ -205,16 +211,17 @@ public class History {
             }
             final JSONArray json = RecentHistory.toJson(states);
             FileSaver.save(getSavedHistoryFile(), json.toString());
-        } catch (Exception e) {
+            preferences.edit().remove(OLD_HISTORY_PREFS_KEY).apply();
-            Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
+        } catch (IOException e) {
+            errorReporter.onException(e);
         }
     }
 
-    private void init() {
+    private void initAsync() {
         Check.isNotMainThread();
         migrateOldHistory();
-        final List<HistoryState> recentStates = loadStates(getRecentHistoryFile());
+        final List<HistoryState> recentStates = tryLoadStates(getRecentHistoryFile());
-        final List<HistoryState> savedStates = loadStates(getSavedHistoryFile());
+        final List<HistoryState> savedStates = tryLoadStates(getSavedHistoryFile());
         handler.post(new Runnable() {
             @Override
             public void run() {
@@ -226,6 +233,16 @@ public class History {
         });
     }
 
+    @Nonnull
+    private List<HistoryState> tryLoadStates(@NonNull File file) {
+        try {
+            return loadStates(file);
+        } catch (IOException | JSONException e) {
+            errorReporter.onException(e);
+        }
+        return Collections.emptyList();
+    }
+
     public void addRecent(@Nonnull HistoryState state) {
         Check.isMainThread();
         recent.add(state);
@@ -318,8 +335,8 @@ public class History {
     }
 
     private void applyHistoryState(@Nonnull HistoryState state) {
-        App.getEditor().setState(state.editor);
+        editor.setState(state.editor);
-        App.getDisplay().setState(state.display);
+        display.setState(state.display);
     }
 
     public void removeSaved(@Nonnull HistoryState state) {
@@ -364,12 +381,16 @@ public class History {
             Check.isMainThread();
             // don't need to save intermediate states, thus {@link History#getRecent}
             final List<HistoryState> states = recent ? getRecent() : getSaved();
-            App.getBackground().execute(new Runnable() {
+            backgroundThread.execute(new Runnable() {
                 @Override
                 public void run() {
                     final File file = recent ? getRecentHistoryFile() : getSavedHistoryFile();
                     final JSONArray array = RecentHistory.toJson(states);
+                    try {
                         FileSaver.save(file, array.toString());
+                    } catch (IOException e) {
+                        errorReporter.onException(e);
+                    }
                 }
             });
         }

app/src/main/java/org/solovyev/android/calculator/view/EditorTextProcessor.java

@@ -2,17 +2,14 @@ package org.solovyev.android.calculator.view;
 
 import android.app.Application;
 import android.content.SharedPreferences;
-import android.util.Log;
 
 import org.solovyev.android.calculator.App;
-import org.solovyev.android.calculator.CalculatorParseException;
 import org.solovyev.android.calculator.Preferences;
 import org.solovyev.android.calculator.text.TextProcessor;
 import org.solovyev.android.calculator.text.TextProcessorEditorResult;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import javax.inject.Inject;
 
 import static org.solovyev.android.calculator.Preferences.Gui.colorDisplay;
 import static org.solovyev.android.calculator.Preferences.Gui.theme;
@@ -22,7 +19,7 @@ public final class EditorTextProcessor implements TextProcessor<TextProcessorEdi
     private boolean highlightText = true;
 
     @Nullable
-    private TextProcessor<TextProcessorEditorResult, String> textHighlighter;
+    private TextHighlighter textHighlighter;
 
     public EditorTextProcessor(@Nonnull SharedPreferences preferences) {
         preferences.registerOnSharedPreferenceChangeListener(this);
@@ -31,30 +28,16 @@ public final class EditorTextProcessor implements TextProcessor<TextProcessorEdi
 
     @Nonnull
     @Override
-    public TextProcessorEditorResult process(@Nonnull String text) throws CalculatorParseException {
+    public TextProcessorEditorResult process(@Nonnull String text) {
-        TextProcessorEditorResult result;
+        if (!highlightText) {
-
+            return new TextProcessorEditorResult(text, 0);
-        if (highlightText) {
+        }
-
-            try {
         final TextProcessorEditorResult processesText = getTextHighlighter().process(text);
-
+        return new TextProcessorEditorResult(processesText.getCharSequence(), processesText.getOffset());
-                result = new TextProcessorEditorResult(processesText.getCharSequence(), processesText.getOffset());
-            } catch (CalculatorParseException e) {
-                // set raw text
-                result = new TextProcessorEditorResult(text, 0);
-
-                Log.e(this.getClass().getName(), e.getMessage(), e);
-            }
-        } else {
-            result = new TextProcessorEditorResult(text, 0);
-        }
-
-        return result;
     }
 
     @Nonnull
-    private TextProcessor<TextProcessorEditorResult, String> getTextHighlighter() {
+    private TextHighlighter getTextHighlighter() {
         if (textHighlighter == null) {
             onSharedPreferenceChanged(App.getPreferences(), theme.getKey());
         }

app/src/main/java/org/solovyev/android/calculator/view/TextHighlighter.java

@@ -26,17 +26,24 @@ import android.graphics.Typeface;
 import android.text.SpannableStringBuilder;
 import android.text.style.ForegroundColorSpan;
 import android.text.style.StyleSpan;
+
 import com.google.common.collect.Lists;
+
 import org.solovyev.android.Check;
-import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.BaseNumberBuilder;
+import org.solovyev.android.calculator.CalculatorEngine;
+import org.solovyev.android.calculator.LiteNumberBuilder;
+import org.solovyev.android.calculator.Locator;
+import org.solovyev.android.calculator.NumberBuilder;
 import org.solovyev.android.calculator.math.MathType;
 import org.solovyev.android.calculator.text.TextProcessor;
 import org.solovyev.android.calculator.text.TextProcessorEditorResult;
 
-import javax.annotation.Nonnull;
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.annotation.Nonnull;
+
 public class TextHighlighter implements TextProcessor<TextProcessorEditorResult, String> {
 
     private final int red;
@@ -76,7 +83,7 @@ public class TextHighlighter implements TextProcessor<TextProcessorEditorResult,
 
     @Nonnull
     @Override
-    public TextProcessorEditorResult process(@Nonnull String text) throws CalculatorParseException {
+    public TextProcessorEditorResult process(@Nonnull String text) {
         final CalculatorEngine engine = Locator.getInstance().getEngine();
         final SpannableStringBuilder sb = new SpannableStringBuilder();
         final BaseNumberBuilder nb = !formatNumber ? new LiteNumberBuilder(engine) : new NumberBuilder(engine);

app/src/main/java/org/solovyev/android/io/BaseIoLoader.java

@@ -1,7 +1,6 @@
 package org.solovyev.android.io;
 
 import android.support.annotation.Nullable;
-import android.util.Log;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -11,7 +10,7 @@ import java.io.InputStreamReader;
 public abstract class BaseIoLoader {
 
     @Nullable
-    public CharSequence load() {
+    public CharSequence load() throws IOException {
         BufferedReader reader = null;
         try {
             final InputStream is = getInputStream();
@@ -26,12 +25,9 @@ public abstract class BaseIoLoader {
                 line = reader.readLine();
             }
             return result;
-        } catch (IOException e) {
-            Log.e(getClass().getSimpleName(), e.getMessage(), e);
         } finally {
             Io.close(reader);
         }
-        return null;
     }
 
     @Nullable

app/src/main/java/org/solovyev/android/io/BaseIoSaver.java

@@ -1,14 +1,13 @@
 package org.solovyev.android.io;
 
 import android.support.annotation.NonNull;
-import android.util.Log;
 
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 
-public abstract class BaseIoSaver implements Runnable {
+public abstract class BaseIoSaver {
 
     @NonNull
     private final CharSequence data;
@@ -17,13 +16,11 @@ public abstract class BaseIoSaver implements Runnable {
         this.data = data;
     }
 
-    public void save() {
+    public void save() throws IOException {
         OutputStreamWriter out = null;
         try {
             out = new OutputStreamWriter(getOutputStream());
             out.write(data.toString());
-        } catch (IOException e) {
-            Log.e("FileSaver", e.getMessage(), e);
         } finally {
             Io.close(out);
         }
@@ -31,9 +28,4 @@ public abstract class BaseIoSaver implements Runnable {
 
     @NonNull
     protected abstract FileOutputStream getOutputStream() throws FileNotFoundException;
-
-    @Override
-    public void run() {
-        save();
-    }
 }

app/src/main/java/org/solovyev/android/io/FileLoader.java

@@ -18,7 +18,7 @@ public class FileLoader extends BaseIoLoader {
     }
 
     @Nullable
-    public static CharSequence load(@NonNull File file) {
+    public static CharSequence load(@NonNull File file) throws IOException {
         final FileLoader loader = new FileLoader(file);
         return loader.load();
     }

app/src/main/java/org/solovyev/android/io/FileSaver.java

@@ -5,6 +5,7 @@ import android.support.annotation.NonNull;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
+import java.io.IOException;
 
 public class FileSaver extends BaseIoSaver {
 
@@ -16,7 +17,7 @@ public class FileSaver extends BaseIoSaver {
         this.file = file;
     }
 
-    public static void save(@NonNull File file, @NonNull CharSequence data) {
+    public static void save(@NonNull File file, @NonNull CharSequence data) throws IOException {
         final FileSaver fileSaver = new FileSaver(file, data);
         fileSaver.save();
     }

app/src/test/java/org/solovyev/android/calculator/AbstractCalculatorTest.java

@@ -36,7 +36,7 @@ import java.util.concurrent.Executor;
 public class AbstractCalculatorTest {
 
     protected void setUp() throws Exception {
-        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), CalculatorTestUtils.newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemOutCalculatorLogger(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
+        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), CalculatorTestUtils.newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemErrorReporter(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
         Locator.getInstance().getEngine().init();
     }
 

app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java

@@ -23,8 +23,9 @@
 package org.solovyev.android.calculator;
 
 import android.content.Context;
+
 import com.squareup.otto.Bus;
-import jscl.JsclMathEngine;
+
 import org.junit.Assert;
 import org.mockito.Mockito;
 import org.robolectric.fakes.RoboSharedPreferences;
@@ -32,9 +33,12 @@ import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.android.calculator.language.Languages;
 import org.solovyev.android.calculator.plot.CalculatorPlotter;
 
-import javax.annotation.Nonnull;
+import java.io.ByteArrayInputStream;
-import javax.annotation.Nullable;
+import java.io.ByteArrayOutputStream;
-import java.io.*;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.text.DecimalFormatSymbols;
 import java.util.HashMap;
 import java.util.Map;
@@ -42,6 +46,11 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import jscl.JsclMathEngine;
+
 /**
  * User: serso
  * Date: 10/7/12
@@ -54,7 +63,7 @@ public class CalculatorTestUtils {
 
     public static void staticSetUp() throws Exception {
         App.init(new CalculatorApplication(), new Languages(new RoboSharedPreferences(new HashMap<String, Map<String, Object>>(), "test", 0)));
-        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemOutCalculatorLogger(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
+        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemErrorReporter(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
         Locator.getInstance().getEngine().init();
 
         final DecimalFormatSymbols decimalGroupSymbols = new DecimalFormatSymbols();
@@ -64,7 +73,7 @@ public class CalculatorTestUtils {
     }
 
     public static void staticSetUp(@Nullable Context context) throws Exception {
-        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemOutCalculatorLogger(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
+        Locator.getInstance().init(new CalculatorImpl(Mockito.mock(Bus.class), Mockito.mock(Executor.class)), newCalculatorEngine(), Mockito.mock(CalculatorClipboard.class), Mockito.mock(CalculatorNotifier.class), new SystemErrorReporter(), Mockito.mock(CalculatorPreferenceService.class), Mockito.mock(Keyboard.class), Mockito.mock(CalculatorPlotter.class));
         Locator.getInstance().getEngine().init();
 
         if (context != null) {

app/src/test/java/org/solovyev/android/calculator/history/HistoryTest.java

@@ -43,7 +43,6 @@ import org.solovyev.android.calculator.jscl.JsclOperation;
 
 import java.io.File;
 import java.util.List;
-import java.util.concurrent.Executor;
 
 import javax.annotation.Nonnull;
 
@@ -65,7 +64,9 @@ public class HistoryTest {
 
     @Before
     public void setUp() throws Exception {
-        history = new History(RuntimeEnvironment.application, mock(Bus.class), mock(Executor.class));
+        history = new History();
+        history.application = RuntimeEnvironment.application;
+        history.bus = mock(Bus.class);
         history.handler = mock(Handler.class);
         history.preferences = mock(SharedPreferences.class);
         history.editor = mock(Editor.class);