Tabs

calculatorpp/AndroidManifest.xml

@@ -20,28 +20,27 @@
 
         </activity>
 
-        <!--NOTE: a:configChanges="orientation|keyboardHidden" is needed to correct work of dialog windows (not to close them on orientation change) -->
+        <activity android:label="@string/c_app_settings" android:name=".CalculatorPreferencesActivity"/>
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_app_settings" android:name=".CalculatorPreferencesActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_history" android:name=".history.CalculatorHistoryFragmentActivity"/>
+        <activity android:label="@string/c_history" android:name=".history.CalculatorHistoryFragmentActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_about" android:name=".about.CalculatorAboutTabActivity"/>
+        <activity android:label="@string/c_about" android:name=".about.CalculatorAboutTabActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_about" android:name=".about.CalculatorAboutActivity"/>
+        <activity android:label="@string/c_about" android:name=".about.CalculatorAboutActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_about" android:name=".about.CalculatorReleaseNotesActivity"/>
+        <activity android:label="@string/c_about" android:name=".about.CalculatorReleaseNotesActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_help" android:name=".help.CalculatorHelpTabActivity"/>
+        <activity android:label="@string/c_help" android:name=".help.CalculatorHelpTabActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_help" android:name=".help.HelpFaqActivity"/>
+        <activity android:label="@string/c_help" android:name=".help.HelpFaqActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_help" android:name=".help.HelpHintsActivity"/>
+        <activity android:label="@string/c_help" android:name=".help.HelpHintsActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_help" android:name=".help.HelpScreensActivity"/>
+        <activity android:label="@string/c_help" android:name=".help.HelpScreensActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_functions" android:name=".math.edit.CalculatorFunctionsFragmentActivity"/>
+        <activity android:label="@string/c_functions" android:name=".math.edit.CalculatorFunctionsFragmentActivity"/>
 
-        <activity android:configChanges="orientation|keyboardHidden" android:label="@string/c_operators" android:name=".math.edit.CalculatorOperatorsFragmentActivity"/>
+        <activity android:label="@string/c_operators" android:name=".math.edit.CalculatorOperatorsFragmentActivity"/>
 
         <activity android:label="@string/c_vars_and_constants" android:name=".math.edit.CalculatorVarsFragmentActivity"/>
 

calculatorpp/res/values/text_strings.xml

@@ -209,5 +209,7 @@
 
     <string name="editor">Editor</string>
     <string name="result">Result</string>
+    <string name="other">Other</string>
+    <string name="derivatives">Derivatives/Integrals</string>
 
 </resources>

calculatorpp/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java

@@ -25,6 +25,7 @@ import net.robotmedia.billing.IBillingObserver;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.AndroidUtils;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.calculator.about.CalculatorReleaseNotesActivity;
 import org.solovyev.android.calculator.history.CalculatorHistoryFragment;
 import org.solovyev.android.calculator.history.CalculatorSavedHistoryFragment;
@@ -74,14 +75,12 @@ public class CalculatorActivity extends SherlockFragmentActivity implements Shar
         activityHelper.logDebug("super.onCreate");
 
         if (findViewById(R.id.main_second_pane) != null) {
-            activityHelper.addTab(this, "history", CalculatorHistoryFragment.class, null, R.string.c_history, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.history, null, R.id.main_second_pane);
-            activityHelper.addTab(this, "saved_history", CalculatorSavedHistoryFragment.class, null, R.string.c_saved_history, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.saved_history, null, R.id.main_second_pane);
-            activityHelper.addTab(this, "vars", CalculatorVarsFragment.class, null, R.string.c_vars, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.variables, null, R.id.main_second_pane);
-            activityHelper.addTab(this, "functions", CalculatorFunctionsFragment.class, null, R.string.c_functions, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.functions, null, R.id.main_second_pane);
-            activityHelper.addTab(this, "operators", CalculatorOperatorsFragment.class, null, R.string.c_operators, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.operators, null, R.id.main_second_pane);
-            activityHelper.addTab(this, "plot", CalculatorPlotFragment.class, null, R.string.c_plot, R.id.main_second_pane);
+            activityHelper.addTab(this, CalculatorFragmentType.plotter, null, R.id.main_second_pane);
-
-            activityHelper.restoreSavedTab(this);
         } else {
             getSupportActionBar().hide();
         }
@@ -208,6 +207,13 @@ public class CalculatorActivity extends SherlockFragmentActivity implements Shar
         getCalculator().evaluate();
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
     @Override
 	protected void onResume() {
 		super.onResume();

calculatorpp/src/main/java/org/solovyev/android/calculator/CalculatorActivityHelper.java

@@ -7,6 +7,7 @@ import android.view.View;
 import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 
 /**
  * User: serso
@@ -29,6 +30,9 @@ public interface CalculatorActivityHelper {
     void onResume(@NotNull SherlockFragmentActivity activity);
     void onResume(@NotNull Activity activity);
 
+    void onPause(@NotNull Activity activity);
+    void onPause(@NotNull SherlockFragmentActivity activity);
+
     void onDestroy(@NotNull SherlockFragmentActivity activity);
     void onDestroy(@NotNull Activity activity);
 
@@ -36,11 +40,17 @@ public interface CalculatorActivityHelper {
                 @NotNull String tag,
                 @NotNull Class<? extends Fragment> fragmentClass,
                 @Nullable Bundle fragmentArgs,
-                int captionResId, int parentViewId);
+                int captionResId,
+                int parentViewId);
+
+    void addTab(@NotNull SherlockFragmentActivity activity,
+                @NotNull CalculatorFragmentType fragmentType,
+                @Nullable Bundle fragmentArgs,
+                int parentViewId);
 
-    void restoreSavedTab(@NotNull SherlockFragmentActivity activity);
 
     void logDebug(@NotNull String message);
 
     void processButtons(@NotNull Activity activity, @NotNull View root);
+
 }

calculatorpp/src/main/java/org/solovyev/android/calculator/CalculatorActivityHelperImpl.java

@@ -13,6 +13,7 @@ import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.AndroidUtils;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.sherlock.tabs.ActionBarFragmentTabListener;
 
 import java.util.ArrayList;
@@ -32,7 +33,6 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
     *
     **********************************************************************
     */
-    private static final String SELECTED_NAV = "selected_nav";
 
     /*
     **********************************************************************
@@ -51,8 +51,8 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
 
     @NotNull
     private CalculatorPreferences.Gui.Theme theme;
-    private int navPosition = 0;
 
+    private int selectedNavigationIndex = 0;
 
     public CalculatorActivityHelperImpl(int layoutId, @NotNull String logTag) {
         super(logTag);
@@ -85,10 +85,6 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
         } else {
             Log.e(CalculatorActivityHelperImpl.class.getSimpleName(), "Root is null for " + activity.getClass().getName());
         }
-
-        if (savedInstanceState != null) {
-            navPosition = savedInstanceState.getInt(SELECTED_NAV, 0);
-        }
     }
 
     @Override
@@ -101,29 +97,34 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
         actionBar.setHomeButtonEnabled(false);
         actionBar.setDisplayShowHomeEnabled(true);
 
+        toggleTitle(activity, true);
+        actionBar.setIcon(R.drawable.icon_action_bar);
+    }
+
+    private void toggleTitle(@NotNull SherlockFragmentActivity activity, boolean showTitle) {
+        final ActionBar actionBar = activity.getSupportActionBar();
+
         if (activity instanceof CalculatorActivity) {
             if (AndroidUtils.getScreenOrientation(activity) == Configuration.ORIENTATION_PORTRAIT) {
                 actionBar.setDisplayShowTitleEnabled(true);
             } else {
+                actionBar.setDisplayShowTitleEnabled(false);
             }
         } else {
-            actionBar.setDisplayShowTitleEnabled(true);
+            actionBar.setDisplayShowTitleEnabled(showTitle);
         }
-        actionBar.setIcon(R.drawable.icon_action_bar);
     }
 
-    @Override
     public void restoreSavedTab(@NotNull SherlockFragmentActivity activity) {
         final ActionBar actionBar = activity.getSupportActionBar();
-        if (navPosition >= 0 && navPosition < actionBar.getTabCount()) {
+        if (selectedNavigationIndex >= 0 && selectedNavigationIndex < actionBar.getTabCount()) {
-            activity.getSupportActionBar().setSelectedNavigationItem(navPosition);
+            actionBar.setSelectedNavigationItem(selectedNavigationIndex);
         }
     }
 
     @Override
     public void onSaveInstanceState(@NotNull SherlockFragmentActivity activity, @NotNull Bundle outState) {
         onSaveInstanceState((Activity) activity, outState);
-        outState.putInt(SELECTED_NAV, activity.getSupportActionBar().getSelectedNavigationIndex());
     }
 
     @Override
@@ -140,6 +141,29 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
         }
     }
 
+    @Override
+    public void onPause(@NotNull Activity activity) {
+    }
+
+    @Override
+    public void onPause(@NotNull SherlockFragmentActivity activity) {
+        onPause((Activity) activity);
+
+        final int selectedNavigationIndex = activity.getSupportActionBar().getSelectedNavigationIndex();
+        if (selectedNavigationIndex >= 0) {
+            final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
+            final SharedPreferences.Editor editor = preferences.edit();
+            editor.putInt(getSavedTabPreferenceName(activity), selectedNavigationIndex);
+            editor.commit();
+        }
+
+    }
+
+    @NotNull
+    private String getSavedTabPreferenceName(@NotNull Activity activity) {
+        return "tab_" + activity.getClass().getSimpleName();
+    }
+
     @Override
     public void onDestroy(@NotNull Activity activity) {
         super.onDestroy(activity);
@@ -161,9 +185,10 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
                        @Nullable Bundle fragmentArgs,
                        int captionResId,
                        int parentViewId) {
-        activity.getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
-
         final ActionBar actionBar = activity.getSupportActionBar();
+
+        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
+
         final ActionBar.Tab tab = actionBar.newTab();
         tab.setTag(tag);
         tab.setText(captionResId);
@@ -173,8 +198,11 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
         actionBar.addTab(tab);
 
         fragmentTags.add(tag);
+    }
 
-        restoreSavedTab(activity);
+    @Override
+    public void addTab(@NotNull SherlockFragmentActivity activity, @NotNull CalculatorFragmentType fragmentType, @Nullable Bundle fragmentArgs, int parentViewId) {
+        addTab(activity, fragmentType.getFragmentTag(), fragmentType.getFragmentClass(), fragmentArgs, fragmentType.getDefaultTitleResId(), parentViewId);
     }
 
     @Override
@@ -191,5 +219,9 @@ public class CalculatorActivityHelperImpl extends AbstractCalculatorHelper imple
     @Override
     public void onResume(@NotNull SherlockFragmentActivity activity) {
         onResume((Activity) activity);
+
+        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
+        selectedNavigationIndex = preferences.getInt(getSavedTabPreferenceName(activity), -1);
+        restoreSavedTab(activity);
     }
 }

calculatorpp/src/main/java/org/solovyev/android/calculator/about/CalculatorFragmentType.java

@@ -0,0 +1,59 @@
+package org.solovyev.android.calculator.about;
+
+import android.support.v4.app.Fragment;
+import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.calculator.R;
+import org.solovyev.android.calculator.history.CalculatorHistoryFragment;
+import org.solovyev.android.calculator.history.CalculatorSavedHistoryFragment;
+import org.solovyev.android.calculator.math.edit.CalculatorFunctionsFragment;
+import org.solovyev.android.calculator.math.edit.CalculatorOperatorsFragment;
+import org.solovyev.android.calculator.math.edit.CalculatorVarsFragment;
+import org.solovyev.android.calculator.plot.CalculatorPlotFragment;
+
+/**
+ * User: Solovyev_S
+ * Date: 03.10.12
+ * Time: 11:30
+ */
+public enum CalculatorFragmentType {
+
+    history(CalculatorHistoryFragment.class, "history", R.string.c_history),
+    saved_history(CalculatorSavedHistoryFragment.class, "saved_history", R.string.c_saved_history),
+    variables(CalculatorVarsFragment.class, "vars", R.string.c_vars),
+    functions(CalculatorFunctionsFragment.class, "functions", R.string.c_functions),
+    operators(CalculatorOperatorsFragment.class, "operators", R.string.c_operators),
+    plotter(CalculatorPlotFragment.class, "plotter", R.string.c_plot);
+
+    @NotNull
+    private Class<? extends Fragment> fragmentClass;
+
+    @NotNull
+    private final String fragmentTag;
+
+    private int defaultTitleResId;
+
+    private CalculatorFragmentType(@NotNull Class<? extends Fragment> fragmentClass, @NotNull String fragmentTag, int defaultTitleResId) {
+        this.fragmentClass = fragmentClass;
+        this.fragmentTag = fragmentTag;
+        this.defaultTitleResId = defaultTitleResId;
+    }
+
+    @NotNull
+    public String getFragmentTag() {
+        return fragmentTag;
+    }
+
+    public int getDefaultTitleResId() {
+        return defaultTitleResId;
+    }
+
+    @NotNull
+    public Class<? extends Fragment> getFragmentClass() {
+        return fragmentClass;
+    }
+
+    @NotNull
+    public String createSubFragmentTag(@NotNull String subFragmentTag) {
+        return this.fragmentTag + "_" + subFragmentTag;
+    }
+}

calculatorpp/src/main/java/org/solovyev/android/calculator/history/CalculatorHistoryFragmentActivity.java

@@ -11,6 +11,7 @@ import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 
 /**
  * User: serso
@@ -28,8 +29,8 @@ public class CalculatorHistoryFragmentActivity extends SherlockFragmentActivity
 
         activityHelper.onCreate(this, savedInstanceState);
 
-        activityHelper.addTab(this, "history", CalculatorHistoryFragment.class, null, R.string.c_history, R.id.main_layout);
+        activityHelper.addTab(this, CalculatorFragmentType.history, null, R.id.main_layout);
-        activityHelper.addTab(this, "saved_history", CalculatorSavedHistoryFragment.class, null, R.string.c_saved_history, R.id.main_layout);
+        activityHelper.addTab(this, CalculatorFragmentType.saved_history, null, R.id.main_layout);
     }
 
     @Override
@@ -46,6 +47,14 @@ public class CalculatorHistoryFragmentActivity extends SherlockFragmentActivity
         activityHelper.onResume(this);
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
+
     @Override
     protected void onDestroy() {
         super.onDestroy();

calculatorpp/src/main/java/org/solovyev/android/calculator/math/edit/CalculatorFunctionsFragmentActivity.java

@@ -11,6 +11,7 @@ import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.calculator.history.CalculatorHistoryFragmentActivity;
 import org.solovyev.android.calculator.model.AndroidFunctionsMathRegistry;
 
@@ -30,9 +31,12 @@ public class CalculatorFunctionsFragmentActivity extends SherlockFragmentActivit
 
         activityHelper.onCreate(this, savedInstanceState);
 
+        final CalculatorFragmentType fragmentType = CalculatorFragmentType.functions;
+
         for (AndroidFunctionsMathRegistry.Category category : AndroidFunctionsMathRegistry.Category.getCategoriesByTabOrder()) {
-            activityHelper.addTab(this, category.name(), CalculatorFunctionsFragment.class, AbstractMathEntityListFragment.createBundleFor(category.name()), category.getCaptionId(), R.id.main_layout);
+            activityHelper.addTab(this, fragmentType.createSubFragmentTag(category.name()), fragmentType.getFragmentClass(), AbstractMathEntityListFragment.createBundleFor(category.name()), category.getCaptionId(), R.id.main_layout);
         }
+
     }
 
     @Override
@@ -49,6 +53,14 @@ public class CalculatorFunctionsFragmentActivity extends SherlockFragmentActivit
         activityHelper.onResume(this);
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
+
     @Override
     protected void onDestroy() {
         super.onDestroy();

calculatorpp/src/main/java/org/solovyev/android/calculator/math/edit/CalculatorOperatorsFragmentActivity.java

@@ -11,7 +11,10 @@ import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.calculator.history.CalculatorHistoryFragmentActivity;
+import org.solovyev.android.calculator.model.AndroidFunctionsMathRegistry;
+import org.solovyev.android.calculator.model.AndroidOperatorsMathRegistry;
 
 /**
  * User: serso
@@ -29,7 +32,11 @@ public class CalculatorOperatorsFragmentActivity extends SherlockFragmentActivit
 
         activityHelper.onCreate(this, savedInstanceState);
 
-        activityHelper.addTab(this, "operators", CalculatorOperatorsFragment.class, null, R.string.c_operators, R.id.main_layout);
+        final CalculatorFragmentType fragmentType = CalculatorFragmentType.operators;
+
+        for (AndroidOperatorsMathRegistry.Category category : AndroidOperatorsMathRegistry.Category.getCategoriesByTabOrder()) {
+            activityHelper.addTab(this, fragmentType.createSubFragmentTag(category.name()), fragmentType.getFragmentClass(), AbstractMathEntityListFragment.createBundleFor(category.name()), category.getCaptionId(), R.id.main_layout);
+        }
     }
 
     @Override
@@ -46,6 +53,14 @@ public class CalculatorOperatorsFragmentActivity extends SherlockFragmentActivit
         activityHelper.onResume(this);
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
+
     @Override
     protected void onDestroy() {
         super.onDestroy();

calculatorpp/src/main/java/org/solovyev/android/calculator/math/edit/CalculatorVarsFragmentActivity.java

@@ -12,6 +12,7 @@ import com.actionbarsherlock.app.SherlockFragmentActivity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.calculator.history.CalculatorHistoryFragmentActivity;
 import org.solovyev.android.calculator.model.VarCategory;
 
@@ -40,6 +41,7 @@ public class CalculatorVarsFragmentActivity extends SherlockFragmentActivity imp
             bundle = null;
         }
 
+        final CalculatorFragmentType fragmentType = CalculatorFragmentType.variables;
 
         for (VarCategory category : VarCategory.getCategoriesByTabOrder()) {
 
@@ -52,7 +54,8 @@ public class CalculatorVarsFragmentActivity extends SherlockFragmentActivity imp
                 fragmentParameters = AbstractMathEntityListFragment.createBundleFor(category.name());
             }
 
-            activityHelper.addTab(this, category.name(), CalculatorVarsFragment.class, fragmentParameters, category.getCaptionId(), R.id.main_layout);
+
+            activityHelper.addTab(this, fragmentType.createSubFragmentTag(category.name()), fragmentType.getFragmentClass(), fragmentParameters, category.getCaptionId(), R.id.main_layout);
 
         }
     }
@@ -71,6 +74,14 @@ public class CalculatorVarsFragmentActivity extends SherlockFragmentActivity imp
         activityHelper.onResume(this);
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
+
     @Override
     protected void onDestroy() {
         super.onDestroy();

calculatorpp/src/main/java/org/solovyev/android/calculator/math/edit/VarEditDialogFragment.java

@@ -2,9 +2,7 @@ package org.solovyev.android.calculator.math.edit;
 
 import android.os.Bundle;
 import android.support.v4.app.DialogFragment;
-import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
-import android.support.v4.app.FragmentTransaction;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.LayoutInflater;

calculatorpp/src/main/java/org/solovyev/android/calculator/model/AndroidOperatorsMathRegistry.java

@@ -7,13 +7,17 @@
 package org.solovyev.android.calculator.model;
 
 import android.app.Application;
-import jscl.math.operator.Operator;
+import jscl.math.function.ArcTrigonometric;
+import jscl.math.function.Comparison;
+import jscl.math.function.Trigonometric;
+import jscl.math.operator.*;
 import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.calculator.R;
 import org.solovyev.common.JBuilder;
+import org.solovyev.common.collections.CollectionsUtils;
 import org.solovyev.common.math.MathRegistry;
 
-import java.util.HashMap;
+import java.util.*;
-import java.util.Map;
 
 /**
  * User: serso
@@ -48,7 +52,12 @@ public class AndroidOperatorsMathRegistry extends AbstractAndroidMathRegistry<Op
 	}
 
     @Override
-    public String getCategory(@NotNull Operator mathEntity) {
+    public String getCategory(@NotNull Operator operator) {
+        for (Category category : Category.values()) {
+            if ( category.isInCategory(operator) ) {
+                return category.name();
+            }
+        }
         return null;
     }
 
@@ -89,4 +98,83 @@ public class AndroidOperatorsMathRegistry extends AbstractAndroidMathRegistry<Op
 	protected MathEntityPersistenceContainer<MathPersistenceEntity> createPersistenceContainer() {
 		return null;  //To change body of implemented methods use File | Settings | File Templates.
 	}
+
+    /*
+    **********************************************************************
+    *
+    *                           STATIC
+    *
+    **********************************************************************
+    */
+
+    public static enum Category {
+
+        derivatives(R.string.derivatives, 100){
+            @Override
+            boolean isInCategory(@NotNull Operator operator) {
+                return operator instanceof Derivative || operator instanceof Integral || operator instanceof IndefiniteIntegral;
+            }
+        },
+
+        other(R.string.other, 200) {
+            @Override
+            boolean isInCategory(@NotNull Operator operator) {
+                return operator instanceof Sum || operator instanceof Product;
+            }
+        },
+
+        my(R.string.c_fun_category_my, 0) {
+            @Override
+            boolean isInCategory(@NotNull Operator operator) {
+                return !operator.isSystem();
+            }
+        },
+
+        common(R.string.c_fun_category_common, 50) {
+            @Override
+            boolean isInCategory(@NotNull Operator operator) {
+                for (Category category : values()) {
+                    if ( category != this ) {
+                        if ( category.isInCategory(operator) ) {
+                            return false;
+                        }
+                    }
+                }
+
+                return true;
+            }
+        };
+
+        private final int captionId;
+
+        private final int tabOrder;
+
+        Category(int captionId, int tabOrder) {
+            this.captionId = captionId;
+            this.tabOrder = tabOrder;
+        }
+
+        public int getCaptionId() {
+            return captionId;
+        }
+
+        abstract boolean isInCategory(@NotNull Operator operator);
+
+        @NotNull
+        public static List<Category> getCategoriesByTabOrder() {
+            final List<Category> result = CollectionsUtils.asList(Category.values());
+
+            Collections.sort(result, new Comparator<Category>() {
+                @Override
+                public int compare(Category category, Category category1) {
+                    return category.tabOrder - category1.tabOrder;
+                }
+            });
+
+            // todo serso: current solution (as creating operators is not implemented yet)
+            result.remove(my);
+
+            return result;
+        }
+    }
 }

calculatorpp/src/main/java/org/solovyev/android/calculator/model/AndroidPostfixFunctionsRegistry.java

@@ -47,7 +47,12 @@ public class AndroidPostfixFunctionsRegistry extends AbstractAndroidMathRegistry
 	}
 
     @Override
-    public String getCategory(@NotNull Operator mathEntity) {
+    public String getCategory(@NotNull Operator operator) {
+        for (AndroidOperatorsMathRegistry.Category category : AndroidOperatorsMathRegistry.Category.values()) {
+            if ( category.isInCategory(operator) ) {
+                return category.name();
+            }
+        }
         return null;
     }
 

calculatorpp/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotActivity.java

@@ -8,6 +8,7 @@ import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.CalculatorActivityHelper;
 import org.solovyev.android.calculator.CalculatorApplication;
 import org.solovyev.android.calculator.R;
+import org.solovyev.android.calculator.about.CalculatorFragmentType;
 
 /**
  * User: serso
@@ -34,7 +35,7 @@ public class CalculatorPlotActivity extends SherlockFragmentActivity {
             arguments = null;
         }
 
-        activityHelper.addTab(this, "plot", CalculatorPlotFragment.class, arguments, R.string.c_plot, R.id.main_layout);
+        activityHelper.addTab(this, CalculatorFragmentType.plotter, arguments, R.id.main_layout);
     }
 
     @Override
@@ -51,6 +52,14 @@ public class CalculatorPlotActivity extends SherlockFragmentActivity {
         activityHelper.onResume(this);
     }
 
+    @Override
+    protected void onPause() {
+        this.activityHelper.onPause(this);
+
+        super.onPause();
+    }
+
+
     @Override
     protected void onDestroy() {
         super.onDestroy();