new plotter

android-app-core/res/layout/cpp_plot_function_list_item.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+    a:layout_width="match_parent"
+    a:layout_height="wrap_content"
+    a:orientation="horizontal">
+
+    <TextView
+        a:id="@+id/cpp_plot_function_expression_textview"
+        a:layout_width="0dp"
+        a:layout_height="wrap_content"
+        a:layout_weight="5"/>
+
+    <CheckBox
+        a:id="@+id/cpp_plot_function_pinned_checkbox"
+        a:layout_width="0dp"
+        a:layout_height="wrap_content"
+        a:layout_weight="1"/>
+
+    <CheckBox
+        a:id="@+id/cpp_plot_function_visible_checkbox"
+        a:layout_width="0dp"
+        a:layout_height="wrap_content"
+        a:layout_weight="1"/>
+
+</LinearLayout>

android-app-core/res/layout/plot_functions_fragment_list_item.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<TextView xmlns:a="http://schemas.android.com/apk/res/android"
-			  a:layout_width="match_parent"
-			  a:layout_height="wrap_content"/>

android-app-core/res/values/text_strings.xml

@@ -282,7 +282,9 @@
     <string name="cpp_onscreen_remove_icon_message">You can remove second icon in applications\' list from application settings or by pressing next button</string>
     <string name="cpp_onscreen_remove_icon_button_text">Remove icon</string>
     <string name="cpp_this_change_may_require_reboot">This change may require reboot</string>
-    <string name="cpp_plot_3d">3D</string>
+    <string name="cpp_plot_2d">2D plot</string>
+    <string name="cpp_plot_3d">3D plot</string>
+    <string name="cpp_plot_functions">Graph functions</string>
 
     <string name="cpp_prefs_graph_plot_imag_title">Plot imaginary part of function</string>
     <string name="cpp_prefs_graph_plot_imag_summary">If checked imaginary part of function will be plotted</string>

android-app-core/res/values/theme_gray.xml

@@ -152,7 +152,30 @@
 
                 <item name="dropDownListViewStyle">@style/cpp_default_actionbar_dropdown_listview_style</item>
         <item name="android:dropDownListViewStyle">@style/cpp_default_actionbar_dropdown_listview_style</item>
-
-
     </style>
+
+    <style name="cpp_gray_dialog_theme" parent="Theme.Sherlock.Dialog">
+        <!-- buttons -->
+        <item name="cpp_digit_button_style">@style/cpp_default_digit_button_style</item>
+        <item name="cpp_control_button_style">@style/cpp_default_control_button_style</item>
+        <item name="cpp_control_image_button_style">@style/cpp_default_control_image_button_style</item>
+        <item name="cpp_operation_button_style">@style/cpp_default_operation_button_style</item>
+
+        <!-- other -->
+        <item name="cpp_fragment_title_style">@style/cpp_default_fragment_title_style</item>
+        <item name="cpp_fragment_list_view_style">@style/cpp_default_fragment_list_view_style</item>
+        <item name="cpp_fragment_list_view_item_style">@style/cpp_default_fragment_list_view_item_style</item>
+        <item name="cpp_button_style">@style/cpp_default_button_style</item>
+
+        <item name="cpp_main_layout_style">@style/cpp_default_main_layout_style</item>
+        <item name="cpp_main_multi_pane_layout_style">@style/cpp_default_main_multi_pane_layout_style</item>
+
+        <item name="cpp_fragment_layout_style">@style/cpp_default_fragment_layout_style</item>
+
+        <item name="cpp_dialog_style">@style/cpp_default_dialog_style</item>
+
+        <item name="cpp_pane_style">@style/cpp_default_pane_style</item>
+        <item name="cpp_pane_style_transparent">@style/cpp_default_pane_style_transparent</item>
+    </style>
+
 </resources>

android-app-core/src/main/java/org/solovyev/android/calculator/CalculatorDisplayMenuItem.java

@@ -86,7 +86,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
 
         @Override
         protected boolean isItemVisibleFor(@NotNull Generic generic, @NotNull JsclOperation operation) {
-            return Locator.getInstance().getPlotter().isPlotPossible(generic);
+            return Locator.getInstance().getPlotter().isPlotPossibleFor(generic);
         }
 
     };

android-app-core/src/main/java/org/solovyev/android/calculator/plot/AndroidCalculatorPlotter.java

@@ -77,24 +77,28 @@ public class AndroidCalculatorPlotter implements CalculatorPlotter, SharedPrefer
         return plotter.removeFunction(xyFunction);
     }
 
+    @NotNull
     @Override
-    public void pin(@NotNull PlotFunction plotFunction) {
-        plotter.pin(plotFunction);
+    public PlotFunction pin(@NotNull PlotFunction plotFunction) {
+        return plotter.pin(plotFunction);
     }
 
+    @NotNull
     @Override
-    public void unpin(@NotNull PlotFunction plotFunction) {
-        plotter.unpin(plotFunction);
+    public PlotFunction unpin(@NotNull PlotFunction plotFunction) {
+        return plotter.unpin(plotFunction);
     }
 
+    @NotNull
     @Override
-    public void show(@NotNull PlotFunction plotFunction) {
-        plotter.show(plotFunction);
+    public PlotFunction show(@NotNull PlotFunction plotFunction) {
+        return plotter.show(plotFunction);
     }
 
+    @NotNull
     @Override
-    public void hide(@NotNull PlotFunction plotFunction) {
-        plotter.hide(plotFunction);
+    public PlotFunction hide(@NotNull PlotFunction plotFunction) {
+        return plotter.hide(plotFunction);
     }
 
     @Override
@@ -120,8 +124,13 @@ public class AndroidCalculatorPlotter implements CalculatorPlotter, SharedPrefer
     }
 
     @Override
-    public boolean isPlotPossible(@NotNull Generic expression) {
-        return plotter.isPlotPossible(expression);
+    public boolean is2dPlotPossible() {
+        return plotter.is2dPlotPossible();
+    }
+
+    @Override
+    public boolean isPlotPossibleFor(@NotNull Generic expression) {
+        return plotter.isPlotPossibleFor(expression);
     }
 
     @Override

android-app-core/src/main/java/org/solovyev/android/calculator/plot/ParcelablePlotInputListItem.java

@@ -1,57 +0,0 @@
-package org.solovyev.android.calculator.plot;
-
-import android.content.Context;
-import android.view.View;
-import android.widget.TextView;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.solovyev.android.calculator.core.R;
-import org.solovyev.android.list.ListItem;
-import org.solovyev.android.view.TextViewBuilder;
-import org.solovyev.android.view.UpdatableViewBuilder;
-
-public class ParcelablePlotInputListItem implements ListItem {
-
-	@NotNull
-	private XyFunction plotInput;
-
-	@NotNull
-	private UpdatableViewBuilder<TextView> viewBuilder;
-
-	public ParcelablePlotInputListItem(@NotNull XyFunction plotInput) {
-		this.plotInput = plotInput;
-		// todo serso: use correct tag
-		this.viewBuilder = TextViewBuilder.newInstance(R.layout.plot_functions_fragment_list_item, null);
-	}
-
-	@Nullable
-	@Override
-	public OnClickAction getOnClickAction() {
-		return null;
-	}
-
-	@Nullable
-	@Override
-	public OnClickAction getOnLongClickAction() {
-		return null;
-	}
-
-	@NotNull
-	@Override
-	public View updateView(@NotNull Context context, @NotNull View view) {
-		// todo serso: optimize
-		return build(context);
-	}
-
-	@NotNull
-	@Override
-	public View build(@NotNull Context context) {
-		TextView textView = viewBuilder.build(context);
-		fill(textView);
-		return textView;
-	}
-
-	private void fill(@NotNull TextView textView) {
-		textView.setText(plotInput.getExpressionString());
-	}
-}

android-app-core/src/main/java/org/solovyev/android/calculator/plot/PlotFunctionListItem.java

@@ -0,0 +1,119 @@
+package org.solovyev.android.calculator.plot;
+
+import android.content.Context;
+import android.view.View;
+import android.widget.CheckBox;
+import android.widget.CompoundButton;
+import android.widget.TextView;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.Locator;
+import org.solovyev.android.calculator.core.R;
+import org.solovyev.android.list.ListItem;
+import org.solovyev.android.view.ViewBuilder;
+import org.solovyev.android.view.ViewFromLayoutBuilder;
+
+public class PlotFunctionListItem implements ListItem {
+
+    private static final String PREFIX = "plot_function_";
+
+    @NotNull
+	private PlotFunction plotFunction;
+
+	@NotNull
+	private ViewBuilder<View> viewBuilder;
+
+    @NotNull
+    private String tag;
+
+    public PlotFunctionListItem(@NotNull PlotFunction plotFunction) {
+		this.plotFunction = plotFunction;
+		this.viewBuilder = ViewFromLayoutBuilder.newInstance(R.layout.cpp_plot_function_list_item);
+        this.tag = PREFIX + plotFunction.getXyFunction().getExpressionString();
+    }
+
+	@Nullable
+	@Override
+	public OnClickAction getOnClickAction() {
+		return null;
+	}
+
+	@Nullable
+	@Override
+	public OnClickAction getOnLongClickAction() {
+		return null;
+	}
+
+	@NotNull
+	@Override
+	public View updateView(@NotNull Context context, @NotNull View view) {
+        final Object viewTag = view.getTag();
+        if ( viewTag instanceof String ) {
+            if ( this.tag.equals(viewTag) ) {
+                return view;
+            } else if (((String) viewTag).startsWith(PREFIX)) {
+                fillView(view);
+                return view;
+            } else {
+                return build(context);
+            }
+        }
+
+		return build(context);
+	}
+
+	@NotNull
+	@Override
+	public View build(@NotNull Context context) {
+		final View root = buildView(context);
+		fillView(root);
+		return root;
+	}
+
+    private View buildView(@NotNull Context context) {
+        return viewBuilder.build(context);
+    }
+
+    private void fillView(@NotNull View root) {
+        root.setTag(tag);
+
+        final CalculatorPlotter plotter = Locator.getInstance().getPlotter();
+
+        final TextView expressionTextView = (TextView) root.findViewById(R.id.cpp_plot_function_expression_textview);
+        expressionTextView.setText(plotFunction.getXyFunction().getExpressionString());
+
+        final CheckBox pinnedCheckBox = (CheckBox) root.findViewById(R.id.cpp_plot_function_pinned_checkbox);
+        pinnedCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean pin) {
+                if (pin) {
+                    if (!plotFunction.isPinned()) {
+                        plotFunction = plotter.pin(plotFunction);
+                    }
+                } else {
+                    if (plotFunction.isPinned()) {
+                        plotFunction = plotter.unpin(plotFunction);
+                    }
+                }
+            }
+        });
+        pinnedCheckBox.setChecked(plotFunction.isPinned());
+
+        final CheckBox visibleCheckBox = (CheckBox) root.findViewById(R.id.cpp_plot_function_visible_checkbox);
+        visibleCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean show) {
+                if (show) {
+                    if (!plotFunction.isVisible()) {
+                        plotFunction = plotter.show(plotFunction);
+                    }
+                } else {
+                    if (plotFunction.isVisible()) {
+                        plotFunction = plotter.hide(plotFunction);
+                    }
+                }
+            }
+        });
+        visibleCheckBox.setChecked(plotFunction.isVisible());
+    }
+}

android-app/AndroidManifest.xml

@@ -52,6 +52,7 @@
         <activity android:label="@string/c_vars_and_constants" android:name=".math.edit.CalculatorVarsActivity"/>
 
         <activity android:label="@string/c_plot_graph" android:name=".plot.CalculatorPlotActivity"/>
+        <activity android:label="@string/c_plot_graph" android:name=".plot.CalculatorPlotFunctionsActivity" android:theme="@style/cpp_gray_dialog_theme"/>
 
         <!-- todo serso: strings-->
         <activity android:label="@string/c_plot_graph" android:name=".matrix.CalculatorMatrixActivity"/>

android-app/res/layout/cpp_plot_functions_dialog.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+    a:layout_width="wrap_content"
+    a:layout_height="wrap_content"
+    a:id="@+id/dialog_layout"
+    style="?cpp_dialog_style"
+    a:orientation="vertical">
+
+</LinearLayout>

android-app/res/layout/plot_functions_fragment.xml

@@ -6,13 +6,40 @@
     a:layout_width="match_parent"
     a:layout_height="match_parent">
 
-	<TextView a:id="@+id/fragment_title"
+    <TextView
+        a:id="@+id/fragment_title"
         a:layout_height="wrap_content"
         a:layout_width="match_parent"
-			  style="?cpp_fragment_title_style"/>
+        style="?cpp_fragment_title_style" />
 
-	<include layout="@layout/ad"/>
+    <include layout="@layout/ad" />
 
-	<ListView style="?cpp_fragment_list_view_style"/>
+    <LinearLayout
+        a:layout_width="match_parent"
+        a:layout_height="wrap_content"
+        a:orientation="horizontal">
+
+        <TextView
+            a:layout_width="0dp"
+            a:layout_height="wrap_content"
+            a:layout_weight="5"
+            a:text="Function"/>
+
+        <TextView
+            a:layout_width="0dp"
+            a:layout_height="wrap_content"
+            a:layout_weight="1"
+            a:text="Pinned"/>
+
+        <TextView
+            a:layout_width="0dp"
+            a:layout_height="wrap_content"
+            a:layout_weight="1"
+            a:text="Visible"/>
+
+
+    </LinearLayout>
+
+    <ListView style="?cpp_fragment_list_view_style" />
 
 </LinearLayout>

android-app/res/menu/plot_menu.xml

@@ -8,9 +8,19 @@
 
 <menu xmlns:a="http://schemas.android.com/apk/res/android">
 
+    <item a:id="@+id/menu_plot_2d"
+        a:title="@string/cpp_plot_2d"
+        a:icon="@drawable/ab_plot_2d"
+        a:showAsAction="always"/>
+
     <item a:id="@+id/menu_plot_3d"
         a:title="@string/cpp_plot_3d"
-        a:icon="@drawable/ab_icon"
+        a:icon="@drawable/ab_plot_3d"
+        a:showAsAction="always"/>
+
+    <item a:id="@+id/menu_plot_functions"
+        a:title="@string/cpp_plot_functions"
+        a:icon="@drawable/ab_list"
         a:showAsAction="always"/>
 
 	<item a:id="@+id/menu_plot_settings"

android-app/src/main/java/org/solovyev/android/calculator/plot/AbstractCalculatorPlotFragment.java

@@ -14,10 +14,12 @@ import org.achartengine.renderer.XYMultipleSeriesRenderer;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.*;
+import org.solovyev.android.menu.AMenuItem;
 import org.solovyev.android.menu.ActivityMenu;
 import org.solovyev.android.menu.IdentifiableMenuItem;
 import org.solovyev.android.menu.ListActivityMenu;
 import org.solovyev.android.sherlock.menu.SherlockMenuHelper;
+import org.solovyev.common.JPredicate;
 
 import java.io.Serializable;
 import java.util.ArrayList;
@@ -97,13 +99,6 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
         setHasOptionsMenu(true);
     }
 
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        super.onViewCreated(view, savedInstanceState);
-
-        this.plotData = Locator.getInstance().getPlotter().getPlotData();
-    }
-
     @Override
     public void onSaveInstanceState(Bundle out) {
         super.onSaveInstanceState(out);
@@ -121,8 +116,10 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
     public void onResume() {
         super.onResume();
 
+        plotData = Locator.getInstance().getPlotter().getPlotData();
         createChart(plotData);
         createGraphicalView(getView(), plotData);
+        getActivity().invalidateOptionsMenu();
     }
 
     @Override
@@ -141,6 +138,8 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
         getUiHandler().post(new Runnable() {
             @Override
             public void run() {
+                getActivity().invalidateOptionsMenu();
+
                 createChart(plotData);
 
                 final View view = getView();
@@ -197,13 +196,14 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
     */
 
     @Override
-    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+    public void onCreateOptionsMenu(final Menu menu, MenuInflater inflater) {
         super.onCreateOptionsMenu(menu, inflater);
 
         final List<IdentifiableMenuItem<MenuItem>> menuItems = new ArrayList<IdentifiableMenuItem<MenuItem>>();
         menuItems.add(PlotMenu.preferences);
-        if ( is3dPlotSupported() ) {
-            menuItems.add(new IdentifiableMenuItem<MenuItem>() {
+        menuItems.add(PlotMenu.functions);
+
+        final IdentifiableMenuItem<MenuItem> plot3dMenuItem = new IdentifiableMenuItem<MenuItem>() {
             @NotNull
             @Override
             public Integer getItemId() {
@@ -214,9 +214,37 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
             public void onClick(@NotNull MenuItem data, @NotNull Context context) {
                 Locator.getInstance().getPlotter().setPlot3d(true);
             }
-            });
+        };
+        menuItems.add(plot3dMenuItem);
+
+
+        final IdentifiableMenuItem<MenuItem> plot2dMenuItem = new IdentifiableMenuItem<MenuItem>() {
+            @NotNull
+            @Override
+            public Integer getItemId() {
+                return R.id.menu_plot_2d;
             }
-        fragmentMenu = ListActivityMenu.fromResource(R.menu.plot_menu, menuItems, SherlockMenuHelper.getInstance());
+
+            @Override
+            public void onClick(@NotNull MenuItem data, @NotNull Context context) {
+                Locator.getInstance().getPlotter().setPlot3d(false);
+            }
+        };
+        menuItems.add(plot2dMenuItem);
+
+        final boolean plot3dVisible = !plotData.isPlot3d() && is3dPlotSupported();
+        final boolean plot2dVisible = plotData.isPlot3d() && Locator.getInstance().getPlotter().is2dPlotPossible();
+        fragmentMenu = ListActivityMenu.fromResource(R.menu.plot_menu, menuItems, SherlockMenuHelper.getInstance(), new JPredicate<AMenuItem<MenuItem>>() {
+            @Override
+            public boolean apply(@Nullable AMenuItem<MenuItem> menuItem) {
+                if ( menuItem == plot3dMenuItem ) {
+                    return !plot3dVisible;
+                } else if ( menuItem == plot2dMenuItem ) {
+                    return !plot2dVisible;
+                }
+                return false;
+            }
+        });
 
         final FragmentActivity activity = this.getActivity();
         if (activity != null) {
@@ -251,6 +279,13 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
 
     private static enum PlotMenu implements IdentifiableMenuItem<MenuItem> {
 
+        functions(R.id.menu_plot_functions) {
+            @Override
+            public void onClick(@NotNull MenuItem data, @NotNull Context context) {
+                context.startActivity(new Intent(context, CalculatorPlotFunctionsActivity.class));
+            }
+        },
+
         preferences(R.id.menu_plot_settings) {
             @Override
             public void onClick(@NotNull MenuItem data, @NotNull Context context) {

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotFunctionsActivity.java

@@ -0,0 +1,24 @@
+package org.solovyev.android.calculator.plot;
+
+import android.os.Bundle;
+import com.actionbarsherlock.app.SherlockFragmentActivity;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.R;
+import org.solovyev.android.fragments.FragmentUtils;
+
+/**
+ * User: serso
+ * Date: 1/13/13
+ * Time: 5:05 PM
+ */
+public class CalculatorPlotFunctionsActivity extends SherlockFragmentActivity {
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.cpp_plot_functions_dialog);
+
+        FragmentUtils.createFragment(this, CalculatorPlotFunctionsFragment.class, R.id.dialog_layout, "plot-functions");
+    }
+}

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotFunctionsController.java

@@ -1,37 +0,0 @@
-package org.solovyev.android.calculator.plot;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-final class CalculatorPlotFunctionsController {
-
-	@NotNull
-	private static final CalculatorPlotFunctionsController instance = new CalculatorPlotFunctionsController();
-
-	@NotNull
-	private final List<XyFunction> functions = new ArrayList<XyFunction>();
-
-	private CalculatorPlotFunctionsController() {
-	}
-
-	@NotNull
-	public static CalculatorPlotFunctionsController getInstance() {
-		return instance;
-	}
-
-	@NotNull
-	public List<XyFunction> getFunctions() {
-		return Collections.unmodifiableList(functions);
-	}
-
-	public boolean addFunction(@NotNull XyFunction function) {
-		if (!functions.contains(function)) {
-			return functions.add(function);
-		} else {
-			return false;
-		}
-	}
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotFunctionsFragment.java

@@ -4,6 +4,7 @@ import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import org.jetbrains.annotations.NotNull;
 import org.solovyev.android.calculator.CalculatorListFragment;
+import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.about.CalculatorFragmentType;
 import org.solovyev.android.list.ListItemArrayAdapter;
 
@@ -23,10 +24,11 @@ public class CalculatorPlotFunctionsFragment extends CalculatorListFragment {
 	public void onResume() {
 		super.onResume();
 
-		final List<ParcelablePlotInputListItem> items = Lists.transform(CalculatorPlotFunctionsController.getInstance().getFunctions(), new Function<XyFunction, ParcelablePlotInputListItem>() {
+		final List<PlotFunctionListItem> items = Lists.transform(Locator.getInstance().getPlotter().getFunctions(), new Function<PlotFunction, PlotFunctionListItem>() {
 			@Override
-			public ParcelablePlotInputListItem apply(@Nullable XyFunction input) {
-				return new ParcelablePlotInputListItem(input);
+			public PlotFunctionListItem apply(@Nullable PlotFunction input) {
+                assert input != null;
+                return new PlotFunctionListItem(input);
 			}
 		});
 

core/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotter.java

@@ -26,11 +26,17 @@ public interface CalculatorPlotter {
     boolean removeFunction(@NotNull PlotFunction plotFunction);
     boolean removeFunction(@NotNull XyFunction xyFunction);
 
-    void pin(@NotNull PlotFunction plotFunction);
-    void unpin(@NotNull PlotFunction plotFunction);
+    @NotNull
+    PlotFunction pin(@NotNull PlotFunction plotFunction);
 
-    void show(@NotNull PlotFunction plotFunction);
-    void hide(@NotNull PlotFunction plotFunction);
+    @NotNull
+    PlotFunction unpin(@NotNull PlotFunction plotFunction);
+
+    @NotNull
+    PlotFunction show(@NotNull PlotFunction plotFunction);
+
+    @NotNull
+    PlotFunction hide(@NotNull PlotFunction plotFunction);
 
     void clearAllFunctions();
 
@@ -42,7 +48,9 @@ public interface CalculatorPlotter {
 
     void plot();
 
-    boolean isPlotPossible(@NotNull Generic expression);
+    boolean is2dPlotPossible();
+
+    boolean isPlotPossibleFor(@NotNull Generic expression);
 
     void setPlot3d(boolean plot3d);
 

core/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotterImpl.java

@@ -31,6 +31,8 @@ public class CalculatorPlotterImpl implements CalculatorPlotter {
 
     private boolean plotImag = false;
 
+    private int arity = 0;
+
     @NotNull
     private GraphLineColor realLineColor;
 
@@ -134,6 +136,14 @@ public class CalculatorPlotterImpl implements CalculatorPlotter {
 
     @Override
     public boolean updateFunction(@NotNull PlotFunction newFunction) {
+        boolean changed = updateFunction0(newFunction);
+        if (changed) {
+            firePlotDataChangedEvent();
+        }
+        return changed;
+    }
+
+    public boolean updateFunction0(@NotNull PlotFunction newFunction) {
         boolean changed = false;
 
         synchronized (functions) {
@@ -156,26 +166,40 @@ public class CalculatorPlotterImpl implements CalculatorPlotter {
         return removeFunction(new PlotFunction(xyFunction));
     }
 
+    @NotNull
     @Override
-    public void pin(@NotNull PlotFunction plotFunction) {
-        updateFunction(PlotFunction.pin(plotFunction));
+    public PlotFunction pin(@NotNull PlotFunction plotFunction) {
+        final PlotFunction newFunction = PlotFunction.pin(plotFunction);
+        updateFunction0(newFunction);
+        return newFunction;
     }
 
+    @NotNull
     @Override
-    public void unpin(@NotNull PlotFunction plotFunction) {
-        updateFunction(PlotFunction.unpin(plotFunction));
+    public PlotFunction unpin(@NotNull PlotFunction plotFunction) {
+        final PlotFunction newFunction = PlotFunction.unpin(plotFunction);
+        updateFunction0(newFunction);
+        return newFunction;
     }
 
+    @NotNull
     @Override
-    public void show(@NotNull PlotFunction plotFunction) {
-        updateFunction(PlotFunction.visible(plotFunction));
-        firePlotDataChangedEvent();
+    public PlotFunction show(@NotNull PlotFunction plotFunction) {
+        final PlotFunction newFunction = PlotFunction.visible(plotFunction);
+
+        updateFunction(newFunction);
+
+        return newFunction;
     }
 
+    @NotNull
     @Override
-    public void hide(@NotNull PlotFunction plotFunction) {
-        updateFunction(PlotFunction.invisible(plotFunction));
-        firePlotDataChangedEvent();
+    public PlotFunction hide(@NotNull PlotFunction plotFunction) {
+        final PlotFunction newFunction = PlotFunction.invisible(plotFunction);
+
+        updateFunction(newFunction);
+
+        return newFunction;
     }
 
     @Override
@@ -203,6 +227,8 @@ public class CalculatorPlotterImpl implements CalculatorPlotter {
             plot3d = false;
         }
 
+        arity = maxArity;
+
         firePlotDataChangedEvent();
     }
 
@@ -233,7 +259,12 @@ public class CalculatorPlotterImpl implements CalculatorPlotter {
     }
 
     @Override
-    public boolean isPlotPossible(@NotNull Generic expression) {
+    public boolean is2dPlotPossible() {
+        return arity < 2;
+    }
+
+    @Override
+    public boolean isPlotPossibleFor(@NotNull Generic expression) {
         boolean result = false;
 
         int size = CalculatorUtils.getNotSystemConstants(expression).size();

core/src/main/java/org/solovyev/android/calculator/plot/PlotFunction.java

@@ -42,27 +42,36 @@ public class PlotFunction {
     }
 
     public static PlotFunction pin(@NotNull PlotFunction that) {
+        return togglePinned(that, true);
+    }
+
+    @NotNull
+    public static PlotFunction togglePinned(@NotNull PlotFunction that, boolean pinned) {
         final PlotFunction copy = that.copy();
-        copy.pinned = true;
+        copy.pinned = pinned;
         return copy;
     }
 
+    @NotNull
     public static PlotFunction unpin(@NotNull PlotFunction that) {
-        final PlotFunction copy = that.copy();
-        copy.pinned = false;
-        return copy;
+        return togglePinned(that, false);
     }
 
+    @NotNull
     public static PlotFunction visible(@NotNull PlotFunction that) {
+        return toggleVisible(that, true);
+    }
+
+    @NotNull
+    public static PlotFunction toggleVisible(@NotNull PlotFunction that, boolean visible) {
         final PlotFunction copy = that.copy();
-        copy.visible = true;
+        copy.visible = visible;
         return copy;
     }
 
+    @NotNull
     public static PlotFunction invisible(@NotNull PlotFunction that) {
-        final PlotFunction copy = that.copy();
-        copy.visible = false;
-        return copy;
+        return toggleVisible(that, false);
     }
 
     @NotNull