remove non-functioning billing implementation

Google Play doesn't allow an app signed with a different certificate to
trigger an IAP.

app/build.gradle

@@ -88,7 +88,6 @@ dependencies {
     implementation(project(':jscl')) {
         exclude(module: 'xercesImpl')
     }
-    implementation 'org.solovyev.android:checkout:1.3.1'
     implementation 'com.google.guava:guava:32.1.2-android'
     implementation('org.simpleframework:simple-xml:2.7.1') {
         exclude(module: 'stax')

app/src/main/AndroidManifest.xml

@@ -2,7 +2,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           xmlns:tools="http://schemas.android.com/tools"
     android:installLocation="auto">
-    <uses-permission android:name="com.android.vending.BILLING" />
     <uses-permission android:name="android.permission.VIBRATE" />
 
     <!-- for onscreen -->

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

@@ -1,6 +1,5 @@
 package org.solovyev.android.calculator;
 
-import dagger.Component;
 import org.solovyev.android.calculator.converter.ConverterFragment;
 import org.solovyev.android.calculator.errors.FixableErrorFragment;
 import org.solovyev.android.calculator.errors.FixableErrorsActivity;
@@ -20,7 +19,6 @@ import org.solovyev.android.calculator.plot.PlotEditFunctionFragment;
 import org.solovyev.android.calculator.plot.PlotFunctionsFragment;
 import org.solovyev.android.calculator.preferences.PreferencesActivity;
 import org.solovyev.android.calculator.preferences.PreferencesFragment;
-import org.solovyev.android.calculator.preferences.PurchaseDialogActivity;
 import org.solovyev.android.calculator.variables.EditVariableFragment;
 import org.solovyev.android.calculator.variables.VariablesFragment;
 import org.solovyev.android.calculator.view.Tabs;
@@ -31,6 +29,8 @@ import org.solovyev.android.calculator.wizard.WizardFragment;
 
 import javax.inject.Singleton;
 
+import dagger.Component;
+
 @Singleton
 @Component(modules = AppModule.class)
 public interface AppComponent {
@@ -54,7 +54,6 @@ public interface AppComponent {
     void inject(WidgetReceiver receiver);
     void inject(DisplayFragment fragment);
     void inject(KeyboardFragment fragment);
-    void inject(PurchaseDialogActivity activity);
     void inject(PreferencesActivity activity);
     void inject(BaseKeyboardUi ui);
     void inject(FloatingCalculatorView view);

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

@@ -7,19 +7,15 @@ import android.graphics.Typeface;
 import android.os.Handler;
 import android.os.Looper;
 import android.preference.PreferenceManager;
-import androidx.annotation.NonNull;
 import android.util.Log;
 
-import com.squareup.otto.Bus;
+import androidx.annotation.NonNull;
 
+import com.squareup.otto.Bus;
 import com.squareup.otto.GeneratedHandlerFinder;
+
 import org.solovyev.android.calculator.language.Languages;
 import org.solovyev.android.calculator.wizard.CalculatorWizards;
-import org.solovyev.android.checkout.Billing;
-import org.solovyev.android.checkout.Checkout;
-import org.solovyev.android.checkout.Inventory;
-import org.solovyev.android.checkout.RobotmediaDatabase;
-import org.solovyev.android.checkout.RobotmediaInventory;
 import org.solovyev.android.plotter.Plot;
 import org.solovyev.android.plotter.Plotter;
 import org.solovyev.android.wizard.Wizards;
@@ -31,7 +27,6 @@ import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import javax.inject.Named;
 import javax.inject.Singleton;
 
@@ -182,28 +177,6 @@ public class AppModule {
         return JsclMathEngine.getInstance();
     }
 
-    @Provides
-    @Singleton
-    Billing provideBilling() {
-        return new Billing(application, new Billing.DefaultConfiguration() {
-            @Nonnull
-            @Override
-            public String getPublicKey() {
-                return CalculatorSecurity.getPK();
-            }
-
-            @Nullable
-            @Override
-            public Inventory getFallbackInventory(@Nonnull Checkout checkout, @Nonnull Executor onLoadExecutor) {
-                if (RobotmediaDatabase.exists(application)) {
-                    return new RobotmediaInventory(checkout, onLoadExecutor);
-                } else {
-                    return null;
-                }
-            }
-        });
-    }
-
     @Singleton
     @Provides
     Typeface provideTypeface() {

app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesActivity.java

@@ -4,19 +4,17 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.util.SparseArray;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.StringRes;
 import androidx.annotation.XmlRes;
-import android.util.SparseArray;
 
 import org.solovyev.android.calculator.App;
 import org.solovyev.android.calculator.AppComponent;
 import org.solovyev.android.calculator.BaseActivity;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.language.Languages;
-import org.solovyev.android.checkout.ActivityCheckout;
-import org.solovyev.android.checkout.Billing;
-import org.solovyev.android.checkout.Checkout;
 
 import javax.annotation.Nonnull;
 import javax.inject.Inject;
@@ -42,10 +40,6 @@ public class PreferencesActivity extends BaseActivity implements SharedPreferenc
         preferenceDefs.append(R.xml.preferences_widget, new PrefDef("screen-widget", R.string.cpp_widget));
     }
 
-    ActivityCheckout checkout;
-
-    @Inject
-    Billing billing;
     @Inject
     Languages languages;
 
@@ -84,9 +78,6 @@ public class PreferencesActivity extends BaseActivity implements SharedPreferenc
                     .add(R.id.main, PreferencesFragment.create(preference))
                     .commit();
         }
-
-        checkout = Checkout.forActivity(this, billing);
-        checkout.start();
     }
 
     @Override
@@ -95,17 +86,6 @@ public class PreferencesActivity extends BaseActivity implements SharedPreferenc
         component.inject(this);
     }
 
-    @Override
-    protected void onDestroy() {
-        checkout.stop();
-        super.onDestroy();
-    }
-
-    @Nonnull
-    ActivityCheckout getCheckout() {
-        return checkout;
-    }
-
     static class PrefDef {
         @Nonnull
         public final String id;

app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesFragment.java

@@ -5,31 +5,24 @@ import static org.solovyev.android.calculator.Engine.Preferences.angleUnitName;
 import static org.solovyev.android.calculator.Engine.Preferences.numeralBaseName;
 import static org.solovyev.android.calculator.wizard.CalculatorWizards.DEFAULT_WIZARD_FLOW;
 import static org.solovyev.android.wizard.WizardUi.startWizard;
+
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.util.SparseArray;
 import android.view.View;
-import android.view.ViewGroup;
+
-import android.view.ViewParent;
 import androidx.annotation.NonNull;
 import androidx.fragment.app.FragmentActivity;
 import androidx.preference.ListPreference;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceDialogFragmentCompat;
 import androidx.preference.PreferenceFragmentCompat;
-import androidx.recyclerview.widget.RecyclerView;
+
 import com.squareup.otto.Bus;
 import com.squareup.otto.Subscribe;
-import java.util.Arrays;
+
-import java.util.List;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-import jscl.AngleUnit;
-import jscl.JsclMathEngine;
-import jscl.NumeralBase;
 import org.solovyev.android.calculator.ActivityLauncher;
 import org.solovyev.android.calculator.Engine;
 import org.solovyev.android.calculator.Preferences;
@@ -38,14 +31,20 @@ import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.feedback.FeedbackReporter;
 import org.solovyev.android.calculator.language.Language;
 import org.solovyev.android.calculator.language.Languages;
-import org.solovyev.android.checkout.BillingRequests;
-import org.solovyev.android.checkout.Checkout;
-import org.solovyev.android.checkout.ProductTypes;
-import org.solovyev.android.checkout.RequestListener;
 import org.solovyev.android.prefs.StringPreference;
 import org.solovyev.android.wizard.Wizards;
 import org.solovyev.common.text.CharacterMapper;
 
+import java.util.Arrays;
+import java.util.List;
+
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+
+import jscl.AngleUnit;
+import jscl.JsclMathEngine;
+import jscl.NumeralBase;
+
 
 public class PreferencesFragment extends PreferenceFragmentCompat implements SharedPreferences.OnSharedPreferenceChangeListener {
     @Nonnull
@@ -100,7 +99,9 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Sha
         }
     }
 
-    /** @noinspection deprecation*/
+    /**
+     * @noinspection deprecation
+     */
     @Override
     public void onDisplayPreferenceDialog(@NonNull Preference preference) {
         String fragmentTag = "fragment:" + preference.getKey();
@@ -125,7 +126,6 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Sha
             prepareIntroduction();
             prepareReportBug();
             prepareAbout();
-            prepareSupportProject();
             prepareMode();
             prepareAngles();
             prepareRadix();
@@ -140,26 +140,6 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Sha
 
         prepareLanguagePreference(preference);
         prepareThemePreference(preference);
-
-        getCheckout().whenReady(new Checkout.EmptyListener() {
-            @Override
-            public void onReady(@Nonnull BillingRequests requests) {
-                requests.isPurchased(ProductTypes.IN_APP, "ad_free", new RequestListener<Boolean>() {
-                    @Override
-                    public void onSuccess(@Nonnull Boolean purchased) {
-                        final Preference supportProject = findPreference("prefs.supportProject");
-                        if (supportProject != null) {
-                            supportProject.setEnabled(!purchased);
-                            supportProject.setSelectable(!purchased);
-                        }
-                    }
-
-                    @Override
-                    public void onError(int i, @Nonnull Exception e) {
-                    }
-                });
-            }
-        });
     }
 
     private void prepareReportBug() {
@@ -171,20 +151,6 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Sha
                 return true;
             }
         });
-
-    }
-
-    private void prepareSupportProject() {
-        final Preference supportProject = findPreference("prefs.supportProject");
-        supportProject.setEnabled(false);
-        supportProject.setSelectable(false);
-        supportProject.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
-                startActivity(new Intent(getActivity(), PurchaseDialogActivity.class));
-                return true;
-            }
-        });
     }
 
     private void prepareScreens() {
@@ -379,11 +345,6 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Sha
         });
     }
 
-    @Nonnull
-    private Checkout getCheckout() {
-        return ((PreferencesActivity) getActivity()).getCheckout();
-    }
-
     @Override
     public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
         if (Preferences.Onscreen.showAppIcon.isSameKey(key)) {

app/src/main/java/org/solovyev/android/calculator/preferences/PurchaseDialogActivity.java

@@ -1,157 +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.preferences;
-
-import static org.solovyev.android.calculator.App.cast;
-
-import android.app.Activity;
-import android.content.DialogInterface;
-import android.content.Intent;
-import android.os.Bundle;
-import androidx.annotation.NonNull;
-
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.fragment.app.Fragment;
-import org.solovyev.android.calculator.App;
-import org.solovyev.android.calculator.BaseDialogFragment;
-import org.solovyev.android.calculator.R;
-import org.solovyev.android.checkout.ActivityCheckout;
-import org.solovyev.android.checkout.Billing;
-import org.solovyev.android.checkout.BillingRequests;
-import org.solovyev.android.checkout.Checkout;
-import org.solovyev.android.checkout.ProductTypes;
-import org.solovyev.android.checkout.Purchase;
-import org.solovyev.android.checkout.RequestListener;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import javax.inject.Inject;
-
-public class PurchaseDialogActivity extends AppCompatActivity implements RequestListener<Purchase> {
-
-    @Inject
-    Billing billing;
-    ActivityCheckout checkout;
-
-    @Override
-    protected void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        cast(getApplication()).getComponent().inject(this);
-
-        if (savedInstanceState == null) {
-            App.showDialog(new PurchaseDialogFragment(), PurchaseDialogFragment.FRAGMENT_TAG, getSupportFragmentManager());
-        }
-
-        checkout = Checkout.forActivity(this, billing);
-        checkout.start();
-        checkout.createPurchaseFlow(this);
-    }
-
-    private void purchase() {
-        checkout.whenReady(new Checkout.EmptyListener() {
-            @Override
-            public void onReady(@Nonnull BillingRequests requests) {
-                requests.purchase(ProductTypes.IN_APP, "ad_free", null, checkout.getPurchaseFlow());
-            }
-        });
-    }
-
-    @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
-        super.onActivityResult(requestCode, resultCode, data);
-        checkout.onActivityResult(requestCode, resultCode, data);
-    }
-
-    @Override
-    protected void onDestroy() {
-        checkout.destroyPurchaseFlow();
-        checkout.stop();
-        super.onDestroy();
-    }
-
-    public void onDialogClosed() {
-        final Fragment fragment = getSupportFragmentManager().findFragmentByTag(PurchaseDialogFragment.FRAGMENT_TAG);
-        if (fragment == null) {
-            // activity is closing
-            return;
-        }
-        finish();
-    }
-
-    @Override
-    public void onSuccess(@Nonnull Purchase result) {
-        finish();
-    }
-
-    @Override
-    public void onError(int response, @Nonnull Exception e) {
-        finish();
-    }
-
-    public static class PurchaseDialogFragment extends BaseDialogFragment {
-
-        public static final String FRAGMENT_TAG = "purchase-dialog";
-        @Nullable
-        private PurchaseDialogActivity activity;
-
-        @Override
-        public void onAttach(Activity activity) {
-            super.onAttach(activity);
-            this.activity = (PurchaseDialogActivity) activity;
-        }
-
-        @Override
-        protected void onPrepareDialog(@NonNull AlertDialog.Builder builder) {
-            super.onPrepareDialog(builder);
-            builder.setTitle(R.string.cpp_purchase_title);
-            builder.setMessage(R.string.cpp_purchase_text);
-            builder.setPositiveButton(R.string.cpp_continue, null);
-        }
-
-        @Override
-        public void onClick(DialogInterface dialog, int which) {
-            switch (which) {
-                case DialogInterface.BUTTON_POSITIVE:
-                    if (activity != null) {
-                        activity.purchase();
-                    }
-                    break;
-                default:
-                    super.onClick(dialog, which);
-                    break;
-            }
-        }
-
-        @Override
-        public void onDismiss(DialogInterface dialog) {
-            super.onDismiss(dialog);
-            if (activity != null) {
-                activity.onDialogClosed();
-                activity = null;
-            }
-        }
-    }
-}
-

app/src/main/java/org/solovyev/android/checkout/CppCheckout.java

@@ -1,39 +0,0 @@
-package org.solovyev.android.checkout;
-
-import androidx.annotation.NonNull;
-
-import javax.inject.Inject;
-import javax.inject.Singleton;
-
-/**
- * App-wide {@link Checkout} which counts how many times it has been started.
- */
-@Singleton
-public class CppCheckout extends Checkout {
-    private int started = 0;
-
-    @Inject
-    public CppCheckout(@NonNull Billing billing) {
-        super(null, billing);
-    }
-
-    @Override
-    public void stop() {
-        Check.isMainThread();
-        Check.isTrue(started > 0, "Must be started first");
-        started--;
-        if (started == 0) {
-            super.stop();
-        }
-        started = Math.max(0, started);
-    }
-
-    @Override
-    public void start(Listener listener) {
-        Check.isMainThread();
-        started++;
-        if (started == 1) {
-            super.start(listener);
-        }
-    }
-}

app/src/main/res/xml/preferences.xml

@@ -25,12 +25,6 @@
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
     android:key="screen-main">
     
-    <Preference
-        android:defaultValue="false"
-        android:key="prefs.supportProject"
-        android:summary="@string/c_calc_ad_free_summary"
-        android:title="@string/c_calc_ad_free_title" />
-
     <PreferenceCategory
         android:key="category-basic"
         android:title="@string/cpp_prefs_basic">