Save and restore selected tabs

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

@@ -30,7 +30,6 @@ import android.content.res.Configuration;
 import android.graphics.Color;
 import android.graphics.Typeface;
 import android.os.Bundle;
-import android.preference.PreferenceManager;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.LayoutRes;
 import android.support.design.widget.FloatingActionButton;
@@ -55,6 +54,7 @@ import org.solovyev.android.calculator.view.Tabs;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
+import javax.inject.Named;
 
 import static org.solovyev.android.calculator.App.cast;
 
@@ -91,7 +91,6 @@ public class ActivityUi {
     private Preferences.Gui.Layout layout = Preferences.Gui.Layout.main_calculator;
     @Nonnull
     private Language language = Languages.SYSTEM_LANGUAGE;
-    private int selectedNavigationIndex = 0;
 
     public ActivityUi(@Nonnull AppCompatActivity activity, @LayoutRes int layoutId) {
         this.activity = activity;
@@ -127,11 +126,6 @@ public class ActivityUi {
         App.getGa().getAnalytics().reportActivityStart(activity);
     }
 
-    @Nonnull
-    private static String makeLastTabKey(@Nonnull Activity activity) {
-        return "tab_" + activity.getClass().getSimpleName();
-    }
-
     public static void setFont(@Nonnull TextView view, @Nonnull Typeface newTypeface) {
         final Typeface oldTypeface = view.getTypeface();
         if (oldTypeface == newTypeface) {
@@ -188,26 +182,8 @@ public class ActivityUi {
         actionBar.setDisplayHomeAsUpEnabled(true);
     }
 
-    public void restoreSavedTab() {
-        final ActionBar actionBar = activity.getSupportActionBar();
-        if (actionBar != null) {
-            if (selectedNavigationIndex >= 0 && selectedNavigationIndex < actionBar.getTabCount()) {
-                actionBar.setSelectedNavigationItem(selectedNavigationIndex);
-            }
-        }
-    }
-
     public void onPause() {
-        final ActionBar actionBar = activity.getSupportActionBar();
+        tabs.onPause();
-        if (actionBar != null) {
-            final int selectedNavigationIndex = actionBar.getSelectedNavigationIndex();
-            if (selectedNavigationIndex >= 0) {
-                final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
-                final SharedPreferences.Editor editor = preferences.edit();
-                editor.putInt(makeLastTabKey(activity), selectedNavigationIndex);
-                editor.apply();
-            }
-        }
     }
 
     public void onDestroy() {
@@ -248,10 +224,6 @@ public class ActivityUi {
         if (!restartIfThemeChanged(activity, theme)) {
             restartIfLanguageChanged(activity, language);
         }
-
-        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
-        selectedNavigationIndex = preferences.getInt(makeLastTabKey(activity), -1);
-        restoreSavedTab();
     }
 
     private void addHelpInfo(@Nonnull Activity activity, @Nonnull View root) {

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

@@ -16,6 +16,7 @@ import org.solovyev.android.calculator.preferences.PreferencesActivity;
 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;
 import org.solovyev.android.calculator.wizard.DragButtonWizardStep;
 
 import dagger.Component;
@@ -51,4 +52,5 @@ public interface AppComponent {
     void inject(DragButtonWizardStep fragment);
     void inject(BaseFragment fragment);
     void inject(HistoryActivity activity);
+    void inject(Tabs tabs);
 }

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

@@ -49,6 +49,7 @@ public class AppModule {
     public static final String THREAD_BACKGROUND = "thread-background";
     public static final String DIR_FILES = "dir-files";
     public static final String PREFS_FLOATING = "prefs-floating";
+    public static final String PREFS_TABS = "prefs-tabs";
 
     @NonNull
     private final Application application;
@@ -88,6 +89,13 @@ public class AppModule {
         return application.getSharedPreferences("floating-calculator", Context.MODE_PRIVATE);
     }
 
+    @Provides
+    @Singleton
+    @Named(PREFS_TABS)
+    SharedPreferences provideTabsPreferences() {
+        return application.getSharedPreferences("tabs", Context.MODE_PRIVATE);
+    }
+
     @Provides
     @Singleton
     @Named(THREAD_INIT)

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

@@ -1,34 +1,44 @@
 package org.solovyev.android.calculator.view;
 
+import static org.solovyev.android.calculator.App.cast;
+
+import android.app.Activity;
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.design.widget.TabLayout;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentPagerAdapter;
-import android.support.v4.view.ViewCompat;
 import android.support.v4.view.ViewPager;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
-import android.view.ViewTreeObserver;
+
-import butterknife.Bind;
+import org.solovyev.android.calculator.AppModule;
-import butterknife.ButterKnife;
 import org.solovyev.android.calculator.FragmentTab;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.entities.BaseEntitiesFragment;
 import org.solovyev.android.calculator.entities.Category;
-import org.solovyev.android.views.Adjuster;
 
-import javax.annotation.Nonnull;
+import butterknife.Bind;
+import butterknife.ButterKnife;
+
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+import javax.inject.Named;
+
 public class Tabs {
 
     @Nonnull
     private final AppCompatActivity activity;
     @Nonnull
     private final TabFragments adapter;
+    @Inject
+    @Named(AppModule.PREFS_TABS)
+    SharedPreferences preferences;
     @Nullable
     @Bind(R.id.tabs)
     TabLayout tabLayout;
@@ -42,6 +52,7 @@ public class Tabs {
     }
 
     public void onCreate() {
+        cast(activity.getApplicationContext()).getComponent().inject(this);
         ButterKnife.bind(this, activity);
 
         if (tabLayout == null || viewPager == null) {
@@ -55,26 +66,7 @@ public class Tabs {
         viewPager.setAdapter(adapter);
         tabLayout.setTabMode(tabs > 3 ? TabLayout.MODE_SCROLLABLE : TabLayout.MODE_FIXED);
         tabLayout.setupWithViewPager(viewPager);
-
+        restoreSelectedTab();
-
-        if (ViewCompat.isLaidOut(tabLayout)) {
-            tabLayout.setupWithViewPager(viewPager);
-        } else {
-            final ViewTreeObserver treeObserver = Adjuster.getTreeObserver(tabLayout);
-            if (treeObserver != null) {
-                treeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
-                    @Override
-                    public void onGlobalLayout() {
-                        final ViewTreeObserver anotherTreeObserver = Adjuster.getTreeObserver(tabLayout);
-                        if(anotherTreeObserver != null) {
-                            //noinspection deprecation
-                            anotherTreeObserver.removeGlobalOnLayoutListener(this);
-                        }
-                        tabLayout.setupWithViewPager(viewPager);
-                    }
-                });
-            }
-        }
     }
 
     public void addTab(@Nonnull Category category, @Nonnull FragmentTab tab) {
@@ -103,6 +95,13 @@ public class Tabs {
         return adapter.getItem(viewPager.getCurrentItem());
     }
 
+    public int getCurrentTab() {
+        if (viewPager == null) {
+            return -1;
+        }
+        return viewPager.getCurrentItem();
+    }
+
     private final class TabFragments extends FragmentPagerAdapter {
 
         @Nonnull
@@ -152,4 +151,43 @@ public class Tabs {
             return Fragment.instantiate(activity, fragmentClass.getName(), fragmentArgs);
         }
     }
+
+    public int getTabCount() {
+        return adapter.getCount();
+    }
+
+    public void selectTab(int index) {
+        if(tabLayout == null) {
+            return;
+        }
+        final TabLayout.Tab tab = tabLayout.getTabAt(index);
+        if (tab != null) {
+            tab.select();
+        }
+    }
+
+    public void restoreSelectedTab() {
+        final int selectedTab = preferences.getInt(makeTabKey(activity), -1);
+        if (selectedTab >= 0 && selectedTab < getTabCount()) {
+            selectTab(selectedTab);
+        }
+    }
+
+    public void onPause() {
+        saveSelectedTab();
+    }
+
+    private void saveSelectedTab() {
+        final int selectedTab = getCurrentTab();
+        if (selectedTab >= 0) {
+            final SharedPreferences.Editor editor = preferences.edit();
+            editor.putInt(makeTabKey(activity), selectedTab);
+            editor.apply();
+        }
+    }
+
+    @Nonnull
+    private static String makeTabKey(@Nonnull Activity activity) {
+        return activity.getClass().getSimpleName();
+    }
 }