Bottom tabs selection stack (HW button Android)

e2e/BottomTabs.test.js

@@ -1,5 +1,6 @@
 import Utils from './Utils';
 import TestIDs from '../playground/src/testIDs';
+import Android from './AndroidUtils';
 
 const { elementByLabel, elementById } = Utils;
 
@@ -113,4 +114,28 @@ describe('BottomTabs', () => {
     await elementByLabel('OK').tap();
     await expect(elementByLabel('First Tab')).toBeVisible();
   });
+
+  it.e2e(':android: hardware back tab selection history', async () => {
+    await elementById(TestIDs.SECOND_TAB_BAR_BTN).tap();
+    await elementById(TestIDs.FIRST_TAB_BAR_BUTTON).tap();
+    await elementById(TestIDs.SECOND_TAB_BAR_BTN).tap();
+    await elementById(TestIDs.SECOND_TAB_BAR_BTN).tap();
+    await elementById(TestIDs.FIRST_TAB_BAR_BUTTON).tap();
+
+     Android.pressBack();
+    await expect(elementByLabel('Second Tab')).toBeVisible();
+
+     Android.pressBack();
+    await expect(elementByLabel('First Tab')).toBeVisible();
+
+     Android.pressBack();
+    await expect(elementByLabel('Second Tab')).toBeVisible();
+
+     Android.pressBack();
+    await expect(elementByLabel('First Tab')).toBeVisible();
+
+     Android.pressBack();
+    await expect(elementByLabel('First Tab')).toBeNotVisible();
+    await expect(elementByLabel('Second Tab')).toBeNotVisible();
+  });
 });

lib/android/app/src/main/java/com/reactnativenavigation/options/HardwareBackButtonOptions.kt

@@ -6,10 +6,40 @@ import com.reactnativenavigation.options.parsers.BoolParser
 import org.json.JSONObject
 
 
+sealed class HwBackBottomTabsBehaviour {
+    object Undefined : HwBackBottomTabsBehaviour() {
+        override fun hasValue(): Boolean = false
+    }
+
+    object Exit : HwBackBottomTabsBehaviour()
+    object PrevSelection : HwBackBottomTabsBehaviour()
+    object JumpToFirst : HwBackBottomTabsBehaviour()
+
+    open fun hasValue(): Boolean = true
+
+    companion object {
+        private const val BEHAVIOUR_EXIT = "exit"
+        private const val BEHAVIOUR_PREV = "previous"
+        private const val BEHAVIOUR_FIRST = "first"
+        fun fromString(behaviour: String?): HwBackBottomTabsBehaviour {
+            return when (behaviour) {
+                BEHAVIOUR_PREV -> PrevSelection
+                BEHAVIOUR_FIRST -> JumpToFirst
+                BEHAVIOUR_EXIT -> Exit
+                else -> Undefined
+            }
+        }
+    }
+}
+
 open class HardwareBackButtonOptions(json: JSONObject? = null) {
 
-    @JvmField var dismissModalOnPress: Bool = NullBool()
-    @JvmField var popStackOnPress: Bool = NullBool()
+    @JvmField
+    var dismissModalOnPress: Bool = NullBool()
+
+    @JvmField
+    var popStackOnPress: Bool = NullBool()
+    var bottomTabOnPress: HwBackBottomTabsBehaviour = HwBackBottomTabsBehaviour.Undefined
 
     init {
         parse(json)
@@ -18,16 +48,19 @@ open class HardwareBackButtonOptions(json: JSONObject? = null) {
     fun mergeWith(other: HardwareBackButtonOptions) {
         if (other.dismissModalOnPress.hasValue()) dismissModalOnPress = other.dismissModalOnPress
         if (other.popStackOnPress.hasValue()) popStackOnPress = other.popStackOnPress
+        if (other.bottomTabOnPress.hasValue()) bottomTabOnPress = other.bottomTabOnPress
     }
 
     fun mergeWithDefault(defaultOptions: HardwareBackButtonOptions) {
         if (!dismissModalOnPress.hasValue()) dismissModalOnPress = defaultOptions.dismissModalOnPress
         if (!popStackOnPress.hasValue()) popStackOnPress = defaultOptions.popStackOnPress
+        if (!bottomTabOnPress.hasValue()) bottomTabOnPress = defaultOptions.bottomTabOnPress
     }
 
     private fun parse(json: JSONObject?) {
         json ?: return
         dismissModalOnPress = BoolParser.parse(json, "dismissModalOnPress")
         popStackOnPress = BoolParser.parse(json, "popStackOnPress")
+        bottomTabOnPress = HwBackBottomTabsBehaviour.fromString(json.optString("bottomTabsOnPress"))
     }
 }

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java

@@ -13,6 +13,7 @@
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem;
 import com.reactnativenavigation.options.BottomTabOptions;
+import com.reactnativenavigation.options.HwBackBottomTabsBehaviour;
 import com.reactnativenavigation.options.Options;
 import com.reactnativenavigation.react.CommandListener;
 import com.reactnativenavigation.react.CommandListenerAdapter;
@@ -29,6 +30,8 @@
 import com.reactnativenavigation.views.bottomtabs.BottomTabsLayout;
 
 import java.util.Collection;
+import java.util.Deque;
+import java.util.LinkedList;
 import java.util.List;
 
 import static com.reactnativenavigation.utils.CollectionUtils.forEach;
@@ -39,6 +42,7 @@ public class BottomTabsController extends ParentController<BottomTabsLayout> imp
 
     private BottomTabsContainer bottomTabsContainer;
     private BottomTabs bottomTabs;
+    private final Deque<Integer> selectionStack;
     private final List<ViewController<?>> tabs;
     private final EventEmitter eventEmitter;
     private final ImageLoader imageLoader;
@@ -66,6 +70,7 @@ public BottomTabsController(Activity activity, List<ViewController<?>> tabs, Chi
         this.presenter = bottomTabsPresenter;
         this.tabPresenter = bottomTabPresenter;
         forEach(tabs, tab -> tab.setParentController(this));
+        selectionStack = new LinkedList<>();
     }
 
     @Override
@@ -156,7 +161,27 @@ public void mergeChildOptions(Options options, ViewController<?> child) {
 
     @Override
     public boolean handleBack(CommandListener listener) {
-        return !tabs.isEmpty() && tabs.get(bottomTabs.getCurrentItem()).handleBack(listener);
+        final boolean childBack = !tabs.isEmpty() && tabs.get(bottomTabs.getCurrentItem()).handleBack(listener);
+        final Options options = resolveCurrentOptions();
+        if (!childBack) {
+            if (options.hardwareBack.getBottomTabOnPress() instanceof HwBackBottomTabsBehaviour.PrevSelection) {
+                if (!selectionStack.isEmpty()) {
+                    final int prevSelectedTabIndex = selectionStack.poll();
+                    selectTab(prevSelectedTabIndex, false);
+                    return true;
+                }
+            } else if (options.hardwareBack.getBottomTabOnPress() instanceof HwBackBottomTabsBehaviour.JumpToFirst) {
+                if (getSelectedIndex() != 0) {
+                    selectTab(0, false);
+                    return true;
+                } else {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        }
+        return childBack;
     }
 
     @Override
@@ -203,7 +228,7 @@ private List<AHBottomNavigationItem> createTabs() {
         });
     }
 
-    int getSelectedIndex() {
+    public int getSelectedIndex() {
         return bottomTabs.getCurrentItem();
     }
 
@@ -239,13 +264,28 @@ public void destroy() {
 
     @Override
     public void selectTab(final int newIndex) {
+        final boolean enableSelectionHistory = resolveCurrentOptions().hardwareBack.getBottomTabOnPress() instanceof HwBackBottomTabsBehaviour.PrevSelection;
+        selectTab(newIndex, enableSelectionHistory);
+    }
+
+    private void selectTab(int newIndex, boolean enableSelectionHistory) {
+        saveTabSelection(newIndex, enableSelectionHistory);
         tabsAttacher.onTabSelected(tabs.get(newIndex));
         getCurrentView().setVisibility(View.INVISIBLE);
         bottomTabs.setCurrentItem(newIndex, false);
         getCurrentView().setVisibility(View.VISIBLE);
         getCurrentChild().onViewDidAppear();
     }
 
+    private void saveTabSelection(int newIndex, boolean enableSelectionHistory) {
+        if (enableSelectionHistory) {
+            if (selectionStack.isEmpty()
+                    || selectionStack.peek() != newIndex
+                    || bottomTabs.getCurrentItem() != newIndex)
+                selectionStack.offerFirst(bottomTabs.getCurrentItem());
+        }
+    }
+
     @NonNull
     private ViewGroup getCurrentView() {
         return tabs.get(bottomTabs.getCurrentItem()).getView();