Tab swiping: Integration of the new tab management

app/src/androidTest/java/com/duckduckgo/app/browser/BrowserTabViewModelTest.kt

@@ -2423,14 +2423,29 @@ class BrowserTabViewModelTest {
     }
 
     @Test
-    fun whenUserRequestedToOpenNewTabThenNewTabCommandIssued() {
+    fun whenUserRequestedToOpenNewTabAndNoEmptyTabExistsThenNewTabCommandIssued() {
+        tabsLiveData.value = listOf(TabEntity("1", "https://example.com", position = 0))
         testee.userRequestedOpeningNewTab()
         verify(mockCommandObserver, atLeastOnce()).onChanged(commandCaptor.capture())
         val command = commandCaptor.lastValue
         assertTrue(command is Command.LaunchNewTab)
         verify(mockPixel, never()).fire(AppPixelName.TAB_MANAGER_NEW_TAB_LONG_PRESSED)
     }
 
+    @Test
+    fun whenUserRequestedToOpenNewTabAndEmptyTabExistsThenSelectTheEmptyTab() = runTest {
+        val emptyTabId = "EMPTY_TAB"
+        tabsLiveData.value = listOf(TabEntity(emptyTabId))
+        testee.userRequestedOpeningNewTab()
+
+        verify(mockCommandObserver, atLeastOnce()).onChanged(commandCaptor.capture())
+        val command = commandCaptor.lastValue
+        assertFalse(command is Command.LaunchNewTab)
+
+        verify(mockTabRepository).select(emptyTabId)
+        verify(mockPixel, never()).fire(AppPixelName.TAB_MANAGER_NEW_TAB_LONG_PRESSED)
+    }
+
     @Test
     fun whenUserRequestedToOpenNewTabByLongPressThenPixelFired() {
         testee.userRequestedOpeningNewTab(longPress = true)

app/src/main/java/com/duckduckgo/app/browser/BrowserActivity.kt

@@ -30,7 +30,10 @@ import androidx.activity.OnBackPressedCallback
 import androidx.activity.result.ActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.VisibleForTesting
+import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.viewpager2.widget.MarginPageTransformer
+import androidx.viewpager2.widget.ViewPager2
 import androidx.webkit.ServiceWorkerClientCompat
 import androidx.webkit.ServiceWorkerControllerCompat
 import androidx.webkit.WebViewFeature
@@ -71,6 +74,7 @@ import com.duckduckgo.common.ui.DuckDuckGoActivity
 import com.duckduckgo.common.ui.view.dialog.TextAlertDialogBuilder
 import com.duckduckgo.common.ui.view.gone
 import com.duckduckgo.common.ui.view.show
+import com.duckduckgo.common.ui.view.toPx
 import com.duckduckgo.common.ui.viewbinding.viewBinding
 import com.duckduckgo.common.utils.DispatcherProvider
 import com.duckduckgo.common.utils.playstore.PlayStoreUtils
@@ -80,6 +84,7 @@ import com.duckduckgo.privacy.dashboard.api.ui.PrivacyDashboardHybridScreenParam
 import com.duckduckgo.savedsites.impl.bookmarks.BookmarksActivity.Companion.SAVED_SITE_URL_EXTRA
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
 import timber.log.Timber
 
@@ -129,6 +134,9 @@ open class BrowserActivity : DuckDuckGoActivity() {
     @Inject
     lateinit var appBuildConfig: AppBuildConfig
 
+    @Inject
+    lateinit var isSwipingTabsFeatureEnabled: IsSwipingTabsFeatureEnabled
+
     @Inject
     lateinit var tabManager: TabManager
 
@@ -148,8 +156,33 @@ open class BrowserActivity : DuckDuckGoActivity() {
 
     private val binding: ActivityBrowserBinding by viewBinding()
 
+    val tabPager: ViewPager2 by lazy {
+        binding.tabPager
+    }
+
     private lateinit var toolbarMockupBinding: IncludeOmnibarToolbarMockupBinding
 
+    private val onTabPageChangeListener = object : ViewPager2.OnPageChangeCallback() {
+        private var wasSwipingStarted = false
+
+        override fun onPageSelected(position: Int) {
+            super.onPageSelected(position)
+            Timber.d("### onPageChanged requested for: $position")
+            if (wasSwipingStarted) {
+                Timber.d("### onPageChanged: $position")
+                tabManager.tabPagerAdapter.onPageChanged(position)
+                wasSwipingStarted = false
+            }
+        }
+
+        override fun onPageScrollStateChanged(state: Int) {
+            super.onPageScrollStateChanged(state)
+            if (state == ViewPager2.SCROLL_STATE_DRAGGING) {
+                wasSwipingStarted = true
+            }
+        }
+    }
+
     @VisibleForTesting
     var destroyedByBackPress: Boolean = false
 
@@ -205,6 +238,10 @@ open class BrowserActivity : DuckDuckGoActivity() {
 
     override fun onDestroy() {
         currentTab = null
+
+        binding.tabPager.adapter = null
+        binding.tabPager.unregisterOnPageChangeCallback(onTabPageChangeListener)
+
         super.onDestroy()
     }
 
@@ -341,18 +378,31 @@ open class BrowserActivity : DuckDuckGoActivity() {
         viewModel.command.observe(this) {
             processCommand(it)
         }
-        viewModel.selectedTab.observe(this) {
-            tabManager.onSelectedTabChanged(it)
+
+        lifecycleScope.launch {
+            viewModel.tabs.flowWithLifecycle(lifecycle).collectLatest {
+                tabManager.onTabsUpdated(it)
+                lifecycleScope.launch {
+                    viewModel.onTabsUpdated(it.isEmpty())
+                }
+            }
         }
-        viewModel.tabs.observe(this) {
-            tabManager.onTabsUpdated(it)
+
+        lifecycleScope.launch {
+            viewModel.selectedTab.flowWithLifecycle(lifecycle).collectLatest {
+                tabManager.onSelectedTabChanged(it)
+            }
+        }
+
+        // listen to onboarding completion to enable/disable swiping
+        viewModel.isOnboardingCompleted.observe(this) { isOnboardingCompleted ->
+            tabPager.isUserInputEnabled = isOnboardingCompleted
         }
     }
 
     private fun removeObservers() {
         viewModel.command.removeObservers(this)
-        viewModel.selectedTab.removeObservers(this)
-        viewModel.tabs.removeObservers(this)
+        viewModel.isOnboardingCompleted.removeObservers(this)
     }
 
     private fun processCommand(command: Command) {
@@ -515,6 +565,7 @@ open class BrowserActivity : DuckDuckGoActivity() {
 
         private fun showWebContent() {
             Timber.d("BrowserActivity can now start displaying web content. instance state is $instanceStateBundles")
+            initializeTabs()
             configureObservers()
             binding.clearingInProgressView.gone()
 
@@ -533,6 +584,22 @@ open class BrowserActivity : DuckDuckGoActivity() {
         }
     }
 
+    @SuppressLint("ClickableViewAccessibility", "WrongConstant")
+    private fun initializeTabs() {
+        if (isSwipingTabsFeatureEnabled()) {
+            tabPager.adapter = tabManager.tabPagerAdapter
+            tabPager.offscreenPageLimit = 1
+            tabPager.registerOnPageChangeCallback(onTabPageChangeListener)
+            tabPager.setPageTransformer(MarginPageTransformer(resources.getDimension(com.duckduckgo.mobile.android.R.dimen.keyline_2).toPx().toInt()))
+
+            binding.fragmentContainer.gone()
+            tabPager.show()
+        } else {
+            binding.fragmentContainer.show()
+            tabPager.gone()
+        }
+    }
+
     private val Intent.launchedFromRecents: Boolean
         get() = (flags and Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) == Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY
 
@@ -632,6 +699,12 @@ open class BrowserActivity : DuckDuckGoActivity() {
         playStoreUtils.launchPlayStore()
     }
 
+    fun onMoveToTabRequested(index: Int) {
+        Timber.d("### onMoveToTabRequested: $index")
+
+        tabPager.currentItem = index
+    }
+
     private data class CombinedInstanceState(
         val originalInstanceState: Bundle?,
         val newInstanceState: Bundle?,

app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt

@@ -606,6 +606,8 @@ class BrowserTabFragment :
 
     private var webView: DuckDuckGoWebView? = null
 
+    var isInitialized = false
+
     private val activityResultHandlerEmailProtectionInContextSignup = registerForActivityResult(StartActivityForResult()) { result: ActivityResult ->
         when (result.resultCode) {
             EmailProtectionInContextSignUpScreenResult.SUCCESS -> {
@@ -814,13 +816,16 @@ class BrowserTabFragment :
     }
 
     private fun resumeWebView() {
+        Timber.d("Resuming webview: $tabId")
         webView?.let {
             if (it.isShown) it.onResume()
         }
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
+    override fun onViewCreated(
+        view: View,
+        savedInstanceState: Bundle?,
+    ) {
         omnibar = Omnibar(settingsDataStore.omnibarPosition, changeOmnibarPositionFeature.refactor().isEnabled(), binding)
 
         webViewContainer = binding.webViewContainer
@@ -836,9 +841,8 @@ class BrowserTabFragment :
         configureOmnibar()
 
         if (savedInstanceState == null) {
-            viewModel.onViewReady()
-            messageFromPreviousTab?.let {
-                processMessage(it)
+            if (isActiveTab) {
+                initFragmentIfNecessary()
             }
         } else {
             viewModel.onViewRecreated()
@@ -847,7 +851,7 @@ class BrowserTabFragment :
         lifecycle.addObserver(
             @SuppressLint("NoLifecycleObserver") // we don't observe app lifecycle
             object : DefaultLifecycleObserver {
-                override fun onStop(owner: LifecycleOwner) {
+                override fun onPause(owner: LifecycleOwner) {
                     if (isVisible) {
                         updateOrDeleteWebViewPreview()
                     }
@@ -859,6 +863,16 @@ class BrowserTabFragment :
             (dialog as EditSavedSiteDialogFragment).listener = viewModel
             dialog.deleteBookmarkListener = viewModel
         }
+
+        disableSwipingOutsideTheOmnibar()
+    }
+
+    private fun disableSwipingOutsideTheOmnibar() {
+        newBrowserTab.newTabLayout.setOnTouchListener { v, event ->
+            (v as FrameLayout).requestDisallowInterceptTouchEvent(true)
+            return@setOnTouchListener true
+        }
+        binding.legacyOmnibar.setOnTouchListener { v, event -> false }
     }
 
     private fun configureOmnibar() {
@@ -1136,9 +1150,22 @@ class BrowserTabFragment :
         startActivity(TabSwitcherActivity.intent(activity, tabId))
     }
 
+    private fun initFragmentIfNecessary() {
+        if (!isInitialized) {
+            isInitialized = true
+
+            viewModel.onViewReady()
+            messageFromPreviousTab?.let {
+                processMessage(it)
+            }
+        }
+    }
+
     override fun onResume() {
         super.onResume()
 
+        initFragmentIfNecessary()
+
         if (viewModel.hasOmnibarPositionChanged(omnibar.omnibarPosition)) {
             requireActivity().recreate()
             return
@@ -1308,6 +1335,10 @@ class BrowserTabFragment :
                         // want to ensure that we aren't offering to inject credentials from an inactive tab
                         hideDialogWithTag(CredentialAutofillPickerDialog.TAG)
                     }
+
+                    if (isActiveTab) {
+                        initFragmentIfNecessary()
+                    }
                 }
             },
         )
@@ -1331,7 +1362,7 @@ class BrowserTabFragment :
         newBrowserTab.newTabContainerLayout.show()
         binding.browserLayout.gone()
         webViewContainer.gone()
-        omnibar.setViewMode(Omnibar.ViewMode.NewTab)
+        omnibar.setViewMode(ViewMode.NewTab)
         webView?.onPause()
         webView?.hide()
         errorView.errorLayout.gone()
@@ -1347,7 +1378,7 @@ class BrowserTabFragment :
         webView?.onResume()
         errorView.errorLayout.gone()
         sslErrorView.gone()
-        omnibar.setViewMode(Omnibar.ViewMode.Browser(viewModel.url))
+        omnibar.setViewMode(ViewMode.Browser(viewModel.url))
     }
 
     private fun showError(
@@ -1358,7 +1389,7 @@ class BrowserTabFragment :
         newBrowserTab.newTabLayout.gone()
         newBrowserTab.newTabContainerLayout.gone()
         sslErrorView.gone()
-        omnibar.setViewMode(Omnibar.ViewMode.Error)
+        omnibar.setViewMode(ViewMode.Error)
         webView?.onPause()
         webView?.hide()
         errorView.errorMessage.text = getString(errorType.errorId, url).html(requireContext())
@@ -1379,7 +1410,7 @@ class BrowserTabFragment :
         newBrowserTab.newTabContainerLayout.gone()
         webView?.onPause()
         webView?.hide()
-        omnibar.setViewMode(Omnibar.ViewMode.SSLWarning)
+        omnibar.setViewMode(ViewMode.SSLWarning)
         errorView.errorLayout.gone()
         binding.browserLayout.gone()
         sslErrorView.bind(handler, errorResponse) { action ->
@@ -2424,7 +2455,11 @@ class BrowserTabFragment :
             cancelPendingAutofillRequestsToChooseCredentials()
         } else {
             omnibar.omnibarTextInput.hideKeyboard()
-            binding.focusDummy.requestFocus()
+
+            // prevent a crash when the view is not initiliazed yet
+            if (view != null) {
+                binding.focusDummy.requestFocus()
+            }
         }
     }
 

app/src/main/java/com/duckduckgo/app/browser/BrowserTabViewModel.kt

@@ -2618,7 +2618,15 @@ class BrowserTabViewModel @Inject constructor(
 
     fun userRequestedOpeningNewTab(longPress: Boolean = false) {
         command.value = GenerateWebViewPreviewImage
-        command.value = LaunchNewTab
+
+        val emptyTab = tabs.value?.firstOrNull { it.url.isNullOrBlank() }?.tabId
+        if (emptyTab != null) {
+            viewModelScope.launch {
+                tabRepository.select(tabId = emptyTab)
+            }
+        } else {
+            command.value = LaunchNewTab
+        }
         if (longPress) {
             pixel.fire(AppPixelName.TAB_MANAGER_NEW_TAB_LONG_PRESSED)
         }