Pin navigation ui option #851

app/src/main/kotlin/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -74,6 +74,9 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 	val isNavLabelsVisible: Boolean
 		get() = prefs.getBoolean(KEY_NAV_LABELS, true)
 
+	val isNavBarPinned: Boolean
+		get() = prefs.getBoolean(KEY_NAV_PINNED, false)
+
 	var gridSize: Int
 		get() = prefs.getInt(KEY_GRID_SIZE, 100)
 		set(value) = prefs.edit { putInt(KEY_GRID_SIZE, value) }
@@ -653,6 +656,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val KEY_RELATED_MANGA = "related_manga"
 		const val KEY_NAV_MAIN = "nav_main"
 		const val KEY_NAV_LABELS = "nav_labels"
+		const val KEY_NAV_PINNED = "nav_pinned"
 		const val KEY_32BIT_COLOR = "enhanced_colors"
 		const val KEY_SOURCES_ORDER = "sources_sort_order"
 		const val KEY_SOURCES_CATALOG = "sources_catalog"

app/src/main/kotlin/org/koitharu/kotatsu/core/ui/widgets/HideBottomNavigationOnScrollBehavior.kt

@@ -25,6 +25,15 @@ class HideBottomNavigationOnScrollBehavior @JvmOverloads constructor(
 
 	private var dyRatio = 1F
 
+	var isPinned: Boolean = false
+		set(value) {
+			field = value
+			if (value) {
+				offsetAnimator?.cancel()
+				offsetAnimator = null
+			}
+		}
+
 	override fun layoutDependsOn(parent: CoordinatorLayout, child: BottomNavigationView, dependency: View): Boolean {
 		return dependency is AppBarLayout
 	}
@@ -51,7 +60,7 @@ class HideBottomNavigationOnScrollBehavior @JvmOverloads constructor(
 		axes: Int,
 		type: Int,
 	): Boolean {
-		if (axes != ViewCompat.SCROLL_AXIS_VERTICAL) {
+		if (isPinned || axes != ViewCompat.SCROLL_AXIS_VERTICAL) {
 			return false
 		}
 		lastStartedType = type
@@ -69,7 +78,9 @@ class HideBottomNavigationOnScrollBehavior @JvmOverloads constructor(
 		type: Int,
 	) {
 		super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type)
-		child.translationY = (child.translationY + (dy * dyRatio)).coerceIn(0F, child.height.toFloat())
+		if (!isPinned) {
+			child.translationY = (child.translationY + (dy * dyRatio)).coerceIn(0F, child.height.toFloat())
+		}
 	}
 
 	override fun onStopNestedScroll(
@@ -78,7 +89,7 @@ class HideBottomNavigationOnScrollBehavior @JvmOverloads constructor(
 		target: View,
 		type: Int,
 	) {
-		if (lastStartedType == ViewCompat.TYPE_TOUCH || type == ViewCompat.TYPE_NON_TOUCH) {
+		if (!isPinned && (lastStartedType == ViewCompat.TYPE_TOUCH || type == ViewCompat.TYPE_NON_TOUCH)) {
 			animateBottomNavigationVisibility(child, child.translationY < child.height / 2)
 		}
 	}

app/src/main/kotlin/org/koitharu/kotatsu/core/ui/widgets/SlidingBottomNavigationView.kt

@@ -38,6 +38,15 @@ class SlidingBottomNavigationView @JvmOverloads constructor(
 	private var currentState = STATE_UP
 	private var behavior = HideBottomNavigationOnScrollBehavior()
 
+	var isPinned: Boolean
+		get() = behavior.isPinned
+		set(value) {
+			behavior.isPinned = value
+			if (value) {
+				translationX = 0f
+			}
+		}
+
 	override fun getBehavior(): CoordinatorLayout.Behavior<*> {
 		return behavior
 	}

app/src/main/kotlin/org/koitharu/kotatsu/main/ui/MainActivity.kt

@@ -13,6 +13,7 @@ import androidx.appcompat.view.ActionMode
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
 import androidx.core.graphics.Insets
+import androidx.core.view.children
 import androidx.core.view.inputmethod.EditorInfoCompat
 import androidx.core.view.isInvisible
 import androidx.core.view.isVisible
@@ -131,6 +132,7 @@ class MainActivity : BaseActivity<ActivityMainBinding>(), AppBarOwner, BottomNav
 		viewModel.onFirstStart.observeEvent(this) {
 			WelcomeSheet.show(supportFragmentManager)
 		}
+		viewModel.isBottomNavPinned.observe(this, ::setNavbarPinned)
 		searchSuggestionViewModel.isIncognitoModeEnabled.observe(this, this::onIncognitoModeChanged)
 	}
 
@@ -399,6 +401,22 @@ class MainActivity : BaseActivity<ActivityMainBinding>(), AppBarOwner, BottomNav
 		}
 	}
 
+	private fun setNavbarPinned(isPinned: Boolean) {
+		viewBinding.bottomNav?.isPinned = isPinned
+		for (view in viewBinding.appbar.children) {
+			val lp = view.layoutParams as? AppBarLayout.LayoutParams ?: continue
+			val scrollFlags = if (isPinned) {
+				lp.scrollFlags and SCROLL_FLAG_SCROLL.inv()
+			} else {
+				lp.scrollFlags or SCROLL_FLAG_SCROLL
+			}
+			if (scrollFlags != lp.scrollFlags) {
+				lp.scrollFlags = scrollFlags
+				view.layoutParams = lp
+			}
+		}
+	}
+
 	private inner class CloseSearchCallback : OnBackPressedCallback(false) {
 
 		override fun handleOnBackPressed() {

app/src/main/kotlin/org/koitharu/kotatsu/main/ui/MainViewModel.kt

@@ -4,11 +4,13 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.plus
 import org.koitharu.kotatsu.core.exceptions.EmptyHistoryException
 import org.koitharu.kotatsu.core.github.AppUpdateRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.core.prefs.observeAsFlow
 import org.koitharu.kotatsu.core.ui.BaseViewModel
 import org.koitharu.kotatsu.core.util.ext.MutableEventFlow
 import org.koitharu.kotatsu.core.util.ext.call
@@ -46,6 +48,12 @@ class MainViewModel @Inject constructor(
 		.withErrorHandling()
 		.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Lazily, 0)
 
+	val isBottomNavPinned = settings.observeAsFlow(
+		AppSettings.KEY_NAV_PINNED,
+	) {
+		isNavBarPinned
+	}.flowOn(Dispatchers.Default)
+
 	init {
 		launchJob {
 			appUpdateRepository.fetchUpdate()

app/src/main/res/layout/fragment_feed.xml

@@ -19,7 +19,7 @@
 			android:orientation="vertical"
 			android:paddingVertical="@dimen/list_spacing_normal"
 			app:bubbleSize="small"
-			app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+			app:layoutManager=".core.ui.list.FitHeightLinearLayoutManager"
 			tools:listitem="@layout/item_feed" />
 
 	</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

app/src/main/res/values/strings.xml

@@ -634,4 +634,6 @@
 	<string name="more_frequently">More frequently</string>
 	<string name="frequency_of_check">Frequency of check</string>
 	<string name="new_chapters_pattern">%1$s: %2$d</string>
+	<string name="pin_navigation_ui">Pin navigation UI</string>
+	<string name="pin_navigation_ui_summary">Do not hide navgation bar and search view on scroll</string>
 </resources>

app/src/main/res/xml/pref_appearance.xml

@@ -76,6 +76,12 @@
 		android:key="nav_labels"
 		android:title="@string/show_labels_in_navbar" />
 
+	<SwitchPreferenceCompat
+		android:defaultValue="false"
+		android:key="nav_pinned"
+		android:summary="@string/pin_navigation_ui_summary"
+		android:title="@string/pin_navigation_ui" />
+
 	<org.koitharu.kotatsu.settings.utils.ActivityListPreference
 		android:key="app_locale"
 		android:title="@string/language" />