Refactored the KiwixSearchView to use externally provided placeholder for searchView.

* Created the `PageFragmentScreenState` to encapsulates the all UI-related state to reduce the complexity in fragment.

core/src/main/java/org/kiwix/kiwixmobile/core/page/PageFragment.kt

@@ -28,31 +28,26 @@ import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
 import androidx.appcompat.widget.SearchView
-import androidx.appcompat.widget.Toolbar
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.Delete
 import androidx.compose.runtime.MutableState
-import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.referentialEqualityPolicy
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.ComposeView
 import androidx.core.view.MenuHost
 import androidx.core.view.MenuProvider
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProvider
-import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import io.reactivex.disposables.CompositeDisposable
 import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.base.BaseFragment
 import org.kiwix.kiwixmobile.core.base.FragmentActivityExtensions
 import org.kiwix.kiwixmobile.core.databinding.FragmentPageBinding
+import org.kiwix.kiwixmobile.core.downloader.downloadManager.ZERO
 import org.kiwix.kiwixmobile.core.extensions.closeKeyboard
-import org.kiwix.kiwixmobile.core.extensions.setToolTipWithContentDescription
 import org.kiwix.kiwixmobile.core.extensions.setUpSearchView
 import org.kiwix.kiwixmobile.core.main.CoreMainActivity
 import org.kiwix.kiwixmobile.core.page.adapter.OnItemClickListener
@@ -98,19 +93,28 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
       policy = referentialEqualityPolicy()
     )
 
-  /**
-   * Controls the visibility of the "Switch", and its controls.
-   *
-   * A [Triple] containing:
-   *  - [String]: The text displayed with switch.
-   *  - [Boolean]: Whether the switch is checked or not.
-   *  - [Boolean]: Whether the switch is enabled or disabled.
-   */
-  private val pageSwitchItem = mutableStateOf(Triple("", true, true))
+  private val pageScreenState = mutableStateOf(
+    // Initial values are empty because this is an abstract class.
+    // Before the view is created, the abstract variables have no values.
+    // We update this state in `onViewCreated`, once the view is created and the
+    // abstract variables are initialized.
+    PageFragmentScreenState(
+      pageState = pageState.value,
+      isSearchActive = false,
+      searchQueryHint = "",
+      searchText = "",
+      searchValueChangedListener = {},
+      screenTitle = ZERO,
+      noItemsString = "",
+      switchString = "",
+      switchIsChecked = true,
+      switchIsEnabled = true,
+      onSwitchCheckedChanged = {},
+      deleteIconTitle = ZERO,
+      clearSearchButtonClickListener = {}
+    )
+  )
   private var fragmentPageBinding: FragmentPageBinding? = null
-  override val fragmentToolbar: Toolbar? by lazy {
-    fragmentPageBinding?.root?.findViewById(R.id.toolbar)
-  }
 
   private val actionModeCallback: ActionMode.Callback =
     object : ActionMode.Callback {
@@ -177,15 +181,28 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
 
   override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
     super.onViewCreated(view, savedInstanceState)
+    pageScreenState.value = pageScreenState.value.copy(
+      isSearchActive = pageScreenState.value.isSearchActive,
+      searchQueryHint = searchQueryHint,
+      searchText = "",
+      searchValueChangedListener = { onTextChanged(it) },
+      clearSearchButtonClickListener = { onTextChanged("") },
+      screenTitle = screenTitle,
+      noItemsString = noItemsString,
+      switchString = switchString,
+      switchIsChecked = pageScreenState.value.switchIsChecked,
+      onSwitchCheckedChanged = { onSwitchCheckedChanged(it) },
+      deleteIconTitle = deleteIconTitle
+    )
     // setupMenu()
     val activity = requireActivity() as CoreMainActivity
-    fragmentPageBinding?.recyclerView?.apply {
-      layoutManager =
-        LinearLayoutManager(activity, RecyclerView.VERTICAL, false)
-      adapter = pageAdapter
-      fragmentTitle?.let(::setToolTipWithContentDescription)
-    }
-    fragmentPageBinding?.noPage?.text = noItemsString
+    // fragmentPageBinding?.recyclerView?.apply {
+    //   layoutManager =
+    //     LinearLayoutManager(activity, RecyclerView.VERTICAL, false)
+    //   adapter = pageAdapter
+    //   fragmentTitle?.let(::setToolTipWithContentDescription)
+    // }
+    // fragmentPageBinding?.noPage?.text = noItemsString
 
     // fragmentPageBinding?.pageSwitch?.apply {
     //   text = switchString
@@ -216,24 +233,20 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
   ): View? {
     return ComposeView(requireContext()).apply {
       setContent {
-        val isSearchActive = remember { mutableStateOf(false) }
         PageScreen(
-          pageState = pageState.value,
-          pageSwitchItem = pageSwitchItem.value,
-          screenTitle = screenTitle,
-          noItemsString = noItemsString,
-          searchQueryHint = searchQueryHint,
-          onSwitchChanged = { onSwitchCheckedChanged(it) },
+          state = pageScreenState.value,
           itemClickListener = this@PageFragment,
           navigationIcon = {
             NavigationIcon(
-              iconItem = navigationIconItem(isSearchActive.value),
-              onClick = navigationIconClick(isSearchActive)
+              iconItem = navigationIconItem(pageScreenState.value.isSearchActive),
+              onClick = navigationIconClick()
             )
           },
           actionMenuItems = actionMenuList(
-            isSearchActive = isSearchActive.value,
-            onSearchClick = { isSearchActive.value = true },
+            isSearchActive = pageScreenState.value.isSearchActive,
+            onSearchClick = {
+              pageScreenState.value = pageScreenState.value.copy(isSearchActive = true)
+            },
             onDeleteClick = { pageViewModel.actions.offer(Action.UserClickedDeleteButton) }
           )
         )
@@ -241,8 +254,13 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
     }
   }
 
+  private fun onTextChanged(searchText: String) {
+    pageScreenState.value = pageScreenState.value.copy(searchText = searchText)
+    pageViewModel.actions.offer(Action.Filter(searchText))
+  }
+
   private fun onSwitchCheckedChanged(isChecked: Boolean): () -> Unit = {
-    pageSwitchItem.value = pageSwitchItem.value.copy(second = isChecked)
+    pageScreenState.value = pageScreenState.value.copy(switchIsChecked = isChecked)
     pageViewModel.actions.offer(Action.UserClickedShowAllToggle(isChecked))
   }
 
@@ -252,9 +270,9 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
     IconItem.Vector(Icons.AutoMirrored.Filled.ArrowBack)
   }
 
-  private fun navigationIconClick(isSearchActive: MutableState<Boolean>): () -> Unit = {
-    if (isSearchActive.value) {
-      isSearchActive.value = false
+  private fun navigationIconClick(): () -> Unit = {
+    if (pageScreenState.value.isSearchActive) {
+      pageScreenState.value = pageScreenState.value.copy(isSearchActive = false)
       pageViewModel.actions.offer(Action.Exit)
     } else {
       requireActivity().onBackPressedDispatcher.onBackPressed()
@@ -293,8 +311,10 @@ abstract class PageFragment : OnItemClickListener, BaseFragment(), FragmentActiv
   }
 
   private fun render(state: PageState<*>) {
-    pageState.value = state
-    pageSwitchItem.value = Triple(switchString, switchIsChecked, !state.isInSelectionState)
+    pageScreenState.value = pageScreenState.value.copy(
+      switchIsEnabled = !state.isInSelectionState,
+      pageState = state,
+    )
     if (state.isInSelectionState) {
       if (actionMode == null) {
         actionMode =

core/src/main/java/org/kiwix/kiwixmobile/core/page/PageFragmentScreenState.kt

@@ -0,0 +1,45 @@
+/*
+ * Kiwix Android
+ * Copyright (c) 2025 Kiwix <android.kiwix.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.kiwix.kiwixmobile.core.page
+
+import androidx.annotation.StringRes
+import org.kiwix.kiwixmobile.core.page.viewmodel.PageState
+
+/**
+ * Represents the UI state for the PageFragment Screen.
+ * A Base screen for Bookmarks, History, and Notes screens.
+ *
+ * This data class encapsulates all UI-related states in a single object,
+ * reducing complexity in the Fragment.
+ */
+data class PageFragmentScreenState(
+  val pageState: PageState<*>,
+  val isSearchActive: Boolean,
+  val searchQueryHint: String,
+  val searchText: String,
+  val searchValueChangedListener: (String) -> Unit,
+  val clearSearchButtonClickListener: () -> Unit,
+  @StringRes val screenTitle: Int,
+  val noItemsString: String,
+  val switchString: String,
+  val switchIsChecked: Boolean,
+  val switchIsEnabled: Boolean = true,
+  val onSwitchCheckedChanged: (Boolean) -> Unit,
+  @StringRes val deleteIconTitle: Int
+)

core/src/main/java/org/kiwix/kiwixmobile/core/page/PageScreen.kt

@@ -19,6 +19,7 @@
 package org.kiwix.kiwixmobile.core.page
 
 import androidx.activity.compose.LocalActivity
+import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -39,89 +40,95 @@ import org.kiwix.kiwixmobile.core.main.CoreMainActivity
 import org.kiwix.kiwixmobile.core.page.adapter.OnItemClickListener
 import org.kiwix.kiwixmobile.core.page.adapter.Page
 import org.kiwix.kiwixmobile.core.page.history.adapter.HistoryListItem.DateItem
-import org.kiwix.kiwixmobile.core.page.viewmodel.PageState
 import org.kiwix.kiwixmobile.core.ui.components.KiwixAppBar
+import org.kiwix.kiwixmobile.core.ui.components.KiwixSearchView
 import org.kiwix.kiwixmobile.core.ui.models.ActionMenuItem
+import org.kiwix.kiwixmobile.core.ui.theme.Black
 import org.kiwix.kiwixmobile.core.ui.theme.KiwixTheme
-import org.kiwix.kiwixmobile.core.utils.ComposeDimens.EIGHT_DP
 import org.kiwix.kiwixmobile.core.utils.ComposeDimens.SIXTEEN_DP
 
-@Suppress(
-  "LongParameterList",
-  "IgnoredReturnValue",
-  "UnusedParameter",
-  "ComposableLambdaParameterNaming"
-)
+@Suppress("ComposableLambdaParameterNaming")
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun PageScreen(
-  pageState: PageState<out Page>,
-  pageSwitchItem: Triple<String, Boolean, Boolean>,
-  screenTitle: Int,
-  noItemsString: String,
-  searchQueryHint: String,
-  onSwitchChanged: (Boolean) -> Unit,
+  state: PageFragmentScreenState,
   itemClickListener: OnItemClickListener,
   actionMenuItems: List<ActionMenuItem>,
-  navigationIcon: @Composable () -> Unit,
+  navigationIcon: @Composable () -> Unit
 ) {
-  val context = LocalActivity.current as CoreMainActivity
-
   KiwixTheme {
     Scaffold(
       topBar = {
         Column {
           KiwixAppBar(
-            titleId = screenTitle,
+            titleId = state.screenTitle,
             navigationIcon = navigationIcon,
-            actionMenuItems = actionMenuItems
+            actionMenuItems = actionMenuItems,
+            searchBar = searchBarIfActive(state)
           )
-          // hide switches for custom apps, see more info here https://github.com/kiwix/kiwix-android/issues/3523
-          if (!context.isCustomApp()) {
-            Row(
-              modifier = Modifier
-                .fillMaxWidth()
-                .padding(horizontal = SIXTEEN_DP, vertical = EIGHT_DP),
-              verticalAlignment = Alignment.CenterVertically
-            ) {
-              Text(pageSwitchItem.first, modifier = Modifier.weight(1f))
-              Switch(
-                checked = pageSwitchItem.second,
-                onCheckedChange = onSwitchChanged,
-                enabled = pageSwitchItem.third
-              )
-            }
-          }
+          PageSwitchRow(state)
         }
       }
     ) { padding ->
-      val items = pageState.pageItems
+      val items = state.pageState.pageItems
       Box(modifier = Modifier.padding(padding)) {
         if (items.isEmpty()) {
           Text(
-            text = noItemsString,
+            text = state.noItemsString,
             style = MaterialTheme.typography.headlineSmall,
             modifier = Modifier.align(Alignment.Center)
           )
         } else {
           LazyColumn {
-            items(pageState.visiblePageItems) { item ->
+            items(state.pageState.visiblePageItems) { item ->
               when (item) {
-                is Page -> {
-                  PageListItem(
-                    page = item,
-                    itemClickListener = itemClickListener
-                  )
+                is Page -> PageListItem(page = item, itemClickListener = itemClickListener)
+                is DateItem -> DateItemText(item)
+              }
+            }
+          }
+        }
+      }
+    }
+  }
 }
 
-                is DateItem -> {
-                  DateItemText(item)
-                }
-              }
-            }
-          }
+@Composable
+private fun searchBarIfActive(
+  state: PageFragmentScreenState
+): (@Composable () -> Unit)? = {
+  if (state.isSearchActive) {
+    KiwixSearchView(
+      placeholder = state.searchQueryHint,
+      value = state.searchText,
+      testTag = "",
+      onValueChange = { state.searchValueChangedListener(it) },
+      onClearClick = { state.clearSearchButtonClickListener.invoke() }
+    )
+  } else {
+    null
   }
 }
+
+@Composable
+fun PageSwitchRow(
+  state: PageFragmentScreenState
+) {
+  val context = LocalActivity.current as CoreMainActivity
+  // hide switches for custom apps, see more info here https://github.com/kiwix/kiwix-android/issues/3523
+  if (!context.isCustomApp()) {
+    Row(
+      modifier = Modifier
+        .fillMaxWidth()
+        .background(Black),
+      verticalAlignment = Alignment.CenterVertically
+    ) {
+      Text(state.switchString)
+      Switch(
+        checked = state.switchIsChecked,
+        onCheckedChange = { state.onSwitchCheckedChanged(it) },
+        enabled = state.switchIsEnabled
+      )
     }
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/ui/components/KiwixSearchView.kt

@@ -39,8 +39,9 @@ import org.kiwix.kiwixmobile.core.utils.ComposeDimens
 
 @Composable
 fun KiwixSearchView(
-  modifier: Modifier,
+  modifier: Modifier = Modifier,
   value: String,
+  placeholder: String = stringResource(R.string.search_label),
   testTag: String = "",
   onValueChange: (String) -> Unit,
   onClearClick: () -> Unit
@@ -65,7 +66,7 @@ fun KiwixSearchView(
     value = value,
     placeholder = {
       Text(
-        text = stringResource(R.string.search_label),
+        text = placeholder,
         color = Color.LightGray,
         fontSize = ComposeDimens.EIGHTEEN_SP
       )