Refined the BookItem for better readability and maintainability.

* Created `ZimFileLanguageHeader` for showing the languages of ZIM files.

app/src/main/java/org/kiwix/kiwixmobile/ui/BookItem.kt

@@ -18,7 +18,8 @@
 
 package org.kiwix.kiwixmobile.ui
 
-import androidx.compose.foundation.clickable
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
@@ -36,61 +37,95 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.dimensionResource
+import androidx.compose.ui.graphics.painter.Painter
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextOverflow
-import androidx.compose.ui.unit.dp
 import org.kiwix.kiwixmobile.core.R
 import org.kiwix.kiwixmobile.core.extensions.faviconToPainter
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.BOOK_ICON_SIZE
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.EIGHT_DP
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.FIVE_DP
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.FOUR_DP
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.SIXTEEN_DP
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.TEN_DP
 import org.kiwix.kiwixmobile.core.zim_manager.fileselect_view.SelectionMode
 import org.kiwix.kiwixmobile.core.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 
-@Suppress("UnusedParameter", "LongMethod", "ComposableLambdaParameterNaming")
+@OptIn(ExperimentalFoundationApi::class)
 @Composable
 fun BookItem(
   bookOnDisk: BookOnDisk,
-  onClick: (BookOnDisk) -> Unit,
+  onClick: ((BookOnDisk) -> Unit)? = null,
-  onLongClick: (BookOnDisk) -> Unit,
+  onLongClick: ((BookOnDisk) -> Unit)? = null,
-  onMultiSelect: (BookOnDisk) -> Unit,
+  onMultiSelect: ((BookOnDisk) -> Unit)? = null,
-  selectionMode: SelectionMode,
+  selectionMode: SelectionMode = SelectionMode.NORMAL,
-  isCheckboxVisible: Boolean = false,
+  onCheckedChange: (Boolean) -> Unit = {}
-  isChecked: Boolean = false,
-  onCheckedChange: (Boolean) -> Unit = {},
-  tags: @Composable () -> Unit = {}
 ) {
   Card(
     modifier = Modifier
       .fillMaxWidth()
-      .padding(dimensionResource(id = R.dimen.card_margin))
+      .padding(FIVE_DP)
-      .clickable { onClick(bookOnDisk) },
+      .combinedClickable(
+        onClick = {
+          when (selectionMode) {
+            SelectionMode.MULTI -> onMultiSelect?.invoke(bookOnDisk)
+            SelectionMode.NORMAL -> onClick?.invoke(bookOnDisk)
+          }
+        },
+        onLongClick = {
+          if (selectionMode == SelectionMode.NORMAL) {
+            onLongClick?.invoke(bookOnDisk)
+          }
+        }
+      ),
     shape = MaterialTheme.shapes.medium,
     elevation = CardDefaults.elevatedCardElevation()
   ) {
+    BookContent(bookOnDisk, selectionMode, onCheckedChange)
+  }
+}
+
+@Composable
+private fun BookContent(
+  bookOnDisk: BookOnDisk,
+  selectionMode: SelectionMode,
+  onCheckedChange: (Boolean) -> Unit
+) {
   Row(
-      modifier = Modifier
+    modifier = Modifier.padding(SIXTEEN_DP).fillMaxWidth(),
-        .padding(dimensionResource(id = R.dimen.activity_horizontal_margin))
-        .fillMaxWidth(),
     verticalAlignment = Alignment.CenterVertically
   ) {
-      if (isCheckboxVisible) {
+    if (selectionMode == SelectionMode.MULTI) {
-        Checkbox(
+      BookCheckbox(bookOnDisk, onCheckedChange)
-          checked = isChecked,
-          onCheckedChange = onCheckedChange,
-          modifier = Modifier.padding(end = 10.dp)
-        )
     }
+    BookIcon(bookOnDisk.book.faviconToPainter())
+    BookDetails(Modifier.weight(1f), bookOnDisk)
+  }
+}
 
+@Composable
+private fun BookCheckbox(bookOnDisk: BookOnDisk, onCheckedChange: (Boolean) -> Unit) {
+  Checkbox(
+    checked = bookOnDisk.isSelected,
+    onCheckedChange = onCheckedChange,
+    modifier = Modifier.padding(end = TEN_DP)
+  )
+}
+
+@Composable
+fun BookIcon(painter: Painter) {
   Icon(
-        painter = bookOnDisk.book.faviconToPainter(),
+    painter = painter,
     contentDescription = stringResource(R.string.fav_icon),
     modifier = Modifier
-          .size(40.dp)
+      .size(BOOK_ICON_SIZE)
-          .padding(end = 10.dp)
+      .padding(end = TEN_DP)
   )
+}
 
-      Column(
+@Composable
-        modifier = Modifier.weight(1f)
+private fun BookDetails(modifier: Modifier, bookOnDisk: BookOnDisk) {
-      ) {
+  Column(modifier = modifier) {
     Text(
       text = bookOnDisk.book.title,
       style = MaterialTheme.typography.titleMedium
@@ -104,29 +139,27 @@ fun BookItem(
     )
     Row(
       verticalAlignment = Alignment.CenterVertically,
-          modifier = Modifier.padding(top = 4.dp)
+      modifier = Modifier.padding(top = FOUR_DP)
     ) {
       Text(
         text = bookOnDisk.book.date,
         style = MaterialTheme.typography.bodySmall,
         color = MaterialTheme.colorScheme.onSurfaceVariant
       )
-          Spacer(modifier = Modifier.width(8.dp))
+      Spacer(modifier = Modifier.width(EIGHT_DP))
       Text(
         text = bookOnDisk.book.size,
         style = MaterialTheme.typography.bodySmall,
         color = MaterialTheme.colorScheme.onSurfaceVariant
       )
-          Spacer(modifier = Modifier.width(8.dp))
+      Spacer(modifier = Modifier.width(EIGHT_DP))
       Text(
         text = bookOnDisk.book.articleCount.orEmpty(),
         style = MaterialTheme.typography.bodySmall,
         color = MaterialTheme.colorScheme.onSurfaceVariant
       )
     }
-        Spacer(modifier = Modifier.height(4.dp))
+    Spacer(modifier = Modifier.height(FOUR_DP))
-        tags()
+    TagsView(bookOnDisk.tags)
-      }
-    }
   }
 }

app/src/main/java/org/kiwix/kiwixmobile/ui/ZimFilesLanguageHeader.kt

@@ -24,16 +24,16 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.dp
+import org.kiwix.kiwixmobile.core.utils.ComposeDimens.EIGHT_DP
 import org.kiwix.kiwixmobile.core.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.LanguageItem
 
 @Composable
-fun LanguageHeader(languageItem: LanguageItem) {
+fun ZimFilesLanguageHeader(languageItem: LanguageItem) {
   Text(
     text = languageItem.text,
     style = MaterialTheme.typography.titleMedium,
     modifier = Modifier
       .fillMaxWidth()
-      .padding(vertical = 8.dp)
+      .padding(vertical = EIGHT_DP)
   )
 }

core/src/main/java/org/kiwix/kiwixmobile/core/qr/GenerateQR.kt

@@ -24,6 +24,8 @@ import com.google.zxing.BarcodeFormat
 import com.google.zxing.EncodeHintType
 import com.google.zxing.qrcode.QRCodeWriter
 import javax.inject.Inject
+import androidx.core.graphics.createBitmap
+import androidx.core.graphics.set
 
 /**
  * Utility class to generate QR codes.
@@ -47,10 +49,10 @@ class GenerateQR @Inject constructor() {
       it[EncodeHintType.MARGIN] = 1
     }
     val bits = QRCodeWriter().encode(code, BarcodeFormat.QR_CODE, size, size, hints)
-    return Bitmap.createBitmap(size, size, Bitmap.Config.RGB_565).also {
+    return createBitmap(size, size, Bitmap.Config.RGB_565).also {
       for (x in 0 until size) {
         for (y in 0 until size) {
-          it.setPixel(x, y, if (bits[x, y]) foregroundColor else backgroundColor)
+          it[x, y] = if (bits[x, y]) foregroundColor else backgroundColor
         }
       }
     }

core/src/main/java/org/kiwix/kiwixmobile/core/utils/ComposeDimens.kt

@@ -90,4 +90,7 @@ object ComposeDimens {
   val MINIMUM_HEIGHT_OF_QR_CODE = 76.dp
   val MAXIMUM_HEIGHT_OF_QR_CODE = 128.dp
   val MINIMUM_HEIGHT_OF_BOOKS_LIST = 256.dp
+
+  // BookItem dimes
+  val BOOK_ICON_SIZE = 40.dp
 }