Shift double pages button moved to bottom of the screen for tablets

Since that's quite a reach in the toolbar

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -63,6 +63,7 @@ import eu.kanade.tachiyomi.util.system.getResourceColor
 import eu.kanade.tachiyomi.util.system.hasSideNavBar
 import eu.kanade.tachiyomi.util.system.isBottomTappable
 import eu.kanade.tachiyomi.util.system.isLTR
+import eu.kanade.tachiyomi.util.system.isTablet
 import eu.kanade.tachiyomi.util.system.launchIO
 import eu.kanade.tachiyomi.util.system.launchUI
 import eu.kanade.tachiyomi.util.system.openInBrowser
@@ -310,12 +311,15 @@ class ReaderActivity :
 
     override fun onPrepareOptionsMenu(menu: Menu?): Boolean {
         val splitItem = menu?.findItem(R.id.action_shift_double_page)
-        splitItem?.isVisible = (viewer as? PagerViewer)?.config?.doublePages ?: false
+        splitItem?.isVisible = ((viewer as? PagerViewer)?.config?.doublePages ?: false) && !isTablet()
+        binding.chaptersSheet.shiftPageButton.isVisible = ((viewer as? PagerViewer)?.config?.doublePages ?: false) && isTablet()
         (viewer as? PagerViewer)?.config?.let { config ->
-            splitItem?.icon = ContextCompat.getDrawable(
+            val icon = ContextCompat.getDrawable(
                 this,
                 if ((!config.shiftDoublePage).xor(viewer is R2LPagerViewer)) R.drawable.ic_page_previous_outline_24dp else R.drawable.ic_page_next_outline_24dp
             )
+            splitItem?.icon = icon
+            binding.chaptersSheet.shiftPageButton.setImageDrawable(icon)
         }
         setBottomNavButtons(preferences.pageLayout().get())
         (binding.toolbar.background as? LayerDrawable)?.let { layerDrawable ->
@@ -353,20 +357,24 @@ class ReaderActivity :
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
             R.id.action_shift_double_page -> {
-                (viewer as? PagerViewer)?.config?.let { config ->
+                shiftDoublePages()
-                    config.shiftDoublePage = !config.shiftDoublePage
-                    presenter.viewerChapters?.let {
-                        (viewer as? PagerViewer)?.updateShifting()
-                        (viewer as? PagerViewer)?.setChaptersDoubleShift(it)
-                        invalidateOptionsMenu()
-                    }
-                }
             }
             else -> return super.onOptionsItemSelected(item)
         }
         return true
     }
 
+    fun shiftDoublePages() {
+        (viewer as? PagerViewer)?.config?.let { config ->
+            config.shiftDoublePage = !config.shiftDoublePage
+            presenter.viewerChapters?.let {
+                (viewer as? PagerViewer)?.updateShifting()
+                (viewer as? PagerViewer)?.setChaptersDoubleShift(it)
+                invalidateOptionsMenu()
+            }
+        }
+    }
+
     private fun popToMain() {
         presenter.onBackPressed()
         if (fromUrl) {
@@ -483,6 +491,9 @@ class ReaderActivity :
                 preferences.pageLayout().set(1 - preferences.pageLayout().get())
             }
         }
+        binding.chaptersSheet.shiftPageButton.setOnClickListener {
+            shiftDoublePages()
+        }
         binding.readerNav.leftChapter.setOnClickListener {
             if (isLoading) {
                 return@setOnClickListener

app/src/main/java/eu/kanade/tachiyomi/util/system/ContextExtensions.kt

@@ -148,6 +148,8 @@ val Float.dpToPxEnd: Float
 val Resources.isLTR
     get() = configuration.layoutDirection == View.LAYOUT_DIRECTION_LTR
 
+fun Context.isTablet() = resources.getBoolean(R.bool.isTablet)
+
 /**
  * Helper method to create a notification builder.
  *
@@ -155,7 +157,10 @@ val Resources.isLTR
  * @param block the function that will execute inside the builder.
  * @return a notification to be displayed or updated.
  */
-fun Context.notificationBuilder(channelId: String, block: (NotificationCompat.Builder.() -> Unit)? = null): NotificationCompat.Builder {
+fun Context.notificationBuilder(
+    channelId: String,
+    block: (NotificationCompat.Builder.() -> Unit)? = null
+): NotificationCompat.Builder {
     val builder = NotificationCompat.Builder(this, channelId)
         .setColor(ContextCompat.getColor(this, R.color.colorAccent))
     if (block != null) {
@@ -197,7 +202,9 @@ val Context.powerManager: PowerManager
  * @param intent intent that contains broadcast information
  */
 fun Context.sendLocalBroadcast(intent: Intent) {
-    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).sendBroadcast(intent)
+    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).sendBroadcast(
+        intent
+    )
 }
 
 /**
@@ -206,7 +213,9 @@ fun Context.sendLocalBroadcast(intent: Intent) {
  * @param intent intent that contains broadcast information
  */
 fun Context.sendLocalBroadcastSync(intent: Intent) {
-    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).sendBroadcastSync(intent)
+    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).sendBroadcastSync(
+        intent
+    )
 }
 
 /**
@@ -215,7 +224,10 @@ fun Context.sendLocalBroadcastSync(intent: Intent) {
  * @param receiver receiver that gets registered.
  */
 fun Context.registerLocalReceiver(receiver: BroadcastReceiver, filter: IntentFilter) {
-    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).registerReceiver(receiver, filter)
+    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).registerReceiver(
+        receiver,
+        filter
+    )
 }
 
 /**
@@ -224,7 +236,9 @@ fun Context.registerLocalReceiver(receiver: BroadcastReceiver, filter: IntentFil
  * @param receiver receiver that gets unregistered.
  */
 fun Context.unregisterLocalReceiver(receiver: BroadcastReceiver) {
-    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).unregisterReceiver(receiver)
+    androidx.localbroadcastmanager.content.LocalBroadcastManager.getInstance(this).unregisterReceiver(
+        receiver
+    )
 }
 
 /**

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

@@ -76,9 +76,26 @@
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintStart_toEndOf="@id/webview_button"
             app:layout_constraintTop_toTopOf="parent"
-            app:layout_constraintEnd_toStartOf="@id/display_options"
+            app:layout_constraintEnd_toStartOf="@id/shift_page_button"
             app:srcCompat="@drawable/ic_book_open_variant_24dp" />
 
+        <ImageButton
+            android:id="@+id/shift_page_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:background="?selectableItemBackgroundBorderless"
+            android:contentDescription="@string/next_title"
+            android:padding="@dimen/material_layout_keylines_screen_edge_margin"
+            app:tint="?actionBarTintColor"
+            android:visibility="gone"
+            app:layout_constraintHorizontal_chainStyle="spread"
+            android:tooltipText="@string/shift_one_page_over"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintStart_toEndOf="@id/double_page"
+            app:layout_constraintTop_toTopOf="parent"
+            app:layout_constraintEnd_toStartOf="@id/display_options"
+            app:srcCompat="@drawable/ic_page_next_outline_24dp" />
+
         <ImageButton
             android:id="@+id/display_options"
             android:layout_width="wrap_content"
@@ -90,7 +107,7 @@
             app:layout_constraintHorizontal_chainStyle="spread"
             android:tooltipText="@string/display_options"
             app:layout_constraintBottom_toBottomOf="parent"
-            app:layout_constraintStart_toEndOf="@id/double_page"
+            app:layout_constraintStart_toEndOf="@id/shift_page_button"
             app:layout_constraintTop_toTopOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:srcCompat="@drawable/ic_tune_24dp" />

app/src/main/res/values-sw600dp/attrs.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <bool name="isTablet">true</bool>
+</resources>

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

@@ -21,4 +21,6 @@
         <attr name="android:entries"/>
         <attr name="summary" format="reference|string" />
     </declare-styleable>
+
+    <bool name="isTablet">false</bool>
 </resources>