diff --git a/app/src/main/java/com/lhw/pdf/MainActivity.kt b/app/src/main/java/com/lhw/pdf/MainActivity.kt
index ff56d7f..634469f 100644
--- a/app/src/main/java/com/lhw/pdf/MainActivity.kt
+++ b/app/src/main/java/com/lhw/pdf/MainActivity.kt
@@ -58,17 +58,9 @@ class MainActivity : AppCompatActivity() {
     }
 
     private val displayListener = object: DisplayListener {
-        override fun onDisplayAdded(p0: Int) {
-            reevaluateDisplay(p0)
-        }
-
-        override fun onDisplayChanged(p0: Int) {
-            reevaluateDisplay(p0)
-        }
-
-        override fun onDisplayRemoved(p0: Int) {
-            reevaluateDisplay(p0)
-        }
+        override fun onDisplayAdded(p0: Int) { reevaluateDisplay(p0) }
+        override fun onDisplayChanged(p0: Int) { reevaluateDisplay(p0) }
+        override fun onDisplayRemoved(p0: Int) { reevaluateDisplay(p0) }
     }
 
     private fun reevaluateDisplay(p0: Int) {
@@ -102,13 +94,13 @@ class MainActivity : AppCompatActivity() {
         updateBitmaps(maxWidth, maxHeight)
         val key = Pair(maxWidth, maxHeight)
         val bitmapPages = pdfDocument.bitmapPages[key]
-        val bitmaps = pageGroups.withIndex()
-            .mapNotNull { (i, group) -> if (group in hiddenPageGroups) null else bitmapPages?.get(i) }
-            .toList()
+        val bitmaps = viewModel.enabledPageIds.value?.mapNotNull { bitmapPages?.get(it) }?.toList() ?: listOf()
         p.updateImages(bitmaps)
     }
 
     private fun updatePresentations(reRender: Boolean = true) {
+        viewModel.enabledPageIds.value = pageGroups.mapIndexedNotNull { i, group -> if (group !in hiddenPageGroups) i else null }.toList()
+
         if (reRender) pdfDocument.invalidateCache()
         presentations.values.forEach(::updatePresentationImages)
     }
diff --git a/app/src/main/java/com/lhw/pdf/ui/gallery/GalleryViewModel.kt b/app/src/main/java/com/lhw/pdf/ui/gallery/GalleryViewModel.kt
index 2c44217..32963fd 100644
--- a/app/src/main/java/com/lhw/pdf/ui/gallery/GalleryViewModel.kt
+++ b/app/src/main/java/com/lhw/pdf/ui/gallery/GalleryViewModel.kt
@@ -8,6 +8,7 @@ class GalleryViewModel : ViewModel() {
     val pageThumbnails = MutableLiveData<List<Bitmap>>().apply { value = listOf() }
     val hiddenPageGroups = MutableLiveData<Set<Int>>().apply { value = setOf() }
     val pageGroups = MutableLiveData<List<Int>>().apply { value = listOf() }
+    val enabledPageIds = MutableLiveData<List<Int>>().apply { value = listOf() }
     val thumbnailScrollProgress = MutableLiveData<Float>().apply { value = 0F }
     val textDisplays = MutableLiveData<String>().apply { value = "" }
     val pagesPerLandscape = MutableLiveData<Float>().apply { value = 3F }