Fix catalog covers' flickering when adding a page

app/src/main/java/eu/kanade/tachiyomi/ui/catalogue/CatalogueAdapter.kt

@@ -26,7 +26,7 @@ class CatalogueAdapter(val fragment: CatalogueFragment) : FlexibleAdapter<Catalo
         get() = mItems
 
     init {
-        mItems = ArrayList<Manga>()
+        mItems = ArrayList()
         setHasStableIds(true)
     }
 
@@ -36,8 +36,9 @@ class CatalogueAdapter(val fragment: CatalogueFragment) : FlexibleAdapter<Catalo
      * @param list the list to add.
      */
     fun addItems(list: List<Manga>) {
+        val sizeBeforeAdding = mItems.size
         mItems.addAll(list)
-        notifyDataSetChanged()
+        notifyItemRangeInserted(sizeBeforeAdding, list.size)
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/catalogue/CatalogueFragment.kt

@@ -2,7 +2,6 @@ package eu.kanade.tachiyomi.ui.catalogue
 
 import android.content.res.Configuration
 import android.os.Bundle
-import android.support.v7.app.AppCompatActivity
 import android.support.v7.widget.GridLayoutManager
 import android.support.v7.widget.SearchView
 import android.support.v7.widget.Toolbar
@@ -24,8 +23,7 @@ import eu.kanade.tachiyomi.ui.manga.MangaActivity
 import eu.kanade.tachiyomi.util.getResourceDrawable
 import eu.kanade.tachiyomi.util.snack
 import eu.kanade.tachiyomi.util.toast
-import eu.kanade.tachiyomi.widget.EndlessGridScrollListener
-import eu.kanade.tachiyomi.widget.EndlessListScrollListener
+import eu.kanade.tachiyomi.widget.EndlessScrollListener
 import eu.kanade.tachiyomi.widget.NpaLinearLayoutManager
 import kotlinx.android.synthetic.main.fragment_catalogue.*
 import kotlinx.android.synthetic.main.toolbar.*
@@ -56,12 +54,12 @@ class CatalogueFragment : BaseRxFragment<CataloguePresenter>(), FlexibleViewHold
     /**
      * Scroll listener for grid mode. It loads next pages when the end of the list is reached.
      */
-    private lateinit var gridScrollListener: EndlessGridScrollListener
+    private lateinit var gridScrollListener: EndlessScrollListener
 
     /**
      * Scroll listener for list mode. It loads next pages when the end of the list is reached.
      */
-    private lateinit var listScrollListener: EndlessListScrollListener
+    private lateinit var listScrollListener: EndlessScrollListener
 
     /**
      * Query of the search box.
@@ -135,13 +133,13 @@ class CatalogueFragment : BaseRxFragment<CataloguePresenter>(), FlexibleViewHold
         adapter = CatalogueAdapter(this)
 
         val glm = catalogue_grid.layoutManager as GridLayoutManager
-        gridScrollListener = EndlessGridScrollListener(glm, { requestNextPage() })
+        gridScrollListener = EndlessScrollListener(glm, { requestNextPage() })
         catalogue_grid.setHasFixedSize(true)
         catalogue_grid.adapter = adapter
         catalogue_grid.addOnScrollListener(gridScrollListener)
 
         val llm = NpaLinearLayoutManager(activity)
-        listScrollListener = EndlessListScrollListener(llm, { requestNextPage() })
+        listScrollListener = EndlessScrollListener(llm, { requestNextPage() })
         catalogue_list.setHasFixedSize(true)
         catalogue_list.adapter = adapter
         catalogue_list.layoutManager = llm

app/src/main/java/eu/kanade/tachiyomi/widget/EndlessGridScrollListener.java

@@ -1,49 +0,0 @@
-package eu.kanade.tachiyomi.widget;
-
-import android.support.v7.widget.GridLayoutManager;
-import android.support.v7.widget.RecyclerView;
-
-import rx.functions.Action0;
-
-public class EndlessGridScrollListener extends RecyclerView.OnScrollListener {
-
-    private int previousTotal = 0; // The total number of items in the dataset after the last load
-    private boolean loading = true; // True if we are still waiting for the last set of data to load.
-    private static final int VISIBLE_THRESHOLD = 5; // The minimum amount of items to have below your current scroll position before loading more.
-    private int firstVisibleItem, visibleItemCount, totalItemCount;
-
-    private final GridLayoutManager layoutManager;
-
-    private final Action0 requestNext;
-
-    public EndlessGridScrollListener(GridLayoutManager layoutManager, Action0 requestNext) {
-        this.layoutManager = layoutManager;
-        this.requestNext = requestNext;
-    }
-
-    public void resetScroll() {
-        previousTotal = 0;
-        loading = true;
-    }
-
-    @Override
-    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
-        super.onScrolled(recyclerView, dx, dy);
-
-        visibleItemCount = recyclerView.getChildCount();
-        totalItemCount = layoutManager.getItemCount();
-        firstVisibleItem = layoutManager.findFirstVisibleItemPosition();
-
-        if (loading && (totalItemCount > previousTotal)) {
-            loading = false;
-            previousTotal = totalItemCount;
-        }
-        if (!loading && (totalItemCount - visibleItemCount)
-                <= (firstVisibleItem + VISIBLE_THRESHOLD)) {
-            // End has been reached
-            requestNext.call();
-            loading = true;
-        }
-    }
-
-}

app/src/main/java/eu/kanade/tachiyomi/widget/EndlessListScrollListener.java

@@ -1,49 +0,0 @@
-package eu.kanade.tachiyomi.widget;
-
-import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.RecyclerView;
-
-import rx.functions.Action0;
-
-public class EndlessListScrollListener extends RecyclerView.OnScrollListener {
-
-    private int previousTotal = 0; // The total number of items in the dataset after the last load
-    private boolean loading = true; // True if we are still waiting for the last set of data to load.
-    private static final int VISIBLE_THRESHOLD = 5; // The minimum amount of items to have below your current scroll position before loading more.
-    private int firstVisibleItem, visibleItemCount, totalItemCount;
-
-    private LinearLayoutManager layoutManager;
-
-    private final Action0 requestNext;
-
-    public EndlessListScrollListener(LinearLayoutManager layoutManager, Action0 requestNext) {
-        this.layoutManager = layoutManager;
-        this.requestNext = requestNext;
-    }
-
-    public void resetScroll() {
-        previousTotal = 0;
-        loading = true;
-    }
-
-    @Override
-    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
-        super.onScrolled(recyclerView, dx, dy);
-
-        visibleItemCount = recyclerView.getChildCount();
-        totalItemCount = layoutManager.getItemCount();
-        firstVisibleItem = layoutManager.findFirstVisibleItemPosition();
-
-        if (loading && (totalItemCount > previousTotal)) {
-            loading = false;
-            previousTotal = totalItemCount;
-        }
-        if (!loading && (totalItemCount - visibleItemCount)
-                <= (firstVisibleItem + VISIBLE_THRESHOLD)) {
-            // End has been reached
-            requestNext.call();
-            loading = true;
-        }
-    }
-
-}

app/src/main/java/eu/kanade/tachiyomi/widget/EndlessScrollListener.java

@@ -1,61 +0,0 @@
-package eu.kanade.tachiyomi.widget;
-
-import android.widget.AbsListView;
-
-import rx.functions.Action0;
-
-public class EndlessScrollListener implements AbsListView.OnScrollListener {
-    // The minimum amount of items to have below your current scroll position
-    // before loading more.
-    private static final int VISIBLE_THRESHOLD = 5;
-    // The total number of items in the dataset after the last load
-    private int previousTotalItemCount = 0;
-    // True if we are still waiting for the last set of data to load.
-    private boolean loading = true;
-
-    private final Action0 requestNext;
-
-    public EndlessScrollListener(Action0 requestNext) {
-        this.requestNext = requestNext;
-    }
-
-    public void resetScroll() {
-        this.previousTotalItemCount = 0;
-        this.loading = true;
-    }
-
-    // This happens many times a second during a scroll, so be wary of the code you place here.
-    // We are given a few useful parameters to help us work out if we need to load some more data,
-    // but first we check if we are waiting for the previous load to finish.
-    @Override
-    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
-    {
-        // If the total item count is zero and the previous isn't, assume the
-        // list is invalidated and should be reset back to initial state
-        if (totalItemCount < previousTotalItemCount) {
-            this.previousTotalItemCount = totalItemCount;
-            if (totalItemCount == 0) { this.loading = true; }
-        }
-        // If it’s still loading, we check to see if the dataset count has
-        // changed, if so we conclude it has finished loading and update the current page
-        // number and total item count.
-        if (loading && (totalItemCount > previousTotalItemCount)) {
-            loading = false;
-            previousTotalItemCount = totalItemCount;
-        }
-
-        // If it isn’t currently loading, we check to see if we have breached
-        // the visibleThreshold and need to reload more data.
-        // If we do need to reload some more data, we execute onLoadMore to fetch the data.
-        if (!loading && (totalItemCount - visibleItemCount)<=(firstVisibleItem + VISIBLE_THRESHOLD)) {
-            requestNext.call();
-            loading = true;
-        }
-    }
-
-    @Override
-    public void onScrollStateChanged(AbsListView view, int scrollState) {
-        // Don't take any action on changed
-    }
-
-}

app/src/main/java/eu/kanade/tachiyomi/widget/EndlessScrollListener.kt

@@ -0,0 +1,46 @@
+package eu.kanade.tachiyomi.widget
+
+import android.support.v7.widget.LinearLayoutManager
+import android.support.v7.widget.RecyclerView
+
+class EndlessScrollListener(
+        private val layoutManager: LinearLayoutManager,
+        private val requestNext: () -> Unit)
+: RecyclerView.OnScrollListener() {
+
+    companion object {
+        // The minimum amount of items to have below your current scroll position before loading
+        // more.
+        private val VISIBLE_THRESHOLD = 5
+    }
+
+    private var previousTotal = 0 // The total number of items in the dataset after the last load
+    private var loading = true // True if we are still waiting for the last set of data to load.
+    private var firstVisibleItem = 0
+    private var visibleItemCount = 0
+    private var totalItemCount = 0
+
+    fun resetScroll() {
+        previousTotal = 0
+        loading = true
+    }
+
+    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+        super.onScrolled(recyclerView, dx, dy)
+
+        visibleItemCount = recyclerView.childCount
+        totalItemCount = layoutManager.itemCount
+        firstVisibleItem = layoutManager.findFirstVisibleItemPosition()
+
+        if (loading && totalItemCount > previousTotal) {
+            loading = false
+            previousTotal = totalItemCount
+        }
+        if (!loading && totalItemCount - visibleItemCount <= firstVisibleItem + VISIBLE_THRESHOLD) {
+            // End has been reached
+            requestNext()
+            loading = true
+        }
+    }
+
+}