Fix GalleryView pause and resume

app/src/main/java/com/hippo/ehviewer/gallery/gl/GalleryView.java

@@ -144,6 +144,7 @@ public class GalleryView extends GLView implements GestureRecognizer.Listener {
     private final List<Object[]> mArgsListTemp = new ArrayList<>(5);
 
     private final AtomicInteger mCurrentIndex = new AtomicInteger(GalleryPageView.INVALID_INDEX);
+    private boolean mPause;
 
     @SuppressWarnings("deprecation")
     public GalleryView(@NonNull Context context, @NonNull Adapter adapter,
@@ -262,7 +263,7 @@ public class GalleryView extends GLView implements GestureRecognizer.Listener {
     }
 
     private void pauseInternal() {
-        detachLayoutManager();
+        mPause = true;
     }
 
     public void pause() {
@@ -270,11 +271,12 @@ public class GalleryView extends GLView implements GestureRecognizer.Listener {
     }
 
     private void resumeInternal() {
-        if (null == mPageTextTexture) {
-            // Not attached
-            return;
+        if (mPause) {
+            mPause = false;
+            if (null != mLayoutManager) {
+                mLayoutManager.bindUnloadedPage();
+            }
         }
-        attachLayoutManager();
     }
 
     public void resume() {
@@ -831,9 +833,7 @@ public class GalleryView extends GLView implements GestureRecognizer.Listener {
 
     @RenderThread
     public GalleryPageView findPageByIndex(int id) {
-        GalleryUtils.assertInRenderThread();
-
-        if (mLayoutManager != null) {
+        if (!mPause && mLayoutManager != null) {
             return mLayoutManager.findPageByIndex(id);
         } else {
             return null;
@@ -975,6 +975,8 @@ public class GalleryView extends GLView implements GestureRecognizer.Listener {
 
         public abstract void onDataChanged();
 
+        public abstract void bindUnloadedPage();
+
         public abstract void onPageLeft();
 
         public abstract void onPageRight();

app/src/main/java/com/hippo/ehviewer/gallery/gl/PagerLayoutManager.java

@@ -717,6 +717,23 @@ public class PagerLayoutManager extends GalleryView.LayoutManager {
         mGalleryView.requestFill();
     }
 
+    @Override
+    public void bindUnloadedPage() {
+        if (null == mAdapter) {
+            return;
+        }
+
+        if (null != mCurrent && !mCurrent.getImageView().isLoaded()) {
+            mAdapter.bind(mCurrent, mIndex);
+        }
+        if (null != mPrevious && !mPrevious.getImageView().isLoaded()) {
+            mAdapter.bind(mPrevious, mIndex - 1);
+        }
+        if (null != mNext && !mNext.getImageView().isLoaded()) {
+            mAdapter.bind(mNext, mIndex + 1);
+        }
+    }
+
     @Override
     public void onPageLeft() {
         int size = mAdapter.size();

app/src/main/java/com/hippo/ehviewer/gallery/gl/ScrollLayoutManager.java

@@ -653,6 +653,21 @@ public class ScrollLayoutManager extends GalleryView.LayoutManager {
         mGalleryView.requestFill();
     }
 
+    @Override
+    public void bindUnloadedPage() {
+        if (null == mAdapter || 0 <= mPages.size()) {
+            return;
+        }
+
+        int index = mIndex;
+        for (GalleryPageView page: mPages) {
+            if (!page.getImageView().isLoaded()) {
+                mAdapter.bind(page, index);
+            }
+            index++;
+        }
+    }
+
     @Override
     public void onPageLeft() {
         int size = mAdapter.size();