Add GalleryProvider.cancelRequest(int), fix SpiderQueen.request(int, boolean)

app/src/main/java/com/hippo/ehviewer/gallery/ZipGalleryProvider.java

@@ -22,6 +22,7 @@ import android.util.Log;
 
 import com.hippo.ehviewer.GetText;
 import com.hippo.ehviewer.R;
+import com.hippo.ehviewer.gallery.gl.GalleryPageView;
 import com.hippo.image.Image;
 import com.hippo.yorozuya.PriorityThread;
 import com.hippo.yorozuya.StringUtils;
@@ -47,6 +48,7 @@ public class ZipGalleryProvider extends GalleryProvider implements Runnable {
 
     private final File mFile;
     private final Stack<Integer> mRequests = new Stack<>();
+    private final AtomicInteger mDecodingIndex = new AtomicInteger(GalleryPageView.INVALID_INDEX);
     @Nullable
     private Thread mBgThread;
     private volatile int mSize = STATE_WAIT;
@@ -83,12 +85,21 @@ public class ZipGalleryProvider extends GalleryProvider implements Runnable {
     @Override
     public void request(int index) {
         synchronized (mRequests) {
-            mRequests.add(index);
-            mRequests.notify();
+            if (!mRequests.contains(index) && index != mDecodingIndex.get()) {
+                mRequests.add(index);
+                mRequests.notify();
+            }
         }
         notifyPageWait(index);
     }
 
+    @Override
+    public void cancelRequest(int index) {
+        synchronized (mRequests) {
+            mRequests.remove(Integer.valueOf(index));
+        }
+    }
+
     @Override
     public String getError() {
         return mError;
@@ -150,10 +161,12 @@ public class ZipGalleryProvider extends GalleryProvider implements Runnable {
                     continue;
                 }
                 index = mRequests.pop();
+                mDecodingIndex.lazySet(index);
             }
 
             // Check index valid
             if (index < 0 || index >= filenames.size()) {
+                mDecodingIndex.lazySet(GalleryPageView.INVALID_INDEX);
                 notifyPageFailed(index, GetText.getString(R.string.error_out_of_range));
                 continue;
             }
@@ -163,15 +176,18 @@ public class ZipGalleryProvider extends GalleryProvider implements Runnable {
                 if (zipEntry != null) {
                     InputStream is = zipFile.getInputStream(zipEntry);
                     Image image = Image.decode(is, false);
+                    mDecodingIndex.lazySet(GalleryPageView.INVALID_INDEX);
                     if (image != null) {
                         notifyPageSucceed(index, image);
                     } else {
                         notifyPageFailed(index, GetText.getString(R.string.error_decoding_failed));
                     }
                 } else {
+                    mDecodingIndex.lazySet(GalleryPageView.INVALID_INDEX);
                     notifyPageFailed(index, GetText.getString(R.string.error_reading_failed));
                 }
             } catch (IOException e) {
+                mDecodingIndex.lazySet(GalleryPageView.INVALID_INDEX);
                 notifyPageFailed(index, GetText.getString(R.string.error_reading_failed));
             }
         }