1 files changed, 121 insertions, 0 deletions
diff --git a/android/source/src/java/org/libreoffice/ThumbnailCreator.java b/android/source/src/java/org/libreoffice/ThumbnailCreator.java
new file mode 100644
index 000000000..c0c097747
--- /dev/null
+++ b/android/source/src/java/org/libreoffice/ThumbnailCreator.java
@@ -0,0 +1,121 @@
+/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.libreoffice;
+
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.widget.ImageView;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Create thumbnails for the parts of the document.
+ */
+public class ThumbnailCreator {
+    private static final String LOG_TAG = ThumbnailCreator.class.getSimpleName();
+    private static final int THUMBNAIL_SIZE = 256;
+
+    private static boolean needsThumbnailCreation(int partNumber, ImageView imageView) {
+        ThumbnailCreationTask thumbnailCreationTask = currentThumbnailCreationTask(imageView);
+
+        if (thumbnailCreationTask == null) {
+            return true;
+        }
+
+        if (thumbnailCreationTask.partNumber != partNumber) {
+            thumbnailCreationTask.cancel();
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    private static ThumbnailCreationTask currentThumbnailCreationTask(ImageView imageView) {
+        if (imageView == null) {
+            return null;
+        }
+        Drawable drawable = imageView.getDrawable();
+        if (drawable instanceof ThumbnailDrawable) {
+            return ((ThumbnailDrawable) drawable).thumbnailCreationTask.get();
+        } else {
+            return null;
+        }
+    }
+
+    public void createThumbnail(int partNumber, ImageView imageView) {
+        if (needsThumbnailCreation(partNumber, imageView)) {
+            ThumbnailCreationTask task = new ThumbnailCreationTask(imageView, partNumber);
+            ThumbnailDrawable thumbnailDrawable = new ThumbnailDrawable(task);
+            imageView.setImageDrawable(thumbnailDrawable);
+            imageView.setMinimumHeight(THUMBNAIL_SIZE);
+            LOKitShell.sendThumbnailEvent(task);
+        }
+    }
+
+    static class ThumbnailDrawable extends ColorDrawable {
+        public final WeakReference<ThumbnailCreationTask> thumbnailCreationTask;
+
+        public ThumbnailDrawable(ThumbnailCreationTask thumbnailCreationTask) {
+            super(Color.WHITE);
+            this.thumbnailCreationTask = new WeakReference<ThumbnailCreationTask>(thumbnailCreationTask);
+        }
+    }
+
+    class ThumbnailCreationTask{
+        private final WeakReference<ImageView> imageViewReference;
+        private final int partNumber;
+        private boolean cancelled = false;
+
+        public ThumbnailCreationTask(ImageView imageView, int partNumber) {
+            imageViewReference = new WeakReference<ImageView>(imageView);
+            this.partNumber = partNumber;
+        }
+
+        public void cancel() {
+            cancelled = true;
+        }
+
+        public Bitmap getThumbnail(TileProvider tileProvider) {
+            int currentPart = tileProvider.getCurrentPartNumber();
+            tileProvider.changePart(partNumber);
+            final Bitmap bitmap = tileProvider.thumbnail(THUMBNAIL_SIZE);
+            tileProvider.changePart(currentPart);
+            return bitmap;
+        }
+
+        private void changeBitmap(Bitmap bitmap) {
+            if (cancelled) {
+                bitmap = null;
+            }
+
+            if (imageViewReference == null) {
+                return;
+            }
+            ImageView imageView = imageViewReference.get();
+            ThumbnailCreationTask thumbnailCreationTask = currentThumbnailCreationTask(imageView);
+            if (this == thumbnailCreationTask) {
+                imageView.setImageBitmap(bitmap);
+            }
+        }
+
+        public void applyBitmap(final Bitmap bitmap) {
+            // run on UI thread
+            LibreOfficeApplication.getMainHandler().post(new Runnable() {
+                @Override
+                public void run() {
+                    changeBitmap(bitmap);
+                }
+            });
+        }
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */