Add provider level support for PDF Thumbnails (d522fe64) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/content/FileSystemProvider.java

+14 −1

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ import android.database.MatrixCursor.RowBuilder;
		import android.graphics.Point;
		import android.net.Uri;
		import android.os.Binder;
		import android.os.Build;
		import android.os.CancellationSignal;
		import android.os.FileObserver;
		import android.os.FileUtils;
		@@ -68,6 +69,8 @@ public abstract class FileSystemProvider extends DocumentsProvider {

		private Handler mHandler;

		private static final String MIMETYPE_PDF = "application/pdf";

		protected abstract File getFileForDocId(String docId, boolean visible)
		throws FileNotFoundException;

		@@ -387,6 +390,13 @@ public abstract class FileSystemProvider extends DocumentsProvider {
		String documentId, Point sizeHint, CancellationSignal signal)
		throws FileNotFoundException {
		final File file = getFileForDocId(documentId);
		if (getTypeForFile(file).equals(MIMETYPE_PDF)) {
		try {
		return PdfUtils.openPdfThumbnail(file, sizeHint);
		} catch (Exception e) {
		Log.v(TAG, "Could not load PDF's thumbnail", e);
		}
		}
		return DocumentsContract.openImageThumbnail(file);
		}

		@@ -416,7 +426,10 @@ public abstract class FileSystemProvider extends DocumentsProvider {

		final String mimeType = getTypeForFile(file);
		final String displayName = file.getName();
		if (mimeType.startsWith("image/")) {
		// As of right now, we aren't sure on the performance affect of loading all PDF Thumbnails
		// Until a solution is found, it will be behind a debuggable flag.
		if (mimeType.startsWith("image/")
		\|\| (mimeType.equals(MIMETYPE_PDF) && Build.IS_DEBUGGABLE)) {
		flags \|= Document.FLAG_SUPPORTS_THUMBNAIL;
		}

core/java/com/android/internal/content/PdfUtils.java

0 → 100644

+96 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2017 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.internal.content;

		import android.annotation.Nullable;
		import android.content.res.AssetFileDescriptor;
		import android.graphics.Bitmap;
		import android.graphics.Point;
		import android.graphics.Rect;
		import android.graphics.pdf.PdfRenderer;
		import android.os.AsyncTask;
		import android.os.ParcelFileDescriptor;

		import libcore.io.IoUtils;
		import libcore.io.Streams;

		import java.io.ByteArrayInputStream;
		import java.io.ByteArrayOutputStream;
		import java.io.File;
		import java.io.FileOutputStream;
		import java.io.IOException;

		/**
		* Utils class for extracting PDF Thumbnails
		*/
		public final class PdfUtils {

		private PdfUtils() {
		}

		/**
		* Returns the front page of the pdf as a thumbnail
		* @param file Given PDF File
		* @param size Cropping of the front page.
		* @return AssetFileDescriptor containing the thumbnail as a bitmap.
		* @throws IOException if the file isn't a pdf or if the file doesn't exist.
		*/
		public static @Nullable AssetFileDescriptor openPdfThumbnail(File file, Point size)
		throws IOException {
		// Create the bitmap of the PDF's first page
		ParcelFileDescriptor pdfDescriptor =
		ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
		PdfRenderer renderer = new PdfRenderer(pdfDescriptor);
		PdfRenderer.Page frontPage = renderer.openPage(0);
		Bitmap thumbnail = Bitmap.createBitmap(size.x, size.y,
		Bitmap.Config.ARGB_8888);
		frontPage.render(thumbnail, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);

		// Create an AssetFileDescriptor that contains the Bitmap's information
		final ByteArrayOutputStream out = new ByteArrayOutputStream();
		// Quality is an integer that determines how much compression is used.
		// However, this integer is ignored when using the PNG format
		int quality = 100;
		// The use of Bitmap.CompressFormat.JPEG leads to a black PDF background on the thumbnail
		thumbnail.compress(Bitmap.CompressFormat.PNG, quality, out);

		final ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());

		final ParcelFileDescriptor[] fds = ParcelFileDescriptor.createReliablePipe();
		new AsyncTask<Object, Object, Object>() {
		@Override
		protected Object doInBackground(Object... params) {
		final FileOutputStream fos = new FileOutputStream(fds[1].getFileDescriptor());
		try {
		Streams.copy(in, fos);
		} catch (IOException e) {
		throw new RuntimeException(e);
		}
		IoUtils.closeQuietly(fds[1]);
		try {
		pdfDescriptor.close();
		} catch (IOException e) {
		throw new RuntimeException(e);
		}
		return null;
		}
		}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
		pdfDescriptor.close();
		return new AssetFileDescriptor(fds[0], 0, AssetFileDescriptor.UNKNOWN_LENGTH);
		}

		}