Add MimeTypeFilter to support Web Share Target v2.

The purpose of this CL is to refactor the MimeTypeFilter code inside chrome/android/java/src/org/chromium/chrome/browser/photo_picker/MimeTypeFileFilter.java,
and modify it for the purpose of mime type filtering in Web share target v2.

The specific usage of MimeTypeFilter is to help determine
whether a mime type is accepted by a list of accepted mime types.

In order to fit the spec for Web Share Target v2, one new additional logic is added.
"*/*" is now recognized as accepting all mime types.

The Web Share Target v2 CL in reference is:
https://chromium-review.googlesource.com/c/chromium/src/+/1271776

Change-Id: I9daa21e4049ae7a153858dc084f64294fe4f2584
Reviewed-on: https://chromium-review.googlesource.com/c/1324096
Commit-Queue: Ethan Xu <xuethan@google.com>
Reviewed-by: Bence Béky <bnc@chromium.org>
Reviewed-by: Glenn Hartmann <hartmanng@chromium.org>
Reviewed-by: Peter Kotwicz <pkotwicz@chromium.org>
Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609901}

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/FileEnumWorkerTask.java

@@ -11,6 +11,7 @@ import android.provider.MediaStore;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.task.AsyncTask;
+import org.chromium.net.MimeTypeFilter;
 import org.chromium.ui.base.WindowAndroid;
 
 import java.io.File;
@@ -39,7 +40,7 @@ class FileEnumWorkerTask extends AsyncTask<List<PickerBitmap>> {
     private FilesEnumeratedCallback mCallback;
 
     // The filter to apply to the list.
-    private MimeTypeFileFilter mFilter;
+    private MimeTypeFilter mFilter;
 
     // The camera directory undir DCIM.
     private static final String SAMPLE_DCIM_SOURCE_SUB_DIRECTORY = "Camera";
@@ -50,8 +51,8 @@ class FileEnumWorkerTask extends AsyncTask<List<PickerBitmap>> {
      * @param callback The callback to use to communicate back the results.
      * @param filter The file filter to apply to the list.
      */
-    public FileEnumWorkerTask(WindowAndroid windowAndroid, FilesEnumeratedCallback callback,
-            MimeTypeFileFilter filter) {
+    public FileEnumWorkerTask(
+            WindowAndroid windowAndroid, FilesEnumeratedCallback callback, MimeTypeFilter filter) {
         mWindowAndroid = windowAndroid;
         mCallback = callback;
         mFilter = filter;

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/PickerCategoryView.java

@@ -27,6 +27,7 @@ import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.util.ConversionUtils;
 import org.chromium.chrome.browser.widget.selection.SelectableListLayout;
 import org.chromium.chrome.browser.widget.selection.SelectionDelegate;
+import org.chromium.net.MimeTypeFilter;
 import org.chromium.ui.PhotoPickerListener;
 import org.chromium.ui.UiUtils;
 
@@ -365,7 +366,7 @@ public class PickerCategoryView extends RelativeLayout
 
         mEnumStartTime = SystemClock.elapsedRealtime();
         mWorkerTask = new FileEnumWorkerTask(
-                mActivity.getWindowAndroid(), this, new MimeTypeFileFilter(mMimeTypes));
+                mActivity.getWindowAndroid(), this, new MimeTypeFilter(mMimeTypes, true));
         mWorkerTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 

chrome/android/java_sources.gni

@@ -1230,7 +1230,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/photo_picker/DecoderService.java",
   "java/src/org/chromium/chrome/browser/photo_picker/DecoderServiceHost.java",
   "java/src/org/chromium/chrome/browser/photo_picker/FileEnumWorkerTask.java",
-  "java/src/org/chromium/chrome/browser/photo_picker/MimeTypeFileFilter.java",
   "java/src/org/chromium/chrome/browser/photo_picker/PhotoPickerDialog.java",
   "java/src/org/chromium/chrome/browser/photo_picker/PhotoPickerToolbar.java",
   "java/src/org/chromium/chrome/browser/photo_picker/PickerAdapter.java",

net/android/BUILD.gn

@@ -16,6 +16,7 @@ android_library("net_java") {
     "java/src/org/chromium/net/HttpNegotiateAuthenticator.java",
     "java/src/org/chromium/net/HttpNegotiateConstants.java",
     "java/src/org/chromium/net/HttpUtil.java",
+    "java/src/org/chromium/net/MimeTypeFilter.java",
     "java/src/org/chromium/net/NetStringUtil.java",
     "java/src/org/chromium/net/NetworkChangeNotifier.java",
     "java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java",
@@ -157,6 +158,7 @@ android_library("net_javatests") {
     "javatests/src/org/chromium/net/AndroidProxyConfigServiceTestUtil.java",
     "javatests/src/org/chromium/net/AndroidProxySelectorTest.java",
     "javatests/src/org/chromium/net/HttpUtilTest.java",
+    "javatests/src/org/chromium/net/MimeTypeFilterTest.java",
     "javatests/src/org/chromium/net/NetErrorsTest.java",
     "javatests/src/org/chromium/net/NetworkChangeNotifierNoNativeTest.java",
     "javatests/src/org/chromium/net/NetworkChangeNotifierTest.java",

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/MimeTypeFileFilter.java → net/android/java/src/org/chromium/net/MimeTypeFilter.java

-// Copyright 2017 The Chromium Authors. All rights reserved.
+// Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-package org.chromium.chrome.browser.photo_picker;
+package org.chromium.net;
 
+import android.net.Uri;
 import android.support.annotation.NonNull;
 import android.webkit.MimeTypeMap;
 
@@ -14,72 +15,75 @@ import java.util.List;
 import java.util.Locale;
 
 /**
- * A file filter for handling extensions mapping to MIME types (such as images/jpeg and images/*).
+ *  A mime type filter that supports filtering both mime types and file extensions.
+ *  Note that this class is used specifically to implement
+ *  the mime type filtering for web share target spec:
+ *  https://pr-preview.s3.amazonaws.com/ewilligers/web-share-target/pull/53.html#determining-if-a-file-is-accepted.
+ *  It is also used inside chrome/android/java/src/org/chromium/chrome/browser/photo_picker.
  */
-class MimeTypeFileFilter implements FileFilter {
+public class MimeTypeFilter implements FileFilter {
     private HashSet<String> mExtensions = new HashSet<>();
     private HashSet<String> mMimeTypes = new HashSet<>();
     private HashSet<String> mMimeSupertypes = new HashSet<>();
     private MimeTypeMap mMimeTypeMap;
+    private boolean mAcceptAllMimeTypes;
+    private boolean mAcceptDirectory;
 
     /**
-     * Contructs a MimeTypeFileFilter object.
+     * Contructs a MimeTypeFilter object.
      * @param mimeTypes A list of MIME types this filter accepts.
      *                  For example: images/gif, video/*.
      */
-    public MimeTypeFileFilter(@NonNull List<String> mimeTypes) {
+    public MimeTypeFilter(@NonNull List<String> mimeTypes, boolean acceptDirectory) {
         for (String field : mimeTypes) {
             field = field.trim().toLowerCase(Locale.US);
             if (field.startsWith(".")) {
                 mExtensions.add(field.substring(1));
+            } else if (field.equals("*/*")) {
+                mAcceptAllMimeTypes = true;
             } else if (field.endsWith("/*")) {
                 mMimeSupertypes.add(field.substring(0, field.length() - 2));
             } else if (field.contains("/")) {
                 mMimeTypes.add(field);
-            } else {
-                // Throw exception?
             }
         }
 
         mMimeTypeMap = MimeTypeMap.getSingleton();
+        mAcceptDirectory = acceptDirectory;
     }
 
-    @Override
-    public boolean accept(@NonNull File file) {
-        if (file.isDirectory()) {
+    /**
+     * Returns true if either the uri or the mimeType is accepted by the MimeTypeFilter
+     * @param uri
+     * @param mimeType
+     */
+    public boolean accept(Uri uri, String mimeType) {
+        if (uri != null) {
+            String fileExtension =
+                    MimeTypeMap.getFileExtensionFromUrl(uri.toString()).toLowerCase(Locale.US);
+            if (mExtensions.contains(fileExtension)) {
                 return true;
             }
-
-        String uri = file.toURI().toString();
-        String ext = MimeTypeMap.getFileExtensionFromUrl(uri).toLowerCase(Locale.US);
-        if (mExtensions.contains(ext)) {
-            return true;
+            if (mimeType == null) {
+                mimeType = getMimeTypeFromExtension(fileExtension);
+            }
         }
 
-        String mimeType = getMimeTypeFromExtension(ext);
         if (mimeType != null) {
-            if (mMimeTypes.contains(mimeType)
+            if (mAcceptAllMimeTypes || mMimeTypes.contains(mimeType)
                     || mMimeSupertypes.contains(getMimeSupertype(mimeType))) {
                 return true;
             }
         }
-
         return false;
     }
 
-    private HashSet<String> getAcceptedSupertypes() {
-        HashSet<String> supertypes = new HashSet<>();
-        supertypes.addAll(mMimeSupertypes);
-        for (String mimeType : mMimeTypes) {
-            supertypes.add(getMimeSupertype(mimeType));
-        }
-        for (String ext : mExtensions) {
-            String mimeType = getMimeTypeFromExtension(ext);
-            if (mimeType != null) {
-                supertypes.add(getMimeSupertype(mimeType));
-            }
+    @Override
+    public boolean accept(@NonNull File file) {
+        if (file.isDirectory()) {
+            return mAcceptDirectory;
         }
-        return supertypes;
+        return accept(Uri.fromFile(file), null);
     }
 
     private String getMimeTypeFromExtension(@NonNull String ext) {
@@ -88,7 +92,7 @@ class MimeTypeFileFilter implements FileFilter {
     }
 
     @NonNull
-    private String getMimeSupertype(@NonNull String mimeType) {
+    private static String getMimeSupertype(@NonNull String mimeType) {
         return mimeType.split("/", 2)[0];
     }
 }

net/android/javatests/src/org/chromium/net/MimeTypeFilterTest.java

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.net;
+
+import android.net.Uri;
+import android.support.test.filters.SmallTest;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.test.BaseJUnit4ClassRunner;
+
+import java.util.ArrayList;
+
+/**
+ * Tests for MimeTypeFilter.
+ */
+@RunWith(BaseJUnit4ClassRunner.class)
+public class MimeTypeFilterTest {
+    @Test
+    @SmallTest
+    public void testAcceptAllMimeTypes() {
+        ArrayList<String> mimeTypes = new ArrayList<String>();
+        mimeTypes.add("*/*");
+        MimeTypeFilter mimeFilter = new MimeTypeFilter(mimeTypes, false);
+        Assert.assertTrue(mimeFilter.accept(null, "image/jpeg"));
+    }
+
+    @Test
+    @SmallTest
+    public void testAcceptAllImageTypes() {
+        ArrayList<String> mimeTypes = new ArrayList<String>();
+        mimeTypes.add("image/*");
+        MimeTypeFilter mimeFilter = new MimeTypeFilter(mimeTypes, false);
+        Assert.assertTrue(mimeFilter.accept(null, "image/jpeg"));
+        Assert.assertTrue(mimeFilter.accept(null, "image/gif"));
+    }
+
+    @Test
+    @SmallTest
+    public void testAcceptOnlyOneType() {
+        ArrayList<String> mimeTypes = new ArrayList<String>();
+        mimeTypes.add("text/plain");
+        MimeTypeFilter mimeFilter = new MimeTypeFilter(mimeTypes, false);
+        Assert.assertTrue(mimeFilter.accept(null, "text/plain"));
+        Assert.assertFalse(mimeFilter.accept(null, "image/gif"));
+    }
+
+    @Test
+    @SmallTest
+    public void testAcceptExtension() {
+        ArrayList<String> mimeTypes = new ArrayList<String>();
+        mimeTypes.add(".jpeg");
+        MimeTypeFilter mimeFilter = new MimeTypeFilter(mimeTypes, false);
+        Uri jpegUri = Uri.parse("image.jpeg");
+        Uri gifUri = Uri.parse("image.gif");
+        Assert.assertTrue(mimeFilter.accept(jpegUri, ""));
+        Assert.assertFalse(mimeFilter.accept(gifUri, ""));
+    }
+}