Bug 1674428 - Part 1. Implement folder upload picker API. r=geckoview-reviewers,owlish,ohall

Differential Revision: https://phabricator.services.mozilla.com/D227912

mobile/android/geckoview/api.txt

@@ -1464,6 +1464,7 @@ package org.mozilla.geckoview {
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onCreditCardSelect(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.AutocompleteRequest<Autocomplete.CreditCardSelectOption>);
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onDateTimePrompt(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.DateTimePrompt);
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onFilePrompt(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.FilePrompt);
+    method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onFolderUploadPrompt(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.FolderUploadPrompt);
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onLoginSave(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.AutocompleteRequest<Autocomplete.LoginSaveOption>);
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onLoginSelect(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.AutocompleteRequest<Autocomplete.LoginSelectOption>);
     method @Nullable @UiThread default public GeckoResult<GeckoSession.PromptDelegate.PromptResponse> onPopupPrompt(@NonNull GeckoSession, @NonNull GeckoSession.PromptDelegate.PopupPrompt);
@@ -1643,10 +1644,17 @@ package org.mozilla.geckoview {
 
   public static class GeckoSession.PromptDelegate.FilePrompt.Type {
     ctor protected Type();
+    field public static final int FOLDER = 3;
     field public static final int MULTIPLE = 2;
     field public static final int SINGLE = 1;
   }
 
+  public static class GeckoSession.PromptDelegate.FolderUploadPrompt extends GeckoSession.PromptDelegate.BasePrompt {
+    ctor protected FolderUploadPrompt(@NonNull String, @Nullable String, @NonNull GeckoSession.PromptDelegate.BasePrompt.Observer);
+    method @NonNull @UiThread public GeckoSession.PromptDelegate.PromptResponse confirm(@Nullable AllowOrDeny);
+    field @Nullable public final String directoryName;
+  }
+
   public static final class GeckoSession.PromptDelegate.IdentityCredential {
     ctor public IdentityCredential();
   }

mobile/android/geckoview/src/androidTest/assets/www/prompts.html

@@ -30,6 +30,8 @@
       accept="image/*,.pdf"
     />
 
+    <input type="file" id="direxample" webkitdirectory />
+
     <datalist id="colorlist">
       <option>#000000</option>
       <option>#808080</option>

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/PromptDelegateTest.kt

@@ -4,9 +4,11 @@
 
 package org.mozilla.geckoview.test
 
+import android.net.Uri
 import android.view.KeyEvent
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.MediumTest
+import androidx.test.platform.app.InstrumentationRegistry
 import org.hamcrest.Matchers.* // ktlint-disable no-wildcard-imports
 import org.junit.Assert
 import org.junit.Test
@@ -1102,6 +1104,7 @@ class PromptDelegateTest : BaseSessionTest(
                 assertThat("First accept attribute should match", "image/*", equalTo(prompt.mimeTypes?.get(0)))
                 assertThat("Second accept attribute should match", ".pdf", equalTo(prompt.mimeTypes?.get(1)))
                 assertThat("Capture attribute should match", PromptDelegate.FilePrompt.Capture.USER, equalTo(prompt.capture))
+                assertThat("Type should match", prompt.type, equalTo(PromptDelegate.FilePrompt.Type.SINGLE))
                 return GeckoResult.fromValue(prompt.dismiss())
             }
         })
@@ -1131,6 +1134,44 @@ class PromptDelegateTest : BaseSessionTest(
         })
     }
 
+    @WithDisplay(width = 100, height = 100)
+    @Test
+    fun directoryTest() {
+        sessionRule.setPrefsUntilTestEnd(
+            mapOf(
+                "dom.disable_open_during_load" to false,
+                "dom.webkitBlink.dirPicker.enabled" to true,
+            ),
+        )
+
+        mainSession.loadTestPath(PROMPT_HTML_PATH)
+        mainSession.waitForPageStop()
+
+        sessionRule.delegateUntilTestEnd(object : PromptDelegate {
+            @AssertCalled(count = 1)
+            override fun onFilePrompt(session: GeckoSession, prompt: PromptDelegate.FilePrompt): GeckoResult<PromptDelegate.PromptResponse> {
+                assertThat("Type should match", prompt.type, equalTo(PromptDelegate.FilePrompt.Type.FOLDER))
+                return GeckoResult.fromValue(
+                    prompt.confirm(
+                        InstrumentationRegistry.getInstrumentation().targetContext,
+                        Uri.parse("file:///storage/emulated/0/Download"),
+                    ),
+                )
+            }
+        })
+
+        mainSession.evaluateJS("document.addEventListener('click', () => document.getElementById('direxample').click(), { once: true });")
+        mainSession.synthesizeTap(1, 1)
+
+        sessionRule.waitUntilCalled(object : PromptDelegate {
+            @AssertCalled(count = 1)
+            override fun onFolderUploadPrompt(session: GeckoSession, prompt: PromptDelegate.FolderUploadPrompt): GeckoResult<PromptDelegate.PromptResponse>? {
+                assertThat("directoryName should match", prompt.directoryName, equalTo("Download"))
+                return GeckoResult.fromValue(prompt.confirm(AllowOrDeny.ALLOW))
+            }
+        })
+    }
+
     @Test fun shareTextSucceeds() {
         sessionRule.setPrefsUntilTestEnd(mapOf("dom.webshare.requireinteraction" to false))
         mainSession.loadTestPath(HELLO_HTML_PATH)

mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/IntentUtils.java

@@ -6,13 +6,26 @@
 
 package org.mozilla.gecko.util;
 
+import android.content.ContentResolver;
+import android.content.Context;
 import android.content.Intent;
+import android.database.Cursor;
 import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+import android.provider.DocumentsContract;
+import android.util.Log;
 import java.net.URISyntaxException;
 import java.util.Locale;
 
 /** Utilities for Intents. */
 public class IntentUtils {
+  private static final String LOGTAG = "IntentUtils";
+  private static final boolean DEBUG = false;
+
+  private static final String EXTERNAL_STORAGE_PROVIDER_AUTHORITY =
+      "com.android.externalstorage.documents";
+
   private IntentUtils() {}
 
   /**
@@ -117,4 +130,90 @@ public class IntentUtils {
   private static void nullIntentSelector(final Intent intent) {
     intent.setSelector(null);
   }
+
+  /**
+   * Return a local path from the Uri that is content schema.
+   *
+   * @param context The context.
+   * @param uri The URI.
+   * @return A local path if resolved. If this cannot resolve URI, return null.
+   */
+  public static String resolveContentUri(final Context context, final Uri uri) {
+    final ContentResolver cr = context.getContentResolver();
+    try (final Cursor cur =
+        cr.query(
+            uri, new String[] {"_data"}, /* selection */ null, /* args */ null, /* sort */ null)) {
+      final int idx = cur.getColumnIndex("_data");
+      if (idx < 0 || !cur.moveToFirst()) {
+        return null;
+      }
+      do {
+        try {
+          final String path = cur.getString(idx);
+          if (path != null && !path.isEmpty()) {
+            return path;
+          }
+        } catch (final Exception e) {
+        }
+      } while (cur.moveToNext());
+    } catch (final UnsupportedOperationException e) {
+      Log.e(LOGTAG, "Failed to query child documents", e);
+    }
+
+    if (DEBUG) {
+      Log.e(LOGTAG, "Failed to resolve uri. uri=" + uri.toString());
+    }
+    return null;
+  }
+
+  /**
+   * Return a local path from tree Uri.
+   *
+   * @param context The context.
+   * @param uri The uri that @{link DoumentContract#isTreeUri} returns true.
+   * @return A local path if resolved. If this cannot resolve URI, return null.
+   */
+  public static String resolveTreeUri(final Context context, final Uri uri) {
+    final Uri docDirUri =
+        DocumentsContract.buildDocumentUriUsingTree(uri, DocumentsContract.getTreeDocumentId(uri));
+    return resolveDocumentUri(context, docDirUri);
+  }
+
+  /**
+   * Return a local path from document Uri.
+   *
+   * @param context The context.
+   * @param uri The uri that @{link DoumentContract#isDocumentUri} returns true.
+   * @return A local path if resolved. If this cannot resolve URI, return null.
+   */
+  public static String resolveDocumentUri(final Context context, final Uri uri) {
+    if (EXTERNAL_STORAGE_PROVIDER_AUTHORITY.equals(uri.getAuthority())) {
+      final String docId = DocumentsContract.getDocumentId(uri);
+      final String[] split = docId.split(":");
+
+      if (split[0].equals("primary")) {
+        // This is the internal storage.
+        final StringBuilder sb =
+            new StringBuilder(Environment.getExternalStorageDirectory().toString());
+        if (split.length > 1) {
+          sb.append("/").append(split[1]);
+        }
+        return sb.toString();
+      }
+
+      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+        // This might be sd card. /storage/xxxx-xxxx/...
+        final StringBuilder sb = new StringBuilder(Environment.getStorageDirectory().toString());
+        sb.append("/").append(split[0]);
+        if (split.length > 1) {
+          sb.append("/").append(split[1]);
+        }
+        return sb.toString();
+      }
+    }
+    if (DEBUG) {
+      Log.e(LOGTAG, "Failed to resolve uri. uri=" + uri.toString());
+    }
+    return null;
+  }
 }

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java

@@ -11,9 +11,7 @@ import static org.mozilla.geckoview.GeckoSession.GeckoPrintException.ERROR_NO_PR
 import android.Manifest;
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
-import android.content.ContentResolver;
 import android.content.Context;
-import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.Matrix;
 import android.graphics.Point;
@@ -27,6 +25,7 @@ import android.os.IInterface;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.SystemClock;
+import android.provider.DocumentsContract;
 import android.text.TextUtils;
 import android.util.Base64;
 import android.util.Log;
@@ -5502,6 +5501,42 @@ public class GeckoSession {
       }
     }
 
+    /**
+     * FolderUploadPrompt represents a prompt shown whenever the browser needs to upload folder data
+     */
+    class FolderUploadPrompt extends BasePrompt {
+      /** The directory name to confirm folder tries to uploading. */
+      public final @Nullable String directoryName;
+
+      /**
+       * A constructor for FolderUploadPrompt
+       *
+       * @param id The identification for this prompt.
+       * @param directoryName The directory that is confirmed.
+       * @param observer A callback to notify when the prompt has been completed.
+       */
+      protected FolderUploadPrompt(
+          @NonNull final String id,
+          @Nullable final String directoryName,
+          @NonNull final Observer observer) {
+        super(id, null, observer);
+        this.directoryName = directoryName;
+      }
+
+      /**
+       * Confirms the prompt.
+       *
+       * @param allowOrDeny whether the browser should allow resubmitting data.
+       * @return A {@link PromptResponse} which can be used to complete the {@link GeckoResult}
+       *     associated with this prompt.
+       */
+      @UiThread
+      public @NonNull PromptResponse confirm(final @Nullable AllowOrDeny allowOrDeny) {
+        ensureResult().putBoolean("allow", allowOrDeny != AllowOrDeny.DENY);
+        return super.confirm();
+      }
+    }
+
     /**
      * RepostConfirmPrompt represents a prompt shown whenever the browser needs to resubmit POST
      * data (e.g. due to page refresh).
@@ -6372,7 +6407,7 @@ public class GeckoSession {
      */
     class FilePrompt extends BasePrompt {
       @Retention(RetentionPolicy.SOURCE)
-      @IntDef({Type.SINGLE, Type.MULTIPLE})
+      @IntDef({Type.SINGLE, Type.MULTIPLE, Type.FOLDER})
       public @interface FileType {}
 
       /** Types of file prompts. */
@@ -6383,6 +6418,9 @@ public class GeckoSession {
         /** Prompt for multiple files. */
         public static final int MULTIPLE = 2;
 
+        /** Prompt for directory. */
+        public static final int FOLDER = 3;
+
         protected Type() {}
       }
 
@@ -6458,7 +6496,7 @@ public class GeckoSession {
       @UiThread
       public @NonNull PromptResponse confirm(
           @NonNull final Context context, @NonNull final Uri[] uris) {
-        if (Type.SINGLE == type && (uris == null || uris.length != 1)) {
+        if ((Type.SINGLE == type || Type.FOLDER == type) && (uris == null || uris.length != 1)) {
           throw new IllegalArgumentException();
         }
 
@@ -6483,33 +6521,14 @@ public class GeckoSession {
         if ("file".equals(uri.getScheme())) {
           return uri.getPath();
         }
-        final ContentResolver cr = context.getContentResolver();
+        if ("content".equals(uri.getScheme())) {
-        final Cursor cur =
+          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && DocumentsContract.isTreeUri(uri)) {
-            cr.query(
+            return IntentUtils.resolveTreeUri(context, uri);
-                uri,
-                new String[] {"_data"}, /* selection */
-                null,
-                /* args */ null, /* sort */
-                null);
-        if (cur == null) {
-          return null;
           }
-        try {
+          if (DocumentsContract.isDocumentUri(context, uri)) {
-          final int idx = cur.getColumnIndex("_data");
+            return IntentUtils.resolveDocumentUri(context, uri);
-          if (idx < 0 || !cur.moveToFirst()) {
-            return null;
           }
-          do {
+          return IntentUtils.resolveContentUri(context, uri);
-            try {
-              final String path = cur.getString(idx);
-              if (path != null && !path.isEmpty()) {
-                return path;
-              }
-            } catch (final Exception e) {
-            }
-          } while (cur.moveToNext());
-        } finally {
-          cur.close();
         }
         return null;
       }
@@ -6709,6 +6728,20 @@ public class GeckoSession {
       return null;
     }
 
+    /**
+     * Display a folder upload prompt.
+     *
+     * @param session GeckoSession that triggered the prompt.
+     * @param prompt The {@link FolderUploadPrompt} that describes the prompt.
+     * @return A {@link GeckoResult} resolving to a {@link PromptResponse} which includes all
+     *     necessary information to resolve the prompt.
+     */
+    @UiThread
+    default @Nullable GeckoResult<PromptResponse> onFolderUploadPrompt(
+        @NonNull final GeckoSession session, @NonNull final FolderUploadPrompt prompt) {
+      return null;
+    }
+
     /**
      * Display a text prompt.
      *

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/PromptController.java

@@ -29,6 +29,7 @@ import org.mozilla.geckoview.GeckoSession.PromptDelegate.ChoicePrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.ColorPrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.DateTimePrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.FilePrompt;
+import org.mozilla.geckoview.GeckoSession.PromptDelegate.FolderUploadPrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.IdentityCredential.AccountSelectorPrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.IdentityCredential.PrivacyPolicyPrompt;
 import org.mozilla.geckoview.GeckoSession.PromptDelegate.IdentityCredential.ProviderSelectorPrompt;
@@ -362,6 +363,8 @@ import org.mozilla.geckoview.GeckoSession.PromptDelegate.TextPrompt;
         intMode = FilePrompt.Type.SINGLE;
       } else if ("multiple".equals(mode)) {
         intMode = FilePrompt.Type.MULTIPLE;
+      } else if ("folder".equals(mode)) {
+        intMode = FilePrompt.Type.FOLDER;
       } else {
         return null;
       }
@@ -379,6 +382,22 @@ import org.mozilla.geckoview.GeckoSession.PromptDelegate.TextPrompt;
     }
   }
 
+  private static final class FolderUploadHandler implements PromptHandler<FolderUploadPrompt> {
+    @Override
+    public FolderUploadPrompt newPrompt(final GeckoBundle info, final Observer observer) {
+      return new FolderUploadPrompt(
+          info.getString("id"), info.getString("directoryName"), observer);
+    }
+
+    @Override
+    public GeckoResult<PromptResponse> callDelegate(
+        final FolderUploadPrompt prompt,
+        final GeckoSession session,
+        final PromptDelegate delegate) {
+      return delegate.onFolderUploadPrompt(session, prompt);
+    }
+  }
+
   private static final class PopupHandler implements PromptHandler<PopupPrompt> {
     @Override
     public PopupPrompt newPrompt(final GeckoBundle info, final Observer observer) {
@@ -727,6 +746,7 @@ import org.mozilla.geckoview.GeckoSession.PromptDelegate.TextPrompt;
     sPromptHandlers.register(new ColorHandler(), "color");
     sPromptHandlers.register(new DateTimeHandler(), "datetime");
     sPromptHandlers.register(new FileHandler(), "file");
+    sPromptHandlers.register(new FolderUploadHandler(), "folderUpload");
     sPromptHandlers.register(new PopupHandler(), "popup");
     sPromptHandlers.register(new RepostHandler(), "repost");
     sPromptHandlers.register(new ShareHandler(), "share");

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/doc-files/CHANGELOG.md

@@ -13,6 +13,18 @@ exclude: true
 
 ⚠️  breaking change and deprecation notices
 
+## v138
+- Added [`GeckoSession.Loader.originalInput`][138.1] option, which allows passing through the original user address bar input
+- Added [`PromptDelegate.FilePrompt.Type.FOLDER`][138.2] to show directory picker.
+  ([bug 1674428]({{bugzilla}}1674428))
+- Added [`onFolderUploadPrompt`][138.3] and [`PromptDelegate.FolderUploadPrompt`][138.4] to confirm folder upload.
+  ([bug 1674428]({{bugzilla}}1674428))
+
+[138.1]: {{javadoc_uri}}/GeckoSession.Loader.html#originalInput(java.lang.String)
+[138.2]: {{javadoc_uri}}/GeckoSession.PromptDelegate.FilePrompt.Type.html#FOLDER
+[138.3]: {{javadoc_uri}}/GeckoSession.PromptDelegate.html#onFolderUploadPrompt(org.mozilla.geckoview.GeckoSession,org.mozilla.geckoview.GeckoSession.PromptDelegate.FolderUploadPrompt)
+[138.4]: {{javadoc_uri}}/GeckoSession.PromptDelegate.FolderUploadPrompt.html
+
 ## v137
 - ⚠️ [`GeckoSession.requestAnalysis`][118.4], [`GeckoSession.requestCreateAnalysis`][122.2], [`GeckoSession.requestAnalysisStatus`][137.1], [`GeckoSession.sendPlacementAttributionEvent`][123.3], [`GeckoSession.pollForAnalysisCompleted`][137.2], [`GeckoSession.sendClickAttributionEvent`][121.4], [`GeckoSession.sendImpressionAttributionEvent`][121.5], [`GeckoSession.sendPlacementAttributionEvent`][123.3], [`GeckoSession.requestRecommendations`][118.5], [`GeckoSession.reportBackInStock`][122.1], `AnalysisStatusResponse`, [`ReviewAnalysis`][120.2] and [`Recommendation`][120.3] are deprecated, and it will be deleted in version 139 see https://bugzilla.mozilla.org/show_bug.cgi?id=1941470.
 - Added support for controlling `network.trr.default_provider_uri` via [`GeckoRuntimeSettings.setDefaultRecursiveResolverUri`][137.3] and [`GeckoRuntimeSettings.getDefaultRecursiveResolverUri`][137.4]
@@ -1677,4 +1689,4 @@ to allow adding gecko profiler markers.
 [65.24]: {{javadoc_uri}}/CrashReporter.html#sendCrashReport(android.content.Context,android.os.Bundle,java.lang.String)
 [65.25]: {{javadoc_uri}}/GeckoResult.html
 
-[api-version]: 5457ccf9a76bbdba450eede7c0f8084747965685
+[api-version]: c4088b9c37d508e0a5346aa173795fc7d82ff6f2

mobile/android/geckoview_example/src/main/java/org/mozilla/geckoview_example/BasicGeckoViewPrompt.java

@@ -205,6 +205,39 @@ final class BasicGeckoViewPrompt implements GeckoSession.PromptDelegate {
     return res;
   }
 
+  @Nullable
+  @Override
+  public GeckoResult<PromptResponse> onFolderUploadPrompt(
+      final GeckoSession session, final FolderUploadPrompt prompt) {
+    final Activity activity = mActivity;
+    if (activity == null) {
+      return GeckoResult.fromValue(prompt.dismiss());
+    }
+    final AlertDialog.Builder builder =
+        new AlertDialog.Builder(activity)
+            .setTitle(R.string.folder_upload_title)
+            .setMessage(R.string.folder_upload_message);
+
+    final GeckoResult<PromptResponse> res = new GeckoResult<>();
+
+    final DialogInterface.OnClickListener listener =
+        (dialog, which) -> {
+          if (which == DialogInterface.BUTTON_POSITIVE) {
+            res.complete(prompt.confirm(AllowOrDeny.ALLOW));
+          } else if (which == DialogInterface.BUTTON_NEGATIVE) {
+            res.complete(prompt.confirm(AllowOrDeny.DENY));
+          } else {
+            res.complete(prompt.dismiss());
+          }
+        };
+
+    builder.setPositiveButton(R.string.folder_upload_confirm_accept, listener);
+    builder.setNegativeButton(R.string.folder_upload_confirm_cancel, listener);
+
+    createStandardDialog(builder, prompt, res).show();
+    return res;
+  }
+
   private int getViewPadding(final AlertDialog.Builder builder) {
     final TypedArray attr =
         builder
@@ -857,6 +890,24 @@ final class BasicGeckoViewPrompt implements GeckoSession.PromptDelegate {
     return res;
   }
 
+  private GeckoResult<PromptResponse> onFolderPrompt(
+      final GeckoSession session, final FilePrompt prompt) {
+    final Activity activity = mActivity;
+    final Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
+    intent.addCategory(Intent.CATEGORY_DEFAULT);
+    final GeckoResult<PromptResponse> res = new GeckoResult<PromptResponse>();
+
+    try {
+      mFileResponse = res;
+      mFilePrompt = prompt;
+      activity.startActivityForResult(intent, filePickerRequestCode);
+    } catch (final ActivityNotFoundException e) {
+      Log.e(LOGTAG, "Cannot launch activity", e);
+      return GeckoResult.fromValue(prompt.dismiss());
+    }
+    return res;
+  }
+
   @Override
   @TargetApi(19)
   public GeckoResult<PromptResponse> onFilePrompt(GeckoSession session, FilePrompt prompt) {
@@ -865,6 +916,10 @@ final class BasicGeckoViewPrompt implements GeckoSession.PromptDelegate {
       return GeckoResult.fromValue(prompt.dismiss());
     }
 
+    if (prompt.type == FilePrompt.Type.FOLDER) {
+      return onFolderPrompt(session, prompt);
+    }
+
     // Merge all given MIME types into one, using wildcard if needed.
     String mimeType = null;
     String mimeSubtype = null;
@@ -951,6 +1006,8 @@ final class BasicGeckoViewPrompt implements GeckoSession.PromptDelegate {
         uris.add(clip.getItemAt(i).getUri());
       }
       res.complete(prompt.confirm(mActivity, uris.toArray(new Uri[uris.size()])));
+    } else if (prompt.type == FilePrompt.Type.FOLDER) {
+      res.complete(prompt.confirm(mActivity, uri));
     }
   }
 

mobile/android/geckoview_example/src/main/res/values/strings.xml

@@ -175,4 +175,9 @@
     <string name="repost_confirm_title">Are you sure?</string>
     <string name="repost_confirm_resend">Resend</string>
     <string name="repost_confirm_cancel">Cancel</string>
+
+    <string name="folder_upload_message">Are you sure you want to upload all files? Only do this if you trust the site.</string>
+    <string name="folder_upload_title">Confirm Upload</string>
+    <string name="folder_upload_confirm_accept">Upload</string>
+    <string name="folder_upload_confirm_cancel">Cancel</string>
 </resources>

mobile/shared/components/geckoview/FilePickerDelegate.sys.mjs

@@ -16,10 +16,18 @@ const { debug, warn } = GeckoViewUtils.initLogging("FilePickerDelegate");
 export class FilePickerDelegate {
   /* ----------  nsIFilePicker  ---------- */
   init(aBrowsingContext, aTitle, aMode) {
-    if (
+    let mode;
-      aMode === Ci.nsIFilePicker.modeGetFolder ||
+    switch (aMode) {
-      aMode === Ci.nsIFilePicker.modeSave
+      case Ci.nsIFilePicker.modeOpen:
-    ) {
+        mode = "single";
+        break;
+      case Ci.nsIFilePicker.modeGetFolder:
+        mode = "folder";
+        break;
+      case Ci.nsIFilePicker.modeOpenMultiple:
+        mode = "multiple";
+        break;
+      default:
         throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
     }
     this._browsingContext = aBrowsingContext;
@@ -27,7 +35,7 @@ export class FilePickerDelegate {
     this._msg = {
       type: "file",
       title: aTitle,
-      mode: aMode === Ci.nsIFilePicker.modeOpenMultiple ? "multiple" : "single",
+      mode,
     };
     this._mode = aMode;
     this._mimeTypes = [];
@@ -68,10 +76,10 @@ export class FilePickerDelegate {
 
     try {
       for (const file of aFiles) {
-        const domFile = await this._getDOMFile(file);
+        const domFileOrDir = await this._getDOMFileOrDir(file);
         fileData.push({
           file,
-          domFile,
+          domFileOrDir,
         });
       }
     } catch (ex) {
@@ -106,7 +114,7 @@ export class FilePickerDelegate {
 
     for (const fileData of this._fileData) {
       if (aDOMFile) {
-        yield fileData.domFile;
+        yield fileData.domFileOrDir;
       }
       yield new lazy.FileUtils.File(fileData.file);
     }
@@ -116,6 +124,20 @@ export class FilePickerDelegate {
     return this._getEnumerator(/* aDOMFile */ false);
   }
 
+  _getDOMFileOrDir(aPath) {
+    if (this.mode == Ci.nsIFilePicker.modeGetFolder) {
+      return this._getDOMDir(aPath);
+    }
+    return this._getDOMFile(aPath);
+  }
+
+  _getDOMDir(aPath) {
+    if (this._prompt.domWin) {
+      return new this._prompt.domWin.Directory(aPath);
+    }
+    return new Directory(aPath);
+  }
+
   _getDOMFile(aPath) {
     if (this._prompt.domWin) {
       return this._prompt.domWin.File.createFromFileName(aPath);
@@ -127,7 +149,7 @@ export class FilePickerDelegate {
     if (!this._fileData) {
       throw Components.Exception("", Cr.NS_ERROR_NOT_AVAILABLE);
     }
-    return this._fileData[0] ? this._fileData[0].domFile : null;
+    return this._fileData[0]?.domFileOrDir;
   }
 
   get domFileOrDirectoryEnumerator() {

mobile/shared/components/geckoview/PromptCollection.sys.mjs

@@ -32,9 +32,14 @@ export class PromptCollection {
     }).then(result => !!result?.allow);
   }
 
-  confirmFolderUpload() {
+  confirmFolderUpload(browsingContext, directoryName) {
-    // Folder upload is not supported by GeckoView yet, see Bug 1674428.
+    const msg = {
-    return false;
+      type: "folderUpload",
+      directoryName,
+    };
+    const prompter = new lazy.GeckoViewPrompter(browsingContext);
+    const result = prompter.showPrompt(msg);
+    return !!result?.allow;
   }
 }