From 943b5e338be8d73956bc4a9dc454ce06b4170630 Mon Sep 17 00:00:00 2001
From: Chandra Srinivasan <chsriniv@microsoft.com>
Date: Tue, 30 Jun 2020 10:00:27 -0700
Subject: [PATCH] Adding initial spec for Reunion Picker API.

---
 specs/Picker-API_spec.md | 116 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 specs/Picker-API_spec.md

diff --git a/specs/Picker-API_spec.md b/specs/Picker-API_spec.md
new file mode 100644
index 00000000000..3f2af581c16
--- /dev/null
+++ b/specs/Picker-API_spec.md
@@ -0,0 +1,116 @@
+# Background
+
+The current FilePicker API for UWP has several limitations. Some of the top limitations 
+are as described below:
+
+**1. Unable to pick files and folders in a single instance of the Picker dialog**
+
+   The Picker dialog allows developers to specify picker mode to be single file or multiple
+   files. It does not however, allow developers to specify a mode to pick both files and folders.
+   There has been feedback indicating that this behaviour is limiting, requiring developers
+   to build their own picker experience. 
+
+**2. Unable to pick multiple folders.**
+
+   The Picker dialog (FolderPicker) does not allow users to pick multiple folders. The developer
+   experience currently is to select a single folder and repeat the dialog for more folders. This 
+   is a less than ideal experience for application developers.
+
+The Reunion picker dialog is going to address the above issues. This Reunion API will be based upon the below
+APIs in the Windows SDK. The Reunion Picker API will remove the deprecated APIs and add additional methods
+for the functionality file and folder picker, multiple folder picker.
+
+- Windows.Storage.Pickers.FileOpenPicker (https://docs.microsoft.com/en-us/uwp/api/Windows.Storage.Pickers.FileOpenPicker)
+- Windows.Storage.Pickers.FileSavePicker (https://docs.microsoft.com/en-us/uwp/api/windows.storage.pickers.filesavepicker)
+- Windows.Storage.Pickers.FolderPicker (https://docs.microsoft.com/en-us/uwp/api/windows.storage.pickers.folderpicker) 
+
+# Description
+
+The goal of this API is to address the gaps in the existing File/Folder picker APIs. The API surface is similar to the existing
+Picker APIs in Windows SDK with additional methods to support File + Folder picker and multiple folder picker. The API removes the
+deprecated methods from Windows SDK.
+
+# Examples
+
+## Show file and folder picker
+    ```c#
+    var picker = StorageItemPicker::CreateFilePicker();
+    picker.Filters.add("*.jpg");
+    picker.Filters.add("*.png");
+    picker.StartLocation = startLocation;
+    IReadOnlyList<StorageItem> storageItems = await picker.PickStorageItemAsync();
+
+    if(0 < storageItems.Count)
+    {
+    }
+    ```
+
+## Show single folder picker
+    ```c#
+    var picker = StorageItemPicker::CreateFolderPicker();
+    Windows.Storage.StorageFolder folder = await picker.PickSingleFolderAsync();
+    ```
+
+
+## Show multi folder picker
+    ```c#
+    var picker = StorageItemPicker::CreateFolderPicker();
+    IReadOnlyList<Windows.Storage.StorageFolder> folders = picker.PickMultipleFoldersAsync();
+    ```
+
+# Remarks
+
+# API Notes
+
+
+# API Details
+
+    ```c#
+    namespace Microsoft.Reunion.Storage.Pickers
+    {
+        typedef enum PickerViewMode
+        {
+            List = 0,
+            Details,
+            Tiles,
+            Content
+        } PickerViewMode;
+
+        runtimeclass StorageItemPicker
+        {
+            /// Static constructor
+            static FileOpenPicker CreateFileOpenPicker();
+            static FileSaveFileAsync CreateFileSavePicker();
+            static FolderPicker CreateFolderPicker();
+
+            String StartLocation{ set; }
+            String OkButtonText { set; }
+            String CancelButtonText { set; }
+            Windows.Foundation.Collections.IMap<String, String> FilterAndDescription{ get; }
+            PickerViewMode ViewMode{ get; set; }
+        }
+
+        runtimeclass FileOpenPicker : StorageItemPicker
+        {
+            Windows.Foundation.IAsyncOperation<Windows.Storage.StorageFile> PickSingleFileAsync();
+            Windows.Foundation.IAsyncOperation<Windows.Foundation.Collections.IVectorView<Windows.Storage.StorageFile>> PickMutipleFilesAsync();
+            Windows.Foundation.IAsyncOperation<Windows.Foundation.Collections.IVectorView<Windows.Storage.StorageItem>> PickStorageItemsAsync();
+        }
+
+        runtimeclass FileSavePicker : StorageItemPicker
+        {
+            String SuggestedSaveFile{ get; set; }
+            String DefaultFileExtension{ get; set; }
+
+            Windows.Foundation.IAsyncOperation<Windows.Storage.StorageFile> PickSaveFileAsync();
+        }
+
+        runtimeclass FolderPicker : StorageItemPicker
+        {
+            Windows.Foundation.IAsyncOperation<Windows.Storage.StorageFolder> PickSingleFolderAsync();
+            Windows.Foundation.IAsyncOperation<Windows.Foundation.Collections.IVectorView<Windows.Storage.StorageFolder>> PickMultipleFoldersAsync();
+        }
+    }
+    ```
+
+# Appendix
\ No newline at end of file