Windows - implement modern File/Folder dialogs with comtypes

changes/2786.feature.rst

@@ -0,0 +1 @@
+Introduced `IFileOpenDialog`, replacing `SHBrowseForFolder` for improved file selection dialogs.

testbed/pyproject.toml

@@ -66,6 +66,7 @@ test_sources = [
 ]
 requires = [
  "../winforms",
+ "comtypes",
 ]
 
 # Mobile deployments

winforms/src/toga_winforms/dialogs.py

@@ -1,7 +1,23 @@
 import asyncio
+import os
+from ctypes import (
+ HRESULT,
+ POINTER,
+ byref,
+ c_void_p,
+ c_wchar_p,
+ cast as cast_with_ctypes,
+ windll,
+)
+from ctypes.wintypes import HWND
 from pathlib import Path
+from typing import List, Optional, Tuple, Union
 
+import comtypes
+import comtypes.client
 import System.Windows.Forms as WinForms
+from comtypes import GUID
+from comtypes.hresult import S_OK
 from System.Drawing import (
  ContentAlignment,
  Font as WinFont,
@@ -11,6 +27,18 @@
 )
 from System.Windows.Forms import DialogResult, MessageBoxButtons, MessageBoxIcon
 
+from toga_winforms.libs.com.constants import COMDLG_FILTERSPEC, FileOpenOptions
+from toga_winforms.libs.com.identifiers import (
+ CLSID_FileOpenDialog,
+ CLSID_FileSaveDialog,
+)
+from toga_winforms.libs.com.interfaces import (
+ IFileOpenDialog,
+ IFileSaveDialog,
+ IShellItem,
+ IShellItemArray,
+)
+
 from .libs.wrapper import WeakrefCallable
 
 
@@ -190,108 +218,171 @@ def winforms_Click_accept(self, sender, event):
 class FileDialog(BaseDialog):
  def __init__(
  self,
- native,
- title,
- initial_directory,
+ native: Union[IFileOpenDialog, IFileSaveDialog],
+ title: str,
+ initial_directory: Union[os.PathLike, str],
  *,
- filename=None,
- file_types=None,
+ filename: Optional[str] = None,
+ file_types: Optional[List[str]] = None,
  ):
  super().__init__()
- self.native = native
+ self.native: Union[IFileOpenDialog, IFileSaveDialog] = native
 
  self._set_title(title)
  if filename is not None:
- native.FileName = filename
+ self.native.SetFileName(filename)
 
  if initial_directory is not None:
  self._set_initial_directory(str(initial_directory))
 
  if file_types is not None:
- filters = [f"{ext} files (*.{ext})|*.{ext}" for ext in file_types] + [
- "All files (*.*)|*.*"
+ filters: List[Tuple[str, str]] = [
+ (f"{ext.upper()} files", f"*.{ext}") for ext in file_types
  ]
-
- if len(file_types) > 1:
-  pattern = ";".join([f"*.{ext}" for ext in file_types])
-  filters.insert(0, f"All matching files ({pattern})|{pattern}")
-
- native.Filter = "|".join(filters)
+ filterspec = (COMDLG_FILTERSPEC * len(file_types))(
+  *[(c_wchar_p(name), c_wchar_p(spec)) for name, spec in filters]
+ )
+ self.native.SetFileTypes(
+ len(filterspec), cast_with_ctypes(filterspec, POINTER(c_void_p))
+ )
 
  def _show(self):
- response = self.native.ShowDialog()
- if response == DialogResult.OK:
+ hwnd = HWND(0)
+ hr: int = self.native.Show(hwnd)
+ if hr == S_OK:
+ assert isinstance(
+ self, (SaveFileDialog, OpenFileDialog, SelectFolderDialog)
+ )
  self.future.set_result(self._get_filenames())
  else:
  self.future.set_result(None)
 
  def _set_title(self, title):
- self.native.Title = title
+ self.native.SetTitle(title)
 
  def _set_initial_directory(self, initial_directory):
- self.native.InitialDirectory = initial_directory
+ if initial_directory is None:
+ return
+ folder_path: Path = Path(initial_directory).resolve()
+ if folder_path.is_dir(): # sourcery skip: extract-method
+ SHCreateItemFromParsingName = windll.shell32.SHCreateItemFromParsingName
+ SHCreateItemFromParsingName.argtypes = [
+ c_wchar_p, # LPCWSTR (wide string, null-terminated)
+ POINTER(
+ comtypes.IUnknown
+ ), # IBindCtx* (can be NULL, hence POINTER(IUnknown))
+ POINTER(GUID), # REFIID (pointer to the interface ID, typically GUID)
+ POINTER(
+ POINTER(IShellItem)
+ ), # void** (output pointer to the requested interface)
+ ]
+ SHCreateItemFromParsingName.restype = HRESULT
+ shell_item = POINTER(IShellItem)()
+ hr = SHCreateItemFromParsingName(
+ str(folder_path), None, IShellItem._iid_, byref(shell_item)
+ )
+ if hr == S_OK:
+ self.native.SetFolder(shell_item)
 
 
 class SaveFileDialog(FileDialog):
- def __init__(self, title, filename, initial_directory, file_types):
+ def __init__(
+ self,
+ title: str,
+ filename: str,
+ initial_directory: Union[os.PathLike, str],
+ file_types: List[str],
+ ):
  super().__init__(
- WinForms.SaveFileDialog(),
+ comtypes.client.CreateObject(
+ CLSID_FileSaveDialog, interface=IFileSaveDialog
+ ),
  title,
  initial_directory,
  filename=filename,
  file_types=file_types,
  )
 
  def _get_filenames(self):
- return Path(self.native.FileName)
+ shell_item: IShellItem = self.native.GetResult()
+ display_name: str = shell_item.GetDisplayName(0x80058000) # SIGDN_FILESYSPATH
+ return Path(display_name)
 
 
 class OpenFileDialog(FileDialog):
  def __init__(
  self,
- title,
- initial_directory,
- file_types,
- multiple_select,
+ title: str,
+ initial_directory: Union[os.PathLike, str],
+ file_types: List[str],
+ multiple_select: bool,
  ):
  super().__init__(
- WinForms.OpenFileDialog(),
+ comtypes.client.CreateObject(
+ CLSID_FileOpenDialog, interface=IFileOpenDialog
+ ),
  title,
  initial_directory,
  file_types=file_types,
  )
  if multiple_select:
- self.native.Multiselect = True
+ self.native.SetOptions(FileOpenOptions.FOS_ALLOWMULTISELECT)
 
- # Provided as a stub that can be mocked in test conditions
  def selected_paths(self):
- return self.native.FileNames
-
- def _get_filenames(self):
- if self.native.Multiselect:
- return [Path(filename) for filename in self.selected_paths()]
- else:
- return Path(self.native.FileName)
+ # This is a stub method; we provide functionality using the COM API
+ return self._get_filenames()
+
+ def _get_filenames(self) -> List[Path]:
+ assert isinstance(self.native, IFileOpenDialog)
+ results: List[Path] = []
+ shell_item_array: IShellItemArray = self.native.GetResults()
+ item_count: int = shell_item_array.GetCount()
+ for i in range(item_count):
+ shell_item: IShellItem = shell_item_array.GetItemAt(i)
+ szFilePath: str = str(
+ shell_item.GetDisplayName(0x80058000)
+ ) # SIGDN_FILESYSPATH
+ results.append(Path(szFilePath))
+ return results
 
 
 class SelectFolderDialog(FileDialog):
- def __init__(self, title, initial_directory, multiple_select):
+ def __init__(
+ self,
+ title: str,
+ initial_directory: Union[os.PathLike, str],
+ multiple_select: bool,
+ ):
  super().__init__(
- WinForms.FolderBrowserDialog(),
+ comtypes.client.CreateObject(
+ CLSID_FileOpenDialog,
+ interface=IFileOpenDialog,
+ ),
  title,
  initial_directory,
  )
+ self.native.SetOptions(FileOpenOptions.FOS_PICKFOLDERS)
+ self.multiple_select: bool = multiple_select
 
- # The native dialog doesn't support multiple selection, so the only effect
- # this has is to change whether we return a list.
- self.multiple_select = multiple_select
-
- def _get_filenames(self):
- filename = Path(self.native.SelectedPath)
- return [filename] if self.multiple_select else filename
+ def _get_filenames(self) -> Union[List[Path], Path]:
+ shell_item: IShellItem = self.native.GetResult()
+ display_name: str = shell_item.GetDisplayName(0x80058000) # SIGDN_FILESYSPATH
+ return [Path(display_name)] if self.multiple_select else Path(display_name)
 
  def _set_title(self, title):
- self.native.Description = title
+ self.native.SetTitle(title)
 
  def _set_initial_directory(self, initial_directory):
- self.native.SelectedPath = initial_directory
+ if initial_directory is None:
+ return
+ folder_path: Path = Path(initial_directory).resolve()
+ if folder_path.is_dir(): # sourcery skip: extract-method
+ shell_item = POINTER(IShellItem)()
+ hr = windll.shell32.SHCreateItemFromParsingName(
+ str(folder_path),
+ None,
+ IShellItem._iid_,
+ byref(shell_item),
+ )
+ if hr == S_OK:
+ self.native.SetFolder(shell_item)

winforms/src/toga_winforms/libs/com/constants.py

@@ -0,0 +1,119 @@
+from __future__ import annotations
+
+from ctypes import Structure, c_int, c_ulong
+from ctypes.wintypes import LPCWSTR
+from enum import IntFlag
+from typing import TYPE_CHECKING, Sequence
+
+if TYPE_CHECKING:
+ from ctypes import _CData
+
+
+class FileOpenOptions(IntFlag):
+ FOS_UNKNOWN1 = 0x00000001
+ FOS_OVERWRITEPROMPT = 0x00000002
+ FOS_STRICTFILETYPES = 0x00000004
+ FOS_NOCHANGEDIR = 0x00000008
+ FOS_UNKNOWN2 = 0x00000010
+ FOS_PICKFOLDERS = 0x00000020
+ FOS_FORCEFILESYSTEM = 0x00000040
+ FOS_ALLNONSTORAGEITEMS = 0x00000080
+ FOS_NOVALIDATE = 0x00000100
+ FOS_ALLOWMULTISELECT = 0x00000200
+ FOS_UNKNOWN4 = 0x00000400
+ FOS_PATHMUSTEXIST = 0x00000800
+ FOS_FILEMUSTEXIST = 0x00001000
+ FOS_CREATEPROMPT = 0x00002000
+ FOS_SHAREAWARE = 0x00004000
+ FOS_NOREADONLYRETURN = 0x00008000
+ FOS_NOTESTFILECREATE = 0x00010000
+ FOS_HIDEMRUPLACES = 0x00020000
+ FOS_HIDEPINNEDPLACES = 0x00040000
+ FOS_UNKNOWN5 = 0x00080000
+ FOS_NODEREFERENCELINKS = 0x00100000
+ FOS_UNKNOWN6 = 0x00200000
+ FOS_UNKNOWN7 = 0x00400000
+ FOS_UNKNOWN8 = 0x00800000
+ FOS_UNKNOWN9 = 0x01000000
+ FOS_DONTADDTORECENT = 0x02000000
+ FOS_UNKNOWN10 = 0x04000000
+ FOS_UNKNOWN11 = 0x08000000
+ FOS_FORCESHOWHIDDEN = 0x10000000
+ FOS_DEFAULTNOMINIMODE = 0x20000000
+ FOS_FORCEPREVIEWPANEON = 0x40000000
+ FOS_UNKNOWN12 = 0x80000000
+
+
+# Shell Folder Get Attributes Options
+SFGAOF = c_ulong
+
+
+class SFGAO(IntFlag):
+ SFGAO_CANCOPY = 0x00000001 # Objects can be copied.
+ SFGAO_CANMOVE = 0x00000002 # Objects can be moved.
+ SFGAO_CANLINK = 0x00000004 # Objects can be linked.
+ SFGAO_STORAGE = 0x00000008 # Objects can be stored.
+ SFGAO_CANRENAME = 0x00000010 # Objects can be renamed.
+ SFGAO_CANDELETE = 0x00000020 # Objects can be deleted.
+ SFGAO_HASPROPSHEET = 0x00000040 # Objects have property sheets.
+ SFGAO_DROPTARGET = 0x00000100 # Objects are drop targets.
+ SFGAO_CAPABILITYMASK = 0x00000177 # Mask for all capability flags.
+ SFGAO_ENCRYPTED = 0x00002000 # Object is encrypted (use alt color).
+ SFGAO_ISSLOW = 0x00004000 # Accessing this object is slow.
+ SFGAO_GHOSTED = 0x00008000 # Object is ghosted (dimmed).
+ SFGAO_LINK = 0x00010000 # Shortcut (link).
+ SFGAO_SHARE = 0x00020000 # Shared.
+ SFGAO_READONLY = 0x00040000 # Read-only.
+ SFGAO_HIDDEN = 0x00080000 # Hidden object.
+ SFGAO_DISPLAYATTRMASK = 0x000FC000 # Mask for display attributes.
+ SFGAO_FILESYSANCESTOR = 0x10000000 # May contain children with file system folders.
+ SFGAO_FOLDER = 0x20000000 # Is a folder.
+ SFGAO_FILESYSTEM = 0x40000000 # Is part of the file system.
+ SFGAO_HASSUBFOLDER = 0x80000000 # May contain subfolders.
+ SFGAO_CONTENTSMASK = 0x80000000 # Mask for contents.
+ SFGAO_VALIDATE = 0x01000000 # Invalidate cached information.
+ SFGAO_REMOVABLE = 0x02000000 # Is a removable media.
+ SFGAO_COMPRESSED = 0x04000000 # Object is compressed.
+ SFGAO_BROWSABLE = 0x08000000 # Supports browsing.
+ SFGAO_NONENUMERATED = 0x00100000 # Is not enumerated.
+ SFGAO_NEWCONTENT = 0x00200000 # New content is present.
+ SFGAO_CANMONIKER = 0x00400000 # Can create monikers for this item.
+ SFGAO_HASSTORAGE = 0x00400000 # Supports storage interfaces.
+ SFGAO_STREAM = 0x00400000 # Is a stream object.
+ SFGAO_STORAGEANCESTOR = 0x00800000 # May contain children with storage folders.
+ SFGAO_STORAGECAPMASK = 0x70C50008 # Mask for storage capability attributes.
+ SFGAO_PKEYSFGAOMASK = (
+ 0x81044000 # Attributes that are part of the PKEY_SFGAOFlags property.
+ )
+
+
+class SIGDN(c_int):
+ SIGDN_NORMALDISPLAY = 0x00000000
+ SIGDN_PARENTRELATIVEPARSING = 0x80018001
+ SIGDN_PARENTRELATIVEFORADDRESSBAR = 0x8001C001
+ SIGDN_DESKTOPABSOLUTEPARSING = 0x80028000
+ SIGDN_PARENTRELATIVEEDITING = 0x80031001
+ SIGDN_DESKTOPABSOLUTEEDITING = 0x8004C000
+ SIGDN_FILESYSPATH = 0x80058000
+ SIGDN_URL = 0x80068000
+
+
+class FDAP(c_int):
+ FDAP_BOTTOM = 0x00000000
+ FDAP_TOP = 0x00000001
+
+
+class FDE_SHAREVIOLATION_RESPONSE(c_int): # noqa: N801
+ FDESVR_DEFAULT = 0x00000000
+ FDESVR_ACCEPT = 0x00000001
+ FDESVR_REFUSE = 0x00000002
+
+
+FDE_OVERWRITE_RESPONSE = FDE_SHAREVIOLATION_RESPONSE
+
+
+class COMDLG_FILTERSPEC(Structure): # noqa: N801
+ _fields_: Sequence[tuple[str, type[_CData]] | tuple[str, type[_CData], int]] = [
+ ("pszName", LPCWSTR),
+ ("pszSpec", LPCWSTR),
+ ]