Filedialog widget for magicgui

examples/file_dialog.py

@@ -0,0 +1,17 @@
+"""FileDialog with magicgui."""
+from pathlib import Path
+from magicgui import event_loop, magicgui
+
+
+# may also add Qt-style filter to filename options:
+# e.g. {"filter": "Images (*.tif *.tiff)"}
+@magicgui(filename={"mode": "r"})
+def filepicker(filename=Path("~")):
+    """Take a filename and do something with it."""
+    print("The filename is:", filename)
+    return filename
+
+
+with event_loop():
+    gui = filepicker.Gui(show=True)
+    gui.filename_changed.connect(print)

magicgui/_qt.py

@@ -1,11 +1,24 @@
 # -*- coding: utf-8 -*-
 """Widgets and type-to-widget conversion for the Qt backend."""
 
+import os
 import sys
 from contextlib import contextmanager
 import datetime
 from enum import Enum, EnumMeta
-from typing import Any, Callable, Dict, Iterable, NamedTuple, Optional, Tuple, Type
+from pathlib import Path
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    NamedTuple,
+    Optional,
+    Tuple,
+    Type,
+    Union,
+)
 
 from qtpy.QtCore import Qt, Signal
 from qtpy.QtWidgets import (
@@ -17,6 +30,7 @@
     QComboBox,
     QDateTimeEdit,
     QDoubleSpinBox,
+    QFileDialog,
     QFormLayout,
     QGridLayout,
     QGroupBox,
@@ -153,13 +167,18 @@ def type2widget(type_: type) -> Optional[Type[WidgetType]]:
         int: QSpinBox,
         float: QDoubleSpinBox,
         str: QLineEdit,
+        Path: MagicFileDialog,
         datetime.datetime: QDateTimeEdit,
         type(None): QLineEdit,
     }
     if type_ in simple:
         return simple[type_]
     elif isinstance(type_, EnumMeta):
         return QDataComboBox
+    else:
+        for key in simple.keys():
+            if issubclass(type_, key):
+                return simple[key]
     return None
 
 
@@ -219,6 +238,10 @@ def getter():
         )
     elif isinstance(widget, QSplitter):
         return GetSetOnChange(widget.sizes, widget.setSizes, widget.splitterMoved)
+    elif isinstance(widget, MagicFileDialog):
+        return GetSetOnChange(
+            widget.get_path, widget.set_path, widget.line_edit.textChanged
+        )
     raise ValueError(f"Unrecognized widget Type: {widget}")
 
 
@@ -286,6 +309,11 @@ def make_widget(
         if setter:
             setter(val)
 
+    if isinstance(widget, MagicFileDialog):
+        if "mode" in kwargs:
+            widget.mode = kwargs["mode"]
+        if "filter" in kwargs:
+            widget.filter = kwargs["filter"]
     return widget
 
 
@@ -312,3 +340,106 @@ def setValue(self, value):
     def setMaximum(self, value):
         """Set maximum position of slider in float units."""
         super().setMaximum(value * self.PRECISION)
+
+
+class FileDialogMode(Enum):
+    """FileDialog mode options.
+
+    EXISTING_FILE - returns one existing file.
+    EXISTING_FILES - return one or more existing files.
+    OPTIONAL_FILE - return one file name that does not have to exist.
+    EXISTING_DIRECTORY - returns one existing directory.
+    R - read mode, returns one or more existing files.
+        Alias of EXISTING_FILES.
+    W - write mode, returns one file name that does not have to exist.
+        Alias of OPTIONAL_FILE.
+    """
+
+    EXISTING_FILE = "getOpenFileName"
+    EXISTING_FILES = "getOpenFileNames"
+    OPTIONAL_FILE = "getSaveFileName"
+    EXISTING_DIRECTORY = "getExistingDirectory"
+    # Aliases
+    R = "getOpenFileNames"
+    W = "getSaveFileName"
+
+
+class MagicFileDialog(QWidget):
+    """A LineEdit widget with a QFileDialog button."""
+
+    def __init__(
+        self,
+        parent=None,
+        mode: Union[FileDialogMode, str] = FileDialogMode.OPTIONAL_FILE,
+        filter: str = "",
+    ):
+        super().__init__(parent)
+        self.line_edit = QLineEdit(self)
+        self.choose_btn = QPushButton("Choose file", self)
+        self.choose_btn.clicked.connect(self._on_choose_clicked)
+        self.mode = mode
+        self.filter: str = filter
+        layout = QHBoxLayout(self)
+        layout.addWidget(self.line_edit)
+        layout.addWidget(self.choose_btn)
+
+    def _help_text(self):
+        if self.mode is FileDialogMode.EXISTING_DIRECTORY:
+            return "Choose directory"
+        else:
+            return "Select file" + ("s" if self.mode.name.endswith("S") else "")
+
+    @property
+    def mode(self):
+        """Mode for the FileDialog."""
+        return self._mode
+
+    @mode.setter
+    def mode(self, value: Union[FileDialogMode, str]):
+        mode: Union[FileDialogMode, str] = value
+        if isinstance(value, str):
+            try:
+                mode = FileDialogMode(value)
+            except ValueError:
+                try:
+                    mode = FileDialogMode[value.upper()]
+                except KeyError:
+                    pass
+        if not isinstance(mode, FileDialogMode):
+            raise ValueError(
+                f"{mode!r} is not a valid FileDialogMode. "
+                f"Options include {set(i.name.lower() for i in FileDialogMode)}"
+            )
+        self._mode = mode
+        self.choose_btn.setText(self._help_text())
+
+    def _on_choose_clicked(self):
+        show_dialog = getattr(QFileDialog, self.mode.value)
+        start_path = self.get_path()
+        if isinstance(start_path, tuple):
+            start_path = start_path[0]
+        start_path = os.fspath(os.path.abspath(os.path.expanduser(start_path)))
+        caption = self._help_text()
+        if self.mode is FileDialogMode.EXISTING_DIRECTORY:
+            result = show_dialog(self, caption, start_path)
+        else:
+            result, _ = show_dialog(self, caption, start_path, self.filter)
+        if result:
+            self.set_path(result)
+
+    def get_path(self) -> Union[Tuple[Path, ...], Path]:
+        """Get current file path."""
+        text = self.line_edit.text()
+        if self.mode is FileDialogMode.EXISTING_FILES:
+            return tuple(Path(p) for p in text.split(", "))
+        return Path(text)
+
+    def set_path(self, value: Union[List[str], Tuple[str, ...], str, Path]):
+        """Set current file path."""
+        if isinstance(value, (list, tuple)):
+            value = ", ".join([os.fspath(p) for p in value])
+        if not isinstance(value, (str, Path)):
+            raise TypeError(
+                f"value must be a string, or list/tuple of strings, got {type(value)}"
+            )
+        self.line_edit.setText(str(value))

magicgui/_tests/test_ qt.py

@@ -2,8 +2,9 @@
 
 """Tests for `magicgui._qt` module."""
 
-from enum import Enum
 import datetime
+from enum import Enum
+from pathlib import Path, PosixPath, WindowsPath
 
 import pytest
 from qtpy import QtCore
@@ -40,6 +41,7 @@ def test_event():
         QtW.QSplitter,
         QtW.QSlider,
         _qt.QDoubleSlider,
+        _qt.MagicFileDialog,
     ],
 )
 def test_get_set_change(qtbot, WidgetClass):
@@ -76,6 +78,15 @@ def test_setters(qtbot):
     assert w.maximum() == 10
 
 
+def test_make_widget_magicfiledialog(qtbot):
+    """Test MagicFileDialog creation with kwargs 'mode' and 'filter'."""
+    w = _qt.make_widget(_qt.MagicFileDialog, "magicfiledialog",
+                        mode="r",
+                        filter="Images (*.tif *.tiff)")
+    assert w.mode == _qt.FileDialogMode.EXISTING_FILES
+    assert w.filter == "Images (*.tif *.tiff)"
+
+
 def test_datetimeedit(qtbot):
     """Test the datetime getter."""
     getter, setter, onchange = _qt.getter_setter_onchange(QtW.QDateTimeEdit())
@@ -90,3 +101,66 @@ def test_set_categorical(qtbot):
     assert [w.itemText(i) for i in range(w.count())] == ["a", "b"]
     _qt.set_categorical_choices(w, (("a", 1), ("c", 3)))
     assert [w.itemText(i) for i in range(w.count())] == ["a", "c"]
+
+
+def test_magicfiledialog(qtbot):
+    """Test the MagicFileDialog class."""
+    filewidget = _qt.MagicFileDialog()
+
+    # check default values
+    assert filewidget.get_path() == Path('.')
+    assert filewidget.mode == _qt.FileDialogMode.OPTIONAL_FILE
+
+    # set the mode
+    filewidget.mode = _qt.FileDialogMode.EXISTING_FILES  # Enum input
+    assert filewidget.mode == _qt.FileDialogMode.EXISTING_FILES
+    filewidget.mode = "oPtioNal_FiLe"  # improper capitalization
+    assert filewidget.mode == _qt.FileDialogMode.OPTIONAL_FILE
+    filewidget.mode = "EXISTING_DIRECTORY"  # string input
+    assert filewidget.mode == _qt.FileDialogMode.EXISTING_DIRECTORY
+    with pytest.raises(ValueError):
+        filewidget.mode = 123  # invalid mode
+        filewidget.mode = 'invalid_string'
+
+    # set the path
+    filewidget.set_path('my/example/path/')
+    assert filewidget.get_path() == Path('my/example/path/')
+
+    filewidget.mode = _qt.FileDialogMode.EXISTING_FILES
+    filewidget.set_path(['path/one.txt', 'path/two.txt'])
+    assert filewidget.get_path() == (Path('path/one.txt'), Path('path/two.txt'))
+    filewidget.set_path(['path/3.txt, path/4.txt'])
+    assert filewidget.get_path() == (Path('path/3.txt'), Path('path/4.txt'))
+
+    with pytest.raises(TypeError):
+        filewidget.set_path(123)  # invalid type, only str/Path accepted
+
+
+@pytest.mark.skipif("sys.platform == 'darwin'")  # dialog box hangs on Mac
+@pytest.mark.parametrize("mode", [
+    ('r'),  # existing file
+    ('EXISTING_DIRECTORY'),
+])
+def test_magicfiledialog_opens_chooser(qtbot, mode):
+    """Test the choose button opens a popup file dialog."""
+    filewidget = _qt.MagicFileDialog()
+    filewidget.set_path(('.',))  # set_path with tuple for better code coverage
+    filewidget.mode = mode
+
+    def handle_dialog():
+        popup_filedialog = next(
+            child
+            for child in filewidget.children()
+            if isinstance(child, QtW.QFileDialog)
+        )
+        assert isinstance(popup_filedialog, QtW.QFileDialog)
+        popup_filedialog.reject()
+
+    QtCore.QTimer().singleShot(400, handle_dialog)
+    filewidget._on_choose_clicked()
+
+
+@pytest.mark.parametrize("pathtype", [PosixPath, WindowsPath, Path])
+def test_linux_mac_magifiledialog(pathtype):
+    """Test we get a MagicFileDialog from a various Path types."""
+    assert _qt.type2widget(pathtype) == _qt.MagicFileDialog