Remember most recently selected filetype in Render dialog

Some users prefer to always render their files as .mkv or another
filetype. This commit changes corrscope's render dialog to remember the
most recently selected filetype, and default to it on next render.

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Implement split stereo bar colors (#491)
 - Add "Reload Font List" menu item to fix missing fonts (#492)
+- Remember most recently selected filetype in Render dialog (#493)
 
 ### Major Changes
 

corrscope/cli.py

@@ -36,9 +36,6 @@ YAML_EXTS = [".yaml"]
 # Default extension when writing Config.
 YAML_NAME = YAML_EXTS[0]
 
-# Default output extension, only used in GUI and unit tests
-VIDEO_NAME = ".mp4"
-
 
 DEFAULT_NAME = corrscope.app_name
 

corrscope/gui/__init__.py

@@ -566,17 +566,20 @@ class MainWindow(qw.QMainWindow, Ui_MainWindow):
         cfg_filename = self.get_save_filename(cli.YAML_NAME)
 
         # Folder is obtained from self.pref.file_dir_ref.
-        filters = ["YAML files (*.yaml)", "All files (*)"]
-        path = get_save_file_path(
+        extensions = {
+            ".yaml": "YAML files (*.yaml)",
+            None: "All files (*)",
+        }
+        save_name = get_save_file_path(
             self,
             "Save As",
             self.pref.file_dir_ref,
             cfg_filename,
-            filters,
+            extensions,
             cli.YAML_NAME,
         )
-        if path:
-            self._cfg_path = path
+        if save_name:
+            self._cfg_path = Path(save_name.name)
             self.load_title()
             self.on_action_save()
             return True
@@ -618,30 +621,34 @@ class MainWindow(qw.QMainWindow, Ui_MainWindow):
                 return
 
         # Name and extension (no folder).
-        video_filename = self.get_save_filename(cli.VIDEO_NAME)
-        filters = [
-            "MP4 files (*.mp4)",
-            "Matroska files (*.mkv)",
-            "WebM files (*.webm)",
-            "All files (*)",
-        ]
+
+        video_stem = cli.get_file_stem(self._cfg_path, self.cfg, default="")
 
         # Points to either `file_dir` or `render_dir`.
         # Folder is obtained from `dir_ref`.
         dir_ref = self.pref.render_dir_ref
 
-        path = get_save_file_path(
-            self, "Render to Video", dir_ref, video_filename, filters, cli.VIDEO_NAME
+        suffix = self.pref.render_ext
+        extensions = {
+            ".mp4": "MP4 files (*.mp4)",
+            ".mkv": "Matroska files (*.mkv)",
+            ".webm": "WebM files (*.webm)",
+            None: "All files (*)",
+        }
+        assert gp.VIDEO_NAME in extensions
+        save_name = get_save_file_path(
+            self, "Render to Video", dir_ref, video_stem, extensions, suffix
         )
-        if path:
-            name = str(path)
+        if save_name:
+            self.pref.render_ext = save_name.suffix
+
             dlg = CorrProgressDialog(self, "Rendering video")
 
             # FFmpegOutputConfig contains only hashable/immutable strs,
             # so get_ffmpeg_cfg() can be shared across threads without copying.
             # Optionally copy_config() first.
 
-            outputs = [self.cfg.get_ffmpeg_cfg(name)]
+            outputs = [self.cfg.get_ffmpeg_cfg(save_name.name)]
             self.play_thread(outputs, PreviewOrRender.render, dlg)
 
     def play_thread(

corrscope/gui/history_file_dlg.py

@@ -11,21 +11,17 @@ Name = str
 Filter = str
 
 
-@attr.dataclass
-class FileName:
-    file_name: Optional[str]
-    file_list: Optional[List[str]]
-    sel_filter: str
+T = TypeVar("T")
 
 
 def _get_hist_name(
-    func: Callable[..., Tuple[str, str]],
+    func: Callable[..., Tuple[T, str]],
     parent: qw.QWidget,
     title: str,
     history_dir: _gp.Ref[_gp.GlobalPrefs],
     default_name: Optional[str],
     filters: List[str],
-) -> Optional[FileName]:
+) -> Optional[T]:
     """
     Get file name.
     Default folder is history folder, and `default_name`.folder is discarded.
@@ -48,14 +44,12 @@ def _get_hist_name(
     if isinstance(name, list):
         assert func == qw.QFileDialog.getOpenFileNames
         dir = os.path.dirname(name[0])
-        history_dir.set(dir)
-        return FileName(None, name, sel_filter)
-
     else:
         assert isinstance(name, str)
         dir = os.path.dirname(name)
-        history_dir.set(dir)
-        return FileName(name, None, sel_filter)
+
+    history_dir.set(dir)
+    return name
 
 
 def get_open_file_name(
@@ -68,8 +62,8 @@ def get_open_file_name(
         qw.QFileDialog.getOpenFileName, parent, title, history_dir, None, filters
     )
     if name:
-        assert name.file_name is not None
-        return name.file_name
+        assert isinstance(name, str)
+        return name
     return None
 
 
@@ -83,35 +77,91 @@ def get_open_file_list(
         qw.QFileDialog.getOpenFileNames, parent, title, history_dir, None, filters
     )
     if name:
-        assert name.file_list is not None
-        return name.file_list
+        assert isinstance(name, list)
+        return name
     return None
 
 
-# Returns Path for legacy reasons. Others return str.
+@attr.dataclass
+class KeyFilter:
+    key: Optional[str]
+    filter: str
+
+
+@attr.dataclass
+class SaveName:
+    name: str
+
+    # Used to key into get_save_file_path(filters).
+    suffix: Optional[str]
+
+
 def get_save_file_path(
     parent: qw.QWidget,
     title: str,
     history_dir: _gp.Ref[_gp.GlobalPrefs],
-    default_name: str,
-    filters: List[str],
-    default_suffix: str,
-) -> Optional[Path]:
-    name = _get_hist_name(
-        qw.QFileDialog.getSaveFileName,
-        parent,
-        title,
-        history_dir,
-        default_name,
-        filters,
+    initial_stem: str,
+    filters: Dict[Optional[str], str],
+    suffix: Optional[str],
+) -> Optional[SaveName]:
+    """
+    Given a working directory and initial filename, request and return a filename to
+    save a file.
+
+    This function takes multiple filetypes, an initial filetype (by string
+    extension), and additionally returns the filetype the user selected.
+    """
+
+    init_filter = filters.get(suffix, None)
+    # If unsupported save extension (newer version?), use default extension.
+    if not init_filter:
+        suffix, init_filter = next(iter(filters.items()))
+
+    # Get initial directory for the dialog.
+    init_path: str = history_dir.get()
+
+    # Get initial filename if present.
+    if initial_stem:
+        init_path = os.path.join(init_path, os.path.basename(initial_stem))
+        # Append file extension.
+        if suffix:
+            init_path += suffix
+
+    # Get filename from dialog.
+    filter_str = ";;".join(filters.values())
+    out_name, sel_filter = qw.QFileDialog.getSaveFileName(
+        parent, title, init_path, filter_str, init_filter
     )
-    if name:
-        assert name.file_name is not None
-        path = Path(name.file_name)
-
-        if name.sel_filter == filters[0] and path.suffix == "":
-            path = path.with_suffix(default_suffix)
-
-        return path
-    else:
+    if not out_name:
         return None
+
+    for suffix, filter in filters.items():
+        if filter == sel_filter:
+            out_suffix = suffix
+            break
+    else:
+        # getSaveFileName() will always return a filter from the list (with whitespace collapsed,
+        # https://github.com/qt/qtbase/blob/ec011141b8d17a2edc58e0d5b6ebb0f1632fff90/src/widgets/dialogs/qfiledialog.cpp#L1415).
+        # This block is only reachable if the returned filter is not in `filter_str` passed in.
+        # This indicates a bug in the caller (incorrect whitespace in filters.values()).
+        raise RuntimeError(
+            f"unrecognized file filter {repr(sel_filter)} in {list(filters.values())}"
+        )
+
+    user_suffix = Path(out_name).suffix
+
+    # If user explicitly types a different extension, use it next time (even if they
+    # don't change the dropdown). This works on Windows and FIXME Linux? Mac?
+    # FIXME it seems confusing to pick a different default extension if you type but don't dropdown? IDK.
+    if user_suffix and user_suffix in filters:
+        out_suffix = user_suffix
+
+    # Append suffix if missing in user-specified name but present in dialog.
+    # getSaveFileName() does not automatically append a suffix on Linux KDE.
+    if user_suffix == "" and out_suffix:
+        out_name += out_suffix
+
+    # Update recently used dir.
+    dir = os.path.dirname(out_name)
+    history_dir.set(dir)
+    return SaveName(out_name, out_suffix)

corrscope/settings/global_prefs.py

@@ -6,6 +6,9 @@ from atomicwrites import atomic_write
 from corrscope.config import DumpableAttrs, yaml
 from corrscope.settings import paths
 
+# Default output extension.
+VIDEO_NAME = ".mp4"
+
 
 Attrs = TypeVar("Attrs", bound=DumpableAttrs)
 
@@ -40,6 +43,9 @@ class GlobalPrefs(DumpableAttrs, always_dump="*"):
     separate_render_dir: bool = False
     render_dir: str = ""  # Set to "" whenever separate_render_dir=False.
 
+    # Most recent video filetype, including period.
+    render_ext: Optional[str] = VIDEO_NAME
+
     @property
     def render_dir_ref(self) -> "Ref[GlobalPrefs]":
         if self.separate_render_dir: