Add a formatting function for file extension filters for file dialogs

novelwriter/common.py

@@ -41,7 +41,7 @@ from PyQt5.QtCore import QCoreApplication, QUrl
 
 from novelwriter.enum import nwItemClass, nwItemType, nwItemLayout
 from novelwriter.error import logException
-from novelwriter.constants import nwConst, nwUnicode
+from novelwriter.constants import nwConst, nwLabels, nwUnicode, trConst
 
 if TYPE_CHECKING:  # pragma: no cover
     from typing import TypeGuard  # Requires Python 3.10
@@ -248,6 +248,19 @@ def formatVersion(value: str) -> str:
     return value.lower().replace("a", " Alpha ").replace("b", " Beta ").replace("rc", " RC ")
 
 
+def formatFileFilter(extensions: list[str | tuple[str, str]]) -> str:
+    """Format a list of extensions, or extension + label pairs into a
+    QFileDialog extensions filter.
+    """
+    result = []
+    for ext in extensions:
+        if isinstance(ext, str):
+            result.append(f"{trConst(nwLabels.FILE_FILTERS.get(ext))} ({ext})")
+        elif isinstance(ext, tuple) and len(ext) == 2:
+            result.append(f"{ext[0]} ({ext[1]})")
+    return ";;".join(result)
+
+
 ##
 #  String Functions
 ##

novelwriter/constants.py

@@ -270,6 +270,12 @@ class nwLabels:
         nwBuildFmt.J_HTML: ".json",
         nwBuildFmt.J_NWD:  ".json",
     }
+    FILE_FILTERS = {
+        "*.txt": QT_TRANSLATE_NOOP("Constant", "Text files"),
+        "*.md":  QT_TRANSLATE_NOOP("Constant", "Markdown files"),
+        "*.nwd": QT_TRANSLATE_NOOP("Constant", "novelWriter files"),
+        "*":     QT_TRANSLATE_NOOP("Constant", "All files"),
+    }
     UNIT_NAME = {
         "mm": QT_TRANSLATE_NOOP("Constant", "Millimetres"),
         "cm": QT_TRANSLATE_NOOP("Constant", "Centimetres"),

tests/test_base/test_base_common.py

@@ -34,11 +34,11 @@ from PyQt5.QtCore import QUrl
 
 from novelwriter.common import (
     checkBool, checkFloat, checkInt, checkIntTuple, checkPath, checkString,
-    checkStringNone, checkUuid, formatInt, formatTime, formatTimeStamp,
+    checkStringNone, checkUuid, formatFileFilter, formatInt, formatTime,
-    formatVersion, fuzzyTime, getFileSize, hexToInt, isHandle, isItemClass,
+    formatTimeStamp, formatVersion, fuzzyTime, getFileSize, hexToInt, isHandle,
-    isItemLayout, isItemType, isTitleTag, jsonEncode, makeFileNameSafe, minmax,
+    isItemClass, isItemLayout, isItemType, isTitleTag, jsonEncode,
-    numberToRoman, NWConfigParser, openExternalPath, readTextFile, simplified,
+    makeFileNameSafe, minmax, numberToRoman, NWConfigParser, openExternalPath,
-    transferCase, xmlIndent, yesNo
+    readTextFile, simplified, transferCase, xmlIndent, yesNo
 )
 
 
@@ -346,6 +346,18 @@ def testBaseCommon_formatVersion():
 # END Test testBaseCommon_formatVersion
 
 
+@pytest.mark.base
+def testBaseCommon_formatFileFilter():
+    """Test the formatFileFilter function."""
+    assert formatFileFilter(["*.txt"]) == "Text files (*.txt)"
+    assert formatFileFilter(["*.txt", "*"]) == "Text files (*.txt);;All files (*)"
+    assert formatFileFilter([("Stuff", "*.stuff"), "*.txt", "*"]) == (
+        "Stuff (*.stuff);;Text files (*.txt);;All files (*)"
+    )
+
+# END Test testBaseCommon_formatFileFilter
+
+
 @pytest.mark.base
 def testBaseCommon_simplified():
     """Test the simplified function."""