2249: Create a global stylesheet and allow user-built themes

src/sas/qtgui/MainWindow/MainWindow.py

@@ -5,7 +5,7 @@
 import sys
 
 from sas import config
-from sas.system import env, version
+from sas.system import env, version, style
 
 from PyQt5.QtWidgets import QMainWindow
 from PyQt5.QtWidgets import QMdiArea
@@ -98,7 +98,7 @@ def run_sasview():
     splash.show()
     app.setAttribute(Qt.AA_EnableHighDpiScaling)
     # Main application style.
-    #app.setStyle('Fusion')
+    app.setStyleSheet(style.style_sheet())
 
     # fix for pyinstaller packages app to avoid ReactorAlreadyInstalledError
     if 'twisted.internet.reactor' in sys.modules:

src/sas/system/__init__.py

@@ -3,4 +3,4 @@
 from .env import env
 from .config.config import config
 
-__all__ = ["web", "legal", "env", "config"]
+__all__ = ["web", "legal", "env", "config", "style"]

src/sas/system/sasview.css

@@ -0,0 +1,6 @@
+* {font-size: 10pt;}
+
+QLineEdit {background-color: white; color: black;}
+QLineEdit:focus {background-color: #98dbcc; color: #333333}
+
+.warning {background-color: red;}

src/sas/system/style.py

@@ -0,0 +1,73 @@
+import os
+import pkg_resources
+import sys
+
+from sas.system import user
+
+DEFAULT_STYLE_SHEET_NAME = 'sasview.css'
+
+
+class StyleSheet:
+    """
+    The directory where the per-user style sheet is stored.
+
+    Returns ~/.sasview/sasview.css, creating it if it does not already exist.
+    """
+    def __init__(self):
+        self.style_sheet = None
+        self._find_style_sheet()
+        self.save()
+
+    def style_sheet_filename(self):
+        """Filename for saving config items"""
+        user_dir = user.get_user_dir()
+        self.style_sheet = os.path.join(user_dir, DEFAULT_STYLE_SHEET_NAME)
+
+    def save(self):
+        self._find_style_sheet()
+        sheet = self()
+        self.style_sheet_filename()
+        with open(self.style_sheet, 'a') as file:
+            file.write(sheet)
+
+    def _find_style_sheet(self, filename=DEFAULT_STYLE_SHEET_NAME):
+        '''
+        The style sheet is in:
+        User directory ~/.sasview/
+        Debug .
+        Packaging: sas/sasview/
+        Packaging / production does not work well with absolute paths
+        thus the multiple paths below
+        '''
+        self.style_sheet_filename()
+        places_to_look_for_conf_file = [
+            self.style_sheet,
+            os.path.join(os.path.abspath(os.path.dirname(__file__)), filename),
+            filename,
+            os.path.join("sas", "system", filename),
+            os.path.join(os.getcwd(), "sas", "system", filename),
+            os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])), filename)  #For OSX app
+        ]
+
+        # To avoid the exception in OSx
+        # NotImplementedError: resource_filename() only supported for .egg, not .zip
+        try:
+            places_to_look_for_conf_file.append(
+                pkg_resources.resource_filename(__name__, filename))
+        except NotImplementedError:
+            pass
+
+        for filepath in places_to_look_for_conf_file:
+            if os.path.exists(filepath):
+                self.style_sheet = filepath
+                return
+        print(f"'{filename}' not found.", file=sys.stderr)
+        self.style_sheet = None
+
+    def __call__(self, *args, **kwargs):
+        with open(self.style_sheet) as f:
+            style = f.read()
+        return style
+
+
+style_sheet = StyleSheet()