Refactor extract parts of new_group module that need to be usable without wx

Author: davidfstr

src/crystal/browser/new_group.py

@@ -1,6 +1,7 @@
 # TODO: Consider extracting functions shared between dialogs to own module
 from collections.abc import Callable
 from crystal.browser.entitytree import ResourceGroupNode, RootResourceNode
+from crystal.browser.new_group_info import NewGroupDialogInfo
 from crystal.browser.new_root_url import (
     fields_hide_hint_when_focused, NewRootUrlDialog,
 )
@@ -32,7 +33,7 @@
 
 class NewGroupDialog:
     _INITIAL_URL_PATTERN_WIDTH = NewRootUrlDialog._INITIAL_URL_WIDTH
-    _MAX_VISIBLE_PREVIEW_URLS = 100
+    _MAX_VISIBLE_PREVIEW_URLS = NewGroupDialogInfo._MAX_VISIBLE_PREVIEW_URLS
 
     # === Init ===
 
@@ -458,30 +459,7 @@ def _update_preview_urls(self) -> None:
 
     @classmethod
     def _calculate_preview_urls(cls, project: Project, url_pattern: str) -> list[str]:
-        url_pattern_re = ResourceGroup.create_re_for_url_pattern(url_pattern)
-        literal_prefix = ResourceGroup.literal_prefix_for_url_pattern(url_pattern)
-        
-        url_pattern_is_literal = (len(literal_prefix) == len(url_pattern))
-        if url_pattern_is_literal:
-            member = project.get_resource(literal_prefix)
-            if member is None:
-                (matching_urls, approx_match_count) = ([], 0)
-            else:
-                (matching_urls, approx_match_count) = ([member.url], 1)
-        else:
-            (matching_urls, approx_match_count) = project.urls_matching_pattern(
-                url_pattern_re, literal_prefix, limit=cls._MAX_VISIBLE_PREVIEW_URLS)
-        
-        if len(matching_urls) == 0:
-            return []
-        else:
-            more_count = approx_match_count - len(matching_urls)
-            more_items = (
-                [f'... about {more_count:n} more']
-                if more_count != 0
-                else []
-            )
-            return matching_urls + more_items
+        return NewGroupDialogInfo._calculate_preview_urls(project, url_pattern)
 
     # === Events ===
 

src/crystal/browser/new_group_info.py

@@ -0,0 +1,39 @@
+"""
+Data and algorithms extracted from the "new_group" module that must be
+usable even if wx is not available.
+"""
+
+from crystal.model import Project, ResourceGroup
+
+
+class NewGroupDialogInfo:
+    _MAX_VISIBLE_PREVIEW_URLS = 100
+    
+    # === Operations ===
+    
+    @classmethod
+    def _calculate_preview_urls(cls, project: Project, url_pattern: str) -> list[str]:
+        url_pattern_re = ResourceGroup.create_re_for_url_pattern(url_pattern)
+        literal_prefix = ResourceGroup.literal_prefix_for_url_pattern(url_pattern)
+        
+        url_pattern_is_literal = (len(literal_prefix) == len(url_pattern))
+        if url_pattern_is_literal:
+            member = project.get_resource(literal_prefix)
+            if member is None:
+                (matching_urls, approx_match_count) = ([], 0)
+            else:
+                (matching_urls, approx_match_count) = ([member.url], 1)
+        else:
+            (matching_urls, approx_match_count) = project.urls_matching_pattern(
+                url_pattern_re, literal_prefix, limit=cls._MAX_VISIBLE_PREVIEW_URLS)
+        
+        if len(matching_urls) == 0:
+            return []
+        else:
+            more_count = approx_match_count - len(matching_urls)
+            more_items = (
+                [f'... about {more_count:n} more']
+                if more_count != 0
+                else []
+            )
+            return matching_urls + more_items