Tool System: optionally cycle tools in a group

Add the ability for key bindings to set a tool-group,
which cycles to the next tool when the tool is already active.

release/scripts/startup/bl_operators/wm.py

@@ -55,6 +55,15 @@ rna_relative_prop = BoolProperty(
         default=False,
         )
 
+rna_space_type_prop = EnumProperty(
+        name="Type",
+        items=tuple(
+            (e.identifier, e.name, "", e. value)
+            for e in bpy.types.Space.bl_rna.properties["type"].enum_items
+           ),
+        default='EMPTY',
+        )
+
 
 def context_path_validate(context, data_path):
     try:
@@ -2335,21 +2344,27 @@ class WM_OT_tool_set_by_name(Operator):
             name="Text",
             description="Display name of the tool",
             )
-    space_type = EnumProperty(
-            name="Type",
-            items=tuple(
-                (e.identifier, e.name, "", e. value)
-                for e in bpy.types.Space.bl_rna.properties["type"].enum_items
-            ),
-            default='EMPTY',
+
+    cycle = BoolProperty(
+            name="Cycle",
+            description="Cycle through tools in this group",
+            default=False,
+            options={'SKIP_SAVE'},
             )
 
+    space_type = rna_space_type_prop
+
     def execute(self, context):
-        from bl_ui.space_toolsystem_common import activate_by_name
+        from bl_ui.space_toolsystem_common import (
+            activate_by_name,
+            activate_by_name_or_cycle,
+        )
         space_type = self.space_type
         if space_type == 'EMPTY':
             space_type = context.space_data.type
-        if activate_by_name(context, space_type, self.name):
+
+        fn = activate_by_name_or_cycle if self.cycle else activate_by_name
+        if fn(context, space_type, self.name):
             return {'FINISHED'}
         else:
             self.report({'WARNING'}, f"Tool {self.name!r} not found.")

release/scripts/startup/bl_ui/space_toolsystem_common.py

@@ -262,8 +262,8 @@ class ToolSelectPanelHelper:
             for item, index in ToolSelectPanelHelper._tools_flatten_with_tool_index(cls.tools_from_context(context)):
                 if item is not None:
                     if item.text == text:
-                        return (item, index)
-        return None, -1
+                        return (cls, item, index)
+        return None, None, -1
 
     @staticmethod
     def _tool_active_from_context(context, space_type, mode=None, create=False):
@@ -564,20 +564,60 @@ class WM_MT_toolsystem_submenu(Menu):
             ).name = item.text
 
 
+def _activate_by_item(context, space_type, item, index):
+    tool = ToolSelectPanelHelper._tool_active_from_context(context, space_type, create=True)
+    tool.setup(
+        name=item.text,
+        keymap=item.keymap[0].name if item.keymap is not None else "",
+        cursor=item.cursor or 'DEFAULT',
+        manipulator_group=item.widget or "",
+        data_block=item.data_block or "",
+        index=index,
+    )
+
+
 def activate_by_name(context, space_type, text):
-    item, index = ToolSelectPanelHelper._tool_get_by_name(context, space_type, text)
-    if item is not None:
-        tool = ToolSelectPanelHelper._tool_active_from_context(context, space_type, create=True)
-        tool.setup(
-            name=text,
-            keymap=item.keymap[0].name if item.keymap is not None else "",
-            cursor=item.cursor or 'DEFAULT',
-            manipulator_group=item.widget or "",
-            data_block=item.data_block or "",
-            index=index,
-        )
-        return True
-    return False
+    cls, item, index = ToolSelectPanelHelper._tool_get_by_name(context, space_type, text)
+    if item is None:
+        return False
+    _activate_by_item(context, space_type, item, index)
+    return True
+
+
+def activate_by_name_or_cycle(context, space_type, text, offset=1):
+
+    # Only cycle when the active tool is activated again.
+    cls, item, index = ToolSelectPanelHelper._tool_get_by_name(context, space_type, text)
+    if item is None:
+        return False
+
+    tool_active = ToolSelectPanelHelper._tool_active_from_context(context, space_type)
+    text_active = getattr(tool_active, "name", None)
+
+    text_current = ""
+    for item_group in cls.tools_from_context(context):
+        if type(item_group) is tuple:
+            index_current = cls._tool_group_active.get(item_group[0].text, 0)
+            ok = False
+            for i, sub_item in enumerate(item_group):
+                if sub_item.text == text:
+                    text_current = item_group[index_current].text
+                    break
+            if text_current:
+                break
+
+    if text_current == "":
+        return activate_by_name(context, space_type, text)
+    if text_active != text_current:
+        return activate_by_name(context, space_type, text_current)
+
+    index_found = (tool_active.index + offset) % len(item_group)
+
+    cls._tool_group_active[item_group[0].text] = index_found
+
+    item_found = item_group[index_found]
+    _activate_by_item(context, space_type, item_found, index_found)
+    return True
 
 
 def keymap_from_context(context, space_type):