parser: add support for warps and and no selection

when using preferences template, without_selection can be used to alert the user; if False, a toast notification will be displayed preventing the navigation.

warps can be used to run a command given a condition from another step; only supported by without_selection in the preferences template

recipe.json

@@ -14,6 +14,20 @@
             "icon": "vanilla-package-symbolic",
             "title": "Package Manager",
             "description": "Choose one or more package managers to install",
+            "without_selection": {
+                "allowed": true,
+                "message": "You have chosen not to install any package manager, you will only be able to install packages using apx.\n\nGNOME Software will be disabled if you choose to enable the immutability feature later.",
+                "title": "No package manager selected",
+                "final": [
+                    {
+                        "if": "warp::immutability",
+                        "type": "command",
+                        "commands": [
+                            "sudo apt remove -y gnome-software"
+                        ]
+                    }
+                ]
+            },
             "preferences": [
                 {
                     "id": "flatpak",

vanilla_first_setup/gtk/window.ui

@@ -29,6 +29,8 @@
             </child>
           </object>
         </child>
+        <child>
+          <object class="AdwToastOverlay" id="toasts">
             <child>
               <object class="AdwCarousel" id="carousel">
                 <property name="vexpand">True</property>
@@ -40,5 +42,7 @@
             </child>
           </object>
         </child>
+      </object>
+    </child>
   </template>
 </interface>

vanilla_first_setup/layouts/preferences.py

@@ -18,6 +18,7 @@ import time
 from gi.repository import Gtk, Gio, GLib, Adw
 
 from vanilla_first_setup.utils.run_async import RunAsync
+from vanilla_first_setup.dialog import VanillaDialog
 
 
 @Gtk.Template(resource_path='/io/github/vanilla-os/FirstSetup/gtk/layout-preferences.ui')
@@ -38,7 +39,7 @@ class VanillaLayoutPreferences(Adw.Bin):
         self.__build_ui()
 
         # signals
-        self.btn_next.connect("clicked", self.__window.next)
+        self.btn_next.connect("clicked", self.__next_step)
 
     def __build_ui(self):
         self.status_page.set_icon_name(self.__step["icon"])
@@ -59,10 +60,34 @@ class VanillaLayoutPreferences(Adw.Bin):
 
             self.__register_widgets.append((item["id"], _switcher))
             
+    def __next_step(self, widget):
+        ws = self.__step.get("without_selection", {})
+
+        if not any([x[1].get_active() for x in self.__register_widgets]):
+            if not ws.get("allowed", True):
+                self.__window.toast("Please select at least one option.")
+                return
+
+            if ws.get("message", None):
+                dialog = VanillaDialog(
+                    self.__window,
+                    ws.get("title", "No selection"),
+                    ws.get("message"),
+                )
+                dialog.show()
+        self.__window.next()
+
     def get_finals(self):
+        ws = self.__step.get("without_selection", {})
         finals = {"vars": {}, "funcs": [x for x in self.__step["final"]]}
 
         for _id, switcher in self.__register_widgets:
             finals["vars"][_id] = switcher.get_active()
 
+        if not any([x[1].get_active() for x in self.__register_widgets]) \
+            and ws.get("allowed", True) \
+            and ws.get("final", None):
+            finals["vars"]["_managed"] = True
+            finals["funcs"].extend(ws["final"])
+
         return finals

vanilla_first_setup/utils/parser.py

@@ -29,12 +29,22 @@ class Parser:
     @staticmethod
     def parse(finals):
         commands = []
+        warps = []
+        all_vars = []
 
         for final in finals:
             if len(final) == 0:
                 continue
 
             _vars = final["vars"]
+            for k, v in _vars.items():
+                if k in all_vars:
+                    logger.error(
+                        f"variable {k} is defined multiple times")
+                    sys.exit(1)
+                if not v:
+                    continue
+                all_vars.append(k)
 
             for _func in final["funcs"]:
 
@@ -42,7 +52,7 @@ class Parser:
                     logger.critical(f"Missing an 'if' operand in {_func}")
                     sys.exit(1)
 
-                if _func["if"] not in _vars:
+                if _func["if"] not in _vars and not _func["if"].startswith("warp::"):
                     logger.critical(
                         f"Missing a variable named '{_func['if']}' in the 'vars' section.")
                     sys.exit(1)
@@ -52,6 +62,14 @@ class Parser:
                         f"Unsupported final type: {_func.get('type')}")
                     sys.exit(1)
 
+                if _func["if"].startswith("warp::"):
+                    _var = _func["if"].split("::")[1]
+                    warps.append({
+                        "vars": [_var],
+                        "func": [_func]
+                    })
+                    continue
+
                 # assume True if no condition is given
                 _condition = _func.get("condition", True)
 
@@ -59,4 +77,17 @@ class Parser:
                 if _condition == _vars[_func["if"]]:
                     commands += _func["commands"]
         
+        # set-up warps if any
+        for warp in warps:
+            _vars = warp["vars"]
+
+            for var in _vars:
+                if var not in all_vars:
+                    continue
+
+            for _func in warp["func"]:
+                _if = _func["if"].split("::")[1]
+                if _if in all_vars:
+                    commands += _func["commands"]
+
         return commands

vanilla_first_setup/window.py

@@ -32,6 +32,7 @@ class VanillaWindow(Adw.ApplicationWindow):
 
     carousel = Gtk.Template.Child()
     btn_back = Gtk.Template.Child()
+    toasts = Gtk.Template.Child()
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
@@ -102,3 +103,8 @@ class VanillaWindow(Adw.ApplicationWindow):
         cur_index = self.carousel.get_position()
         page = self.carousel.get_nth_page(cur_index - 1)
         self.carousel.scroll_to(page, True)
+    
+    def toast(self, message, timeout=3):
+        toast = Adw.Toast.new(message)
+        toast.props.timeout = timeout
+        self.toasts.add_toast(toast)