implement Save As... in the TUI

this allows for loading an existing GP2040-CE dump or board in BOOTSEL
over USB and saving the parsed configuration to a new .bin/.uf2 file.
might be useful for making quick backups or variants of configs

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

gp2040ce_bintools/config_tree.css

@@ -10,7 +10,7 @@ Button {
     margin: 0 1;
 }
 
-EditScreen, MessageScreen {
+EditScreen, MessageScreen, SaveAsScreen {
     align: center middle;
 }
 
@@ -30,7 +30,7 @@ EditScreen Label {
     visibility: hidden;
 }
 
-#edit-dialog {
+#edit-dialog, #save-as-dialog {
     padding: 0 1;
     grid-rows: 1fr 1fr 1fr 1fr;
     width: 50%;

gp2040ce_bintools/gui.py

@@ -16,7 +16,7 @@ from textual.app import App, ComposeResult
 from textual.containers import Container, Grid, Horizontal
 from textual.logging import TextualHandler
 from textual.screen import ModalScreen
-from textual.validation import Number
+from textual.validation import Length, Number
 from textual.widgets import Button, Footer, Header, Input, Label, Pretty, Select, TextArea, Tree
 from textual.widgets.tree import TreeNode
 
@@ -125,11 +125,61 @@ class MessageScreen(ModalScreen):
         self.app.pop_screen()
 
 
+class SaveAsScreen(ModalScreen):
+    """Present the option of saving the configuration as a new file."""
+
+    def __init__(self, config, *args, **kwargs):
+        """Initialize a filename argument to be populated."""
+        self.config = config
+        super().__init__(*args, **kwargs)
+
+    def compose(self) -> ComposeResult:
+        """Build the pop-up window prompting for the new filename to save the configuration as."""
+        self.filename_field = Input(value=None, id='field-input', validators=[Length(minimum=1)])
+        yield Grid(
+            Container(Label("Filename (.uf2 or .bin) to write to:", id='field-name'), id='field-name-container'),
+            Container(self.filename_field, id='input-field-container'),
+            Container(Pretty('', id='input-errors', classes='hidden'), id='error-container'),
+            Horizontal(Container(Button("Cancel", id='cancel-button'), id='cancel-button-container'),
+                       Container(Button("Confirm", id='confirm-button'), id='confirm-button-container'),
+                       id='button-container'),
+            id='save-as-dialog',
+        )
+
+    @on(Input.Changed)
+    def show_invalid_reasons(self, event: Input.Changed) -> None:
+        """Update the UI to show why validation failed."""
+        if event.validation_result:
+            error_field = self.query_one(Pretty)
+            save_button = self.query_one('#confirm-button', Button)
+            if not event.validation_result.is_valid:
+                error_field.update(event.validation_result.failure_descriptions)
+                error_field.classes = ''
+                save_button.disabled = True
+            else:
+                error_field.update('')
+                error_field.classes = 'hidden'
+                save_button.disabled = False
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        """Process the button actions."""
+        if event.button.id == 'confirm-button':
+            logger.debug("calling _save")
+            self._save()
+        self.app.pop_screen()
+
+    def _save(self):
+        """Save the configuration to the specified file."""
+        write_new_config_to_filename(self.config, self.filename_field.value, inject=False)
+        self.notify(f"Saved to {self.filename_field.value}.", title="Configuration Saved")
+
+
 class ConfigEditor(App):
     """Display the GP2040-CE configuration as a tree."""
 
     BINDINGS = [
-        ('a', 'add_node', "Add Node"),
+        ('a', 'save_as', "Save As..."),
+        ('n', 'add_node', "Add Node"),
         ('s', 'save', "Save Config"),
         ('q', 'quit', "Quit"),
         ('?', 'about', "About"),
@@ -238,6 +288,10 @@ class ConfigEditor(App):
             self.notify(f"Saved to {self.config_filename}.",
                         title="Configuration Saved")
 
+    def action_save_as(self) -> None:
+        """Present a new dialog to save the configuration as a new standalone file."""
+        self.push_screen(SaveAsScreen(self.config))
+
     def action_quit(self) -> None:
         """Quit the application."""
         self.exit()

tests/test_gui.py

@@ -183,7 +183,7 @@ async def test_add_node_to_repeated():
         tree.root.expand_all()
         await pilot.wait_for_scheduled_animations()
         tree.select_node(altpinmappings_node)
-        await pilot.press('a')
+        await pilot.press('n')
         newpinmappings_node = altpinmappings_node.children[0]
         newpinmappings_node.expand()
         await pilot.wait_for_scheduled_animations()
@@ -216,3 +216,28 @@ async def test_save(config_binary, tmp_path):
 
     config = get_config_from_file(new_filename)
     assert config.boardVersion == 'v0.7.5-bss-wuz-here'
+
+
+@pytest.mark.asyncio
+@with_pb2s
+async def test_save_as(config_binary, tmp_path):
+    """Test that we can save to a new file."""
+    filename = os.path.join(tmp_path, 'config-original.bin')
+    with open(filename, 'wb') as file:
+        file.write(config_binary)
+    original_config = get_config(config_binary)
+
+    app = ConfigEditor(config_filename=filename)
+    async with app.run_test() as pilot:
+        await pilot.press('a')
+        await pilot.wait_for_scheduled_animations()
+        await pilot.click('Input#field-input')
+        await pilot.wait_for_scheduled_animations()
+        await pilot.press('/', 't', 'm', 'p', '/', 'g', 'p', 't', 'e', 's', 't')
+        await pilot.wait_for_scheduled_animations()
+        await pilot.click('Button#confirm-button')
+
+    with open('/tmp/gptest', 'rb') as new_file:
+        test_config_binary = new_file.read()
+    test_config = get_config(test_config_binary)
+    assert original_config == test_config