fix: InteractiveViewer failing to render when alignment is set

CHANGELOG.md

@@ -2,12 +2,14 @@
 
 ### Improvements
 
+* `flet run` and `ft.run()` now print a warning with the desktop client's path when they use one from a previous `flet build` in `build/<platform>`, so an outdated client that lacks an extension is easy to spot ([#6821](https://github.com/flet-dev/flet/issues/6821)) by @ndonkoHenri.
 * `flet build` and `flet debug` pass the arguments that follow a `--` separator to Flutter, e.g. `flet build apk -- --obfuscate --split-debug-info=build/symbols`, as an alternative to repeating `--flutter-build-args` ([#6879](https://github.com/flet-dev/flet/pull/6879)) by @ndonkoHenri.
 * `flet pack` passes the arguments that follow a `--` separator to PyInstaller, e.g. `flet pack main.py -- --clean`, as an alternative to repeating `--pyinstaller-build-args` ([#6879](https://github.com/flet-dev/flet/pull/6879)) by @ndonkoHenri.
 * `flet test` passes the arguments that follow a `--` separator to pytest, e.g. `flet test -k screenshot -- -x --maxfail=1` ([#6879](https://github.com/flet-dev/flet/pull/6879)) by @ndonkoHenri.
 
 ### Bug fixes
 
+* Fix `InteractiveViewer` failing to render when `alignment` is set ([#6744](https://github.com/flet-dev/flet/issues/6744), [#6887](https://github.com/flet-dev/flet/pull/6887)) by @ndonkoHenri.
 * flet-charts: Fix `ScatterChart` failing to render when a `ScatterChartSpot` has `x_error` or `y_error` set. Error ranges are now set with the new `ChartErrorRange` type and drawn as error bars in the color of their spot ([#6885](https://github.com/flet-dev/flet/pull/6885)) by @ndonkoHenri.
 * Fix iOS apps that use `sqlite3` stopping with `Assertion failed: (0), function isBulkReadStatement` when run from Xcode on iOS 18 and later, by turning off Xcode's Thread Performance Checker in the scheme generated by `flet build` ([#5480](https://github.com/flet-dev/flet/issues/5480), [#6882](https://github.com/flet-dev/flet/pull/6882)) by @ndonkoHenri.
 * Fix `Button(icon=...)` and other material buttons rendering an error box when `content` is not set. Icon-only buttons now render the icon centered ([#6886](https://github.com/flet-dev/flet/issues/6886), [#6889](https://github.com/flet-dev/flet/pull/6889)) by @FeodorFitsner.

packages/flet/lib/src/controls/interactive_viewer.dart

@@ -7,6 +7,7 @@ import 'package:vector_math/vector_math_64.dart' show Matrix4, Quad, Vector3;
 
 import '../extensions/control.dart';
 import '../models/control.dart';
+import '../utils/alignment.dart';
 import '../utils/edge_insets.dart';
 import '../utils/events.dart';
 import '../utils/misc.dart';
@@ -158,7 +159,7 @@ class _InteractiveViewerControlState extends State<InteractiveViewerControl>
       scaleFactor: widget.control.getDouble("scale_factor", 200)!,
       clipBehavior:
           widget.control.getClipBehavior("clip_behavior", Clip.hardEdge)!,
-      alignment: widget.control.get("alignment"),
+      alignment: widget.control.getAlignment("alignment"),
       boundaryMargin:
           widget.control.getMargin("boundary_margin", EdgeInsets.zero)!,
       onInteractionStart: !widget.control.disabled

sdk/python/examples/extensions/audio/audio_playback_controls/pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "audio-playback-controls"
 version = "1.0.0"
-description = "Controls audio playback, seek position, volume, and balance for a remote track."
+description = "Controls audio playback, seek position, volume, and balance for a local track."
 requires-python = ">=3.10"
 keywords = ["services", "audio", "playback", "seek", "volume", "balance", "async"]
 authors = [{ name = "Flet team", email = "hello@flet.dev" }]
@@ -15,6 +15,7 @@ categories = ["Media/Audio"]
 
 [tool.flet.metadata]
 title = "Audio playback controls"
+docs_intro = "Plays `viper.mp3` from the example's [`assets`](https://github.com/flet-dev/flet/tree/main/sdk/python/examples/extensions/audio/audio_playback_controls/assets) folder. To run the code on its own, put that file in an `assets` folder next to your script, or set [`src`][flet_audio.Audio.src] to the URL of an audio file."
 controls = ["SafeArea", "Column", "Row", "Button", "Audio"]
 layout_pattern = "inline-actions"
 complexity = "basic"

sdk/python/packages/flet-desktop/src/flet_desktop/__init__.py

@@ -421,6 +421,25 @@ def find_macos_app_bundle(directory) -> Path | None:
     return None
 
 
+def __log_build_client(build_dir: str, client_path: str | Path) -> None:
+    """
+    Reports that a client from a previous `flet build` is used instead of the
+    standard one.
+
+    Logged as a warning, so it is shown even without `flet run -v`: a client
+    built before an extension was added lacks that extension, and the app's
+    calls to it then time out without pointing at the client.
+
+    Args:
+        build_dir: The `build/<platform>` directory the client was found in.
+        client_path: The client executable or `.app` bundle that is launched.
+    """
+    logger.warning(
+        f"Using the Flet client from a previous `flet build`: {client_path}. "
+        f"Move, rename or delete {build_dir} to use the standard client."
+    )
+
+
 def __linux_identity_args(args: list) -> tuple:
     """
     Give the client window a per-app identity on Linux, without touching it.
@@ -604,6 +623,8 @@ def __locate_and_unpack_flet_view(page_url, assets_dir, hidden):
             for f in os.listdir(build_windows):
                 if f.endswith(".exe"):
                     flet_path = os.path.join(build_windows, f)
+            if flet_path:
+                __log_build_client(build_windows, flet_path)
 
         # 2. Check FLET_VIEW_PATH (developer mode)
         if not flet_path:
@@ -631,7 +652,7 @@ def __locate_and_unpack_flet_view(page_url, assets_dir, hidden):
         build_macos = os.path.join(os.getcwd(), "build", "macos")
         app_path = find_macos_app_bundle(build_macos)
         if app_path:
-            logger.info(f"Flet.app found in {build_macos}")
+            __log_build_client(build_macos, app_path)
 
         # 2. Check FLET_VIEW_PATH (developer mode)
         if not app_path:
@@ -668,6 +689,8 @@ def __locate_and_unpack_flet_view(page_url, assets_dir, hidden):
                 ef = os.path.join(build_linux, f)
                 if os.path.isfile(ef) and stat.S_IXUSR & os.stat(ef)[stat.ST_MODE]:
                     app_path = ef
+            if app_path:
+                __log_build_client(build_linux, app_path)
 
         # 2. Check FLET_VIEW_PATH (developer mode)
         if not app_path:

sdk/python/packages/flet/src/flet/controls/core/interactive_viewer.py

@@ -135,7 +135,19 @@ class InteractiveViewer(LayoutControl):
 
     alignment: Optional[Alignment] = None
     """
-    The alignment of the :attr:`content` within this viewer.
+    The origin of the transformation applied to the :attr:`content` when it is
+    zoomed or panned, relative to the content's size.
+
+    :meth:`zoom` scales the content around this point. It does not change where the
+    content is placed in this viewer; to position the content, wrap it in a control
+    that aligns its child, such as a :class:`~flet.Container` with
+    :attr:`~flet.Container.alignment` set.
+
+    Note:
+        Gestures and the limits of :meth:`pan` treat the top-left corner as the
+        origin. With any other value, the content drifts away from the pointer while
+        zooming with a gesture, and once zoomed in, panning stops short of one edge
+        of the content and goes past the opposite one, leaving empty space.
     """
 
     boundary_margin: MarginValue = field(default_factory=lambda: Margin.all(0))

website/docs/getting-started/running-app.md

@@ -86,9 +86,11 @@ require rebuilding the client. See
 [Creating an Extension](../extend/user-extensions.md#change-python-files) for an
 example of this workflow.
 
-To use the standard client again, move or rename the corresponding
-`build/<platform>` directory and unset `FLET_VIEW_PATH` if it is set. Setting
-`FLET_VIEW_PATH` alone does not override a client found in `build/<platform>`.
+When Flet uses a client from `build/<platform>`, it prints a warning with the
+client's path. To use the standard client again, move, rename or delete the
+corresponding `build/<platform>` directory and unset `FLET_VIEW_PATH` if it is
+set. Setting `FLET_VIEW_PATH` alone does not override a client found in
+`build/<platform>`.
 
 :::note
 Opening the built executable directly runs the packaged app, including the Python