fix(ResponsiveRow): handle unbounded width and child controls with col=0 (#6354)

* add error handling for unbounded width in ResponsiveRow

* add test for unbounded width error in ResponsiveRow

* add tests for unbounded height in various components

* improve logging.md

* revert `NavigationRailDestination.icon` type change

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix #3805: treat ResponsiveRow child controls with `col=0` as hidden

* docs: clarify behavior of `col=0` in ResponsiveRow

* fix: add validation rules for ResponsiveRow columns to ensure positive values

* fix #5209: clarify possible container expansion due to alignment being set

* Update changelogs with ResponsiveRow fixes

Add entries to top-level and packages/flet CHANGELOGs documenting fixes: explicit error for unbounded width in ResponsiveRow, treating child controls with col=0 as hidden at the current breakpoint, and clarifying Container expansion behavior when alignment is set. References issues/PRs #1951, #3805, #5209, #6354 and author @ndonkoHenri.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Feodor Fitsner <feodor@appveyor.com>

Author: 3 people

.agents/skills/flet-validation/SKILL.md

@@ -141,6 +141,8 @@ When a property has validation, document it in that property’s docstring (goog
      `sdk/python/packages/flet/src/flet/utils/validation.py`.
    - Each `V.*` helper includes `Property docstring Raises wording`.
    - Keep property `Raises` entries as negations of the annotation rule.
+   - For strict inequalities, say `"strictly"`.
+     For example: `V.gt(x)` -> `ValueError: If it is not strictly greater than \`x\`.`
    - For sign-neutral divisibility helpers (`factor_of`, `multiple_of`), add
      explicit sign rules (`V.gt(0)` or `V.lt(0)`) when direction matters, and
      include separate `Raises` entries for those sign rules.

CHANGELOG.md

@@ -11,6 +11,7 @@
 ### Bug fixes
 
 * Fix `flet build` and `flet publish` dependency parsing for `project.dependencies` and Poetry constraints with `<`/`<=`, and add coverage for normalized requirement handling ([#6332](https://github.com/flet-dev/flet/issues/6332), [#6340](https://github.com/flet-dev/flet/pull/6340)) by @td3447.
+* Handle unbounded width in `ResponsiveRow` with an explicit error, treat child controls with `col=0` as hidden, and clarify `Container` expansion behavior when `alignment` is set ([#1951](https://github.com/flet-dev/flet/issues/1951), [#3805](https://github.com/flet-dev/flet/issues/3805), [#5209](https://github.com/flet-dev/flet/issues/5209), [#6354](https://github.com/flet-dev/flet/pull/6354)) by @ndonkoHenri.
 * Fix `find_platform_image` selecting incompatible icon formats (e.g. `.icns` on Windows) by ranking glob results per target platform ([#6381](https://github.com/flet-dev/flet/pull/6381)) by @HG-ha.
 
 ### Other changes

packages/flet/CHANGELOG.md

@@ -6,6 +6,8 @@
 
 ### Bug fixes
 
+* Handle unbounded width in `ResponsiveRow` with an explicit error and treat child controls with `col=0` as hidden at the current breakpoint ([#1951](https://github.com/flet-dev/flet/issues/1951), [#3805](https://github.com/flet-dev/flet/issues/3805), [#6354](https://github.com/flet-dev/flet/pull/6354)) by @ndonkoHenri.
+
 ### Other changes
 
 ## 0.84.0

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

@@ -25,7 +25,17 @@ class ResponsiveRowControl extends StatelessWidget with FletStoreMixin {
     return withPageSize((context, view) {
       var result = LayoutBuilder(
           builder: (BuildContext context, BoxConstraints constraints) {
-        // breakpoints
+        if (!constraints.hasBoundedWidth) {
+          return const ErrorControl(
+            "Error displaying ResponsiveRow: width is unbounded.",
+            description:
+                "Set a fixed width, a non-zero expand, or place it inside a control with bounded width.",
+          );
+        }
+
+        // Resolve the active breakpoint map once per layout pass. Responsive
+        // properties such as `columns`, `spacing`, and child `col` values are
+        // all interpreted against this map.
         final rawBreakpoints =
             control.get<Map>("breakpoints", view.breakpoints)!;
         final breakpoints = <String, double>{};
@@ -45,13 +55,28 @@ class ResponsiveRowControl extends StatelessWidget with FletStoreMixin {
         for (var ctrl in control.children("controls")) {
           final col = ctrl.getResponsiveNumber("col", 12)!;
           var bpCol = getBreakpointNumber(col, view.size.width, breakpoints);
+
+          // `col=0` means "do not occupy any columns" for the current
+          // breakpoint, so the child should not participate in layout.
+          if (bpCol <= 0) {
+            continue;
+          }
+
           totalCols += bpCol;
 
-          // calculate child width
+          // Convert virtual columns into a fixed pixel width for this child.
+          // We first remove the total horizontal gaps from the available width,
+          // then divide the remaining width across the configured columns.
           var colWidth =
               (constraints.maxWidth - bpSpacing * (bpColumns - 1)) / bpColumns;
           var childWidth = colWidth * bpCol + bpSpacing * (bpCol - 1);
 
+          // Guard against tiny/invalid available widths so Flutter never sees
+          // negative box constraints.
+          if (childWidth < 0) {
+            childWidth = 0;
+          }
+
           controls.add(ConstrainedBox(
             constraints:
                 BoxConstraints(minWidth: childWidth, maxWidth: childWidth),
@@ -62,6 +87,8 @@ class ResponsiveRowControl extends StatelessWidget with FletStoreMixin {
         var wrap = (totalCols > bpColumns);
 
         try {
+          // Keep a single row when everything fits; otherwise switch to Wrap so
+          // children can continue on the next line.
           return wrap
               ? Wrap(
                   direction: Axis.horizontal,

sdk/python/packages/flet/integration_tests/controls/core/golden/macos/page_view/unbounded_height.png

@@ -1,10 +1,17 @@
 import pytest
+import pytest_asyncio
 
 import flet as ft
 import flet.testing as ftt
 
 
-@pytest.mark.asyncio(loop_scope="module")
+# Create a new flet_app instance for each test method
+@pytest_asyncio.fixture(scope="function", autouse=True)
+def flet_app(flet_app_function):
+    return flet_app_function
+
+
+@pytest.mark.asyncio(loop_scope="function")
 async def test_basic(flet_app: ftt.FletTestApp, request):
     await flet_app.assert_control_screenshot(
         request.node.name,
@@ -30,3 +37,29 @@ async def test_basic(flet_app: ftt.FletTestApp, request):
             ],
         ),
     )
+
+
+@pytest.mark.asyncio(loop_scope="function")
+async def test_unbounded_height(flet_app: ftt.FletTestApp, request):
+    flet_app.page.theme_mode = ft.ThemeMode.LIGHT
+    await flet_app.assert_control_screenshot(
+        request.node.name,
+        ft.Column(
+            controls=[
+                ft.PageView(
+                    controls=[
+                        ft.Container(
+                            bgcolor=ft.Colors.PURPLE,
+                            alignment=ft.Alignment.CENTER,
+                            content=ft.Text("One", color=ft.Colors.WHITE),
+                        ),
+                        ft.Container(
+                            bgcolor=ft.Colors.TEAL,
+                            alignment=ft.Alignment.CENTER,
+                            content=ft.Text("Two", color=ft.Colors.WHITE),
+                        ),
+                    ],
+                )
+            ]
+        ),
+    )

sdk/python/packages/flet/integration_tests/controls/core/golden/macos/pagelet/unbounded_height.png

@@ -111,3 +111,19 @@ async def test_cupertino_adaptive(flet_app: ftt.FletTestApp, request):
             ),
         ),
     )
+
+
+@pytest.mark.asyncio(loop_scope="function")
+async def test_unbounded_height(flet_app: ftt.FletTestApp, request):
+    flet_app.page.theme_mode = ft.ThemeMode.LIGHT
+    await flet_app.assert_control_screenshot(
+        request.node.name,
+        ft.Column(
+            controls=[
+                ft.Pagelet(
+                    appbar=ft.AppBar(title="Pagelet AppBar"),
+                    content=ft.Text("Pagelet Content"),
+                )
+            ]
+        ),
+    )