feat: Added more youtube refs to widgets docstrings (#96484)

packages/flutter/lib/src/cupertino/scrollbar.dart

@@ -32,6 +32,8 @@ const double _kScrollbarCrossAxisMargin = 3.0;
 /// To add a scrollbar to a [ScrollView], simply wrap the scroll view widget in
 /// a [CupertinoScrollbar] widget.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=DbkIQSvwnZc}
+///
 /// {@macro flutter.widgets.Scrollbar}
 ///
 /// When dragging a [CupertinoScrollbar] thumb, the thickness and radius will

packages/flutter/lib/src/foundation/isolates.dart

@@ -26,9 +26,11 @@ typedef ComputeCallback<Q, R> = FutureOr<R> Function(Q message);
 /// few milliseconds, consider [SchedulerBinding.scheduleTask] instead.
 ///
 /// {@template flutter.foundation.compute.types}
-/// `Q` is the type of the message that kicks off the computation.
+/// The [compute] method accepts the following parameters:
 ///
-/// `R` is the type of the value returned.
+///  * `Q` is the type of the message that kicks off the computation.
+///
+///  * `R` is the type of the value returned.
 /// {@endtemplate}
 ///
 /// The `callback` argument must be a top-level function, not a closure or an
@@ -44,7 +46,11 @@ typedef ComputeCallback<Q, R> = FutureOr<R> Function(Q message);
 /// [Timeline]. This is useful when profiling an application.
 typedef ComputeImpl = Future<R> Function<Q, R>(ComputeCallback<Q, R> callback, Q message, { String? debugLabel });
 
-/// A function that spawns an isolate and runs a callback on that isolate.
+/// A function that spawns an isolate and runs a callback on that isolate. This
+/// method should be used to execute parallel tasks that reduce the risk of
+/// skipping frames.
+///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=5AxWC49ZMzs}
 ///
 /// See also:
 ///

packages/flutter/lib/src/material/expansion_panel.dart

@@ -58,6 +58,8 @@ typedef ExpansionPanelHeaderBuilder = Widget Function(BuildContext context, bool
 /// expanded or collapsed. The body of the panel is only visible when it is
 /// expanded.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=2aJZzRMziJc}
+///
 /// Expansion panels are only intended to be used as children for
 /// [ExpansionPanelList].
 ///

packages/flutter/lib/src/material/refresh_indicator.dart

@@ -60,6 +60,8 @@ enum RefreshIndicatorTriggerMode {
 
 /// A widget that supports the Material "swipe to refresh" idiom.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=ORApMlzwMdM}
+///
 /// When the child's [Scrollable] descendant overscrolls, an animated circular
 /// progress indicator is faded into view. When the scroll ends, if the
 /// indicator has been dragged far enough for it to become completely opaque,

packages/flutter/lib/src/material/scrollbar.dart

@@ -23,6 +23,8 @@ const Duration _kScrollbarTimeToFade = Duration(milliseconds: 600);
 /// To add a scrollbar to a [ScrollView], wrap the scroll view
 /// widget in a [Scrollbar] widget.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=DbkIQSvwnZc}
+///
 /// {@macro flutter.widgets.Scrollbar}
 ///
 /// Dynamically changes to an iOS style scrollbar that looks like

packages/flutter/lib/src/material/tabs.dart

@@ -1551,6 +1551,8 @@ class TabPageSelectorIndicator extends StatelessWidget {
 
 /// Displays a row of small circular indicators, one per tab.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=Q628ue9Cq7U}
+///
 /// The selected tab's indicator is highlighted. Often used in conjunction with
 /// a [TabBarView].
 ///

packages/flutter/lib/src/material/theme.dart

@@ -18,6 +18,8 @@ const Duration kThemeAnimationDuration = Duration(milliseconds: 200);
 ///
 /// A theme describes the colors and typographic choices of an application.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=oTvQDJOBXmM}
+///
 /// Descendant widgets obtain the current theme's [ThemeData] object using
 /// [Theme.of]. When a widget uses [Theme.of], it is automatically rebuilt if
 /// the theme later changes, so that the changes can be applied.

packages/flutter/lib/src/rendering/object.dart

@@ -1114,6 +1114,8 @@ class PipelineOwner {
 /// The [RenderObject] class hierarchy is the core of the rendering
 /// library's reason for being.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=zmbmrw07qBc}
+///
 /// [RenderObject]s have a [parent], and have a slot called [parentData] in
 /// which the parent [RenderObject] can store child-specific data, for example,
 /// the child position. The [RenderObject] class also implements the basic

packages/flutter/lib/src/widgets/basic.dart

@@ -4832,6 +4832,8 @@ class Row extends Flex {
 /// case is typically to remove the [Expanded] or [Flexible] widgets from around
 /// the inner children.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=jckqXR5CrPI}
+///
 /// For more discussion about constraints, see [BoxConstraints].
 ///
 /// ### The yellow and black striped banner
@@ -6155,6 +6157,8 @@ class Listener extends SingleChildRenderObjectWidget {
 
 /// A widget that tracks the movement of mice.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=1oF3pI5umck}
+///
 /// [MouseRegion] is used
 /// when it is needed to compare the list of objects that a mouse pointer is
 /// hovering over between this frame and the last frame. This means entering

packages/flutter/lib/src/widgets/framework.dart

@@ -438,14 +438,6 @@ abstract class Widget extends DiagnosticableTree {
 ///  * Use `const` widgets where possible, and provide a `const` constructor for
 ///    the widget so that users of the widget can also do so.
 ///
-///  * When trying to create a reusable piece of UI, prefer using a widget
-///    rather than a helper method. For example, if there was a function used to
-///    build a widget, a [State.setState] call would require Flutter to entirely
-///    rebuild the returned wrapping widget. If a [Widget] was used instead,
-///    Flutter would be able to efficiently re-render only those parts that
-///    really need to be updated. Even better, if the created widget is `const`,
-///    Flutter would short-circuit most of the rebuild work.
-///
 ///  * Consider refactoring the stateless widget into a stateful widget so that
 ///    it can use some of the techniques described at [StatefulWidget], such as
 ///    caching common parts of subtrees and using [GlobalKey]s when changing the
@@ -459,6 +451,20 @@ abstract class Widget extends DiagnosticableTree {
 ///    part of the build function that builds the inner-most widget into its own
 ///    widget, so that only the inner-most widget needs to be rebuilt when the
 ///    theme changes.
+/// {@template flutter.flutter.widgets.framework.prefer_const_over_helper}
+///  * When trying to create a reusable piece of UI, prefer using a widget
+///    rather than a helper method. For example, if there was a function used to
+///    build a widget, a [State.setState] call would require Flutter to entirely
+///    rebuild the returned wrapping widget. If a [Widget] was used instead,
+///    Flutter would be able to efficiently re-render only those parts that
+///    really need to be updated. Even better, if the created widget is `const`,
+///    Flutter would short-circuit most of the rebuild work.
+/// {@endtemplate}
+///
+/// This video gives more explainations on why `const` constructors are important
+/// and why a [Widget] is better than a helper method.
+///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=IOyq-eTRhvo}
 ///
 /// {@tool snippet}
 ///
@@ -650,24 +656,16 @@ abstract class StatelessWidget extends Widget {
 ///    this ideal, the more efficient it will be.)
 ///
 ///  * If a subtree does not change, cache the widget that represents that
-///    subtree and re-use it each time it can be used. It is massively more
-///    efficient for a widget to be re-used than for a new (but
-///    identically-configured) widget to be created. Factoring out the stateful
-///    part into a widget that takes a child argument is a common way of doing
-///    this. Another caching strategy consists of assigning a widget to a
-///    `final` state variable which can be used in the build method.
+///    subtree and re-use it each time it can be used. To do this, simply assign
+///    a widget to a `final` state variable and re-use it in the build method. It
+///    is massively more efficient for a widget to be re-used than for a new (but
+///    identically-configured) widget to be created. Another caching stragegy
+///    consists in extracting the mutable part of the widget into a [StatefulWidget]
+///    which accepts a child parameter.
 ///
 ///  * Use `const` widgets where possible. (This is equivalent to caching a
 ///    widget and re-using it.)
 ///
-///  * When trying to create a reusable piece of UI, prefer using a widget
-///    rather than a helper method. For example, if there was a function used to
-///    build a widget, a [State.setState] call would require Flutter to entirely
-///    rebuild the returned wrapping widget. If a [Widget] was used instead,
-///    Flutter would be able to efficiently re-render only those parts that
-///    really need to be updated. Even better, if the created widget is `const`,
-///    Flutter would short-circuit most of the rebuild work.
-///
 ///  * Avoid changing the depth of any created subtrees or changing the type of
 ///    any widgets in the subtree. For example, rather than returning either the
 ///    child or the child wrapped in an [IgnorePointer], always wrap the child
@@ -684,6 +682,13 @@ abstract class StatelessWidget extends Widget {
 ///    [KeyedSubtree] widget may be useful for this purpose if no other widget
 ///    can conveniently be assigned the key.)
 ///
+/// {@macro flutter.flutter.widgets.framework.prefer_const_over_helper}
+///
+/// This video gives more explainations on why `const` constructors are important
+/// and why a [Widget] is better than a helper method.
+///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=IOyq-eTRhvo}
+///
 /// {@tool snippet}
 ///
 /// This is a skeleton of a stateful widget subclass called `YellowBird`.
@@ -2065,6 +2070,8 @@ typedef ElementVisitor = void Function(Element element);
 /// the methods on this class should not be cached beyond the execution of a
 /// single synchronous function.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=rIaaH87z1-g}
+///
 /// [BuildContext] objects are actually [Element] objects. The [BuildContext]
 /// interface is used to discourage direct manipulation of [Element] objects.
 abstract class BuildContext {

packages/flutter/lib/src/widgets/gesture_detector.dart

@@ -114,6 +114,8 @@ class GestureRecognizerFactoryWithHandlers<T extends GestureRecognizer> extends
 /// If this widget has a child, it defers to that child for its sizing behavior.
 /// If it does not have a child, it grows to fit the parent instead.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=WhVXkCFPmK4}
+///
 /// By default a GestureDetector with an invisible child ignores touches;
 /// this behavior can be controlled with [behavior].
 ///

packages/flutter/lib/src/widgets/scroll_view.dart

@@ -237,6 +237,8 @@ abstract class ScrollView extends StatelessWidget {
   /// scroll view needs to be recomputed whenever the scroll position changes.
   ///
   /// Defaults to false.
+  ///
+  /// {@youtube 560 315 https://www.youtube.com/watch?v=LUqDNnv_dh0}
   /// {@endtemplate}
   final bool shrinkWrap;
 

packages/flutter/lib/src/widgets/scrollbar.dart

@@ -760,6 +760,8 @@ class ScrollbarPainter extends ChangeNotifier implements CustomPainter {
 /// To add a scrollbar to a [ScrollView], like a [ListView] or a
 /// [CustomScrollView], wrap the scroll view widget in a [RawScrollbar] widget.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=DbkIQSvwnZc}
+///
 /// {@template flutter.widgets.Scrollbar}
 /// A scrollbar thumb indicates which portion of a [ScrollView] is actually
 /// visible.