tsacdop-podcast-app-android/lib/util/mypopupmenu.dart

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import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter/material.dart';
const Duration _kMenuDuration = Duration(milliseconds: 300);
const double _kMenuCloseIntervalEnd = 2.0 / 3.0;
const double _kMenuMaxWidth = 5.0 * _kMenuWidthStep;
const double _kMenuMinWidth = 2.0 * _kMenuWidthStep;
const double _kMenuVerticalPadding = 8.0;
const double _kMenuWidthStep = 56.0;
const double _kMenuScreenPadding = 8.0;
class _MenuItem extends SingleChildRenderObjectWidget {
const _MenuItem({
Key key,
@required this.onLayout,
Widget child,
}) : assert(onLayout != null),
super(key: key, child: child);
final ValueChanged<Size> onLayout;
@override
RenderObject createRenderObject(BuildContext context) {
return _RenderMenuItem(onLayout);
}
@override
void updateRenderObject(
BuildContext context, covariant _RenderMenuItem renderObject) {
renderObject.onLayout = onLayout;
}
}
class _RenderMenuItem extends RenderShiftedBox {
_RenderMenuItem(this.onLayout, [RenderBox child])
: assert(onLayout != null),
super(child);
ValueChanged<Size> onLayout;
@override
void performLayout() {
if (child == null) {
size = Size.zero;
} else {
child.layout(constraints, parentUsesSize: true);
size = constraints.constrain(child.size);
}
final BoxParentData childParentData = child.parentData as BoxParentData;
childParentData.offset = Offset.zero;
onLayout(size);
}
}
class _PopupMenu<T> extends StatelessWidget {
const _PopupMenu({
Key key,
this.route,
this.semanticLabel,
}) : super(key: key);
final _PopupMenuRoute<T> route;
final String semanticLabel;
@override
Widget build(BuildContext context) {
final double unit = 1.0 /
(route.items.length +
1.5); // 1.0 for the width and 0.5 for the last item's fade.
final List<Widget> children = <Widget>[];
final PopupMenuThemeData popupMenuTheme = PopupMenuTheme.of(context);
for (int i = 0; i < route.items.length; i += 1) {
final double start = (i + 1) * unit;
final double end = (start + 1.5 * unit).clamp(0.0, 1.0) as double;
final CurvedAnimation opacity = CurvedAnimation(
parent: route.animation,
curve: Interval(start, end),
);
Widget item = route.items[i];
if (route.initialValue != null &&
route.items[i].represents(route.initialValue)) {
item = Container(
color: Theme.of(context).highlightColor,
child: item,
);
}
children.add(
_MenuItem(
onLayout: (Size size) {
route.itemSizes[i] = size;
},
child: FadeTransition(
opacity: opacity,
child: item,
),
),
);
}
final CurveTween opacity =
CurveTween(curve: const Interval(0.0, 1.0 / 3.0));
final CurveTween width = CurveTween(curve: Interval(0.0, unit));
final CurveTween height =
CurveTween(curve: Interval(0.0, unit * route.items.length));
final Widget child = ConstrainedBox(
constraints: const BoxConstraints(
minWidth: _kMenuMinWidth,
maxWidth: _kMenuMaxWidth,
),
child: IntrinsicWidth(
stepWidth: _kMenuWidthStep,
child: Semantics(
scopesRoute: true,
namesRoute: true,
explicitChildNodes: true,
label: semanticLabel,
child: SingleChildScrollView(
padding: const EdgeInsets.only(
bottom: _kMenuVerticalPadding
),
child: ListBody(children: children),
),
),
),
);
return AnimatedBuilder(
animation: route.animation,
builder: (BuildContext context, Widget child) {
return Opacity(
opacity: opacity.evaluate(route.animation),
child: Material(
shape: route.shape ?? popupMenuTheme.shape,
color: route.color ?? popupMenuTheme.color,
type: MaterialType.card,
elevation: route.elevation ?? popupMenuTheme.elevation ?? 8.0,
child: Align(
alignment: AlignmentDirectional.topEnd,
widthFactor: width.evaluate(route.animation),
heightFactor: height.evaluate(route.animation),
child: child,
),
),
);
},
child: child,
);
}
}
class _PopupMenuRouteLayout extends SingleChildLayoutDelegate {
_PopupMenuRouteLayout(this.position, this.itemSizes, this.selectedItemIndex,
this.textDirection);
final RelativeRect position;
List<Size> itemSizes;
final int selectedItemIndex;
final TextDirection textDirection;
@override
BoxConstraints getConstraintsForChild(BoxConstraints constraints) {
return BoxConstraints.loose(
constraints.biggest -
const Offset(_kMenuScreenPadding * 2.0, _kMenuScreenPadding * 2.0)
as Size,
);
}
@override
Offset getPositionForChild(Size size, Size childSize) {
double y = position.top;
if (selectedItemIndex != null && itemSizes != null) {
double selectedItemOffset =
_kMenuVerticalPadding;
for (int index = 0; index < selectedItemIndex; index += 1)
selectedItemOffset += itemSizes[index].height;
selectedItemOffset += itemSizes[selectedItemIndex].height / 2;
y = position.top +
(size.height - position.top - position.bottom) / 2.0 -
selectedItemOffset;
}
double x;
if (position.left > position.right) {
x = size.width - position.right - childSize.width;
} else if (position.left < position.right) {
// Menu button is closer to the left edge, so grow to the right, aligned to the left edge.
x = position.left;
} else {
// Menu button is equidistant from both edges, so grow in reading direction.
assert(textDirection != null);
switch (textDirection) {
case TextDirection.rtl:
x = size.width - position.right - childSize.width;
break;
case TextDirection.ltr:
x = position.left;
break;
}
}
if (x < _kMenuScreenPadding)
x = _kMenuScreenPadding;
else if (x + childSize.width > size.width - _kMenuScreenPadding)
x = size.width - childSize.width - _kMenuScreenPadding;
if (y < _kMenuScreenPadding)
y = _kMenuScreenPadding;
else if (y + childSize.height > size.height - _kMenuScreenPadding)
y = size.height - childSize.height - _kMenuScreenPadding;
return Offset(x, y);
}
@override
bool shouldRelayout(_PopupMenuRouteLayout oldDelegate) {
assert(itemSizes.length == oldDelegate.itemSizes.length);
return position != oldDelegate.position ||
selectedItemIndex != oldDelegate.selectedItemIndex ||
textDirection != oldDelegate.textDirection ||
!listEquals(itemSizes, oldDelegate.itemSizes);
}
}
class _PopupMenuRoute<T> extends PopupRoute<T> {
_PopupMenuRoute({
this.position,
this.items,
this.initialValue,
this.elevation,
this.theme,
this.popupMenuTheme,
this.barrierLabel,
this.semanticLabel,
this.shape,
this.color,
this.showMenuContext,
this.captureInheritedThemes,
}) : itemSizes = List<Size>(items.length);
final RelativeRect position;
final List<PopupMenuEntry<T>> items;
final List<Size> itemSizes;
final T initialValue;
final double elevation;
final ThemeData theme;
final String semanticLabel;
final ShapeBorder shape;
final Color color;
final PopupMenuThemeData popupMenuTheme;
final BuildContext showMenuContext;
final bool captureInheritedThemes;
@override
Animation<double> createAnimation() {
return CurvedAnimation(
parent: super.createAnimation(),
curve: Curves.linear,
reverseCurve: const Interval(0.0, _kMenuCloseIntervalEnd),
);
}
@override
Duration get transitionDuration => _kMenuDuration;
@override
bool get barrierDismissible => true;
@override
Color get barrierColor => null;
@override
final String barrierLabel;
@override
Widget buildPage(BuildContext context, Animation<double> animation,
Animation<double> secondaryAnimation) {
int selectedItemIndex;
if (initialValue != null) {
for (int index = 0;
selectedItemIndex == null && index < items.length;
index += 1) {
if (items[index].represents(initialValue)) selectedItemIndex = index;
}
}
Widget menu = _PopupMenu<T>(route: this, semanticLabel: semanticLabel);
if (captureInheritedThemes) {
menu = InheritedTheme.captureAll(showMenuContext, menu);
} else {
if (theme != null) menu = Theme(data: theme, child: menu);
}
return MediaQuery.removePadding(
context: context,
removeTop: true,
removeBottom: true,
removeLeft: true,
removeRight: true,
child: Builder(
builder: (BuildContext context) {
return CustomSingleChildLayout(
delegate: _PopupMenuRouteLayout(
position,
itemSizes,
selectedItemIndex,
Directionality.of(context),
),
child: menu,
);
},
),
);
}
}
Future<T> _showMenu<T>({
@required BuildContext context,
@required RelativeRect position,
@required List<PopupMenuEntry<T>> items,
T initialValue,
double elevation,
String semanticLabel,
ShapeBorder shape,
Color color,
bool captureInheritedThemes = true,
bool useRootNavigator = false,
}) {
assert(context != null);
assert(position != null);
assert(useRootNavigator != null);
assert(items != null && items.isNotEmpty);
assert(captureInheritedThemes != null);
assert(debugCheckHasMaterialLocalizations(context));
String label = semanticLabel;
switch (Theme.of(context).platform) {
case TargetPlatform.iOS:
case TargetPlatform.macOS:
label = semanticLabel;
break;
case TargetPlatform.android:
case TargetPlatform.fuchsia:
case TargetPlatform.linux:
case TargetPlatform.windows:
label = semanticLabel ?? MaterialLocalizations.of(context)?.popupMenuLabel;
}
return Navigator.of(context, rootNavigator: useRootNavigator).push(_PopupMenuRoute<T>(
position: position,
items: items,
initialValue: initialValue,
elevation: elevation,
semanticLabel: label,
theme: Theme.of(context, shadowThemeOnly: true),
popupMenuTheme: PopupMenuTheme.of(context),
barrierLabel: MaterialLocalizations.of(context).modalBarrierDismissLabel,
shape: shape,
color: color,
showMenuContext: context,
captureInheritedThemes: captureInheritedThemes,
));
}
class MyPopupMenuButton<T> extends StatefulWidget {
/// Creates a button that shows a popup menu.
///
/// The [itemBuilder] argument must not be null.
const MyPopupMenuButton({
Key key,
@required this.itemBuilder,
this.initialValue,
this.onSelected,
this.onCanceled,
this.tooltip,
this.elevation,
this.padding = const EdgeInsets.all(8.0),
this.child,
this.icon,
this.offset = Offset.zero,
this.enabled = true,
this.shape,
this.color,
this.captureInheritedThemes = true,
}) : assert(itemBuilder != null),
assert(offset != null),
assert(enabled != null),
assert(captureInheritedThemes != null),
assert(!(child != null && icon != null),
'You can only pass [child] or [icon], not both.'),
super(key: key);
final PopupMenuItemBuilder<T> itemBuilder;
final T initialValue;
final PopupMenuItemSelected<T> onSelected;
final PopupMenuCanceled onCanceled;
final String tooltip;
final double elevation;
final EdgeInsetsGeometry padding;
final Widget child;
final Widget icon;
final Offset offset;
final bool enabled;
final ShapeBorder shape;
final Color color;
final bool captureInheritedThemes;
@override
MyPopupMenuButtonState<T> createState() => MyPopupMenuButtonState<T>();
}
class MyPopupMenuButtonState<T> extends State<MyPopupMenuButton<T>> {
void showButtonMenu() {
final PopupMenuThemeData popupMenuTheme = PopupMenuTheme.of(context);
final RenderBox button = context.findRenderObject() as RenderBox;
final RenderBox overlay =
Overlay.of(context).context.findRenderObject() as RenderBox;
final RelativeRect position = RelativeRect.fromRect(
Rect.fromPoints(
button.localToGlobal(widget.offset, ancestor: overlay),
button.localToGlobal(button.size.bottomRight(Offset.zero),
ancestor: overlay),
),
Offset.zero & overlay.size,
);
final List<PopupMenuEntry<T>> items = widget.itemBuilder(context);
// Only show the menu if there is something to show
if (items.isNotEmpty) {
_showMenu<T>(
context: context,
elevation: widget.elevation ?? popupMenuTheme.elevation,
items: items,
initialValue: widget.initialValue,
position: position,
shape: widget.shape ?? popupMenuTheme.shape,
color: widget.color ?? popupMenuTheme.color,
captureInheritedThemes: widget.captureInheritedThemes,
).then<void>((T newValue) {
if (!mounted) return null;
if (newValue == null) {
if (widget.onCanceled != null) widget.onCanceled();
return null;
}
if (widget.onSelected != null) widget.onSelected(newValue);
});
}
}
Icon _getIcon(TargetPlatform platform) {
assert(platform != null);
switch (platform) {
case TargetPlatform.android:
case TargetPlatform.fuchsia:
return const Icon(Icons.more_vert);
case TargetPlatform.iOS:
case TargetPlatform.macOS:
case TargetPlatform.linux:
case TargetPlatform.windows:
return const Icon(Icons.more_horiz);
}
return null;
}
@override
Widget build(BuildContext context) {
assert(debugCheckHasMaterialLocalizations(context));
if (widget.child != null)
return Tooltip(
message:
widget.tooltip ?? MaterialLocalizations.of(context).showMenuTooltip,
child: InkWell(
onTap: widget.enabled ? showButtonMenu : null,
canRequestFocus: widget.enabled,
child: widget.child,
),
);
return IconButton(
icon: widget.icon ?? _getIcon(Theme.of(context).platform),
padding: widget.padding,
tooltip:
widget.tooltip ?? MaterialLocalizations.of(context).showMenuTooltip,
onPressed: widget.enabled ? showButtonMenu : null,
);
}
}
class MyPopupMenuItem<int> extends PopupMenuEntry<int> {
const MyPopupMenuItem({
Key key,
this.value,
this.enabled = true,
this.height = kMinInteractiveDimension,
this.textStyle,
@required this.child,
}) : assert(enabled != null),
assert(height != null),
super(key: key);
final int value;
final bool enabled;
@override
final double height;
final TextStyle textStyle;
final Widget child;
@override
bool represents(int value) => value == this.value;
@override
MyPopupMenuItemState<int, MyPopupMenuItem<int>> createState() =>
MyPopupMenuItemState<int, MyPopupMenuItem<int>>();
}
class MyPopupMenuItemState<int, W extends MyPopupMenuItem<int>>
extends State<W> {
@protected
Widget buildChild() => widget.child;
@protected
void handleTap() {
Navigator.pop<int>(context, widget.value);
}
@override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
final PopupMenuThemeData popupMenuTheme = PopupMenuTheme.of(context);
TextStyle style = widget.textStyle ??
popupMenuTheme.textStyle ??
theme.textTheme.subtitle1;
Widget item = AnimatedDefaultTextStyle(
style: style,
duration: kThemeChangeDuration,
child: Container(
// alignment: AlignmentDirectional.centerStart,
// constraints: BoxConstraints(minHeight: widget.height),
padding: const EdgeInsets.all(0),
child: buildChild(),
),
);
return item;
// return InkWell(
// onTap: widget.enabled ? handleTap : null,
// canRequestFocus: widget.enabled,
// child: item,
// );
}
}