linkage_picker

Description:

linkage picker

linkage_picker #
A cupertino-picker-style linkage picker widget. Provided [DatePicker] implement and you can extend [LinkagePickerWidget] to achieve what you want in more scene easily.





DatePicker #
DatePicker is a pre-archive linkage picker
DatePicker(
start: DateTime(2000, today.month, today.day),
end: DateTime(2050, today.month, today.day),
date: date,
)
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You can use showAsBottomSheet to show DatePicker as BottomSheet-Style
DatePicker(
...
).showAsBottomSheet(context)
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Or wrap it anywhere just like this
ValueListenableBuilder<bool>(
valueListenable: showPicker,
builder: (context, value, _) {
return value
? Column(
mainAxisSize: MainAxisSize.min,
children: [
DatePicker(
...,
onControllerCreated: (controller) {
this.controller = controller;
},
),
TextButton(
onPressed: () {
showPicker.value = false;
final result = controller.result;
if (result != null) {
content.value = DateFormat('yyyy-MM-dd').format(result);
}
},
child: const Text('Confirm')),
],
)
: const SizedBox.shrink();
})
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CustomPicker #
You can extend LinkagePickerWidget to develop your own linkage picker
class CustomPicker extends LinkagePickerWidget<CustomData, String> {
CustomPicker()
: super(
maxLevel: LinkagePickerLevel.second,
dataBuilder: (level, parent) {
return switch (level) {
LinkagePickerLevel.first => LinkagePickerData<CustomData>[...],
LinkagePickerLevel.second => LinkagePickerData<CustomData>[...],
_ => throw UnimplementedError(),
};
},
equalizer: (level, value1, value2) {
return switch (level) {
_ => (value1 as CustomData).equals(value2 as CustomData),
};
},
resultConverter: (selection) {
final getResultString(selection.first, selection.last);
},
conflictResolver: (level, previous, currents) {
return switch (level) {
LinkagePickerLevel.first => null,
LinkagePickerLevel.second =>
(previous as CustomData).copyWith(...),
_ => throw UnimplementedError(),
};
},
initialValue: <CustomData>[...],
pickerStyle: LinkagePickerStyle(
itemBuilder: (level, data, selected) {
switch (level) {
case LinkagePickerLevel.first:
return buildFirstPickerItem(data, selected);
case LinkagePickerLevel.second:
return buildSecondPickerItem(data, selected);
default:
throw UnimplementedError();
}
},
),
);
}
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LinkagePickerWidget<T,R> #

T: The type of the data source value
R: The type of the result
maxLevel: The maximum level of the picker
dataBuilder: Return the datasource from current level and parent data.
equalizer: Tell Widget whether two value are equal in current level.
resultConverter: Convert the result to the type you want
conflictResolver: Convert picker selected result to navigation result.
initialValue: The initial value of picker
pickerStyle: Customize the style of the picker
onControllerCreated: Callback when controller created

LinkagePickerStyle #

diameterRatio: Same as [CupertinoPicker.diameterRatio]
itemExtent: Same as [CupertinoPicker.itemExtent]
backgroundColor: Same as [CupertinoPicker.backgroundColor]
offAxisFraction: Same as [CupertinoPicker.offAxisFraction]
squeeze: Same as [CupertinoPicker.squeeze]
useMagnifier: Same as [CupertinoPicker.useMagnifier]
magnification: Same as [CupertinoPicker.magnification]
selectionOverlay: Same as [CupertinoPicker.selectionOverlay]
heightRatio: The ratio of the height of the picker to the height of the item
itemBuilder: Customize the item of the picker