ChipGroup 2 路绑定适配器

Question

我想创建 ChipGroup 2 路绑定适配器。我已经复制了默认的 RadioGroup 绑定适配器并进行了一些更改，但它不适用于两种方式。在以编程方式将数据设置为可观察的情况下，ChipGroup 会从中检索更改。但是手动芯片选择不会将更改设置为可观察。

这是我的适配器

@InverseBindingMethods(InverseBindingMethod(type = ChipGroup::class, attribute = "android:checkedButton", method = "getCheckedRadioButtonId"))
class ChipGroupBindingAdapter {
companion object {
    @JvmStatic
    @BindingAdapter("android:checkedButton")
    fun setCheckedChip(view: ChipGroup?, id: Int) {
        if (id != view?.checkedChipId) {
            view?.check(id)
        }
    }

    @JvmStatic
    @BindingAdapter(value = ["android:onCheckedChanged", "android:checkedButtonAttrChanged"], requireAll = false)
    fun setChipsListeners(view: ChipGroup?, listener: ChipGroup.OnCheckedChangeListener?,
                          attrChange: InverseBindingListener?) {
        if (attrChange == null) {
            view?.setOnCheckedChangeListener(listener)
        } else {
            view?.setOnCheckedChangeListener { group, checkedId ->
                listener?.onCheckedChanged(group, checkedId)
                attrChange.onChange()
                }
            }
        }
    }
}

布局文件：

<android.support.design.chip.ChipGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:checkedButton="@{viewModel.checkedBtnObs}"
        app:singleSelection="true">

        <android.support.design.chip.Chip
            android:id="@+id/first_chip"
            style="@style/Widget.MaterialComponents.Chip.Choice"
            android:layout_width="110dp"
            android:layout_height="wrap_content"
            android:checkable="true"
            android:text="@string/month_12"
            app:chipBackgroundColor="@drawable/chip_background_selector" />

        <android.support.design.chip.Chip
            android:id="@+id/second_chip"
            style="@style/Widget.MaterialComponents.Chip.Choice"
            android:layout_width="110dp"
            android:layout_height="wrap_content"
            android:checkable="true"
            android:text="@string/month_6"
            android:textAlignment="center"
            app:chipBackgroundColor="@drawable/chip_background_selector" />

        <android.support.design.chip.Chip
            android:id="@+id/third_chip"
            style="@style/Widget.MaterialComponents.Chip.Choice"
            android:layout_width="110dp"
            android:layout_height="wrap_content"
            android:checkable="true"
            android:text="@string/month_1"
            app:chipBackgroundColor="@drawable/chip_background_selector" />

    </android.support.design.chip.ChipGroup>

并且可以观察到：

val checkedBtnObs = ObservableInt(R.id.second_chip)

Answer 1

最后，我找到了解决方案。 InverseBindingMethod 方法应该是getCheckedChipId 而不是getCheckedRadioButtonId

另外，@= 应该添加到 xml 中 android:checkedButton="@{viewModel.checkedBtnObs}" 像这样 android:checkedButton="@={viewModel.checkedBtnObs}"

现在这个适配器可以用于 ChipGroup 2-way binding

@InverseBindingMethods(InverseBindingMethod(type = ChipGroup::class, attribute = "android:checkedButton", method = "getCheckedChipId"))
class ChipGroupBindingAdapter {
companion object {
    @JvmStatic
    @BindingAdapter("android:checkedButton")
    fun setCheckedChip(view: ChipGroup?, id: Int) {
        if (id != view?.checkedChipId) {
            view?.check(id)
        }
    }

    @JvmStatic
    @BindingAdapter(value = ["android:onCheckedChanged", "android:checkedButtonAttrChanged"], requireAll = false)
    fun setChipsListeners(view: ChipGroup?, listener: ChipGroup.OnCheckedChangeListener?,
                          attrChange: InverseBindingListener?) {
        if (attrChange == null) {
            view?.setOnCheckedChangeListener(listener)
        } else {
            view?.setOnCheckedChangeListener { group, checkedId ->
                listener?.onCheckedChanged(group, checkedId)
                attrChange.onChange()
                }
            }
        }
    }
}

Answer 2

我得到ChipGroup 和DataBinding 按预期工作并使用InverseDataBinding 的推荐方式，如果有人想知道，这是我的实现：

SomeBindingAdapters.kt:

...
object PropertyTypeFilterBindingAdapters {
    @BindingAdapter("propertyTypeFilter")
    @JvmStatic
    fun ChipGroup.bindPropertyTypeFilter(marsApiFilter: MarsApiFilter?) =
        marsApiFilter?.let { filter ->
            when (filter) {
                MarsApiFilter.ALL -> check(R.id.filter_all_properties_chip)
                MarsApiFilter.RENT -> check(R.id.filter_properties_for_rent_chip)
                MarsApiFilter.BUY -> check(R.id.filter_properties_for_buy_chip)
            }
        }

    @InverseBindingAdapter(attribute = "propertyTypeFilter")
    @JvmStatic
    fun ChipGroup.convertToMarsApiFilter(): MarsApiFilter = when (checkedChipId) {
        R.id.filter_properties_for_rent_chip -> MarsApiFilter.RENT
        R.id.filter_properties_for_buy_chip -> MarsApiFilter.BUY
        else -> MarsApiFilter.ALL
    }

    @BindingAdapter("propertyTypeFilterAttrChanged")
    @JvmStatic
    fun ChipGroup.setListeners(attrChange: InverseBindingListener?) =
        setOnCheckedChangeListener { _, _ -> attrChange?.onChange() }
}
...

• MarsApiFilter 是我的具体案例的枚举类。

some_layout.xml:

...
<com.google.android.material.chip.ChipGroup
    android:id="@+id/filter_property_type_chip_group"
    ...
    bind:propertyTypeFilter="@={viewModel.propertyTypeFilter}"
    >

    <com.google.android.material.chip.Chip
        android:id="@+id/filter_all_properties_chip"
        ...
        />

    <com.google.android.material.chip.Chip
        android:id="@+id/filter_properties_for_rent_chip"
        ...
        />

    <com.google.android.material.chip.Chip
        android:id="@+id/filter_properties_for_buy_chip"
        ...
        />
</com.google.android.material.chip.ChipGroup>
...

• bind 只是一个花哨的命名空间，声明为常规命名空间：xmlns:bind="http://schemas.android.com/apk/res-auto"

SomeViewModel.kt:

...
val propertyTypeFilter = MutableLiveData<MarsApiFilter>().apply { value = MarsApiFilter.ALL }
...

Answer 3

if (attrChange == null) {
            view?.setOnCheckedChangeListener(listener)
        } else {
            view?.setOnCheckedChangeListener { group, checkedId ->
                listener?.onCheckedChanged(group, checkedId)
                attrChange.onChange()
                }
            }
        }

也许应该是

if (listener != null) {
            view?.setOnCheckedChangeListener(listener)
        } else {
            view?.setOnCheckedChangeListener { group, checkedId ->
                listener?.onCheckedChanged(group, checkedId)
                attrChange.onChange()
                }
            }
        }