【Compose】Android Compose 监听TextField粘贴事件

背景

项目中需要监听输入框（也就是TextField组件）的粘贴事件，Compose的TextField不像android.view的EditText中一样，重写onTextContextMenuItem方法就可以做到监听，Compose中而是使用改变provider来实现。

实现

1. 获取本地TextToolbar

kotlin 复制代码

val defaultTextToolbar = LocalTextToolbar.current

2. 重写TextToolbar

kotlin 复制代码

val pasteListeningTextToolbar = remember{
    object : TextToolbar {
        override fun hide() {
            defaultTextToolbar.hide()
        }

        override val status: TextToolbarStatus
            get() = defaultTextToolbar.status

        override fun showMenu(
            rect: Rect,
            onCopyRequested: (() -> Unit)?,
            onPasteRequested: (() -> Unit)?,
            onCutRequested: (() -> Unit)?,
            onSelectAllRequested: (() -> Unit)?
        ) {
            val wrappedPasteCallback = {
                onPasteRequested?.invoke()
                println("paste event happen")
            }

            defaultTextToolbar.showMenu(
                rect,
                onCopyRequested,
                wrappedPasteCallback,
                onCutRequested,
                onSelectAllRequested,
            )
        }
    }
}

关键点

只拦截粘贴事件，其他保持不变

kotlin 复制代码

val wrappedPasteCallback = {
    onPasteRequested?.invoke() // 保持原始粘帖功能
    // 添加自定义逻辑，也可以加自定义的callback,我这里直接输入
    println("paste event happen")
}

其后，再把其他功能回调原封不动的传递给默认TextToolbar

kotlin 复制代码

defaultTextToolbar.showMenu(
    rect,
    onCopyRequested,         // 原始复制功能
    wrappedPasteCallback,    // 包装后的粘贴
    onCutRequested,          // 原始剪切功能
    onSelectAllRequested      // 原始全选功能
)

3. 替换默认的TextToolbar

替换原有的TextToolbar，为自定义的TextToolbar

kotlin 复制代码

CompositionLocalProvider(LocalTextToolbar providers pasteListeningTextToolbar){
    TextField(
        value = text,
        onValueChange = { text = id },
    )
}

完整Composeable代码

kotlin 复制代码

@Composable
fun TextFieldWithPasteCallback(
) {
    var text by remember { mutableStateOf("") }
    var state = rememberTextFieldState()
    var defaultTextToolbar = LocalTextToolbar.current

    var pasteListeningToolbar = remember {
        object : TextToolbar {
            override fun hide() {
                defaultTextToolbar.hide()
            }

            override val status: TextToolbarStatus
                get() = defaultTextToolbar.status

            override fun showMenu(
                rect: Rect,
                onCopyRequested: (() -> Unit)?,
                onPasteRequested: (() -> Unit)?,
                onCutRequested: (() -> Unit)?,
                onSelectAllRequested: (() -> Unit)?
            ) {
                val wrappedPasteCallback = {
                    onPasteRequested?.invoke()
                    println("paste event happen")
                }

                defaultTextToolbar.showMenu(
                    rect,
                    onCopyRequested,
                    wrappedPasteCallback,
                    onCutRequested,
                    onSelectAllRequested,
                )
            }
        }
    }

    CompositionLocalProvider(LocalTextToolbar provides pasteListeningToolbar) {
        TextField(
            placeholder = {
                Text("input placeholder")
            },
            value = text,
            onValueChange = {
                println("text:$it")
                text = it
            }
        )
    }
}