Input connection for numeric type keyboard

问题:

I did my custom pin-code view

class StarsPasswordView : LinearLayout {

    constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(context, attrs, defStyle) {
        init(context, attrs)
    }

    val passwordHolder = SpannableStringBuilder()

    var count

    fun init(context: Context, attrs: AttributeSet?) {
        orientation = HORIZONTAL
        isFocusable = true
        isFocusableInTouchMode = true
        gravity = Gravity.CENTER

        val attr = context.obtainStyledAttributes(attrs, R.styleable.StarsPasswordView, 0, 0)
        count = attr.getInteger(R.styleable.StarsPasswordView_count, 4)
        attr.recycle()

        drawView(count)

        setOnKeyListener(View.OnKeyListener { v, keyCode, event ->
            if (event.action == KeyEvent.ACTION_DOWN) {
                if (keyCode == KeyEvent.KEYCODE_ENTER)
                    return@OnKeyListener true
                if (keyCode == KeyEvent.KEYCODE_BACK)
                    return@OnKeyListener false
                if (keyCode == KeyEvent.KEYCODE_DEL) {
                    clear()
                    get(0).requestFocus()
                } else
                    if (passwordHolder.length != count) {
                        passwordHolder.append(event.number)
                        val position = passwordHolder.length
                        select(position - 1)

                        if (position < count)
                            get(position).requestFocus()
                        else {
                            passwordFilled?.invoke(passwordHolder.toString())
                        }
                    }
                return@OnKeyListener true
            }
            false
        })
    }

    fun samsungWorkaround() {
        val position = passwordHolder.length
        select(position - 1)

        if (position == count)
            passwordFilled?.invoke(passwordHolder.toString())
        }
    }


    // toggle whether the keyboard is showing when the view is clicked
    override fun onTouchEvent(event: MotionEvent): Boolean {
        if (enableKeyboard && event.action == MotionEvent.ACTION_UP) {
            val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
            imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, InputMethodManager.HIDE_IMPLICIT_ONLY)
        }
        return true
    }

    override fun onCreateInputConnection(outAttrs: EditorInfo): InputConnection {
        outAttrs.inputType = InputType.TYPE_CLASS_NUMBER
        return InputConnection(this, true)
    }
}

class InputConnection internal constructor(val targetView: StarsPasswordView, fullEditor: Boolean) : BaseInputConnection(targetView, fullEditor) {

    override fun getEditable(): Editable {
        return targetView.passwordHolder
    }
    override fun commitText(text: CharSequence?, newCursorPosition: Int): Boolean {
        val res =  super.commitText(text, newCursorPosition)
        targetView.samsungWorkaround()
        return res
    }
}

The problem comes when you want to set

 outAttrs.inputType = InputType.TYPE_CLASS_NUMBER

at this case

• InputConnection doesn't handle numbers
• getEditable() doesn't fire

• commitText() doesn't fire

  so my workaround was just handling numbs in setOnKeyListener as you can see above.

Does anyone know what the issue is?

回答1:

Depending on the keyboard, not all keys are sent through the InputConnection. Some are sent like hard keys events and must be processed separately. This includes the number pad numbers on the standard keyboard. To the best of my current knowledge, using the OnKeyListener like you did is the way to go (but see @pskink's comments here).

You can separate the text characters from the control characters with KeyEvent.getUnicodeChar() as is shown below.

if (keyEvent.getUnicodeChar() != 0) {
    // unicode text
    char unicodeChar = (char) keyEvent.getUnicodeChar();
} else {
    // control char
}

Handle the control codes that you need, but all the valid Unicode characters (including numbers and the new line (enter) character) will be caught.

I cover some aspects of this in more detail in the question and answers I wrote while preparing to answer this question.

• Differentiating text keycode from control keycode in Android KeyEvent
• Need table of key codes for android and presenter

I also updated my previous answer about custom views receiving keyboard input.