android - 如何区分D-pad运动和操纵杆运动？

我需要有两种不同的行为，一种用于D-pad，另一种用于模拟游戏杆(在同一游戏板上)。

问题是在onGenericMotionEvent回调上，两者在MotionEvent上都具有相同的信息，而我无法区分它们。

// d-pad
MotionEvent { action=ACTION_MOVE, id[0]=0, x[0]=-1.5259255E-5, y[0]=-1.5259255E-5, toolType[0]=TOOL_TYPE_UNKNOWN, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=151637936, downTime=0, deviceId=5, source=0x1000010 }

// analog joystick
MotionEvent { action=ACTION_MOVE, id[0]=0, x[0]=0.64507514, y[0]=0.710811, toolType[0]=TOOL_TYPE_UNKNOWN, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=151650802, downTime=0, deviceId=5, source=0x1000010 }

是否可以确定正在使用哪种输入？如何？

最佳答案

我遇到了同样的问题，我不得不仔细研究this helpful Git user's project以弄清楚他是如何做到的。区分不同操纵杆(和D-pad)的方法是使用每个方向的特定轴。

如果您非常仔细地阅读了Android documentation's page(我没有读过)，它的确显示了如何区分各种操纵杆及其方向:



此图显示左操纵杆使用 AXIS_X 和轴AXIS_Y ，而右操纵杆使用 AXIS_Z 和 AXIS_RZ 。对于D-pad，我使用了 AXIS_HAT_X 和 AXIS_HAT_Y 。我的代码中的以下代码段(在Kotlin中)显示了如何分别访问每个代码:

注意:我的搜索栏也设置为0-100，这就是为什么在processJoystickInput()的底部设置了转换数学的原因。

private fun processJoystickInput(event: MotionEvent, historyPos: Int) {

    val inputDevice = event.device

    val newJoystickValues = floatArrayOf(
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_X, historyPos),
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_Y, historyPos),
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_Z, historyPos),
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_RZ, historyPos),
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_HAT_X, historyPos),
            getCenteredAxis(event, inputDevice, MotionEvent.AXIS_HAT_Y, historyPos))

    // Update based on the new x and y values
    val throttleSeekBar = findViewById<SeekBar>(R.id.throttle_seekBar)
    val yawSeekBar = findViewById<SeekBar>(R.id.yaw_seekBar)
    val pitchSeekBar = findViewById<SeekBar>(R.id.pitch_seekBar)
    val rollSeekBar = findViewById<SeekBar>(R.id.roll_seekBar)
    val dpadXSeekBar = findViewById<SeekBar>(R.id.dpadX_seekBar)
    val dpadYSeekBar = findViewById<SeekBar>(R.id.dpadY_seekBar)

    // Convert the float range (-1.00 to 1.00) to Int (0 to 100)
    yawSeekBar.progress = ((newJoystickValues[0] + 1) * 50).toInt()
    throttleSeekBar.progress = ((newJoystickValues[1] + 1) * 50).toInt()
    rollSeekBar.progress = ((newJoystickValues[2] + 1) * 50).toInt()
    pitchSeekBar.progress = ((newJoystickValues[3] + 1) * 50).toInt()
    dpadXSeekBar.progress = ((newJoystickValues[4] + 1) * 50).toInt()
    dpadYSeekBar.progress = ((newJoystickValues[5] + 1) * 50).toInt()
}

override fun onGenericMotionEvent(event: MotionEvent): Boolean {
    // Check that the event came from a game controller

    return if (event.source and(InputDevice.SOURCE_JOYSTICK) == InputDevice.SOURCE_JOYSTICK
            && event.action == MotionEvent.ACTION_MOVE) {

        // Process the movements starting from the
        // earliest historical position in the batch
        (0 until event.historySize).forEach { i ->
            // Process the event at historical position i
            processJoystickInput(event, i)
        }

        // Process the current movement sample in the batch (position -1)
        processJoystickInput(event, -1)
        true
    } else {
        super.onGenericMotionEvent(event)
    }
}