Android | 测试框架之 UI Testing - 实现多点触控事件

UiAutomator已经现有的的 API 没有提高多点触控的方法，但是我们可以通过注入多点事件的方式来实现。

Android TouchEvent Flow

一个基本的单点事件流

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MotionEvent.ACTION_DOWN
MotionEvent.ACTION_MOVE
MotionEvent.ACTION_UP

如果加上多点事件，基本的事件流是这样的：

MotionEvent.ACTION_DOWN
MotionEvent.ACTION_POINTER_DOWN
MotionEvent.ACTION_MOVE
MotionEvent.ACTION_POINTER_UP
MotionEvent.ACTION_UP

需要明白的点：

无论多点还是单点，正常的事件流是以ACTION_DOWN开始 ACTION_UP结束。

对于多点事件来说，当你第一个手指点击屏幕触发ACTION_DOWN，后面的手指按压触发ACTION_POINTER_DOWN，然后进过ACTION_MOVE，ACTION_POINTER_UP，最终到达ACTION_UP。

事件注入有个原则是： 1.ACTION_POINTER_UP和ACTION_UP的点是ACTION_MOVE后的最后那个点； 2.ACTION_POINTER_UP与ACTION_UP的点和ACTION_POINTER_DOWN与ACTION_DOWN的点应该一一对应的； 3.先DOWN的点应该后UP

代码实现

UiAutomator：事件注入入口

UiAutomator：测试框架已经为我们准备好了相关的方法。

Instrumentation mInstrumentation = InstrumentationRegistry.getInstrumentation();
UiAutomation mUiAutomation = mInstrumentation.getUiAutomation();

// 这就是注入事件的方法
mUiAutomation.injectInputEvent(InputEvent event, boolean sync)

MotionEvent：相关类和方法

MotionEvent.PointerCoords：Point 坐标传输对象，有点像的DTO意思，里面包含了位置，大小，压力等属性，
MotionEvent.PointerProperties：Point 属性传输对象，有点像的DTO意思，里面包含了 ID，TYPE：区分是鼠标，手指等等不同设备的 Pointer

MotionEvent.obtain(long downTime, long eventTime,
            int action, int pointerCount, PointerProperties[] pointerProperties,
            PointerCoords[] pointerCoords, int metaState, int buttonState,
            float xPrecision, float yPrecision, int deviceId,
            int edgeFlags, int source, int flags)

我们使用这个方法来创建一个 MotionEvent，用于事件的注入。

详细代码

public void test() {
    // 伪代码
    // 创建一个二维数组
    // [[PointerCoords，...], [PointerCoords, ..], [PointerCoords, ..], ...]
    // 二维数组的第一个点，为DOWN点，后面的为MOVE点，最后一个就是UP点。

    injectMultiTouch([[PointerCoords，...],[PointerCoords，...]]);
}

private PointerCoords createPoint(int x, int y) {
    PointerCoords pointerCoords = new PointerCoords();
    pointerCoords.x = x;
    pointerCoords.y = y;
    pointerCoords.pressure = 1;
    pointerCoords.size = 1;
    return pointerCoords;
}

// 这里的参数是个二维数组，一维代表点的个度，二维代表点的移动位置
private boolean injectMultiTouch(PointerCoords[]... touches) {
    boolean ret = true;
    if (touches.length < 2) {
        throw new IllegalArgumentException("Must provide coordinates for at least 2 pointers");
    }

    int maxSteps = 0;
    for (int x = 0; x < touches.length; x++)
        maxSteps = (maxSteps < touches[x].length) ? touches[x].length : maxSteps;

    PointerProperties[] properties = new PointerProperties[touches.length];
    PointerCoords[] pointerCoords = new PointerCoords[touches.length];
    for (int x = 0; x < touches.length; x++) {
        MotionEvent.PointerProperties prop = new MotionEvent.PointerProperties();
        prop.id = x;
        prop.toolType = MotionEvent.TOOL_TYPE_FINGER;
        properties[x] = prop;

        pointerCoords[x] = touches[x][0];
    }

    long downTime = SystemClock.uptimeMillis();
    MotionEvent event;
    event = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_DOWN, 1,
            properties, pointerCoords, 0, 0, 1, 1, 0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);
    ret &= mUiAutomation.injectInputEvent(event, true);

    for (int x = 1; x < touches.length; x++) {
        event = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(),
            getPointerAction(MotionEvent.ACTION_POINTER_DOWN, x), x + 1, properties,
            pointerCoords, 0, 0, 1, 1, 0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);
        ret &= mUiAutomation.injectInputEvent(event, true);
    }

    for (int i = 1; i < maxSteps - 1; i++) {
        for (int x = 0; x < touches.length; x++) {
            if (touches[x].length > i)
                pointerCoords[x] = touches[x][i];
            else
                pointerCoords[x] = touches[x][touches[x].length - 1];
        }

        event = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(),
                MotionEvent.ACTION_MOVE, touches.length, properties, pointerCoords, 0, 0, 1, 1,
                0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);

        ret &= mUiAutomation.injectInputEvent(event, true);
        SystemClock.sleep(5);
    }

    for (int x = 0; x < touches.length; x++)
        pointerCoords[x] = touches[x][touches[x].length - 1];

    for (int x = 1; x < touches.length; x++) {
        event = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(),
                getPointerAction(MotionEvent.ACTION_POINTER_UP, x), x + 1, properties,
                pointerCoords, 0, 0, 1, 1, 0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);
        ret &= mUiAutomation.injectInputEvent(event, true);
    }

    event = MotionEvent.obtain(downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_UP, 1,
                properties, pointerCoords, 0, 0, 1, 1, 0, 0, InputDevice.SOURCE_TOUCHSCREEN, 0);
    ret &= mUiAutomation.injectInputEvent(event, true);

    return ret;
}