ADROID 2.1 架构解析 8 触摸屏
8 触摸屏
8.1 分类输入事件
文件：frameworks/base/libs/ui/EventHub.cpp
int EventHub::open_device(const char *deviceName)
{
...
uint8_t key_bitmask[(KEY_MAX+1)/8];
memset(key_bitmask, 0, sizeof(key_bitmask));
LOGV("Getting keys...");
if (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(key_bitmask)), key_bitmask) >= 0) {
//LOGI("MAP/n");
//for (int i=0; i<((KEY_MAX+1)/8); i++) {
// LOGI("%d: 0x%02x/n", i, key_bitmask[i]);
//}
for (int i=0; i<((BTN_MISC+7)/8); i++) {
if (key_bitmask[i] != 0) {
device->classes |= CLASS_KEYBOARD;
break;
}
}
if ((device->classes & CLASS_KEYBOARD) != 0) {
device->keyBitmask = new uint8_t[sizeof(key_bitmask)];
if (device->keyBitmask != NULL) {
memcpy(device->keyBitmask, key_bitmask, sizeof(key_bitmask));
} else {
delete device;
LOGE("out of memory allocating key bitmask");
return -1;
}
}
}
// See if this is a trackball.
if (test_bit(BTN_MOUSE, key_bitmask)) {
uint8_t rel_bitmask[(REL_MAX+1)/8];
memset(rel_bitmask, 0, sizeof(rel_bitmask));
LOGV("Getting relative controllers...");
if (ioctl(fd, EVIOCGBIT(EV_REL, sizeof(rel_bitmask)), rel_bitmask) >= 0)
{
if (test_bit(REL_X, rel_bitmask) && test_bit(REL_Y, rel_bitmask)) {
device->classes |= CLASS_TRACKBALL;
}
}
}
uint8_t abs_bitmask[(ABS_MAX+1)/8];
memset(abs_bitmask, 0, sizeof(abs_bitmask));
LOGV("Getting absolute controllers...");
ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(abs_bitmask)), abs_bitmask);
// Is this a new modern multi-touch driver?
if (test_bit(ABS_MT_TOUCH_MAJOR, abs_bitmask)
&& test_bit(ABS_MT_POSITION_X, abs_bitmask)
&& test_bit(ABS_MT_POSITION_Y, abs_bitmask)) {
device->classes |= CLASS_TOUCHSCREEN | CLASS_TOUCHSCREEN_MT;
// Is this an old style single-touch driver?
} else if (test_bit(BTN_TOUCH, key_bitmask)
&& test_bit(ABS_X, abs_bitmask) && test_bit(ABS_Y, abs_bitmask)) {
device->classes |= CLASS_TOUCHSCREEN;
}
...
}
输入事件有：键盘、轨迹球、单点触摸、多点触摸
8.2 输入事件服务
文件：frameworks/base/services/java/com/android/server/KeyInputQueue.java
8.2.1 获取事件
Thread mThread = new Thread("InputDeviceReader") {
public void run() {
if (DEBUG) Log.v(TAG, "InputDeviceReader.run()");
android.os.Process.setThreadPriority(
android.os.Process.THREAD_PRIORITY_URGENT_DISPLAY);
RawInputEvent ev = new RawInputEvent();
while (true) {
try {
...
// block, doesn't release the monitor
readEvent(ev);
...
调用readEvent，将输入事件读取到ev类，即RawInputEvent的变量里，readEvent对应jni的android_server_KeyInputQueue_readEvent
8.2.2 获取触摸点数据
// Process position events from multitouch protocol.
else if (ev.type == RawInputEvent.EV_ABS &&
(classes&RawInputEvent.CLASS_TOUCHSCREEN_MT) != 0) {
if (ev.scancode == RawInputEvent.ABS_MT_TOUCH_MAJOR) {
di.mAbs.changed = true;
di.mAbs.mNextData[di.mAbs.mAddingPointerOffset
+ MotionEvent.SAMPLE_PRESSURE] = ev.value;
} else if (ev.scancode == RawInputEvent.ABS_MT_POSITION_X) {
di.mAbs.changed = true;
di.mAbs.mNextData[di.mAbs.mAddingPointerOffset
+ MotionEvent.SAMPLE_X] = ev.value;
if (DEBUG_POINTERS) Log.v(TAG, "MT @"
+ di.mAbs.mAddingPointerOffset
+ " X:" + ev.value);
} else if (ev.scancode == RawInputEvent.ABS_MT_POSITION_Y) {
di.mAbs.changed = true;
di.mAbs.mNextData[di.mAbs.mAddingPointerOffset
+ MotionEvent.SAMPLE_Y] = ev.value;
if (DEBUG_POINTERS) Log.v(TAG, "MT @"
+ di.mAbs.mAddingPointerOffset
+ " Y:" + ev.value);
} else if (ev.scancode == RawInputEvent.ABS_MT_WIDTH_MAJOR) {
di.mAbs.changed = true;
di.mAbs.mNextData[di.mAbs.mAddingPointerOffset
+ MotionEvent.SAMPLE_SIZE] = ev.value;
}
// Process position events from single touch protocol.
} else if (ev.type == RawInputEvent.EV_ABS &&
(classes&RawInputEvent.CLASS_TOUCHSCREEN) != 0) {
if (ev.scancode == RawInputEvent.ABS_X) {
di.mAbs.changed = true;
di.curTouchVals[MotionEvent.SAMPLE_X] = ev.value;
} else if (ev.scancode == RawInputEvent.ABS_Y) {
di.mAbs.changed = true;
di.curTouchVals[MotionEvent.SAMPLE_Y] = ev.value;
} else if (ev.scancode == RawInputEvent.ABS_PRESSURE) {
di.mAbs.changed = true;
di.curTouchVals[MotionEvent.SAMPLE_PRESSURE] = ev.value;
di.curTouchVals[MotionEvent.NUM_SAMPLE_DATA
+ MotionEvent.SAMPLE_PRESSURE] = ev.value;
} else if (ev.scancode == RawInputEvent.ABS_TOOL_WIDTH) {
di.mAbs.changed = true;
di.curTouchVals[MotionEvent.SAMPLE_SIZE] = ev.value;
di.curTouchVals[MotionEvent.NUM_SAMPLE_DATA
+ MotionEvent.SAMPLE_SIZE] = ev.value;
}
}
多点触摸和单点触摸的处理：保存多点或单点触摸的数据。
8.2.3 获取转换后触点数据
if (doMotion) {
// XXX Need to be able to generate
// multiple events here, for example
// if two fingers change up/down state
// at the same time.
do {
me = ms.generateAbsMotion(di, curTime,
curTimeNano, mDisplay,
mOrientation, mGlobalMetaState);
if (DEBUG_POINTERS) Log.v(TAG, "Absolute: x="
+ di.mAbs.mNextData[MotionEvent.SAMPLE_X]
+ " y="
+ di.mAbs.mNextData[MotionEvent.SAMPLE_Y]
+ " ev=" + me);
if (me != null) {
if (WindowManagerPolicy.WATCH_POINTER) {
Log.i(TAG, "Enqueueing: " + me);
}
addLocked(di, curTimeNano, ev.flags,
RawInputEvent.CLASS_TOUCHSCREEN, me);
}
} while (ms.hasMore());
}
获取转换后触摸点数据并加入到输入事件队列。
8.3 读取触摸点数据的流程
文件：frameworks/base/services/java/com/android/server/KeyInputQueue.java
readEvent(ev);
di.curTouchVals[MotionEvent.SAMPLE_X] = ev.value;
文件：frameworks/base/services/jni/com_android_server_KeyInputQueue.cpp
{ "readEvent", "(Landroid/view/RawInputEvent;)Z",
(void*) android_server_KeyInputQueue_readEvent },
..
static jboolean
android_server_KeyInputQueue_readEvent(JNIEnv* env, jobject clazz,
jobject event)
{
...
bool res = hub->getEvent(&deviceId, &type, &scancode, &keycode,
&flags, &value, &when);
...
}
文件：frameworks/base/libs/ui/EventHub.cpp
bool EventHub::getEvent(int32_t* outDeviceId, int32_t* outType,
int32_t* outScancode, int32_t* outKeycode, uint32_t *outFlags,
int32_t* outValue, nsecs_t* outWhen)
{
...
res = read(mFDs[i].fd, &iev, sizeof(iev));
...
*outValue = iev.value;
..
}
8.4 触点数据转换
文件：frameworks/base/services/java/com/android/server/InutDevice.java
MotionEvent generateAbsMotion(InputDevice device, long curTime,
long curTimeNano, Display display, int orientation,
int metaState) {
if (mSkipLastPointers) {
mSkipLastPointers = false;
mLastNumPointers = 0;
}
if (mNextNumPointers <= 0 && mLastNumPointers <= 0) {
return null;
}
final int lastNumPointers = mLastNumPointers;
final int nextNumPointers = mNextNumPointers;
if (mNextNumPointers > MAX_POINTERS) {
Log.w("InputDevice", "Number of pointers " + mNextNumPointers
+ " exceeded maximum of " + MAX_POINTERS);
mNextNumPointers = MAX_POINTERS;
}
int upOrDownPointer = updatePointerIdentifiers();
final float[] reportData = mReportData;
final int[] rawData;
if (KeyInputQueue.BAD_TOUCH_HACK) {
rawData = generateAveragedData(upOrDownPointer, lastNumPointers,
nextNumPointers);
} else {
rawData = mLastData;
}
final int numPointers = mLastNumPointers;
if (DEBUG_POINTERS) Log.v("InputDevice", "Processing "
+ numPointers + " pointers (going from " + lastNumPointers
+ " to " + nextNumPointers + ")");
for (int i=0; i final int pos = i * MotionEvent.NUM_SAMPLE_DATA; reportData[pos + MotionEvent.SAMPLE_X] = rawData[pos + MotionEvent.SAMPLE_X]; reportData[pos + MotionEvent.SAMPLE_Y] = rawData[pos + MotionEvent.SAMPLE_Y]; reportData[pos + MotionEvent.SAMPLE_PRESSURE] = rawData[pos + MotionEvent.SAMPLE_PRESSURE]; reportData[pos + MotionEvent.SAMPLE_SIZE] = rawData[pos + MotionEvent.SAMPLE_SIZE]; } int action; int edgeFlags = 0; if (nextNumPointers != lastNumPointers) { if (nextNumPointers > lastNumPointers) { if (lastNumPointers == 0) { action = MotionEvent.ACTION_DOWN; mDownTime = curTime; } else { action = MotionEvent.ACTION_POINTER_DOWN | (upOrDownPointer << MotionEvent.ACTION_POINTER_ID_SHIFT); } } else { if (numPointers == 1) { action = MotionEvent.ACTION_UP; } else { action = MotionEvent.ACTION_POINTER_UP | (upOrDownPointer << MotionEvent.ACTION_POINTER_ID_SHIFT); } } currentMove = null; } else { action = MotionEvent.ACTION_MOVE; } final int dispW = display.getWidth()-1; final int dispH = display.getHeight()-1; int w = dispW; int h = dispH; if (orientation == Surface.ROTATION_90 || orientation == Surface.ROTATION_270) { int tmp = w; w = h; h = tmp; } final AbsoluteInfo absX = device.absX; final AbsoluteInfo absY = device.absY; final AbsoluteInfo absPressure = device.absPressure; final AbsoluteInfo absSize = device.absSize; for (int i=0; i final int j = i * MotionEvent.NUM_SAMPLE_DATA; if (absX != null) { reportData[j + MotionEvent.SAMPLE_X] = ((reportData[j + MotionEvent.SAMPLE_X]-absX.minValue) / absX.range) * w; } if (absY != null) { reportData[j + MotionEvent.SAMPLE_Y] = ((reportData[j + MotionEvent.SAMPLE_Y]-absY.minValue) / absY.range) * h; } if (absPressure != null) { reportData[j + MotionEvent.SAMPLE_PRESSURE] = ((reportData[j + MotionEvent.SAMPLE_PRESSURE]-absPressure.minValue) / (float)absPressure.range); } if (absSize != null) { reportData[j + MotionEvent.SAMPLE_SIZE] = ((reportData[j + MotionEvent.SAMPLE_SIZE]-absSize.minValue) / (float)absSize.range); } switch (orientation) { case Surface.ROTATION_90: { final float temp = reportData[j + MotionEvent.SAMPLE_X]; reportData[j + MotionEvent.SAMPLE_X] = reportData[j + MotionEvent.SAMPLE_Y]; reportData[j + MotionEvent.SAMPLE_Y] = w-temp; break; } case Surface.ROTATION_180: { reportData[j + MotionEvent.SAMPLE_X] = w-reportData[j + MotionEvent.SAMPLE_X]; reportData[j + MotionEvent.SAMPLE_Y] = h-reportData[j + MotionEvent.SAMPLE_Y]; break; } case Surface.ROTATION_270: { final float temp = reportData[j + MotionEvent.SAMPLE_X]; reportData[j + MotionEvent.SAMPLE_X] = h-reportData[j + MotionEvent.SAMPLE_Y]; reportData[j + MotionEvent.SAMPLE_Y] = temp; break; } } } // We only consider the first pointer when computing the edge // flags, since they are global to the event. if (action == MotionEvent.ACTION_DOWN) { if (reportData[MotionEvent.SAMPLE_X] <= 0) { edgeFlags |= MotionEvent.EDGE_LEFT; } else if (reportData[MotionEvent.SAMPLE_X] >= dispW) { edgeFlags |= MotionEvent.EDGE_RIGHT; } if (reportData[MotionEvent.SAMPLE_Y] <= 0) { edgeFlags |= MotionEvent.EDGE_TOP; } else if (reportData[MotionEvent.SAMPLE_Y] >= dispH) { edgeFlags |= MotionEvent.EDGE_BOTTOM; } } if (currentMove != null) { if (false) Log.i("InputDevice", "Adding batch x=" + reportData[MotionEvent.SAMPLE_X] + " y=" + reportData[MotionEvent.SAMPLE_Y] + " to " + currentMove); currentMove.addBatch(curTime, reportData, metaState); if (WindowManagerPolicy.WATCH_POINTER) { Log.i("KeyInputQueue", "Updating: " + currentMove); } return null; } MotionEvent me = MotionEvent.obtainNano(mDownTime, curTime, curTimeNano, action, numPointers, mPointerIds, reportData, metaState, xPrecision, yPrecision, device.id, edgeFlags); if (action == MotionEvent.ACTION_MOVE) { currentMove = me; } if (nextNumPointers < lastNumPointers) { removeOldPointer(upOrDownPointer); } return me; } 将原始数据点转化为显示屏对应的数据，一般触摸屏校正就在这里对数据点进行较正的。
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