SyncPointerCapture (5/n): Move Pointer Capture to InputDispatcher
This CL re-implements Pointer Capture in InputDispatcher, moving it away
for WindowManagerService.
The pipeline for Pointer Capture is changed so that requests to enable
and disable Pointer Capture from an app are redirected directly to
InputDispatcher by InputManagerService.
The new expected pipeline for Pointer Capture is as follows:
- App requests Pointer Capture through InputManagerService with its
window token.
- InputManagerService gets the InputWindowToken for the WindowToken, and
relays the Pointer Capture request to InputDispatcher.
- Pointer Capture is enabled in InputFlinger:
1. InputDispatcher receives the Pointer Capture request, and ignores
requests from windows that are not focused.
InputDispatcherInterface::requestPointerCapture(windowToken,
enabled)
2. InputDispatcher sets the Pointer Capture state through its policy,
which sends a configuration change to InputReader.
InputDispatcherPolicyInterface::setPointerCapture(enabled)
3. InputReader changes its configuration to enable/disable Pointer
Capture, and sends notifyPointerCaptureChanged to InputDispatcher.
InputListener::notifyPointerCaptureChanged(args)
4. The Pointer Capture change notification is sent to the input
channel.
- App receives a Pointer Capture change event through its InputChannel.
The window that has Pointer Capture is tracked in InputDispatcher. If
the window loses focus, Pointer Capture is disabled immediately, and
InputDispatcher synthesizes a Pointer Capture change event to dispatch
to the app before it sends the event signalling the focus loss.
Bug: 141749603
Test: atest inputflinger_tests
Test: atest PointerCaptureTest (CTS)
Test: manual: Pointer Capture works
Change-Id: Ie27f6e279af9b0d844160fb146476e1812fb02b3
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index ed4f05a..6c44a54 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -454,6 +454,8 @@
mInTouchMode(true),
mMaximumObscuringOpacityForTouch(1.0f),
mFocusedDisplayId(ADISPLAY_ID_DEFAULT),
+ mFocusedWindowRequestedPointerCapture(false),
+ mWindowTokenWithPointerCapture(nullptr),
mCompatService(getCompatService()) {
mLooper = new Looper(false);
mReporter = createInputReporter();
@@ -713,6 +715,14 @@
break;
}
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
+ const auto typedEntry =
+ std::static_pointer_cast<PointerCaptureChangedEntry>(mPendingEvent);
+ dispatchPointerCaptureChangedLocked(currentTime, typedEntry, dropReason);
+ done = true;
+ break;
+ }
+
case EventEntry::Type::KEY: {
std::shared_ptr<KeyEntry> keyEntry = std::static_pointer_cast<KeyEntry>(mPendingEvent);
if (isAppSwitchDue) {
@@ -862,7 +872,8 @@
break;
}
case EventEntry::Type::CONFIGURATION_CHANGED:
- case EventEntry::Type::DEVICE_RESET: {
+ case EventEntry::Type::DEVICE_RESET:
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
// nothing to do
break;
}
@@ -968,6 +979,10 @@
ALOGI("Dropped event because it is stale.");
reason = "inbound event was dropped because it is stale";
break;
+ case DropReason::NO_POINTER_CAPTURE:
+ ALOGI("Dropped event because there is no window with Pointer Capture.");
+ reason = "inbound event was dropped because there is no window with Pointer Capture";
+ break;
case DropReason::NOT_DROPPED: {
LOG_ALWAYS_FATAL("Should not be dropping a NOT_DROPPED event");
return;
@@ -991,6 +1006,9 @@
}
break;
}
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
+ break;
+ }
case EventEntry::Type::FOCUS:
case EventEntry::Type::CONFIGURATION_CHANGED:
case EventEntry::Type::DEVICE_RESET: {
@@ -1176,6 +1194,55 @@
dispatchEventLocked(currentTime, entry, {target});
}
+void InputDispatcher::dispatchPointerCaptureChangedLocked(
+ nsecs_t currentTime, const std::shared_ptr<PointerCaptureChangedEntry>& entry,
+ DropReason& dropReason) {
+ const bool haveWindowWithPointerCapture = mWindowTokenWithPointerCapture != nullptr;
+ if (entry->pointerCaptureEnabled == haveWindowWithPointerCapture) {
+ LOG_ALWAYS_FATAL_IF(mFocusedWindowRequestedPointerCapture,
+ "The Pointer Capture state has already been dispatched to the window.");
+ // Pointer capture was already forcefully disabled because of focus change.
+ dropReason = DropReason::NOT_DROPPED;
+ return;
+ }
+
+ // Set drop reason for early returns
+ dropReason = DropReason::NO_POINTER_CAPTURE;
+
+ sp<IBinder> token;
+ if (entry->pointerCaptureEnabled) {
+ // Enable Pointer Capture
+ if (!mFocusedWindowRequestedPointerCapture) {
+ // This can happen if a window requests capture and immediately releases capture.
+ ALOGW("No window requested Pointer Capture.");
+ return;
+ }
+ token = getValueByKey(mFocusedWindowTokenByDisplay, mFocusedDisplayId);
+ LOG_ALWAYS_FATAL_IF(!token, "Cannot find focused window for Pointer Capture.");
+ mWindowTokenWithPointerCapture = token;
+ } else {
+ // Disable Pointer Capture
+ token = mWindowTokenWithPointerCapture;
+ mWindowTokenWithPointerCapture = nullptr;
+ mFocusedWindowRequestedPointerCapture = false;
+ }
+
+ auto channel = getInputChannelLocked(token);
+ if (channel == nullptr) {
+ // Window has gone away, clean up Pointer Capture state.
+ mWindowTokenWithPointerCapture = nullptr;
+ mFocusedWindowRequestedPointerCapture = false;
+ return;
+ }
+ InputTarget target;
+ target.inputChannel = channel;
+ target.flags = InputTarget::FLAG_DISPATCH_AS_IS;
+ entry->dispatchInProgress = true;
+ dispatchEventLocked(currentTime, entry, {target});
+
+ dropReason = DropReason::NOT_DROPPED;
+}
+
bool InputDispatcher::dispatchKeyLocked(nsecs_t currentTime, std::shared_ptr<KeyEntry> entry,
DropReason* dropReason, nsecs_t* nextWakeupTime) {
// Preprocessing.
@@ -1483,6 +1550,7 @@
displayId = motionEntry.displayId;
break;
}
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED:
case EventEntry::Type::FOCUS:
case EventEntry::Type::CONFIGURATION_CHANGED:
case EventEntry::Type::DEVICE_RESET: {
@@ -2366,8 +2434,10 @@
}
void InputDispatcher::pokeUserActivityLocked(const EventEntry& eventEntry) {
- if (eventEntry.type == EventEntry::Type::FOCUS) {
- // Focus events are passed to apps, but do not represent user activity.
+ if (eventEntry.type == EventEntry::Type::FOCUS ||
+ eventEntry.type == EventEntry::Type::POINTER_CAPTURE_CHANGED) {
+ // Focus or pointer capture changed events are passed to apps, but do not represent user
+ // activity.
return;
}
int32_t displayId = getTargetDisplayId(eventEntry);
@@ -2405,7 +2475,8 @@
}
case EventEntry::Type::FOCUS:
case EventEntry::Type::CONFIGURATION_CHANGED:
- case EventEntry::Type::DEVICE_RESET: {
+ case EventEntry::Type::DEVICE_RESET:
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
LOG_ALWAYS_FATAL("%s events are not user activity",
EventEntry::typeToString(eventEntry.type));
break;
@@ -2617,7 +2688,8 @@
break;
}
- case EventEntry::Type::FOCUS: {
+ case EventEntry::Type::FOCUS:
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
break;
}
case EventEntry::Type::CONFIGURATION_CHANGED:
@@ -2821,6 +2893,7 @@
reportTouchEventForStatistics(motionEntry);
break;
}
+
case EventEntry::Type::FOCUS: {
const FocusEntry& focusEntry = static_cast<const FocusEntry&>(eventEntry);
status = connection->inputPublisher.publishFocusEvent(dispatchEntry->seq,
@@ -2830,6 +2903,15 @@
break;
}
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
+ const auto& captureEntry =
+ static_cast<const PointerCaptureChangedEntry&>(eventEntry);
+ status = connection->inputPublisher
+ .publishCaptureEvent(dispatchEntry->seq, captureEntry.id,
+ captureEntry.pointerCaptureEnabled);
+ break;
+ }
+
case EventEntry::Type::CONFIGURATION_CHANGED:
case EventEntry::Type::DEVICE_RESET: {
LOG_ALWAYS_FATAL("Should never start dispatch cycles for %s events",
@@ -3124,8 +3206,10 @@
static_cast<const MotionEntry&>(*cancelationEventEntry));
break;
}
- case EventEntry::Type::FOCUS: {
- LOG_ALWAYS_FATAL("Canceling focus events is not supported");
+ case EventEntry::Type::FOCUS:
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
+ LOG_ALWAYS_FATAL("Canceling %s events is not supported",
+ EventEntry::typeToString(cancelationEventEntry->type));
break;
}
case EventEntry::Type::CONFIGURATION_CHANGED:
@@ -3185,7 +3269,8 @@
case EventEntry::Type::KEY:
case EventEntry::Type::FOCUS:
case EventEntry::Type::CONFIGURATION_CHANGED:
- case EventEntry::Type::DEVICE_RESET: {
+ case EventEntry::Type::DEVICE_RESET:
+ case EventEntry::Type::POINTER_CAPTURE_CHANGED: {
LOG_ALWAYS_FATAL("%s event should not be found inside Connections's queue",
EventEntry::typeToString(downEventEntry->type));
break;
@@ -3562,7 +3647,17 @@
args->enabled ? "true" : "false");
#endif
- // TODO(prabirmsp): Implement.
+ bool needWake;
+ { // acquire lock
+ std::scoped_lock _l(mLock);
+ auto entry = std::make_unique<PointerCaptureChangedEntry>(args->id, args->eventTime,
+ args->enabled);
+ needWake = enqueueInboundEventLocked(std::move(entry));
+ } // release lock
+
+ if (needWake) {
+ mLooper->wake();
+ }
}
InputEventInjectionResult InputDispatcher::injectInputEvent(
@@ -4456,6 +4551,24 @@
return dump;
}
+std::string InputDispatcher::dumpPointerCaptureStateLocked() {
+ std::string dump;
+
+ dump += StringPrintf(INDENT "FocusedWindowRequestedPointerCapture: %s\n",
+ toString(mFocusedWindowRequestedPointerCapture));
+
+ std::string windowName = "None";
+ if (mWindowTokenWithPointerCapture) {
+ const sp<InputWindowHandle> captureWindowHandle =
+ getWindowHandleLocked(mWindowTokenWithPointerCapture);
+ windowName = captureWindowHandle ? captureWindowHandle->getName().c_str()
+ : "token has capture without window";
+ }
+ dump += StringPrintf(INDENT "CurrentWindowWithPointerCapture: %s\n", windowName.c_str());
+
+ return dump;
+}
+
void InputDispatcher::dumpDispatchStateLocked(std::string& dump) {
dump += StringPrintf(INDENT "DispatchEnabled: %s\n", toString(mDispatchEnabled));
dump += StringPrintf(INDENT "DispatchFrozen: %s\n", toString(mDispatchFrozen));
@@ -4479,6 +4592,7 @@
dump += dumpFocusedWindowsLocked();
dump += dumpPendingFocusRequestsLocked();
+ dump += dumpPointerCaptureStateLocked();
if (!mTouchStatesByDisplay.empty()) {
dump += StringPrintf(INDENT "TouchStatesByDisplay:\n");
@@ -4860,6 +4974,39 @@
return OK;
}
+void InputDispatcher::requestPointerCapture(const sp<IBinder>& windowToken, bool enabled) {
+ { // acquire lock
+ std::scoped_lock _l(mLock);
+ if (DEBUG_FOCUS) {
+ const sp<InputWindowHandle> windowHandle = getWindowHandleLocked(windowToken);
+ ALOGI("Request to %s Pointer Capture from: %s.", enabled ? "enable" : "disable",
+ windowHandle != nullptr ? windowHandle->getName().c_str()
+ : "token without window");
+ }
+
+ const sp<IBinder> focusedToken =
+ getValueByKey(mFocusedWindowTokenByDisplay, mFocusedDisplayId);
+ if (focusedToken != windowToken) {
+ ALOGW("Ignoring request to %s Pointer Capture: window does not have focus.",
+ enabled ? "enable" : "disable");
+ return;
+ }
+
+ if (enabled == mFocusedWindowRequestedPointerCapture) {
+ ALOGW("Ignoring request to %s Pointer Capture: "
+ "window has %s requested pointer capture.",
+ enabled ? "enable" : "disable", enabled ? "already" : "not");
+ return;
+ }
+
+ mFocusedWindowRequestedPointerCapture = enabled;
+ setPointerCaptureLocked(enabled);
+ } // release lock
+
+ // Wake the thread to process command entries.
+ mLooper->wake();
+}
+
std::optional<int32_t> InputDispatcher::findGestureMonitorDisplayByTokenLocked(
const sp<IBinder>& token) {
for (const auto& it : mGestureMonitorsByDisplay) {
@@ -5578,11 +5725,50 @@
enqueueFocusEventLocked(newFocusedToken, true /*hasFocus*/, reason);
}
+ // If a window has pointer capture, then it must have focus. We need to ensure that this
+ // contract is upheld when pointer capture is being disabled due to a loss of window focus.
+ // If the window loses focus before it loses pointer capture, then the window can be in a state
+ // where it has pointer capture but not focus, violating the contract. Therefore we must
+ // dispatch the pointer capture event before the focus event. Since focus events are added to
+ // the front of the queue (above), we add the pointer capture event to the front of the queue
+ // after the focus events are added. This ensures the pointer capture event ends up at the
+ // front.
+ disablePointerCaptureForcedLocked();
+
if (mFocusedDisplayId == displayId) {
notifyFocusChangedLocked(oldFocusedToken, newFocusedToken);
}
}
+void InputDispatcher::disablePointerCaptureForcedLocked() {
+ if (!mFocusedWindowRequestedPointerCapture && !mWindowTokenWithPointerCapture) {
+ return;
+ }
+
+ ALOGD_IF(DEBUG_FOCUS, "Disabling Pointer Capture because the window lost focus.");
+
+ if (mFocusedWindowRequestedPointerCapture) {
+ mFocusedWindowRequestedPointerCapture = false;
+ setPointerCaptureLocked(false);
+ }
+
+ if (!mWindowTokenWithPointerCapture) {
+ // No need to send capture changes because no window has capture.
+ return;
+ }
+
+ if (mPendingEvent != nullptr) {
+ // Move the pending event to the front of the queue. This will give the chance
+ // for the pending event to be dropped if it is a captured event.
+ mInboundQueue.push_front(mPendingEvent);
+ mPendingEvent = nullptr;
+ }
+
+ auto entry = std::make_unique<PointerCaptureChangedEntry>(mIdGenerator.nextId(), now(),
+ false /* hasCapture */);
+ mInboundQueue.push_front(std::move(entry));
+}
+
/**
* Checks if the window token can be focused on a display. The token can be focused if there is
* at least one window handle that is visible with the same token and all window handles with the
@@ -5626,4 +5812,21 @@
return FocusResult::OK;
}
+
+void InputDispatcher::setPointerCaptureLocked(bool enabled) {
+ std::unique_ptr<CommandEntry> commandEntry = std::make_unique<CommandEntry>(
+ &InputDispatcher::doSetPointerCaptureLockedInterruptible);
+ commandEntry->enabled = enabled;
+ postCommandLocked(std::move(commandEntry));
+}
+
+void InputDispatcher::doSetPointerCaptureLockedInterruptible(
+ android::inputdispatcher::CommandEntry* commandEntry) {
+ mLock.unlock();
+
+ mPolicy->setPointerCapture(commandEntry->enabled);
+
+ mLock.lock();
+}
+
} // namespace android::inputdispatcher