InputFlinger: Add DROP_INPUT feature flags
If a window has the feature DROP_INPUT set, then all touch and
key events directed to the window will be dropped. For touch events,
the events will not go to the window behind it.
The flags are used to enable features that allow for a less trusted
interaction model between apps. See the bug for more details.
Test: atest libgui_test InputDispatcherDropInputFeatureTest
Bug: 197296414
Merged-In: I71d7cf5064c8ce4626cff09b92e15ca38b39cbbe
Change-Id: I71d7cf5064c8ce4626cff09b92e15ca38b39cbbe
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 1899c5f..b8f16b0 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -1802,6 +1802,11 @@
return InputEventInjectionResult::FAILED;
}
+ // Drop key events if requested by input feature
+ if (focusedWindowHandle != nullptr && shouldDropInput(entry, focusedWindowHandle)) {
+ return InputEventInjectionResult::FAILED;
+ }
+
// Compatibility behavior: raise ANR if there is a focused application, but no focused window.
// Only start counting when we have a focused event to dispatch. The ANR is canceled if we
// start interacting with another application via touch (app switch). This code can be removed
@@ -2027,6 +2032,11 @@
}
}
+ // Drop touch events if requested by input feature
+ if (newTouchedWindowHandle != nullptr && shouldDropInput(entry, newTouchedWindowHandle)) {
+ newTouchedWindowHandle = nullptr;
+ }
+
// Drop events that can't be trusted due to occlusion
if (newTouchedWindowHandle != nullptr &&
mBlockUntrustedTouchesMode != BlockUntrustedTouchesMode::DISABLED) {
@@ -2113,6 +2123,13 @@
sp<InputWindowHandle> oldTouchedWindowHandle =
tempTouchState.getFirstForegroundWindowHandle();
newTouchedWindowHandle = findTouchedWindowAtLocked(displayId, x, y, &tempTouchState);
+
+ // Drop touch events if requested by input feature
+ if (newTouchedWindowHandle != nullptr &&
+ shouldDropInput(entry, newTouchedWindowHandle)) {
+ newTouchedWindowHandle = nullptr;
+ }
+
if (oldTouchedWindowHandle != newTouchedWindowHandle &&
oldTouchedWindowHandle != nullptr && newTouchedWindowHandle != nullptr) {
if (DEBUG_FOCUS) {
@@ -6116,6 +6133,19 @@
return result == std::cv_status::no_timeout;
}
+bool InputDispatcher::shouldDropInput(const EventEntry& entry,
+ const sp<InputWindowHandle>& windowHandle) const {
+ if (windowHandle->getInfo()->inputFeatures.test(InputWindowInfo::Feature::DROP_INPUT)) {
+ ALOGW("Dropping %s event targeting %s as requested by inputFeatures={%s} on display "
+ "%" PRId32 ".",
+ entry.getDescription().c_str(), windowHandle->getName().c_str(),
+ windowHandle->getInfo()->inputFeatures.string().c_str(),
+ windowHandle->getInfo()->displayId);
+ return true;
+ }
+ return false;
+}
+
/**
* Sets focus to the window identified by the token. This must be called
* after updating any input window handles.