commit 0f6558d6808fcc6f6e852af3b40b2e8e400ad3e7
author Siarhei Vishniakou <svv@google.com> Fri Apr 21 12:05:13 2023 -0700
committer Siarhei Vishniakou <svv@google.com> Mon Apr 24 22:00:36 2023 +0000
tree e90bc8a5fbd5cd1bdc3e4a28747436c483f4795b
parent fe46a177d53b3045080de207287a43996e43e958

Do not slip touch into window with same input channel

When two windows have the same input channel, do not slip touch from one
of them into the other. We don't have a use case for that, and
supporting this behaviour would be harder than simply disabling it.

Without slipping, the input channel also receives a continuous gesture,
which is generally desirable. The original window may not know that
there's a clone out there with the same input channel, and therefore may
not know to remove FLAG_SLIPPERY whenever it desires to receive a
continuous gesture.

Bug: 274073185
Test: m inputflinger_tests && $ANDROID_HOST_OUT/nativetest64/inputflinger_tests/inputflinger_tests
Change-Id: I577724c1c2e77928e695c250b5f5fbe8f1592a2f

services/inputflinger/dispatcher/InputDispatcher.cpp

diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 6b9ad44..97b57b4 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -2402,6 +2402,7 @@
             const bool isStylus = isPointerFromStylus(entry, /*pointerIndex=*/0);
             sp<WindowInfoHandle> oldTouchedWindowHandle =
                     tempTouchState.getFirstForegroundWindowHandle();
+            LOG_ALWAYS_FATAL_IF(oldTouchedWindowHandle == nullptr);
             auto [newTouchedWindowHandle, _] = findTouchedWindowAtLocked(displayId, x, y, isStylus);
 
             // Verify targeted injection.
@@ -2417,13 +2418,11 @@
                 newTouchedWindowHandle = nullptr;
             }
 
-            if (oldTouchedWindowHandle != newTouchedWindowHandle &&
-                oldTouchedWindowHandle != nullptr && newTouchedWindowHandle != nullptr) {
-                if (DEBUG_FOCUS) {
-                    ALOGD("Touch is slipping out of window %s into window %s in display %" PRId32,
-                          oldTouchedWindowHandle->getName().c_str(),
-                          newTouchedWindowHandle->getName().c_str(), displayId);
-                }
+            if (!haveSameToken(oldTouchedWindowHandle, newTouchedWindowHandle)) {
+                ALOGD("Touch is slipping out of window %s into window %s in display %" PRId32,
+                      oldTouchedWindowHandle->getName().c_str(),
+                      newTouchedWindowHandle->getName().c_str(), displayId);
+
                 // Make a slippery exit from the old window.
                 std::bitset<MAX_POINTER_ID + 1> pointerIds;
                 const int32_t pointerId = entry.pointerProperties[0].id;