commit ea3f4fc7e994c883c4a2022aa293625f7b60c682
author arthurhung <arthurhung@google.com> Mon Dec 21 23:18:53 2020 +0800
committer arthurhung <arthurhung@google.com> Tue Dec 29 13:42:33 2020 +0800
tree 86efb4c93f7138311ce79d66e5368c7c8cbba6c8
parent 57563a1020fefe9645e4d52a4a9d9ebdcab6d222

Prevent accidentally click on window with split touch

Currently, inputflinger would send an ACTION_POINTER_UP event with
AKEY_EVENT_FLAG_CANCELED when we have at least 2 pointers down and
one becomes the accidental touch.

An input window could have FLAG_SPLIT that could split a multi touch
event into some single touch events, so we should check the cancel flag
in order to prevent it trigger an accidental click on the target window.

Bug: 161655782
Test: inputflinger_tests
Test: enable twoshay, test accidental touch on slipt window.
Change-Id: I95eae0c9aef1f888f352b31affcece893d557754

services/inputflinger/dispatcher/InputDispatcher.cpp

diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 5832109..0122fb0 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -3414,7 +3414,9 @@
                 // The first/last pointer went down/up.
                 action = maskedAction == AMOTION_EVENT_ACTION_POINTER_DOWN
                         ? AMOTION_EVENT_ACTION_DOWN
-                        : AMOTION_EVENT_ACTION_UP;
+                        : (originalMotionEntry.flags & AMOTION_EVENT_FLAG_CANCELED) != 0
+                                ? AMOTION_EVENT_ACTION_CANCEL
+                                : AMOTION_EVENT_ACTION_UP;
             } else {
                 // A secondary pointer went down/up.
                 uint32_t splitPointerIndex = 0;

services/inputflinger/tests/InputDispatcher_test.cpp

diff --git a/services/inputflinger/tests/InputDispatcher_test.cpp b/services/inputflinger/tests/InputDispatcher_test.cpp
index 0b30ff5..bb9d879 100644
--- a/services/inputflinger/tests/InputDispatcher_test.cpp
+++ b/services/inputflinger/tests/InputDispatcher_test.cpp
@@ -1785,6 +1785,71 @@
     window->assertNoEvents(); // Key event or focus event will not be received
 }
 
+TEST_F(InputDispatcherTest, PointerCancel_SendCancelWhenSplitTouch) {
+    std::shared_ptr<FakeApplicationHandle> application = std::make_shared<FakeApplicationHandle>();
+
+    // Create first non touch modal window that supports split touch
+    sp<FakeWindowHandle> firstWindow =
+            new FakeWindowHandle(application, mDispatcher, "First Window", ADISPLAY_ID_DEFAULT);
+    firstWindow->setFrame(Rect(0, 0, 600, 400));
+    firstWindow->setFlags(InputWindowInfo::Flag::NOT_TOUCH_MODAL |
+                          InputWindowInfo::Flag::SPLIT_TOUCH);
+
+    // Create second non touch modal window that supports split touch
+    sp<FakeWindowHandle> secondWindow =
+            new FakeWindowHandle(application, mDispatcher, "Second Window", ADISPLAY_ID_DEFAULT);
+    secondWindow->setFrame(Rect(0, 400, 600, 800));
+    secondWindow->setFlags(InputWindowInfo::Flag::NOT_TOUCH_MODAL |
+                           InputWindowInfo::Flag::SPLIT_TOUCH);
+
+    // Add the windows to the dispatcher
+    mDispatcher->setInputWindows({{ADISPLAY_ID_DEFAULT, {firstWindow, secondWindow}}});
+
+    PointF pointInFirst = {300, 200};
+    PointF pointInSecond = {300, 600};
+
+    // Send down to the first window
+    NotifyMotionArgs firstDownMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_DOWN, AINPUT_SOURCE_TOUCHSCREEN,
+                               ADISPLAY_ID_DEFAULT, {pointInFirst});
+    mDispatcher->notifyMotion(&firstDownMotionArgs);
+    // Only the first window should get the down event
+    firstWindow->consumeMotionDown();
+    secondWindow->assertNoEvents();
+
+    // Send down to the second window
+    NotifyMotionArgs secondDownMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_POINTER_DOWN |
+                                       (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+                               AINPUT_SOURCE_TOUCHSCREEN, ADISPLAY_ID_DEFAULT,
+                               {pointInFirst, pointInSecond});
+    mDispatcher->notifyMotion(&secondDownMotionArgs);
+    // The first window gets a move and the second a down
+    firstWindow->consumeMotionMove();
+    secondWindow->consumeMotionDown();
+
+    // Send pointer cancel to the second window
+    NotifyMotionArgs pointerUpMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_POINTER_UP |
+                                       (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+                               AINPUT_SOURCE_TOUCHSCREEN, ADISPLAY_ID_DEFAULT,
+                               {pointInFirst, pointInSecond});
+    pointerUpMotionArgs.flags |= AMOTION_EVENT_FLAG_CANCELED;
+    mDispatcher->notifyMotion(&pointerUpMotionArgs);
+    // The first window gets move and the second gets cancel.
+    firstWindow->consumeMotionMove(ADISPLAY_ID_DEFAULT, AMOTION_EVENT_FLAG_CANCELED);
+    secondWindow->consumeMotionCancel(ADISPLAY_ID_DEFAULT, AMOTION_EVENT_FLAG_CANCELED);
+
+    // Send up event.
+    NotifyMotionArgs upMotionArgs =
+            generateMotionArgs(AMOTION_EVENT_ACTION_UP, AINPUT_SOURCE_TOUCHSCREEN,
+                               ADISPLAY_ID_DEFAULT);
+    mDispatcher->notifyMotion(&upMotionArgs);
+    // The first window gets up and the second gets nothing.
+    firstWindow->consumeMotionUp();
+    secondWindow->assertNoEvents();
+}
+
 class FakeMonitorReceiver {
 public:
     FakeMonitorReceiver(const sp<InputDispatcher>& dispatcher, const std::string name,