Allow touch if some pointers are MT_TOOL_PALM

We would cancel all touch when we recevied MT_TOOL_PALM because it
becomes accidental touch, and that would break user gesture when
another non-palm pointer is still active.

- Send ACTION_POINTER_UP with AKEY_EVENT_FLAG_CANCELED when recevie
  MT_TOOL_PALM if at least 2 pointers are active.
- Send ACTION_CANEL when receive MT_TOOL_PALM if only one pointer.
- Add test caseis for touch cancel scenarios, to test it would keep
  dispatching non-palm event.

Test: atest inputflinger_tests
Bug: 137221719
Change-Id: Ife35a692c71e45159bfcc771317dff47fa764dda
diff --git a/include/input/Input.h b/include/input/Input.h
index 40d655f..9525bcb 100644
--- a/include/input/Input.h
+++ b/include/input/Input.h
@@ -87,6 +87,13 @@
 constexpr int32_t VERIFIED_MOTION_EVENT_FLAGS =
         AMOTION_EVENT_FLAG_WINDOW_IS_OBSCURED | AMOTION_EVENT_FLAG_WINDOW_IS_PARTIALLY_OBSCURED;
 
+/**
+ * This flag indicates that the point up event has been canceled.
+ * Typically this is used for palm event when the user has accidental touches.
+ * TODO: Adjust flag to public api
+ */
+constexpr int32_t AMOTION_EVENT_FLAG_CANCELED = 0x20;
+
 enum {
     /* Used when a motion event is not associated with any display.
      * Typically used for non-pointer events. */
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp b/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
index 43bd9f1..0440f49 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
@@ -236,6 +236,20 @@
     mMultiTouchMotionAccumulator.process(rawEvent);
 }
 
+std::optional<int32_t> MultiTouchInputMapper::getActiveBitId(
+        const MultiTouchMotionAccumulator::Slot& inSlot) {
+    if (mHavePointerIds) {
+        int32_t trackingId = inSlot.getTrackingId();
+        for (BitSet32 idBits(mPointerIdBits); !idBits.isEmpty();) {
+            int32_t n = idBits.clearFirstMarkedBit();
+            if (mPointerTrackingIdMap[n] == trackingId) {
+                return std::make_optional(n);
+            }
+        }
+    }
+    return std::nullopt;
+}
+
 void MultiTouchInputMapper::syncTouch(nsecs_t when, RawState* outState) {
     size_t inCount = mMultiTouchMotionAccumulator.getSlotCount();
     size_t outCount = 0;
@@ -250,10 +264,9 @@
         }
 
         if (inSlot->getToolType() == AMOTION_EVENT_TOOL_TYPE_PALM) {
-            if (!mCurrentMotionAborted) {
-                ALOGI("Canceling touch gesture from device %s because the palm event was detected",
-                      getDeviceName().c_str());
-                cancelTouch(when);
+            std::optional<int32_t> id = getActiveBitId(*inSlot);
+            if (id) {
+                outState->rawPointerData.canceledIdBits.markBit(id.value());
             }
             continue;
         }
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
index 190282f..ea6f207 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
@@ -103,6 +103,8 @@
     bool hasStylus() const override;
 
 private:
+    // If the slot is in use, return the bit id. Return std::nullopt otherwise.
+    std::optional<int32_t> getActiveBitId(const MultiTouchMotionAccumulator::Slot& inSlot);
     MultiTouchMotionAccumulator mMultiTouchMotionAccumulator;
 
     // Specifies the pointer id bits that are in use, and their associated tracking id.
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.cpp b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
index 4274ca8..15d5288 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
@@ -104,6 +104,7 @@
     pointerCount = other.pointerCount;
     hoveringIdBits = other.hoveringIdBits;
     touchingIdBits = other.touchingIdBits;
+    canceledIdBits = other.canceledIdBits;
 
     for (uint32_t i = 0; i < pointerCount; i++) {
         pointers[i] = other.pointers[i];
@@ -140,6 +141,7 @@
     pointerCount = 0;
     hoveringIdBits.clear();
     touchingIdBits.clear();
+    canceledIdBits.clear();
 }
 
 void CookedPointerData::copyFrom(const CookedPointerData& other) {
@@ -1444,10 +1446,11 @@
 
 #if DEBUG_RAW_EVENTS
     ALOGD("syncTouch: pointerCount %d -> %d, touching ids 0x%08x -> 0x%08x, "
-          "hovering ids 0x%08x -> 0x%08x",
+          "hovering ids 0x%08x -> 0x%08x, canceled ids 0x%08x",
           last->rawPointerData.pointerCount, next->rawPointerData.pointerCount,
           last->rawPointerData.touchingIdBits.value, next->rawPointerData.touchingIdBits.value,
-          last->rawPointerData.hoveringIdBits.value, next->rawPointerData.hoveringIdBits.value);
+          last->rawPointerData.hoveringIdBits.value, next->rawPointerData.hoveringIdBits.value,
+          next->rawPointerData.canceledIdBits.value);
 #endif
 
     processRawTouches(false /*timeout*/);
@@ -1892,14 +1895,15 @@
         // Dispatch pointer up events.
         while (!upIdBits.isEmpty()) {
             uint32_t upId = upIdBits.clearFirstMarkedBit();
-
-            dispatchMotion(when, policyFlags, mSource, AMOTION_EVENT_ACTION_POINTER_UP, 0, 0,
-                           metaState, buttonState, 0,
+            bool isCanceled = mCurrentCookedState.cookedPointerData.canceledIdBits.hasBit(upId);
+            dispatchMotion(when, policyFlags, mSource, AMOTION_EVENT_ACTION_POINTER_UP, 0,
+                           isCanceled ? AMOTION_EVENT_FLAG_CANCELED : 0, metaState, buttonState, 0,
                            mLastCookedState.cookedPointerData.pointerProperties,
                            mLastCookedState.cookedPointerData.pointerCoords,
                            mLastCookedState.cookedPointerData.idToIndex, dispatchedIdBits, upId,
                            mOrientedXPrecision, mOrientedYPrecision, mDownTime);
             dispatchedIdBits.clearBit(upId);
+            mCurrentCookedState.cookedPointerData.canceledIdBits.clearBit(upId);
         }
 
         // Dispatch move events if any of the remaining pointers moved from their old locations.
@@ -2025,6 +2029,8 @@
             mCurrentRawState.rawPointerData.hoveringIdBits;
     mCurrentCookedState.cookedPointerData.touchingIdBits =
             mCurrentRawState.rawPointerData.touchingIdBits;
+    mCurrentCookedState.cookedPointerData.canceledIdBits =
+            mCurrentRawState.rawPointerData.canceledIdBits;
 
     if (mCurrentCookedState.cookedPointerData.pointerCount == 0) {
         mCurrentCookedState.buttonState = 0;
@@ -3563,7 +3569,11 @@
         if (action == AMOTION_EVENT_ACTION_POINTER_DOWN) {
             action = AMOTION_EVENT_ACTION_DOWN;
         } else if (action == AMOTION_EVENT_ACTION_POINTER_UP) {
-            action = AMOTION_EVENT_ACTION_UP;
+            if ((flags & AMOTION_EVENT_FLAG_CANCELED) != 0) {
+                action = AMOTION_EVENT_ACTION_CANCEL;
+            } else {
+                action = AMOTION_EVENT_ACTION_UP;
+            }
         } else {
             // Can't happen.
             ALOG_ASSERT(false);
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.h b/services/inputflinger/reader/mapper/TouchInputMapper.h
index d437e01..94486a6 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.h
@@ -71,7 +71,7 @@
 
     uint32_t pointerCount;
     Pointer pointers[MAX_POINTERS];
-    BitSet32 hoveringIdBits, touchingIdBits;
+    BitSet32 hoveringIdBits, touchingIdBits, canceledIdBits;
     uint32_t idToIndex[MAX_POINTER_ID + 1];
 
     RawPointerData();
@@ -90,6 +90,7 @@
     inline void clearIdBits() {
         hoveringIdBits.clear();
         touchingIdBits.clear();
+        canceledIdBits.clear();
     }
 
     inline const Pointer& pointerForId(uint32_t id) const { return pointers[idToIndex[id]]; }
@@ -102,7 +103,7 @@
     uint32_t pointerCount;
     PointerProperties pointerProperties[MAX_POINTERS];
     PointerCoords pointerCoords[MAX_POINTERS];
-    BitSet32 hoveringIdBits, touchingIdBits;
+    BitSet32 hoveringIdBits, touchingIdBits, canceledIdBits;
     uint32_t idToIndex[MAX_POINTER_ID + 1];
 
     CookedPointerData();
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index fae7e64..b2c16d0 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -45,16 +45,24 @@
 static const nsecs_t ARBITRARY_TIME = 1234;
 
 // Arbitrary display properties.
-static const int32_t DISPLAY_ID = 0;
-static const int32_t SECONDARY_DISPLAY_ID = DISPLAY_ID + 1;
-static const int32_t DISPLAY_WIDTH = 480;
-static const int32_t DISPLAY_HEIGHT = 800;
-static const int32_t VIRTUAL_DISPLAY_ID = 1;
-static const int32_t VIRTUAL_DISPLAY_WIDTH = 400;
-static const int32_t VIRTUAL_DISPLAY_HEIGHT = 500;
+static constexpr int32_t DISPLAY_ID = 0;
+static constexpr int32_t SECONDARY_DISPLAY_ID = DISPLAY_ID + 1;
+static constexpr int32_t DISPLAY_WIDTH = 480;
+static constexpr int32_t DISPLAY_HEIGHT = 800;
+static constexpr int32_t VIRTUAL_DISPLAY_ID = 1;
+static constexpr int32_t VIRTUAL_DISPLAY_WIDTH = 400;
+static constexpr int32_t VIRTUAL_DISPLAY_HEIGHT = 500;
 static const char* VIRTUAL_DISPLAY_UNIQUE_ID = "virtual:1";
 static constexpr std::optional<uint8_t> NO_PORT = std::nullopt; // no physical port is specified
 
+static constexpr int32_t FIRST_SLOT = 0;
+static constexpr int32_t SECOND_SLOT = 1;
+static constexpr int32_t THIRD_SLOT = 2;
+static constexpr int32_t INVALID_TRACKING_ID = -1;
+static constexpr int32_t FIRST_TRACKING_ID = 0;
+static constexpr int32_t SECOND_TRACKING_ID = 1;
+static constexpr int32_t THIRD_TRACKING_ID = 2;
+
 // Error tolerance for floating point assertions.
 static const float EPSILON = 0.001f;
 
@@ -1880,10 +1888,6 @@
 // --- TouchProcessTest ---
 class TouchIntegrationTest : public InputReaderIntegrationTest {
 protected:
-    static const int32_t FIRST_SLOT = 0;
-    static const int32_t SECOND_SLOT = 1;
-    static const int32_t FIRST_TRACKING_ID = 0;
-    static const int32_t SECOND_TRACKING_ID = 1;
     const std::string UNIQUE_ID = "local:0";
 
     virtual void SetUp() override {
@@ -1954,9 +1958,9 @@
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, args.action);
 
     // ACTION_POINTER_UP (Second slot)
-    mDevice->sendUp();
+    mDevice->sendPointerUp();
     ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
-    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
               args.action);
 
     // ACTION_UP
@@ -1971,11 +1975,13 @@
     const Point centerPoint = mDevice->getCenterPoint();
 
     // ACTION_DOWN
+    mDevice->sendSlot(FIRST_SLOT);
+    mDevice->sendTrackingId(FIRST_TRACKING_ID);
     mDevice->sendDown(centerPoint);
     ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
     ASSERT_EQ(AMOTION_EVENT_ACTION_DOWN, args.action);
 
-    // ACTION_POINTER_DOWN (Second slot)
+    // ACTION_POINTER_DOWN (second slot)
     const Point secondPoint = centerPoint + Point(100, 100);
     mDevice->sendSlot(SECOND_SLOT);
     mDevice->sendTrackingId(SECOND_TRACKING_ID);
@@ -1984,26 +1990,31 @@
     ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
               args.action);
 
-    // ACTION_MOVE (Second slot)
+    // ACTION_MOVE (second slot)
     mDevice->sendMove(secondPoint + Point(1, 1));
     ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
     ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, args.action);
 
-    // Send MT_TOOL_PALM, which indicates that the touch IC has determined this to be a grip event.
-    // Expect to receive ACTION_CANCEL, to abort the entire gesture.
+    // Send MT_TOOL_PALM (second slot), which indicates that the touch IC has determined this to be
+    // a palm event.
+    // Expect to receive the ACTION_POINTER_UP with cancel flag.
     mDevice->sendToolType(MT_TOOL_PALM);
     ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
-    ASSERT_EQ(AMOTION_EVENT_ACTION_CANCEL, args.action);
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              args.action);
+    ASSERT_EQ(AMOTION_EVENT_FLAG_CANCELED, args.flags);
 
-    // ACTION_POINTER_UP (Second slot)
-    mDevice->sendUp();
+    // Send up to second slot, expect first slot send moving.
+    mDevice->sendPointerUp();
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, args.action);
 
-    // ACTION_UP
+    // Send ACTION_UP (first slot)
     mDevice->sendSlot(FIRST_SLOT);
     mDevice->sendUp();
 
-    // Expect no event received after abort the entire gesture.
-    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasNotCalled());
+    ASSERT_NO_FATAL_FAILURE(mTestListener->assertNotifyMotionWasCalled(&args));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_UP, args.action);
 }
 
 // --- InputDeviceTest ---
@@ -7064,10 +7075,10 @@
 }
 
 /**
- * Test touch should be canceled when received the MT_TOOL_PALM event, and the following MOVE and
- * UP events should be ignored.
+ * Test single touch should be canceled when received the MT_TOOL_PALM event, and the following
+ * MOVE and UP events should be ignored.
  */
-TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType) {
+TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType_SinglePointer) {
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(DISPLAY_ORIENTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
@@ -7077,7 +7088,7 @@
 
     // default tool type is finger
     constexpr int32_t x1 = 100, y1 = 200, x2 = 120, y2 = 220, x3 = 140, y3 = 240;
-    processId(mapper, 1);
+    processId(mapper, FIRST_TRACKING_ID);
     processPosition(mapper, x1, y1);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
@@ -7091,19 +7102,19 @@
     ASSERT_EQ(AMOTION_EVENT_ACTION_CANCEL, motionArgs.action);
 
     // Ignore the following MOVE and UP events if had detect a palm event.
-    processId(mapper, 1);
+    processId(mapper, FIRST_TRACKING_ID);
     processPosition(mapper, x2, y2);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasNotCalled());
 
     // finger up.
-    processId(mapper, -1);
+    processId(mapper, INVALID_TRACKING_ID);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasNotCalled());
 
     // new finger down
+    processId(mapper, FIRST_TRACKING_ID);
     processToolType(mapper, MT_TOOL_FINGER);
-    processId(mapper, 1);
     processPosition(mapper, x3, y3);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
@@ -7112,11 +7123,10 @@
 }
 
 /**
- * Test multi-touch should be canceled when received the MT_TOOL_PALM event from some finger,
- * and could be allowed again after all non-MT_TOOL_PALM is release and the new point is
- * MT_TOOL_FINGER.
+ * Test multi-touch should sent POINTER_UP when received the MT_TOOL_PALM event from some finger,
+ * and the rest active fingers could still be allowed to receive the events
  */
-TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType2) {
+TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType_TwoPointers) {
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(DISPLAY_ORIENTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
@@ -7125,8 +7135,8 @@
     NotifyMotionArgs motionArgs;
 
     // default tool type is finger
-    constexpr int32_t x1 = 100, y1 = 200, x2 = 120, y2 = 220, x3 = 140, y3 = 240;
-    processId(mapper, 1);
+    constexpr int32_t x1 = 100, y1 = 200, x2 = 120, y2 = 220;
+    processId(mapper, FIRST_TRACKING_ID);
     processPosition(mapper, x1, y1);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
@@ -7134,51 +7144,232 @@
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
 
     // Second finger down.
-    processSlot(mapper, 1);
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
     processPosition(mapper, x2, y2);
-    processId(mapper, 2);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[1].toolType);
+
+    // If the tool type of the first finger changes to MT_TOOL_PALM,
+    // we expect to receive ACTION_POINTER_UP with cancel flag.
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, FIRST_TRACKING_ID);
+    processToolType(mapper, MT_TOOL_PALM);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
+
+    // The following MOVE events of second finger should be processed.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
+    processPosition(mapper, x2 + 1, y2 + 1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // First finger up. It used to be in palm mode, and we already generated ACTION_POINTER_UP for
+    // it. Second finger receive move.
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // Second finger keeps moving.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
+    processPosition(mapper, x2 + 2, y2 + 2);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // Second finger up.
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_UP, motionArgs.action);
+    ASSERT_NE(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
+}
+
+/**
+ * Test multi-touch should sent POINTER_UP when received the MT_TOOL_PALM event, if only 1 finger
+ * is active, it should send CANCEL after receiving the MT_TOOL_PALM event.
+ */
+TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType_ShouldCancelWhenAllTouchIsPalm) {
+    addConfigurationProperty("touch.deviceType", "touchScreen");
+    prepareDisplay(DISPLAY_ORIENTATION_0);
+    prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
+    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+
+    NotifyMotionArgs motionArgs;
+
+    constexpr int32_t x1 = 100, y1 = 200, x2 = 120, y2 = 220, x3 = 140, y3 = 240;
+    // First finger down.
+    processId(mapper, FIRST_TRACKING_ID);
+    processPosition(mapper, x1, y1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_DOWN, motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
+
+    // Second finger down.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
+    processPosition(mapper, x2, y2);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
               motionArgs.action);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
 
-    // If the tool type of the first pointer changes to MT_TOOL_PALM,
-    // the entire gesture should be aborted, so we expect to receive ACTION_CANCEL.
-    processSlot(mapper, 0);
-    processId(mapper, 1);
+    // If the tool type of the first finger changes to MT_TOOL_PALM,
+    // we expect to receive ACTION_POINTER_UP with cancel flag.
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, FIRST_TRACKING_ID);
+    processToolType(mapper, MT_TOOL_PALM);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (0 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
+
+    // Second finger keeps moving.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
+    processPosition(mapper, x2 + 1, y2 + 1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+
+    // second finger becomes palm, receive cancel due to only 1 finger is active.
+    processId(mapper, SECOND_TRACKING_ID);
     processToolType(mapper, MT_TOOL_PALM);
     processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_CANCEL, motionArgs.action);
 
-    // Ignore the following MOVE and UP events if had detect a palm event.
-    processSlot(mapper, 1);
-    processId(mapper, 2);
+    // third finger down.
+    processSlot(mapper, THIRD_SLOT);
+    processId(mapper, THIRD_TRACKING_ID);
+    processToolType(mapper, MT_TOOL_FINGER);
     processPosition(mapper, x3, y3);
     processSync(mapper);
-    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasNotCalled());
-
-    // second finger up.
-    processId(mapper, -1);
-    processSync(mapper);
-    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasNotCalled());
-
-    // first finger move, but still in palm
-    processSlot(mapper, 0);
-    processId(mapper, 1);
-    processPosition(mapper, x1 - 1, y1 - 1);
-    processSync(mapper);
-    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasNotCalled());
-
-    // second finger down, expect as new finger down.
-    processSlot(mapper, 1);
-    processId(mapper, 2);
-    processPosition(mapper, x2, y2);
-    processSync(mapper);
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
     ASSERT_EQ(AMOTION_EVENT_ACTION_DOWN, motionArgs.action);
     ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // third finger move
+    processId(mapper, THIRD_TRACKING_ID);
+    processPosition(mapper, x3 + 1, y3 + 1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+
+    // first finger up, third finger receive move.
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // second finger up, third finger receive move.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // third finger up.
+    processSlot(mapper, THIRD_SLOT);
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_UP, motionArgs.action);
+    ASSERT_NE(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
+}
+
+/**
+ * Test multi-touch should sent POINTER_UP when received the MT_TOOL_PALM event from some finger,
+ * and the active finger could still be allowed to receive the events
+ */
+TEST_F(MultiTouchInputMapperTest, Process_ShouldHandlePalmToolType_KeepFirstPointer) {
+    addConfigurationProperty("touch.deviceType", "touchScreen");
+    prepareDisplay(DISPLAY_ORIENTATION_0);
+    prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
+    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+
+    NotifyMotionArgs motionArgs;
+
+    // default tool type is finger
+    constexpr int32_t x1 = 100, y1 = 200, x2 = 120, y2 = 220;
+    processId(mapper, FIRST_TRACKING_ID);
+    processPosition(mapper, x1, y1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_DOWN, motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
+
+    // Second finger down.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, SECOND_TRACKING_ID);
+    processPosition(mapper, x2, y2);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_DOWN | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_TOOL_TYPE_FINGER, motionArgs.pointerProperties[0].toolType);
+
+    // If the tool type of the second finger changes to MT_TOOL_PALM,
+    // we expect to receive ACTION_POINTER_UP with cancel flag.
+    processId(mapper, SECOND_TRACKING_ID);
+    processToolType(mapper, MT_TOOL_PALM);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP | (1 << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT),
+              motionArgs.action);
+    ASSERT_EQ(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
+
+    // The following MOVE event should be processed.
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, FIRST_TRACKING_ID);
+    processPosition(mapper, x1 + 1, y1 + 1);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+    ASSERT_EQ(uint32_t(1), motionArgs.pointerCount);
+
+    // second finger up.
+    processSlot(mapper, SECOND_SLOT);
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+
+    // first finger keep moving
+    processSlot(mapper, FIRST_SLOT);
+    processId(mapper, FIRST_TRACKING_ID);
+    processPosition(mapper, x1 + 2, y1 + 2);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_MOVE, motionArgs.action);
+
+    // first finger up.
+    processId(mapper, INVALID_TRACKING_ID);
+    processSync(mapper);
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyMotionWasCalled(&motionArgs));
+    ASSERT_EQ(AMOTION_EVENT_ACTION_UP, motionArgs.action);
+    ASSERT_NE(AMOTION_EVENT_FLAG_CANCELED, motionArgs.flags);
 }
 
 // --- MultiTouchInputMapperTest_ExternalDevice ---
diff --git a/services/inputflinger/tests/UinputDevice.cpp b/services/inputflinger/tests/UinputDevice.cpp
index 0659511..7fec2c8 100644
--- a/services/inputflinger/tests/UinputDevice.cpp
+++ b/services/inputflinger/tests/UinputDevice.cpp
@@ -179,6 +179,11 @@
     injectEvent(EV_SYN, SYN_REPORT, 0);
 }
 
+void UinputTouchScreen::sendPointerUp() {
+    sendTrackingId(0xffffffff);
+    injectEvent(EV_SYN, SYN_REPORT, 0);
+}
+
 void UinputTouchScreen::sendUp() {
     sendTrackingId(0xffffffff);
     injectEvent(EV_KEY, BTN_TOUCH, 0);
diff --git a/services/inputflinger/tests/UinputDevice.h b/services/inputflinger/tests/UinputDevice.h
index 22d1f63..01a557c 100644
--- a/services/inputflinger/tests/UinputDevice.h
+++ b/services/inputflinger/tests/UinputDevice.h
@@ -139,6 +139,7 @@
     void sendTrackingId(int32_t trackingId);
     void sendDown(const Point& point);
     void sendMove(const Point& point);
+    void sendPointerUp();
     void sendUp();
     void sendToolType(int32_t toolType);