Improvement for click detection when clicking quickly between mouse moves (#5786)

* improvement for click detection when clicking quickly between mouse moves

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* remove magic number and introduce constant

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

* add missing update from camera test

Signed-off-by: Tom Hulton-Harrop <82228511+hultonha@users.noreply.github.com>

Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.cpp

@@ -24,11 +24,12 @@ namespace AzFramework
 
     ClickDetector::ClickOutcome ClickDetector::DetectClick(const ClickEvent clickEvent, const ScreenVector& cursorDelta)
     {
+        m_moveAccumulator += ScreenVectorLength(cursorDelta);
+
         const auto previousDetectionState = m_detectionState;
         if (previousDetectionState == DetectionState::WaitingForMove)
         {
             // only allow the action to begin if the mouse has been moved a small amount
-            m_moveAccumulator += ScreenVectorLength(cursorDelta);
             if (m_moveAccumulator > m_deadZone)
             {
                 m_detectionState = DetectionState::Moved;
@@ -43,7 +44,7 @@ namespace AzFramework
                 using FloatingPointSeconds = AZStd::chrono::duration<float, AZStd::chrono::seconds::period>;
 
                 const auto diff = now - m_tryBeginTime.value();
-                if (FloatingPointSeconds(diff).count() < m_doubleClickInterval)
+                if (FloatingPointSeconds(diff).count() < m_doubleClickInterval && m_moveAccumulator < m_deadZone)
                 {
                     return ClickOutcome::Nil;
                 }

Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.h

@@ -15,6 +15,10 @@
 
 namespace AzFramework
 {
+    //! Default value to use for detecting if the mouse has moved far enough after a mouse down to no longer
+    //! register a click when a mouse up occurs.
+    inline constexpr float DefaultMouseMoveDeadZone = 2.0f;
+
     struct ScreenVector;
 
     //! Utility class to help detect different types of mouse click (mouse down and up with
@@ -66,7 +70,7 @@ namespace AzFramework
         };
 
         float m_moveAccumulator = 0.0f; //!< How far the mouse has moved after mouse down.
-        float m_deadZone = 2.0f; //!< How far to move before a click is cancelled (when Move will fire).
+        float m_deadZone = DefaultMouseMoveDeadZone; //!< How far to move before a click is cancelled (when Move will fire).
         float m_doubleClickInterval = 0.4f; //!< Default double click interval, can be overridden.
         DetectionState m_detectionState; //!< Internal state of ClickDetector.
         //! Mouse down time (happens each mouse down, helps with double click handling).

Code/Framework/AzFramework/Tests/ClickDetectorTests.cpp

@@ -144,12 +144,45 @@ namespace UnitTest
     {
         using ::testing::Eq;
 
-        const ClickDetector::ClickOutcome downOutcome =
-            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(0, 0));
-        const ClickDetector::ClickOutcome upOutcome =
-            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(50, 50));
+        const ClickDetector::ClickOutcome downOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome upOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(50, 50));
 
         EXPECT_THAT(downOutcome, Eq(ClickDetector::ClickOutcome::Nil));
         EXPECT_THAT(upOutcome, Eq(ClickDetector::ClickOutcome::Release));
     }
+
+    //! note: ClickDetector does not explicitly return double clicks but if one occurs the ClickOutcome will be Nil
+    TEST_F(ClickDetectorFixture, DoubleClickIsRegisteredIfMouseDeltaHasMovedLessThanDeadzoneInClickInterval)
+    {
+        using ::testing::Eq;
+
+        const ClickDetector::ClickOutcome firstDownOutcome =
+            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome firstUpOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome secondDownOutcome =
+            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome secondUpOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(0, 0));
+
+        EXPECT_THAT(firstDownOutcome, Eq(ClickDetector::ClickOutcome::Nil));
+        EXPECT_THAT(firstUpOutcome, Eq(ClickDetector::ClickOutcome::Click));
+        EXPECT_THAT(secondDownOutcome, Eq(ClickDetector::ClickOutcome::Nil));
+        EXPECT_THAT(secondUpOutcome, Eq(ClickDetector::ClickOutcome::Nil));
+    }
+
+    TEST_F(ClickDetectorFixture, DoubleClickIsNotRegisteredIfMouseDeltaHasMovedMoreThanDeadzoneInClickInterval)
+    {
+        using ::testing::Eq;
+
+        const ClickDetector::ClickOutcome firstDownOutcome =
+            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome firstUpOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(0, 0));
+        const ClickDetector::ClickOutcome secondDownOutcome =
+            m_clickDetector.DetectClick(ClickDetector::ClickEvent::Down, ScreenVector(10, 10));
+        const ClickDetector::ClickOutcome secondUpOutcome = m_clickDetector.DetectClick(ClickDetector::ClickEvent::Up, ScreenVector(0, 0));
+
+        EXPECT_THAT(firstDownOutcome, Eq(ClickDetector::ClickOutcome::Nil));
+        EXPECT_THAT(firstUpOutcome, Eq(ClickDetector::ClickOutcome::Click));
+        EXPECT_THAT(secondDownOutcome, Eq(ClickDetector::ClickOutcome::Nil));
+        EXPECT_THAT(secondUpOutcome, Eq(ClickDetector::ClickOutcome::Click));
+    }
 } // namespace UnitTest