FIX: Parameter editor not reacting to changes to InputSettings (#2130)

Author: ekcoh

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -27,6 +27,7 @@ however, it has to be formatted properly to pass verification tests.
 - Pinned Touch Samples sample package dependencies to avoid errors with Cinemachine 3.x and Probuilder 6.x. [ISXB-1245](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1245)
 - Fixed issue where a binding path is sometimes not saved when chosen from the binding path picker. [ISXB-1221](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1221)
 - Fixed an issue where dropdown menu for Path in Input Actions Editor could not be selected from any button position. [ISXB-1309](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1309)
+- Fixed an issue where changing Input System default parameter settings with the editor open would result in changes in the editor. [ISXB-1351](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1351)
 
 ## [1.12.0] - 2025-01-15
 

Packages/com.unity.inputsystem/InputSystem/Editor/InputParameterEditor.cs

@@ -238,8 +238,10 @@ public void OnDrawVisualElements(VisualElement root, Action onChangedCallback)
                     value = m_DefaultInitializedValue;
 
                 var container = new VisualElement();
-                var settingsContainer = new VisualElement { style = { flexDirection = FlexDirection.Row } };
+                container.RegisterCallback<AttachToPanelEvent>(OnAttachToPanel);
+                container.RegisterCallback<DetachFromPanelEvent>(OnDetachFromPanel);
 
+                var settingsContainer = new VisualElement { style = { flexDirection = FlexDirection.Row } };
 
                 m_FloatField = new FloatField(m_ValueLabel.text) { value = value };
                 m_FloatField.Q("unity-text-input").AddToClassList("float-field");
@@ -260,7 +262,6 @@ public void OnDrawVisualElements(VisualElement root, Action onChangedCallback)
                 m_DefaultToggle.RegisterValueChangedCallback(evt => ToggleUseDefaultValue(evt, onChangedCallback));
                 m_DefaultToggle.Q<Label>().style.minWidth = new StyleLength(StyleKeyword.Auto);
 
-
                 var buttonContainer = new VisualElement
                 {
                     style =
@@ -286,22 +287,28 @@ public void OnDrawVisualElements(VisualElement root, Action onChangedCallback)
                 root.Add(container);
             }
 
-            private void ChangeSettingValue(ChangeEvent<float> evt)
+            private void OnAttachToPanel(AttachToPanelEvent evt)
+            {   // Monitor changes to settings for as long as the panel is attached to a visual tree
+                InputSystem.onSettingsChange += InputSystemOnSettingsChange;
+            }
+
+            private void OnDetachFromPanel(DetachFromPanelEvent evt)
+            {   // Stop monitoring changes to settings when panel is no longer part of a visual tree
+                InputSystem.onSettingsChange -= InputSystemOnSettingsChange;
+            }
+
+            private void InputSystemOnSettingsChange()
             {
-                if (m_UseDefaultValue) return;
+                // Default value may change at any point settings are modified so fetch current default value
+                // if currently configured to display default value and having default coming from settings.
+                if (m_FloatField != null && m_UseDefaultValue && m_DefaultComesFromInputSettings)
+                    m_FloatField.value = m_GetDefaultValue();
+            }
 
-                // ReSharper disable once CompareOfFloatsByEqualityOperator
-                if (evt.newValue == m_DefaultInitializedValue)
-                {
-                    // If user sets a value that is equal to default initialized, change value slightly so it doesn't pass potential default checks.
-                    ////TODO: refactor all of this to use tri-state values instead, there is no obvious float value that we can use as default (well maybe NaN),
-                    ////so instead it would be better to have a separate bool to show if value is present or not.
-                    m_SetValue(evt.newValue + float.Epsilon);
-                }
-                else
-                {
-                    m_SetValue(evt.newValue);
-                }
+            private void ChangeSettingValue(ChangeEvent<float> evt)
+            {
+                if (!m_UseDefaultValue)
+                    SetValue(evt.newValue);
             }
 
             private void OnEditEnd(Action onChangedCallback)
@@ -322,6 +329,21 @@ private void ToggleUseDefaultValue(ChangeEvent<bool> evt, Action onChangedCallba
             }
 
 #endif
+            private void SetValue(float newValue)
+            {
+                // ReSharper disable once CompareOfFloatsByEqualityOperator
+                if (newValue == m_DefaultInitializedValue)
+                {
+                    // If user sets a value that is equal to default initialized, change value slightly so it doesn't pass potential default checks.
+                    ////TODO: refactor all of this to use tri-state values instead, there is no obvious float value that we can use as default (well maybe NaN),
+                    ////so instead it would be better to have a separate bool to show if value is present or not.
+                    m_SetValue(newValue + float.Epsilon);
+                }
+                else
+                {
+                    m_SetValue(newValue);
+                }
+            }
 
             public void OnGUI()
             {
@@ -342,16 +364,7 @@ public void OnGUI()
                 ////TODO: use slider rather than float field
                 var newValue = EditorGUILayout.FloatField(m_ValueLabel, value, GUILayout.ExpandWidth(false));
                 if (!m_UseDefaultValue)
-                {
-                    // ReSharper disable once CompareOfFloatsByEqualityOperator
-                    if (newValue == m_DefaultInitializedValue)
-                        // If user sets a value that is equal to default initialized, change value slightly so it doesn't pass potential default checks.
-                        ////TODO: refactor all of this to use tri-state values instead, there is no obvious float value that we can use as default (well maybe NaN),
-                        ////so instead it would be better to have a separate bool to show if value is present or not.
-                        m_SetValue(newValue + float.Epsilon);
-                    else
-                        m_SetValue(newValue);
-                }
+                    SetValue(newValue);
 
                 EditorGUI.EndDisabledGroup();