Question How to know when the user is at the bottom of a editor scroll view?

Hi!

I'm implementing a simple list of tags in a scroll view, however, I fetch those tags from a rest API that works with pagination.

So I need to know when the user has reached the bottom of the current list of fetched tags to fetch the next page.

This is my current code, but I don't know how to make the method `UserIsAtTheBottomOfScrollView`

Code (CSharp):

1. [CustomEditor(typeof(ObjectTags))]
2. public class ObjectTagsEditor : Editor
3.     {
4.     ...
5.  
6.     private void OnEnable()
7.     {
8.         tagsProperty = serializedObject.FindProperty("tags");
9.     }
10.  
11.     public override void OnInspectorGUI()
12.     {
13.         scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition, GUILayout.Height(300));
14.         List<string> allTags = GetTags().Where(tag => TagContainsText(tag, searchTagText) && !IsTagAlredyPresent(tag)).ToList();
15.         foreach (string tag in allTags)
16.         {
17.             if (GUILayout.Button(tag))
18.             {
19.                 AddTagIfNotPresent(tag);
20.             }
21.         }
22.         EditorGUILayout.EndScrollView();
23.         if (UserIsAtTheBottomOfScrollView())
24.         {
25.             FetchNextPage();
26.         }
27.     }
28.  
29.     private bool UserIsAtTheBottomOfScrollView()
30.     {
31.         // how do I know when the user is at the bottom of the scroll view?
32.     }
33.  
34.     ...
35.  
36. }
37.  

Thank you in advance for your help.

 

I ended up solving my problem this way:

Code (CSharp):

1. [CustomEditor(typeof(ObjectTags))]
2. public class ObjectTagsEditor : Editor
3.     {
4.     ...
5.     private int TAG_BUTTON_HEIGHT = 25;
6.     private int MAX_BUTTONS_IN_SCROLL_VIEW = 9;
7.     private int UNITY_BUTTON_MARGIN = 2; // This is a variable obtained by trial and error
8.  
9.     private void OnEnable()
10.     {
11.         tagsProperty = serializedObject.FindProperty("tags");
12.     }
13.  
14.     public override void OnInspectorGUI()
15.     {
16.         int scrollHeight = MAX_BUTTONS_IN_SCROLL_VIEW * (TAG_BUTTON_HEIGHT + UNITY_BUTTON_MARGIN);
17.         scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition, GUILayout.Height(scrollHeight));
18.         List<string> allTags = GetAllTags().Where(tag => TagContainsText(tag, searchTagText) && !IsTagAlredyPresent(tag)).ToList();
19.         foreach (string tag in allTags)
20.         {
21.             if (GUILayout.Button(tag, GUILayout.Height(TAG_BUTTON_HEIGHT)))
22.             {
23.                 AddTagIfNotPresent(tag);
24.             }
25.         }
26.         EditorGUILayout.EndScrollView();
27.         if(UserIsAtTheBottomOfScrollView(allTags.Count(), scrollPosition.y))
28.         {
29.             Debug.Log("User is at the bottom of the scroll view");
30.         }
31.     }
32.  
33.     private bool UserIsAtTheBottomOfScrollView(int numberOfTags, float scrollY)
34.     {
35.         int maxScroll =
36.             (numberOfTags - MAX_BUTTONS_IN_SCROLL_VIEW) * (TAG_BUTTON_HEIGHT + UNITY_BUTTON_MARGIN) +
37.             UNITY_BUTTON_MARGIN;
38.         int bottomThresholdInPixels = 100;
39.         if (scrollY >= maxScroll - bottomThresholdInPixels)
40.         {
41.             return true;
42.         }
43.         return false;
44.     }
45.  
46.     ...
47.  
48. }

 

Sorry for the mistake! Thank you!