Filtering reagents (#18211)

* Making it work

* Refactoring

* Autoformat revert

* Implementing suggestions

* Changed to file scoped namespaces.

Content.Client/UserInterface/ControlExtensions/ControlExtension.cs

@@ -0,0 +1,96 @@
+using Content.Client.Guidebook.Controls;
+using Robust.Client.UserInterface;
+using Robust.Client.UserInterface.Controls;
+
+namespace Content.Client.UserInterface.ControlExtensions;
+
+public static class ControlExtension
+{
+    public static List<T> GetControlOfType<T>(this Control parent) where T : Control
+    {
+        return parent.GetControlOfType<T>(typeof(T).Name, false);
+    }
+    public static List<T> GetControlOfType<T>(this Control parent, string childType) where T : Control
+    {
+        return parent.GetControlOfType<T>(childType, false);
+    }
+
+    public static List<T> GetControlOfType<T>(this Control parent, bool fullTreeSearch) where T : Control
+    {
+        return parent.GetControlOfType<T>(typeof(T).Name, fullTreeSearch);
+    }
+
+    public static List<T> GetControlOfType<T>(this Control parent, string childType, bool fullTreeSearch) where T : Control
+    {
+        List<T> controlList = new List<T>();
+
+        foreach (var child in parent.Children)
+        {
+            var isType = child.GetType().Name == childType;
+            var hasChildren = child.ChildCount > 0;
+
+            var searchDeeper = hasChildren && !isType;
+
+            if (isType)
+            {
+                controlList.Add((T) child);
+            }
+
+            if (fullTreeSearch || searchDeeper)
+            {
+                controlList.AddRange(child.GetControlOfType<T>(childType, fullTreeSearch));
+            }
+        }
+
+        return controlList;
+    }
+
+    public static List<ISearchableControl> GetSearchableControls(this Control parent, bool fullTreeSearch = false)
+    {
+        List<ISearchableControl> controlList = new List<ISearchableControl>();
+
+        foreach (var child in parent.Children)
+        {
+            var hasChildren = child.ChildCount > 0;
+            var searchDeeper = hasChildren && child is not ISearchableControl;
+
+            if (child is ISearchableControl searchableChild)
+            {
+                controlList.Add(searchableChild);
+            }
+
+            if (fullTreeSearch || searchDeeper)
+            {
+                controlList.AddRange(child.GetSearchableControls(fullTreeSearch));
+            }
+        }
+
+        return controlList;
+    }
+
+    public static bool ChildrenContainText(this Control parent, string search)
+    {
+        var labels = parent.GetControlOfType<Label>();
+        var richTextLabels = parent.GetControlOfType<RichTextLabel>();
+
+        foreach (var label in labels)
+        {
+            if (label.Text != null && label.Text.Contains(search, StringComparison.OrdinalIgnoreCase))
+            {
+                return true;
+            }
+        }
+
+        foreach (var label in richTextLabels)
+        {
+            var text = label.GetMessage();
+
+            if (text != null && text.Contains(search, StringComparison.OrdinalIgnoreCase))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}