ButtonBehavior: Fixed ImGuiButtonFlags_AllowOverlapMode to avoid temp…

…orarily activating widgets on click before they have been correctly double-hovered. (#319, #600)

imgui.cpp

@@ -5821,6 +5821,10 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
     if ((flags & ImGuiButtonFlags_FlattenChilds) && g.HoveredRootWindow == window)
         g.HoveredWindow = backup_hovered_window;
 
+    // AllowOverlap mode (rarely used) requires previous frame HoveredId to be null or to match. This allows using patterns where a later submitted widget overlaps a previous one.
+    if (hovered && (flags & ImGuiButtonFlags_AllowOverlapMode) && (g.HoveredIdPreviousFrame != id && g.HoveredIdPreviousFrame != 0))
+        hovered = false;
+
     if (hovered)
     {
         if (!(flags & ImGuiButtonFlags_NoKeyModifiers) || (!g.IO.KeyCtrl && !g.IO.KeyShift && !g.IO.KeyAlt))
@@ -5880,10 +5884,6 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         }
     }
 
-    // AllowOverlap mode (rarely used) requires previous frame HoveredId to be null or to match. This allows using patterns where a later submitted widget overlaps a previous one.
-    if (hovered && (flags & ImGuiButtonFlags_AllowOverlapMode) && (g.HoveredIdPreviousFrame != id && g.HoveredIdPreviousFrame != 0))
-        hovered = pressed = held = false;
-
     if (out_hovered) *out_hovered = hovered;
     if (out_held) *out_held = held;