ListBox/InputTextMultiline: Better optimized when clipped / non-visible.

docs/CHANGELOG.txt

@@ -54,6 +54,8 @@ Other Changes:
   from using style.ItemSpacing.x to style.ItemInnerSpacing.x, the later being expected to be smaller. (#1086)
 - RadioButton: Fixed label horizontal alignment to precisely match Checkbox().
 - Window: When resizing from an edge, the border is more visible and better follow the rounded corners.
+- ListBox: Better optimized when clipped / non-visible.
+- InputTextMultiline: Better optimized when clipped / non-visible.
 - ImDrawList: Fixed AddCircle(), AddCircleFilled() angle step being off, which was visible when drawing a "circle"
   with a small number of segments (e.g. an hexagon). (#2287) [@baktery]
 - ImGuiTextBuffer: Added append() function (unformatted).

imgui_widgets.cpp

@@ -3138,7 +3138,12 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
     ImGuiWindow* draw_window = window;
     if (is_multiline)
     {
-        ItemAdd(total_bb, id, &frame_bb);
+        if (!ItemAdd(total_bb, id, &frame_bb))
+        {
+            ItemSize(total_bb, style.FramePadding.y);
+            EndGroup();
+            return false;
+        }
         if (!BeginChildFrame(id, frame_bb.GetSize()))
         {
             EndChildFrame();
@@ -5122,6 +5127,13 @@ bool ImGui::ListBoxHeader(const char* label, const ImVec2& size_arg)
     ImRect bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f, 0.0f));
     window->DC.LastItemRect = bb; // Forward storage for ListBoxFooter.. dodgy.
 
+    if (!IsRectVisible(bb.Min, bb.Max))
+    {
+        ItemSize(bb.GetSize(), style.FramePadding.y);
+        ItemAdd(bb, 0, &frame_bb);
+        return false;
+    }
+
     BeginGroup();
     if (label_size.x > 0)
         RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);