Keep the sketch value field on top of the dimension labels

Dimension labels drawn after the value field each lifted their own
window to the front, so a label could print over the number being typed.

src/slic3r/GUI/CAD/DesignSketchTool.cpp

@@ -8988,6 +8988,10 @@ void DesignSketchTool::render(GLCanvas3D& canvas)
     // not there — there is no window to fall back to any more.
     if (inline_editor != nullptr)
         inline_editor->render(*wxGetApp().imgui(), m_render_scale);
+    // ...and on top of the dimension labels, which are all drawn after it and each lift their
+    // own window to the front (draw_dim_label): without this a label prints across the number
+    // being typed. A guard, because the labels come from many of the exit paths below.
+    ScopeGuard field_on_top([this] { if (inline_editor != nullptr) inline_editor->bring_to_front(); });
     if (render_overlays)
         render_overlays();
     (void)canvas;

src/slic3r/GUI/CAD/SketchInlineEditor.cpp

@@ -7,7 +7,7 @@
 #include "libslic3r/Color.hpp"
 
 #include <imgui/imgui.h>
-#include <imgui/imgui_internal.h>   // BringWindowToDisplayFront / GetCurrentWindow
+#include <imgui/imgui_internal.h>   // FindWindowByName / BringWindowToDisplayFront
 
 #include <cstdio>
 #include <cstdlib>
@@ -19,6 +19,8 @@ namespace GUI {
 
 namespace {
 
+const char* const kWindowName = "##sketchvalue";
+
 // Numbers are typed and shown with a POINT, whatever the locale: this field feeds a CAD kernel,
 // and a decimal comma reaching it as a thousands separator is a silent order-of-magnitude error.
 // Parsing accepts either separator because a keyboard's numeric pad may only offer one.
@@ -181,10 +183,9 @@ bool SketchInlineEditor::render(ImGuiWrapper& imgui, float scale)
     ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 3.0f);
     // NoInputs is what every other sketch overlay sets and is exactly what this one must not:
     // it is the only overlay in the tab that the user types into.
-    imgui.begin(std::string("##sketchvalue"),
+    imgui.begin(std::string(kWindowName),
                 ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoDecoration
                     | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoSavedSettings);
-    ImGui::BringWindowToDisplayFront(ImGui::GetCurrentWindow());
 
     if (!m_title.empty() || !m_err.empty()) {
         if (m_err.empty()) {
@@ -243,4 +244,12 @@ bool SketchInlineEditor::render(ImGuiWrapper& imgui, float scale)
     return true;
 }
 
+void SketchInlineEditor::bring_to_front()
+{
+    // Not gated on m_open: a commit closes the field after it was drawn, and that frame still
+    // shows it. A window that did not Begin this frame is not rendered, so lifting it is inert.
+    if (ImGuiWindow* w = ImGui::FindWindowByName(kWindowName))
+        ImGui::BringWindowToDisplayFront(w);
+}
+
 }} // namespace Slic3r::GUI

src/slic3r/GUI/CAD/SketchInlineEditor.hpp

@@ -57,6 +57,8 @@ public:
     // Draw it, and let ImGui do the editing. Called from DesignSketchTool::render() inside the
     // frame's ImGui pass; `scale` is the tool's m_render_scale. Returns true if it drew.
     bool render(ImGuiWrapper& imgui, float scale);
+    // Lift the field above every other overlay. Call it after the frame's last overlay is drawn.
+    void bring_to_front();
 
     // Ask for another frame. THE FIELD DOES NOT WORK WITHOUT THIS, and the reason is a deadlock
     // that only a per-frame trace shows: