Merge branch 'master' of https://github.com/prusa3d/Slic3r into objects_centering

src/slic3r/GUI/GLGizmo.cpp

@@ -2466,11 +2466,13 @@ void GLGizmoCut::on_render_input_window(float x, float y, const GLCanvas3D::Sele
     m_imgui->checkbox(_(L("Keep lower part")), m_keep_lower);
     m_imgui->checkbox(_(L("Rotate lower part upwards")), m_rotate_lower);
 
+    m_imgui->disabled_begin(!m_keep_upper && !m_keep_lower);
     const bool cut_clicked = m_imgui->button(_(L("Perform cut")));
+    m_imgui->disabled_end();
 
     m_imgui->end();
 
-    if (cut_clicked) {
+    if (cut_clicked && (m_keep_upper || m_keep_lower)) {
         perform_cut(selection);
     }
 }

src/slic3r/GUI/ImGuiWrapper.cpp

@@ -12,6 +12,8 @@
 
 #include <GL/glew.h>
 
+#include <imgui/imgui_internal.h>
+
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Utils.hpp"
 #include "GUI.hpp"
@@ -23,6 +25,7 @@ namespace GUI {
 ImGuiWrapper::ImGuiWrapper()
     : m_font_texture(0)
     , m_mouse_buttons(0)
+    , m_disabled(false)
 {
 }
 
@@ -154,6 +157,26 @@ void ImGuiWrapper::text(const wxString &label)
     ImGui::Text(label_utf8.c_str(), NULL);
 }
 
+void ImGuiWrapper::disabled_begin(bool disabled)
+{
+    wxCHECK_RET(!m_disabled, "ImGUI: Unbalanced disabled_begin() call");
+
+    if (disabled) {
+        ImGui::PushItemFlag(ImGuiItemFlags_Disabled, true);
+        ImGui::PushStyleVar(ImGuiStyleVar_Alpha, ImGui::GetStyle().Alpha * 0.5f);
+        m_disabled = true;
+    }
+}
+
+void ImGuiWrapper::disabled_end()
+{
+    if (m_disabled) {
+        ImGui::PopItemFlag();
+        ImGui::PopStyleVar();
+        m_disabled = false;
+    }
+}
+
 bool ImGuiWrapper::want_mouse() const
 {
     return ImGui::GetIO().WantCaptureMouse;

src/slic3r/GUI/ImGuiWrapper.hpp

@@ -21,8 +21,8 @@ class ImGuiWrapper
 
     FontsMap m_fonts;
     unsigned m_font_texture;
-
     unsigned m_mouse_buttons;
+    bool m_disabled;
 
 public:
     ImGuiWrapper();
@@ -50,6 +50,9 @@ public:
     bool checkbox(const wxString &label, bool &value);
     void text(const wxString &label);
 
+    void disabled_begin(bool disabled);
+    void disabled_end();
+
     bool want_mouse() const;
     bool want_keyboard() const;
     bool want_text_input() const;

src/slic3r/GUI/Plater.cpp

@@ -2804,6 +2804,10 @@ void Plater::cut(size_t obj_idx, size_t instance_idx, coordf_t z, bool keep_uppe
 
     wxCHECK_RET(instance_idx < object->instances.size(), "instance_idx out of bounds");
 
+    if (!keep_upper && !keep_lower) {
+        return;
+    }
+
     const auto new_objects = object->cut(instance_idx, z, keep_upper, keep_lower, rotate_lower);
 
     remove(obj_idx);