More misc functions (used to live as static functions in Slic3r::GUI perl file).

Passing -DVAR_ABS and -DVAR_ABS_PATH=/path/to/slic3r/var on compile redirects where Slic3r expects to find its var directory.

src/GUI/misc_ui.cpp

@@ -1,5 +1,8 @@
 #include "misc_ui.hpp"
 #include <wx/stdpaths.h>
+#include <wx/msgdlg.h>
+
+#include <exception>
 
 namespace Slic3r { namespace GUI {
 
@@ -14,11 +17,18 @@ void check_version(bool manual)  {
 #endif
 
 const wxString var(const wxString& in) {
+    // TODO replace center string with path to VAR in actual distribution later
+    if (VAR_ABS) {
+        return VAR_ABS_PATH + "/" + in;
+    } else {
+        return bin() + VAR_REL + "/" + in;
+    }
+}
+
+const wxString bin() { 
     wxFileName f(wxStandardPaths::Get().GetExecutablePath());
     wxString appPath(f.GetPath());
-
+    return appPath;
-    // replace center string with path to VAR in actual distribution later
-    return appPath + "/../var/" + in;
 }
 
 /// Returns the path to Slic3r's default user data directory.
@@ -28,7 +38,6 @@ const wxString home(const wxString& in) {
     return wxGetHomeDir() + "/." + in + "/";
 }
 
-
 wxString decode_path(const wxString& in) {
     // TODO Stub
     return in;
@@ -38,6 +47,21 @@ wxString encode_path(const wxString& in) {
     // TODO Stub
     return in;
 }
+
+void show_error(wxWindow* parent, const wxString& message) {
+    wxMessageDialog(parent, message, _("Error"), wxOK | wxICON_ERROR).ShowModal();
+}
+
+void show_info(wxWindow* parent, const wxString& message, const wxString& title = _("Notice")) {
+    wxMessageDialog(parent, message, title, wxOK | wxICON_INFORMATION).ShowModal();
+}
+
+void fatal_error(wxWindow* parent, const wxString& message) {
+    show_error(parent, message);
+    throw std::runtime_error(message.ToStdString());
+}
+
+
 /*
 sub append_submenu {
     my ($self, $menu, $string, $description, $submenu, $id, $icon) = @_;

src/GUI/misc_ui.hpp

@@ -29,16 +29,47 @@ constexpr bool isDev = true;
 constexpr bool isDev = false;
 #endif
 
+
+/// Mostly useful for Linux distro maintainers, this will change where Slic3r assumes 
+/// its ./var directory lives (where its art assets are). 
+/// Define VAR_ABS and VAR_ABS_PATH 
+#ifndef VAR_ABS
+    #define VAR_ABS false
+#else 
+    #define VAR_ABS true
+#endif
+#ifndef VAR_ABS_PATH
+    #define VAR_ABS_PATH "/usr/share/Slic3r/var"
+#endif
+
+#ifndef VAR_REL // Redefine on compile
+    #define VAR_REL L"/../var"
+#endif
+
 /// Performs a check via the Internet for a new version of Slic3r.
 /// If this version of Slic3r was compiled with -DSLIC3R_DEV, check the development 
 /// space instead of release.
 void check_version(bool manual = false);
 
+/// Provides a path to Slic3r's var dir.
 const wxString var(const wxString& in);
 
+/// Provide a path to where Slic3r exec'd from.
+const wxString bin();
+
 /// Always returns path to home directory.
 const wxString home(const wxString& in = "Slic3r");
 
+/// Shows an error messagebox
+void show_error(wxWindow* parent, const wxString& message);
+
+/// Shows an info messagebox.
+void show_info(wxWindow* parent, const wxString& message, const wxString& title);
+
+/// Show an error messagebox and then throw an exception.
+void fatal_error(wxWindow* parent, const wxString& message);
+
+
 template <typename T>
 void append_menu_item(wxMenu* menu, const wxString& name,const wxString& help, T lambda, int id = wxID_ANY, const wxString& icon = "", const wxString& accel = "") {
     wxMenuItem* tmp = menu->Append(wxID_ANY, name, help);