Lower GTK and Qt version requirements

For GTK lower than 3.20 there is no GtkFileChooserNative so fallback
to using GtkFileChooserDialog

2 files changed, 52 insertions, 10 deletions

diff --git a/configure.ac b/configure.ac
index 2d7c041..0633a84 100644
--- a/configure.ac
+++ b/configure.ac
@@ -141,7 +141,7 @@ AC_ARG_ENABLE([gtk],
   [AC_HELP_STRING([--disable-gtk], [do not use GTK even if found])],
   [gtk_check=$enableval], [gtk_check=yes])
 AS_IF([test x$gtk_check = xyes],
-  [gtk_need="gtk+-3.0 >= 3.20"
+  [gtk_need="gtk+-3.0 >= 3.18"
    PKG_CHECK_EXISTS([$gtk_need],
      [PKG_CHECK_MODULES([GTK], [$gtk_need])
       have_gtk=1])
@@ -156,7 +156,7 @@ AC_ARG_ENABLE([qt],
   [AC_HELP_STRING([--disable-qt], [do not use QT even if found])],
   [qt_check=$enableval], [qt_check=yes])
 AS_IF([test x$qt_check = xyes],
-  [qt_need="Qt5Widgets >= 5.8.0"
+  [qt_need="Qt5Widgets >= 5.5.0"
    PKG_CHECK_EXISTS([$qt_need],
      [PKG_CHECK_MODULES([QT], [$qt_need])
       PKG_CHECK_VAR([QT_CONFIG], [Qt5Core], [qt_config])
diff --git a/src/gui_gtk.cc b/src/gui_gtk.cc
index 20b23ec..574cf84 100644
--- a/src/gui_gtk.cc
+++ b/src/gui_gtk.cc
@@ -720,26 +720,47 @@ public:
   std::string file_dialog(std::string const& title, std::string const& file,
                           uint8_t flags,
                           std::vector<GuiFile::Filter> const& filter) override {
-    shared_gobject<GtkFileChooserNative> chooser(gtk_file_chooser_native_new(
+    GtkFileChooser* chooser;
+#if GTK_CHECK_VERSION(3, 20, 0)
+    shared_gobject<GtkFileChooserNative> native(gtk_file_chooser_native_new(
         title.c_str(),
         reinterpret_cast<GtkWindow*>(impl()),
         flags & GuiFile::FILE_SAVE ? GTK_FILE_CHOOSER_ACTION_SAVE
         : GTK_FILE_CHOOSER_ACTION_OPEN,
         nullptr, nullptr));
+    chooser = GTK_FILE_CHOOSER(native.get());
+#else
+    auto widget = gtk_file_chooser_dialog_new(
+        title.c_str(),
+        reinterpret_cast<GtkWindow*>(impl()),
+        flags & GuiFile::FILE_SAVE ? GTK_FILE_CHOOSER_ACTION_SAVE
+        : GTK_FILE_CHOOSER_ACTION_OPEN,
+	"_Cancel",
+	GTK_RESPONSE_CANCEL,
+	flags & GuiFile::FILE_SAVE ? "_Save" : "_Open",
+	GTK_RESPONSE_ACCEPT,
+	NULL);
+    chooser = GTK_FILE_CHOOSER(widget);
+#endif
     if (flags & GuiFile::FILE_SAVE) {
-      gtk_file_chooser_set_do_overwrite_confirmation(
-          GTK_FILE_CHOOSER(chooser.get()), true);
+      gtk_file_chooser_set_do_overwrite_confirmation(chooser, true);
     }
     if (file.empty()) {
-      gtk_file_chooser_set_filename(
-          GTK_FILE_CHOOSER(chooser.get()), file.c_str());
+      gtk_file_chooser_set_filename(chooser, file.c_str());
     }
-    set_filter(GTK_FILE_CHOOSER(chooser.get()), filter);
+    set_filter(chooser, filter);
     std::string ret_file;
-    auto ret = gtk_native_dialog_run(GTK_NATIVE_DIALOG(chooser.get()));
+#if GTK_CHECK_VERSION(3, 20, 0)
+    auto ret = gtk_native_dialog_run(GTK_NATIVE_DIALOG(native.get()));
+#else
+    auto ret = gtk_dialog_run(GTK_DIALOG(widget));
+#endif
     if (ret == GTK_RESPONSE_ACCEPT) {
-      ret_file = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(chooser.get()));
+      ret_file = gtk_file_chooser_get_filename(chooser);
     }
+#if !GTK_CHECK_VERSION(3, 20, 0)
+    gtk_widget_destroy(widget);
+#endif
     return ret_file;
   }
 
@@ -1168,11 +1189,24 @@ public:
           g_signal_connect(G_OBJECT(v->chooser_), "file-set",
                            G_CALLBACK(file_set), value.get());
         } else {
+#if GTK_CHECK_VERSION(3, 20, 0)
           auto chooser = gtk_file_chooser_native_new(
               v->label_.c_str(),
               GTK_WINDOW(dialog_),
               GTK_FILE_CHOOSER_ACTION_SAVE,
               nullptr, nullptr);
+#else
+	  auto chooser = gtk_file_chooser_dialog_new(
+              v->label_.c_str(),
+              GTK_WINDOW(dialog_),
+              GTK_FILE_CHOOSER_ACTION_SAVE,
+	      "_Cancel",
+	      GTK_RESPONSE_CANCEL,
+	      "_Save",
+	      GTK_RESPONSE_ACCEPT,
+	      NULL);
+#endif
+
           extra = gtk_button_new_with_label("...");
           g_signal_connect(G_OBJECT(extra), "clicked",
                            G_CALLBACK(show_filechooser), v);
@@ -1258,7 +1292,11 @@ public:
             v->value_.clear();
           }
         } else {
+#if GTK_CHECK_VERSION(3, 20, 0)
           g_object_unref(v->chooser_);
+#else
+          gtk_widget_destroy(GTK_WIDGET(v->chooser_));
+#endif
         }
         v->chooser_ = nullptr;
         break;
@@ -1385,7 +1423,11 @@ protected:
 
   static void show_filechooser(GtkButton*, gpointer user_data) {
     auto value = reinterpret_cast<FileValue*>(user_data);
+#if GTK_CHECK_VERSION(3, 20, 0)
     auto ret = gtk_native_dialog_run(GTK_NATIVE_DIALOG(value->chooser_));
+#else
+    auto ret = gtk_dialog_run(GTK_DIALOG(value->chooser_));
+#endif
     if (ret == GTK_RESPONSE_ACCEPT) {
       auto file = gtk_file_chooser_get_filename(value->chooser_);
       value->value_ = file;