[goffice] Image Save: fix problem with auto-format-by-extension

[Morten Welinder <mortenw src gnome org>]

commit 064d643268352b946984750c638dba697550a2e2
Author: Morten Welinder <terra gnome org>
Date:   Sun Apr 19 20:56:24 2020 -0400

    Image Save: fix problem with auto-format-by-extension

 ChangeLog                 |  5 +++++
 goffice/gtk/goffice-gtk.c | 43 ++++++++++++++++++++++++++++++-------------
 2 files changed, 35 insertions(+), 13 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 0381c2ba..8788854e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-19  Morten Welinder  <terra gnome org>
+
+       * goffice/gtk/goffice-gtk.c (cb_format_combo_changed): Take
+       auto-by-extension into account.
+
 2020-04-09  Jean Brefort  <jean brefort normalesup org>
 
        * goffice/graph/gog-series.c (gog_series_dataset_dim_changed): check
diff --git a/goffice/gtk/goffice-gtk.c b/goffice/gtk/goffice-gtk.c
index dc6f80c5..37b7a7ee 100644
--- a/goffice/gtk/goffice-gtk.c
+++ b/goffice/gtk/goffice-gtk.c
@@ -955,6 +955,11 @@ typedef struct {
        double resolution;
        gboolean is_expanded;
        GOImageFormat format;
+
+       // Not saved, but used by handlers
+       gboolean by_ext;
+       GSList *supported_formats;
+       GtkWidget *resolution_widget;
 } SaveInfoState;
 
 static void
@@ -965,14 +970,24 @@ save_info_state_free (SaveInfoState *state)
 }
 
 static void
-cb_format_combo_changed (GtkComboBox *combo, GtkWidget *expander)
+cb_format_combo_changed (GtkComboBox *combo, SaveInfoState *state)
 {
        GOImageFormatInfo const *format_info;
+       gboolean sensitive;
+       int i;
 
-       format_info = go_image_get_format_info (gtk_combo_box_get_active (combo));
-       gtk_widget_set_sensitive (expander,
-                                 format_info != NULL &&
-                                 format_info->is_dpi_useful);
+       i = gtk_combo_box_get_active (combo);
+       if (state->by_ext && i == 0)
+               sensitive = TRUE;
+       else {
+               GOImageFormat fmt = GPOINTER_TO_UINT
+                       (g_slist_nth_data (state->supported_formats,
+                                          i - state->by_ext));
+               GOImageFormatInfo const *format_info =
+                       go_image_get_format_info (fmt);
+               sensitive = format_info && format_info->is_dpi_useful;
+       }
+       gtk_widget_set_sensitive (state->resolution_widget, sensitive);
 }
 
 /**
@@ -1003,7 +1018,6 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
        SaveInfoState *state;
        char const *key = "go_gui_get_image_save_info";
        char *uri = NULL;
-       gboolean by_ext = FALSE;
 
        state = g_object_get_data (G_OBJECT (toplevel), key);
        if (state == NULL) {
@@ -1016,6 +1030,8 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
                g_object_set_data_full (G_OBJECT (toplevel), key,
                                        state, (GDestroyNotify) save_info_state_free);
        }
+       state->supported_formats = supported_formats;
+       state->by_ext = FALSE;
 
        g_object_set (G_OBJECT (fsel), "title", _("Save as"), NULL);
 
@@ -1024,13 +1040,15 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
        if (gui != NULL) {
                GtkWidget *widget;
 
+               state->resolution_widget = resolution_grid = go_gtk_builder_get_widget (gui, 
"resolution-grid");
+
                /* Format selection UI */
                if (supported_formats != NULL && ret_format != NULL) {
                        int i;
                        GSList *l;
                        format_combo = go_gtk_builder_combo_box_init_text (gui, "format_combo");
 
-                       by_ext = TRUE;
+                       state->by_ext = TRUE;
                        go_gtk_combo_box_append_text (format_combo, _("Auto by extension"));
 
                        for (l = supported_formats, i = 0; l != NULL; l = l->next, i++) {
@@ -1064,11 +1082,10 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
                        gtk_widget_hide (expander);
 
                if (resolution != NULL && supported_formats != NULL && ret_format != NULL) {
-                       resolution_grid = go_gtk_builder_get_widget (gui, "resolution-grid");
-
-                       cb_format_combo_changed (format_combo, resolution_grid);
+                       cb_format_combo_changed (format_combo, state);
                        g_signal_connect (GTK_WIDGET (format_combo), "changed",
-                                         G_CALLBACK (cb_format_combo_changed), resolution_grid);
+                                         G_CALLBACK (cb_format_combo_changed),
+                                         state);
                }
 
                g_object_unref (gui);
@@ -1091,7 +1108,7 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
                format = GO_IMAGE_FORMAT_UNKNOWN;
                if (index < 0)
                        ; // That's it.
-               else if (by_ext && index == 0) {
+               else if (state->by_ext && index == 0) {
                        GSList *l;
 
                        for (l = supported_formats; l; l = l->next) {
@@ -1104,7 +1121,7 @@ go_gui_get_image_save_info (GtkWindow *toplevel, GSList *supported_formats,
                                goto loop;
                } else {
                        format = GPOINTER_TO_UINT (g_slist_nth_data
-                               (supported_formats, index - by_ext));
+                               (supported_formats, index - state->by_ext));
                        format_info = go_image_get_format_info (format);
                        if (!go_url_check_extension (uri, format_info->ext, &new_uri) &&
                            !go_gtk_query_yes_no (GTK_WINDOW (fsel), TRUE,