Skeleton for merging via GUI

10 files changed, 603 insertions, 3 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5c5ac445..8ea46558 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -392,8 +392,8 @@ list(APPEND CRYSTFEL_EXECUTABLES cell_tool)
 if (GTK_FOUND)
 
   set(CRYSTFEL_GUI_SOURCES src/crystfel_gui.c src/crystfelimageview.c
-    src/gui_peaksearch.c src/gui_index.c src/gui_backend_local.c
-    src/gui_project.c src/crystfelindexingopts.c)
+    src/gui_peaksearch.c src/gui_index.c src/gui_merge.c src/gui_backend_local.c
+    src/gui_project.c src/crystfelindexingopts.c src/crystfelmergeopts.c)
 
   if (HAVE_SLURM)
     set(CRYSTFEL_GUI_SOURCES ${CRYSTFEL_GUI_SOURCES} src/gui_backend_slurm.c)
diff --git a/meson.build b/meson.build
index 24f29f44..ce0a5325 100644
--- a/meson.build
+++ b/meson.build
@@ -209,8 +209,10 @@ if gtkdep.found()
   gui_sources = ['src/crystfel_gui.c',
                  'src/crystfelimageview.c',
                  'src/crystfelindexingopts.c',
+                 'src/crystfelmergeopts.c',
                  'src/gui_peaksearch.c',
                  'src/gui_index.c',
+                 'src/gui_merge.c',
                  'src/gui_backend_local.c',
                  'src/gui_project.c',
                  versionc]
diff --git a/src/crystfel_gui.c b/src/crystfel_gui.c
index 02196fa5..e7baacdc 100644
--- a/src/crystfel_gui.c
+++ b/src/crystfel_gui.c
@@ -47,6 +47,7 @@
 #include "crystfelimageview.h"
 #include "gui_peaksearch.h"
 #include "gui_index.h"
+#include "gui_merge.h"
 #include "gui_project.h"
 #include "version.h"
 
@@ -827,7 +828,7 @@ static void add_task_buttons(GtkWidget *vbox, struct crystfelproject *proj)
 	add_button(vbox, "Indexing ambiguity", "face-worried",
 	           G_CALLBACK(NULL), proj);
 	add_button(vbox, "Merge", "applications-science",
-	           G_CALLBACK(NULL), proj);
+	           G_CALLBACK(merge_sig), proj);
 	add_button(vbox, "Figures of merit", "trophy-gold",
 	           G_CALLBACK(NULL), proj);
 	add_button(vbox, "Export data", "document-send",
diff --git a/src/crystfelmergeopts.c b/src/crystfelmergeopts.c
new file mode 100644
index 00000000..87b14c85
--- /dev/null
+++ b/src/crystfelmergeopts.c
@@ -0,0 +1,164 @@
+/*
+ * crystfelmergeopts.h
+ *
+ * A GTK widget to set merge options
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *  2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <gtk/gtk.h>
+#include <glib-object.h>
+#include <errno.h>
+#include <math.h>
+
+#include <integration.h>
+#include <index.h>
+
+#include "crystfelmergeopts.h"
+
+
+G_DEFINE_TYPE(CrystFELMergeOpts,
+              crystfel_merge_opts,
+              GTK_TYPE_NOTEBOOK)
+
+
+static void crystfel_merge_opts_class_init(CrystFELMergeOptsClass *klass)
+{
+}
+
+
+static void crystfel_merge_opts_init(CrystFELMergeOpts *mo)
+{
+}
+
+
+static GtkWidget *merge_parameters(CrystFELMergeOpts *mo)
+{
+	GtkWidget *box;
+	GtkWidget *hbox;
+	GtkWidget *label;
+
+	box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 8);
+	gtk_container_set_border_width(GTK_CONTAINER(box), 8);
+
+	hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(hbox),
+	                   FALSE, FALSE, 0);
+	label = gtk_label_new("Model:");
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+	mo->model_combo = gtk_combo_box_text_new();
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(mo->model_combo),
+	                   FALSE, FALSE, 0);
+	gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(mo->model_combo),
+	                          "process_hkl",
+	                          "Simple merging (process_hkl)");
+	gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(mo->model_combo),
+	                          "unity",
+	                          "No partialities (unity)");
+	gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(mo->model_combo),
+	                          "xsphere",
+	                          "Bandwidth integral (xsphere)");
+	gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(mo->model_combo),
+	                          "offset",
+	                          "Monochromatic Ewald sphere offset (offset)");
+
+	/* Symmetry */
+	/* Scale on/off */
+	/* B-factor scaling */
+	/* Post-refinement on/off */
+	/* Polarisation horiz/vert/unpolarized beam/no correction */
+	/* Number of iterations */
+	/* deltaCChalf */
+	/* Detector saturation value */
+	/* Minimum pattern resolution */
+	/* push-res */
+	/* Minimum measurements */
+	/* Custom split file */
+	/* Detwin */
+
+	return box;
+}
+
+
+GtkWidget *crystfel_merge_opts_new()
+{
+	CrystFELMergeOpts *mo;
+
+	mo = g_object_new(CRYSTFEL_TYPE_MERGE_OPTS, NULL);
+
+	gtk_notebook_append_page(GTK_NOTEBOOK(mo),
+	                         merge_parameters(mo),
+	                         gtk_label_new("Merging"));
+
+	gtk_widget_show_all(GTK_WIDGET(mo));
+	return GTK_WIDGET(mo);
+}
+
+
+//int crystfel_merge_opts_get_multi_lattice(CrystFELMergeOpts *opts)
+//{
+//	return gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(opts->multi));
+//}
+
+
+float crystfel_merge_opts_get_push_res(CrystFELMergeOpts *opts)
+{
+	if ( !gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(opts->limit_res)) ) {
+		return INFINITY;
+	} else {
+		const gchar *text;
+		float push_res;
+		char *rval;
+		text = gtk_entry_get_text(GTK_ENTRY(opts->push_res));
+		errno = 0;
+		push_res = strtof(text, &rval);
+		if ( *rval != '\0' ) {
+			printf("Invalid value for push-res (%s)\n",
+			      rval);
+			return INFINITY;
+		}
+		return push_res;
+	}
+}
+
+
+void crystfel_merge_opts_set_push_res(CrystFELMergeOpts *mo,
+                                      float push_res)
+{
+	char tmp[64];
+
+	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(mo->limit_res),
+	                             !isinf(push_res));
+
+	snprintf(tmp, 63, "%f", push_res);
+	gtk_entry_set_text(GTK_ENTRY(mo->push_res), tmp);
+}
diff --git a/src/crystfelmergeopts.h b/src/crystfelmergeopts.h
new file mode 100644
index 00000000..dc4333fc
--- /dev/null
+++ b/src/crystfelmergeopts.h
@@ -0,0 +1,73 @@
+/*
+ * crystfelmergeopts.h
+ *
+ * A GTK widget to set merge options
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *  2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef CRYSTFELMERGEOPTS_H
+#define CRYSTFELMERGEOPTS_H
+
+#include <gtk/gtk.h>
+#include <glib-object.h>
+
+#define CRYSTFEL_TYPE_MERGE_OPTS (crystfel_merge_opts_get_type())
+
+#define CRYSTFEL_MERGE_OPTS(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), \
+                                 CRYSTFEL_TYPE_MERGE_OPTS, CrystFELMergeOpts))
+
+#define CRYSTFEL_IS_MERGE_OPTS(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), \
+                                    CRYSTFEL_TYPE_MERGE_OPTS))
+
+#define CRYSTFEL_MERGE_OPTS_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((obj), \
+                                         CRYSTFEL_TYPE_MERGE_OPTS, CrystFELMergeOpts))
+
+#define CRYSTFEL_IS_MERGE_OPTS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((obj), \
+                                            CRYSTFEL_TYPE_MERGE_OPTS))
+
+#define CRYSTFEL_MERGE_OPTS_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj), \
+                                           CRYSTFEL_TYPE_MERGE_OPTS, CrystFELMergeOpts))
+
+struct _crystfelmergeopts
+{
+	GtkNotebook parent_instance;
+
+	/*< private >*/
+	GtkWidget *model_combo;
+	GtkWidget *limit_res;
+	GtkWidget *push_res;
+};
+
+struct _crystfelmergeoptsclass
+{
+	GtkNotebookClass parent_class;
+};
+
+typedef struct _crystfelmergeopts CrystFELMergeOpts;
+typedef struct _crystfelmergeoptsclass CrystFELMergeOptsClass;
+
+extern GType crystfel_merge_opts_get_type(void);
+extern GtkWidget *crystfel_merge_opts_new(void);
+
+#endif	/* CRYSTFELMERGEOPTS_H */
diff --git a/src/gui_backend_local.c b/src/gui_backend_local.c
index 7a5f440e..28b6e0ec 100644
--- a/src/gui_backend_local.c
+++ b/src/gui_backend_local.c
@@ -45,6 +45,12 @@ struct local_indexing_opts
 };
 
 
+struct local_merge_opts
+{
+	int n_threads;
+};
+
+
 struct local_job
 {
 	double frac_complete;
@@ -368,6 +374,55 @@ static void read_indexing_opt(void *opts_priv,
 }
 
 
+static void n_threads_activate_sig(GtkEntry *entry, gpointer data)
+{
+	struct local_merge_opts *opts = data;
+	convert_int(gtk_entry_get_text(entry), &opts->n_threads);
+}
+
+
+static gboolean n_threads_focus_sig(GtkEntry *entry, GdkEvent *event,
+                                    gpointer data)
+{
+	n_threads_activate_sig(entry, data);
+	return FALSE;
+}
+
+
+static GtkWidget *make_merge_parameters_widget(void *opts_priv)
+{
+	struct local_merge_opts *opts = opts_priv;
+	GtkWidget *vbox;
+	GtkWidget *hbox;
+	GtkWidget *entry;
+	GtkWidget *label;
+	char tmp[64];
+
+	vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 8);
+
+	hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
+	gtk_box_pack_start(GTK_BOX(vbox), GTK_WIDGET(hbox),
+	                   FALSE, FALSE, 0);
+	label = gtk_label_new("Number of threads:");
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+	entry = gtk_entry_new();
+	snprintf(tmp, 63, "%i", opts->n_threads);
+	gtk_entry_set_text(GTK_ENTRY(entry), tmp);
+	gtk_entry_set_width_chars(GTK_ENTRY(entry), 5);
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(entry),
+	                   FALSE, FALSE, 0);
+
+	g_signal_connect(G_OBJECT(entry), "activate",
+	                 G_CALLBACK(n_threads_activate_sig),
+	                 opts);
+	g_signal_connect(G_OBJECT(entry), "focus-out-event",
+	                 G_CALLBACK(n_threads_focus_sig),
+	                 opts);
+	return vbox;
+}
+
+
 int make_local_backend(struct crystfel_backend *be)
 {
 	be->name = "local";
@@ -382,5 +437,7 @@ int make_local_backend(struct crystfel_backend *be)
 	be->write_indexing_opts = write_indexing_opts;
 	be->read_indexing_opt = read_indexing_opt;
 
+	be->make_merge_parameters_widget = make_merge_parameters_widget;
+
 	return 0;
 };
diff --git a/src/gui_merge.c b/src/gui_merge.c
new file mode 100644
index 00000000..ad108933
--- /dev/null
+++ b/src/gui_merge.c
@@ -0,0 +1,247 @@
+/*
+ * gui_merge.c
+ *
+ * Peak search parts of GUI
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <gtk/gtk.h>
+#include <assert.h>
+
+#include "gui_project.h"
+#include "crystfel_gui.h"
+#include "crystfelmergeopts.h"
+
+
+struct new_merge_job_params {
+	struct crystfelproject *proj;
+	GtkWidget *backend_combo;
+	GtkWidget *backend_opts_widget;
+	GtkWidget *backend_opts_box;
+	GtkWidget *job_title_entry;
+	GtkWidget *job_notes_text;
+	GtkWidget *model_combo;
+};
+
+
+static void free_new_merge_job_params(gpointer njp, GClosure *closure)
+{
+	free(njp);
+}
+
+
+static void merge_response_sig(GtkWidget *dialog, gint resp,
+                               struct new_merge_job_params *njp)
+{
+	if ( resp == GTK_RESPONSE_OK ) {
+		STATUS("Doing it!\n");
+	}
+}
+
+
+static GtkWidget *make_merge_job_opts(struct crystfelproject *proj,
+                                      struct new_merge_job_params *njp)
+{
+	GtkWidget *box;
+	GtkWidget *hbox;
+	GtkWidget *label;
+	GtkWidget *scroll;
+
+	box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 8);
+	gtk_container_set_border_width(GTK_CONTAINER(box), 8);
+
+	hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(hbox),
+	                   FALSE, FALSE, 0);
+	label = gtk_label_new("Job name:");
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+	njp->job_title_entry = gtk_entry_new();
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(njp->job_title_entry),
+	                   TRUE, TRUE, 2.0);
+	if ( proj->merge_new_job_title != NULL ) {
+		gtk_entry_set_text(GTK_ENTRY(njp->job_title_entry),
+		                   proj->merge_new_job_title);
+	}
+
+	label = gtk_label_new("This name will be used for a working subfolder");
+	gtk_label_set_markup(GTK_LABEL(label),
+	                     "<i>This name will be used for a working subfolder</i>");
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+	gtk_entry_set_placeholder_text(GTK_ENTRY(njp->job_title_entry),
+	                               "merge-trial-1");
+
+	hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(hbox),
+	                   TRUE, TRUE, 0);
+	label = gtk_label_new("Notes:");
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+	njp->job_notes_text = gtk_text_view_new();
+	scroll = gtk_scrolled_window_new(NULL, NULL);
+	gtk_container_add(GTK_CONTAINER(scroll), njp->job_notes_text);
+	gtk_scrolled_window_set_shadow_type(GTK_SCROLLED_WINDOW(scroll),
+	                                    GTK_SHADOW_ETCHED_IN);
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(scroll),
+	                   TRUE, TRUE, 2.0);
+
+	label = gtk_label_new("The notes above will be placed in the job's folder as 'notes.txt'");
+	gtk_label_set_markup(GTK_LABEL(label),
+	                     "<i>The notes above will be placed in the job's folder as 'notes.txt'</i>");
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+
+	return box;
+}
+
+
+static void merge_backend_changed_sig(GtkWidget *combo,
+                                      struct new_merge_job_params *njp)
+{
+	int backend_idx;
+	struct crystfel_backend *be;
+
+	backend_idx = gtk_combo_box_get_active(GTK_COMBO_BOX(combo));
+	if ( backend_idx < 0 ) return;
+	njp->proj->merge_backend_selected = backend_idx;
+
+	be = &njp->proj->backends[backend_idx];
+
+	if ( njp->backend_opts_widget != NULL ) {
+		gtk_widget_destroy(njp->backend_opts_widget);
+	}
+
+	njp->backend_opts_widget = be->make_merge_parameters_widget(be->merge_opts_priv);
+
+	gtk_box_pack_start(GTK_BOX(njp->backend_opts_box),
+	                   GTK_WIDGET(njp->backend_opts_widget),
+	                   FALSE, FALSE, 0);
+	gtk_widget_show_all(njp->backend_opts_widget);
+}
+
+
+static GtkWidget *make_merge_backend_opts(struct new_merge_job_params *njp)
+{
+	GtkWidget *box;
+	GtkWidget *hbox;
+	GtkWidget *label;
+	int i;
+
+	box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 8);
+	gtk_container_set_border_width(GTK_CONTAINER(box), 8);
+
+	hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
+	gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(hbox),
+	                   FALSE, FALSE, 0);
+	label = gtk_label_new("Batch system:");
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(label),
+	                   FALSE, FALSE, 0);
+
+	njp->backend_combo = gtk_combo_box_text_new();
+	gtk_box_pack_start(GTK_BOX(hbox), GTK_WIDGET(njp->backend_combo),
+	                   FALSE, FALSE, 0);
+
+	for ( i=0; i<njp->proj->n_backends; i++ ) {
+		gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(njp->backend_combo),
+		                          njp->proj->backends[i].name,
+		                          njp->proj->backends[i].friendly_name);
+	}
+
+	njp->backend_opts_box = gtk_box_new(GTK_ORIENTATION_VERTICAL,
+	                                    0);
+	gtk_box_pack_start(GTK_BOX(box),
+	                   GTK_WIDGET(njp->backend_opts_box),
+	                   FALSE, FALSE, 0);
+	njp->backend_opts_widget = NULL;
+
+	/* njp->backend_opts{_box} must exist before the following */
+	g_signal_connect(G_OBJECT(njp->backend_combo), "changed",
+	                 G_CALLBACK(merge_backend_changed_sig), njp);
+	gtk_combo_box_set_active(GTK_COMBO_BOX(njp->backend_combo),
+	                         njp->proj->merge_backend_selected);
+
+	return box;
+}
+
+
+gint merge_sig(GtkWidget *widget, struct crystfelproject *proj)
+{
+	GtkWidget *dialog;
+	GtkWidget *content_area;
+	GtkWidget *vbox;
+	GtkWidget *backend_page;
+	GtkWidget *job_page;
+	GtkWidget *notebook;
+	struct new_merge_job_params *njp;
+
+	njp = malloc(sizeof(struct new_merge_job_params));
+	if ( njp == NULL ) return FALSE;
+
+	njp->proj = proj;
+
+	dialog = gtk_dialog_new_with_buttons("Merge",
+	                                     GTK_WINDOW(proj->window),
+	                                     GTK_DIALOG_DESTROY_WITH_PARENT,
+	                                     "Cancel", GTK_RESPONSE_CANCEL,
+	                                     "Run", GTK_RESPONSE_OK,
+	                                     NULL);
+
+	g_signal_connect_data(G_OBJECT(dialog), "response",
+	                      G_CALLBACK(merge_response_sig),
+	                      njp, free_new_merge_job_params, 0);
+
+	vbox = gtk_vbox_new(FALSE, 0.0);
+	content_area = gtk_dialog_get_content_area(GTK_DIALOG(dialog));
+	gtk_container_add(GTK_CONTAINER(content_area), vbox);
+	gtk_container_set_border_width(GTK_CONTAINER(content_area), 8);
+
+	notebook = crystfel_merge_opts_new();
+	gtk_box_pack_start(GTK_BOX(vbox), GTK_WIDGET(notebook),
+	                   FALSE, FALSE, 8.0);
+
+	job_page = make_merge_job_opts(proj, njp);
+	gtk_notebook_prepend_page(GTK_NOTEBOOK(notebook),
+	                          job_page,
+	                          gtk_label_new("Job name/notes"));
+
+	backend_page = make_merge_backend_opts(njp);
+	gtk_notebook_append_page(GTK_NOTEBOOK(notebook),
+	                         backend_page,
+	                         gtk_label_new("Cluster/batch system"));
+
+	gtk_dialog_set_default_response(GTK_DIALOG(dialog),
+	                                GTK_RESPONSE_OK);
+	gtk_widget_show_all(dialog);
+
+	return FALSE;
+}
diff --git a/src/gui_merge.h b/src/gui_merge.h
new file mode 100644
index 00000000..6d8b6a50
--- /dev/null
+++ b/src/gui_merge.h
@@ -0,0 +1,39 @@
+/*
+ * gui_merge.h
+ *
+ * Merging parts of GUI
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef GUI_MERGE_H
+#define GUI_MERGE_H
+
+#include <gtk/gtk.h>
+
+#include "gui_project.h"
+
+extern gint merge_sig(GtkWidget *widget,
+                      struct crystfelproject *proj);
+
+#endif
diff --git a/src/gui_project.c b/src/gui_project.c
index fe2f72c0..83d9f083 100644
--- a/src/gui_project.c
+++ b/src/gui_project.c
@@ -680,8 +680,10 @@ void default_project(struct crystfelproject *proj)
 	proj->indexing_opts = NULL;
 	proj->n_running_tasks = 0;
 	proj->indexing_new_job_title = NULL;
+	proj->merge_new_job_title = NULL;
 
 	proj->indexing_backend_selected = 0;
+	proj->merge_backend_selected = 0;
 	proj->n_backends = 0;
 	proj->backends = malloc(2*sizeof(struct crystfel_backend));
 	/* FIXME: Crappy error handling */
diff --git a/src/gui_project.h b/src/gui_project.h
index 8a3af512..af4b1037 100644
--- a/src/gui_project.h
+++ b/src/gui_project.h
@@ -89,6 +89,10 @@ struct index_params {
 	float ir_out;
 };
 
+struct merge_params {
+	int nothing;
+};
+
 struct crystfelproject;
 
 struct crystfel_backend {
@@ -125,6 +129,12 @@ struct crystfel_backend {
 	/* Backend should store options for indexing here */
 	void *indexing_opts_priv;
 
+	/* Backend should provide a GTK widget to set options */
+	GtkWidget *(*make_merge_parameters_widget)(void *opts_priv);
+
+	/* Backend should store options for merging here */
+	void *merge_opts_priv;
+
 };
 
 struct gui_task
@@ -189,6 +199,11 @@ struct crystfelproject {
 	GtkWidget *indexing_opts;
 	char *indexing_new_job_title;
 
+	struct merge_params merge_params;
+	int merge_backend_selected;
+	GtkWidget *merge_opts;
+	char *merge_new_job_title;
+
 	GtkWidget *type_combo;
 	GtkWidget *peak_vbox;     /* Box for peak search parameter widgets */
 	GtkWidget *peak_params;   /* Peak search parameter widgets */