From 837b3b4b1cc97c8e2b6809256ec0bb20a1d98c0c Mon Sep 17 00:00:00 2001
From: Thomas White <taw@bitwiz.me.uk>
Date: Tue, 22 Dec 2020 18:04:10 +0100
Subject: Avoid deleting slide when pressing backspace in an empty text
 paragraph

---
 libstorycode/gtk/gtknarrativeview.c | 34 +++++++++++++++++++++++++---------
 libstorycode/narrative.c            | 20 +++++++++++++++-----
 libstorycode/narrative.h            |  2 ++
 3 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/libstorycode/gtk/gtknarrativeview.c b/libstorycode/gtk/gtknarrativeview.c
index 9311812..28a2a33 100644
--- a/libstorycode/gtk/gtknarrativeview.c
+++ b/libstorycode/gtk/gtknarrativeview.c
@@ -703,20 +703,36 @@ static void gtknv_do_backspace(GtkNarrativeView *e, signed int dir)
 		p1 = e->sel_start;
 		p2 = e->sel_end;
 
+		sort_positions(&p1, &p2);
+		o1 = narrative_pos_trail_to_offset(e->n, p1.para, p1.pos, p1.trail);
+		o2 = narrative_pos_trail_to_offset(e->n, p2.para, p2.pos, p2.trail);
+		narrative_delete_block(e->n, p1.para, o1, p2.para, o2);
+		e->cpos = p1;
+
 	} else {
 
 		/* Delete one character, as represented visually */
-		p2 = e->cpos;
-		p1 = p2;
-		gtknv_cursor_moveh(e->n, &p1, dir);
-		set_cursor_h_pos(e);
+
+		if ( narrative_item_is_empty_text(e->n, e->cpos.para) ) {
+			narrative_delete_item(e->n, e->cpos.para);
+			if ( dir == -1 ) {
+				e->cpos.para--;
+			} /* else we are already on the right item */
+		} else {
+
+			p2 = e->cpos;
+			p1 = p2;
+			gtknv_cursor_moveh(e->n, &p1, dir);
+			set_cursor_h_pos(e);
+			sort_positions(&p1, &p2);
+			o1 = narrative_pos_trail_to_offset(e->n, p1.para, p1.pos, p1.trail);
+			o2 = narrative_pos_trail_to_offset(e->n, p2.para, p2.pos, p2.trail);
+			narrative_delete_block(e->n, p1.para, o1, p2.para, o2);
+			e->cpos = p1;
+
+		}
 	}
 
-	sort_positions(&p1, &p2);
-	o1 = narrative_pos_trail_to_offset(e->n, p1.para, p1.pos, p1.trail);
-	o2 = narrative_pos_trail_to_offset(e->n, p2.para, p2.pos, p2.trail);
-	narrative_delete_block(e->n, p1.para, o1, p2.para, o2);
-	e->cpos = p1;
 	gtknv_unset_selection(e);
 
 	/* The only paragraphs which still exist and might have been
diff --git a/libstorycode/narrative.c b/libstorycode/narrative.c
index ffd7dab..34c55aa 100644
--- a/libstorycode/narrative.c
+++ b/libstorycode/narrative.c
@@ -199,6 +199,16 @@ int narrative_item_is_text(Narrative *n, int item)
 }
 
 
+int narrative_item_is_empty_text(Narrative *n, int item)
+{
+	struct narrative_item *i = &n->items[item];
+
+	return (narrative_item_is_text(n, item)
+	     && (i->n_runs == 1)
+	     && (strlen(i->runs[0].text)==0));
+}
+
+
 void narrative_add_stylesheet(Narrative *n, Stylesheet *ss)
 {
 	assert(n->stylesheet == NULL);
@@ -336,7 +346,7 @@ void narrative_insert_slide(Narrative *n, int pos, Slide *slide)
 }
 
 
-static void delete_item(Narrative *n, int del)
+void narrative_delete_item(Narrative *n, int del)
 {
 	int i;
 	narrative_item_destroy(&n->items[del]);
@@ -408,7 +418,7 @@ void narrative_delete_block(Narrative *n, int i1, size_t o1, int i2, size_t o2)
 
 	/* Starting item */
 	if ( !narrative_item_is_text(n, i1) ) {
-		delete_item(n, i1);
+		narrative_delete_item(n, i1);
 		if ( i1 == i2 ) return;  /* only one slide to delete */
 		middle = i1; /* ... which is now the item just after the slide */
 		i2--;
@@ -429,14 +439,14 @@ void narrative_delete_block(Narrative *n, int i1, size_t o1, int i2, size_t o2)
 	for ( i=middle; i<i2; i++ ) {
 		/* Deleting the item moves all the subsequent items up, so the
 		 * index to be deleted doesn't change. */
-		delete_item(n, middle);
+		narrative_delete_item(n, middle);
 		n_del++;
 	}
 	i2 -= n_del;
 
 	/* Last item */
 	if ( !narrative_item_is_text(n, i2) ) {
-		delete_item(n, i2);
+		narrative_delete_item(n, i2);
 		return;
 	}
 
@@ -468,7 +478,7 @@ void narrative_delete_block(Narrative *n, int i1, size_t o1, int i2, size_t o2)
 		}
 		item1->n_runs += item2->n_runs;
 
-		delete_item(n, i2);
+		narrative_delete_item(n, i2);
 		update_timing(item1);
 	}
 }
diff --git a/libstorycode/narrative.h b/libstorycode/narrative.h
index fba69d2..26a2d9c 100644
--- a/libstorycode/narrative.h
+++ b/libstorycode/narrative.h
@@ -52,6 +52,7 @@ extern void narrative_set_unsaved(Narrative *n);
 extern int narrative_get_unsaved(Narrative *n);
 
 extern int narrative_item_is_text(Narrative *n, int item);
+extern int narrative_item_is_empty_text(Narrative *n, int item);
 
 extern void narrative_insert_text(Narrative *n, int pos, struct text_run *runs, int n_runs);
 extern void narrative_insert_bp(Narrative *n, int pos, struct text_run *runs, int n_runs);
@@ -64,6 +65,7 @@ extern void narrative_insert_eop(Narrative *n, int pos);
 extern void narrative_delete_block(Narrative *n, int i1, size_t o1,
                                                  int i2, size_t o2);
 extern void narrative_split_item(Narrative *n, int i1, size_t o1);
+extern void narrative_delete_item(Narrative *n, int del);
 extern int narrative_get_num_items(Narrative *n);
 extern int narrative_get_num_items_to_eop(Narrative *n);
 extern int narrative_get_num_slides(Narrative *n);
-- 
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