Make backspace work (pretty minimally)

3 files changed, 68 insertions, 1 deletions

diff --git a/src/frame.c b/src/frame.c
index c835869..7f61a89 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -750,3 +750,43 @@ void insert_text_in_paragraph(Paragraph *para, size_t offs, const char *t)
 		para->runs[i].para_offs_bytes += ins_len;
 	}
 }
+
+
+void delete_text_in_paragraph(Paragraph *para, size_t offs1, size_t offs2)
+{
+	int nrun1, nrun2;
+	int i;
+	struct text_run *run1;
+	struct text_run *run2;
+	size_t scblock_offs1, scblock_offs2;
+
+	/* Find which run we are in */
+	nrun1 = which_run(para, offs1);
+	nrun2 = which_run(para, offs2);
+	if ( (nrun1 == para->n_runs) || (nrun2 == para->n_runs) ) {
+		fprintf(stderr, "Couldn't find run to delete from.\n");
+		return;
+	}
+	run1 = &para->runs[nrun1];
+	run2 = &para->runs[nrun2];
+
+	/* Translate paragraph offsets into SCBlock offsets */
+	scblock_offs1 = offs1 - run1->para_offs_bytes + run1->scblock_offs_bytes;
+	scblock_offs2 = offs2 - run2->para_offs_bytes + run2->scblock_offs_bytes;
+	sc_delete_text(run1->scblock, scblock_offs1,
+	               run2->scblock, scblock_offs2);
+
+	if ( nrun1 == nrun2 ) {
+		size_t del_len = offs2 - offs1;
+		run1->len_bytes -= del_len;
+		for ( i=nrun1+1; i<para->n_runs; i++ ) {
+			if ( para->runs[i].scblock == run1->scblock ) {
+				para->runs[i].scblock_offs_bytes -= del_len;
+			}
+			para->runs[i].para_offs_bytes -= del_len;
+		}
+	} else {
+		/* FIXME: Implement this case */
+		printf("Multi-run delete!\n");
+	}
+}
diff --git a/src/frame.h b/src/frame.h
index 50fdaca..a6b316f 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -147,4 +147,7 @@ extern void check_callback_click(struct frame *fr, int para);
 extern void insert_text_in_paragraph(Paragraph *para, size_t offs,
                                      const char *t);
 
+extern void delete_text_in_paragraph(Paragraph *para,
+                                     size_t offs1, size_t offs2);
+
 #endif	/* FRAME_H */
diff --git a/src/sc_editor.c b/src/sc_editor.c
index ca37853..c75c8ac 100644
--- a/src/sc_editor.c
+++ b/src/sc_editor.c
@@ -605,7 +605,31 @@ static void insert_text(char *t, SCEditor *e)
 
 static void do_backspace(struct frame *fr, SCEditor *e)
 {
-	/* FIXME: Delete at the cursor */
+	int old_pos = e->cursor_pos;
+	int old_para = e->cursor_para;
+	int old_trail = e->cursor_trail;
+
+	int new_para = old_para;
+	int new_pos = old_pos;
+	int new_trail = old_trail;
+
+	Paragraph *para = e->cursor_frame->paras[old_para];
+
+	cursor_moveh(e->cursor_frame, &new_para, &new_pos, &new_trail, -1);
+	cursor_moveh(e->cursor_frame, &e->cursor_para, &e->cursor_pos,
+	             &e->cursor_trail, -1);
+	if ( e->cursor_para != old_para ) {
+		/* FIXME: Implement this case */
+		printf("Merge paragraphs!\n");
+		return;
+	}
+
+	delete_text_in_paragraph(para, e->cursor_pos+e->cursor_trail,
+	                         old_pos+old_trail);
+
+	wrap_paragraph(para, NULL, e->cursor_frame->w - e->cursor_frame->pad_l
+	                            - e->cursor_frame->pad_r);
+
 	sc_editor_redraw(e);
 }