Clarify that cursor_pos is BYTE offset (not character)

4 files changed, 81 insertions, 22 deletions

diff --git a/src/frame.c b/src/frame.c
index a0124a7..3699b74 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -542,7 +542,7 @@ size_t end_offset_of_para(struct frame *fr, int pn)
 
 
 /* Local x,y in paragraph -> text offset */
-static int text_para_pos(Paragraph *para, double x, double y, int *ptrail)
+static size_t text_para_pos(Paragraph *para, double x, double y, int *ptrail)
 {
 	int idx;
 	pango_layout_xy_to_index(para->layout, pango_units_from_double(x),
@@ -552,7 +552,7 @@ static int text_para_pos(Paragraph *para, double x, double y, int *ptrail)
 
 
 int find_cursor(struct frame *fr, double x, double y,
-                int *ppara, int *ppos, int *ptrail)
+                int *ppara, size_t *ppos, int *ptrail)
 {
 	double pos = fr->pad_t;
 	int i;
@@ -657,16 +657,19 @@ int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
 }
 
 
-void cursor_moveh(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+void cursor_moveh(struct frame *fr, int *cpara, size_t *cpos, int *ctrail,
                   signed int dir)
 {
 	Paragraph *para = fr->paras[*cpara];
+	int np = *cpos;
 
-	if ( (*cpos+*ctrail == end_offset_of_para(fr, *cpara)) && (dir > 0) ) {
-		if ( *cpara < fr->n_paras-1 ) {
-			(*cpara)++;
-			*cpos = 0;
-			*ctrail = 0;
+	pango_layout_move_cursor_visually(para->layout, 1, *cpos, *ctrail,
+	                                  dir, &np, ctrail);
+	if ( np == -1 ) {
+		if ( *cpara > 0 ) {
+			(*cpara)--;
+			*cpos = end_offset_of_para(fr, *cpara) - 1;
+			*ctrail = 1;
 			return;
 		} else {
 			/* Can't move any further */
@@ -674,23 +677,23 @@ void cursor_moveh(struct frame *fr, int *cpara, int *cpos, int *ctrail,
 		}
 	}
 
-	if ( (*cpos+*ctrail == 0) && (dir < 0) ) {
-		if ( *cpara > 0 ) {
-			(*cpara)--;
-			*cpos = end_offset_of_para(fr, *cpara) - 1;
-			*ctrail = 1;
+	if ( np == G_MAXINT ) {
+		if ( *cpara < fr->n_paras-1 ) {
+			(*cpara)++;
+			*cpos = 0;
+			*ctrail = 0;
 			return;
 		} else {
 			/* Can't move any further */
 			return;
 		}
 	}
-	pango_layout_move_cursor_visually(para->layout, 1, *cpos, *ctrail,
-	                                  dir, cpos, ctrail);
+
+	*cpos = np;
 }
 
 
-void cursor_movev(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+void cursor_movev(struct frame *fr, int *cpara, size_t *cpos, int *ctrail,
                   signed int dir)
 {
 }
@@ -793,3 +796,59 @@ void delete_text_in_paragraph(Paragraph *para, size_t offs1, size_t offs2)
 		printf("Multi-run delete!\n");
 	}
 }
+
+
+static void split_text_paragraph(struct frame *fr, int pn, int pos,
+                                 PangoContext *pc)
+{
+	Paragraph *pnew;
+	int i, j;
+	int run;
+	Paragraph *para = fr->paras[pn];
+
+	pnew = insert_paragraph(fr, pn);
+	if ( pnew == NULL ) {
+		fprintf(stderr, "Failed to insert paragraph\n");
+		return;
+	}
+
+	/* Determine which run the cursor is in */
+	run = which_run(para, pos);
+
+	pnew->type = PARA_TYPE_TEXT;
+	pnew->open = para->open;
+	pnew->n_runs = para->n_runs - run;
+	pnew->runs = malloc(pnew->n_runs * sizeof(struct text_run));
+	if ( pnew->runs == NULL ) {
+		fprintf(stderr, "Failed to allocate runs.\n");
+		return; /* Badness is coming */
+	}
+
+	/* If the position is right at the start of a run, the whole run
+	 * gets moved to the next paragraph */
+	if ( para->runs[run].para_offs_bytes ) {
+	}
+
+	j = 0;
+	for ( i=run; i<para->n_runs; i++ ) {
+		pnew->runs[j++] = para->runs[i];
+	}
+
+	para->open = 0;
+	para->n_runs = run+1;
+
+	wrap_paragraph(para, pc, fr->w);
+	wrap_paragraph(pnew, pc, fr->w);
+}
+
+
+void split_paragraph(struct frame *fr, int pn, int pos, PangoContext *pc)
+{
+	Paragraph *para = fr->paras[pn];
+
+	if ( para->type == PARA_TYPE_TEXT ) {
+		split_text_paragraph(fr, pn, pos, pc);
+	} else {
+		/* Other types can't be split */
+	}
+}
diff --git a/src/frame.h b/src/frame.h
index a6b316f..d6d171c 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -128,7 +128,7 @@ extern void wrap_paragraph(Paragraph *para, PangoContext *pc, double w);
 extern size_t end_offset_of_para(struct frame *fr, int pn);
 
 extern int find_cursor(struct frame *fr, double x, double y,
-                       int *ppara, int *ppos, int *ptrail);
+                       int *ppara, size_t *ppos, int *ptrail);
 
 extern int get_para_highlight(struct frame *fr, int cursor_para,
                               double *cx, double *cy, double *cw, double *ch);
@@ -136,10 +136,10 @@ extern int get_para_highlight(struct frame *fr, int cursor_para,
 extern int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
                           double *cx, double *cy, double *ch);
 
-extern void cursor_moveh(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+extern void cursor_moveh(struct frame *fr, int *cpara, size_t *cpos, int *ctrail,
                          signed int dir);
 
-extern void cursor_movev(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+extern void cursor_movev(struct frame *fr, int *cpara, size_t *cpos, int *ctrail,
                          signed int dir);
 
 extern void check_callback_click(struct frame *fr, int para);
diff --git a/src/sc_editor.c b/src/sc_editor.c
index 0ad5e37..5549c54 100644
--- a/src/sc_editor.c
+++ b/src/sc_editor.c
@@ -613,12 +613,12 @@ static void insert_text(char *t, SCEditor *e)
 
 static void do_backspace(struct frame *fr, SCEditor *e)
 {
-	int old_pos = e->cursor_pos;
+	size_t 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;
+	size_t new_pos = old_pos;
 	int new_trail = old_trail;
 
 	Paragraph *para = e->cursor_frame->paras[old_para];
diff --git a/src/sc_editor.h b/src/sc_editor.h
index eaa7f41..594f344 100644
--- a/src/sc_editor.h
+++ b/src/sc_editor.h
@@ -118,7 +118,7 @@ struct _sceditor
 	/* Location of the cursor */
 	struct frame        *cursor_frame;
 	int                  cursor_para; /* paragraph index */
-	int                  cursor_pos;  /* character offset into paragraph */
+	size_t               cursor_pos;  /* byte offset into paragraph */
 	int                  cursor_trail;
 
 	/* Border surrounding actual slide within drawingarea */