Highlight the current paragraph

Has the nice effect of showing which slide is selected.

3 files changed, 43 insertions, 4 deletions

diff --git a/src/frame.c b/src/frame.c
index f71e764..b021b42 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -576,6 +576,31 @@ int find_cursor(struct frame *fr, double x, double y,
 }
 
 
+int get_para_highlight(struct frame *fr, int cursor_para,
+                       double *cx, double *cy, double *cw, double *ch)
+{
+	Paragraph *para;
+	int i;
+	double py = 0.0;
+
+	if ( cursor_para > fr->n_paras ) {
+		fprintf(stderr, "Cursor paragraph number is too high!\n");
+		return 1;
+	}
+
+	para = fr->paras[cursor_para];
+	for ( i=0; i<cursor_para; i++ ) {
+		py += fr->paras[i]->height;
+	}
+
+	*cx = fr->pad_l;
+	*cy = fr->pad_t + py;
+	*cw = fr->w - fr->pad_l - fr->pad_r;
+	*ch = para->height;
+	return 0;
+}
+
+
 int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
                    double *cx, double *cy, double *ch)
 {
@@ -590,14 +615,16 @@ int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
 	}
 
 	para = fr->paras[cursor_para];
+	for ( i=0; i<cursor_para; i++ ) {
+		py += fr->paras[i]->height;
+	}
 
-	if ( para->type != PARA_TYPE_TEXT ) return 1;
+	if ( para->type != PARA_TYPE_TEXT ) {
+		return 1;
+	}
 
 	pango_layout_get_cursor_pos(para->layout, cursor_pos, &rect, NULL);
 
-	for ( i=0; i<cursor_para; i++ ) {
-		py += fr->paras[i]->height;
-	}
 	*cx = pango_units_to_double(rect.x) + fr->pad_l;
 	*cy = pango_units_to_double(rect.y) + fr->pad_t + py;
 	*ch = pango_units_to_double(rect.height);
diff --git a/src/frame.h b/src/frame.h
index 976fc2b..f61f414 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -130,6 +130,9 @@ 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);
 
+extern int get_para_highlight(struct frame *fr, int cursor_para,
+                              double *cx, double *cy, double *cw, double *ch);
+
 extern int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
                           double *cx, double *cy, double *ch);
 
diff --git a/src/sc_editor.c b/src/sc_editor.c
index 379af90..5352028 100644
--- a/src/sc_editor.c
+++ b/src/sc_editor.c
@@ -403,8 +403,17 @@ static void draw_caret(cairo_t *cr, struct frame *fr, int cursor_para,
                        size_t cursor_pos, int cursor_trail)
 {
 	double cx, clow, chigh, h;
+	double cy, w;
 	const double t = 1.8;
 
+	if ( get_para_highlight(fr, cursor_para, &cx, &cy, &w, &h) == 0 ) {
+		cairo_new_path(cr);
+		cairo_rectangle(cr, cx, cy, w, h);
+		cairo_set_source_rgba(cr, 0.7, 0.7, 1.0, 0.5);
+		cairo_set_line_width(cr, 5.0);
+		cairo_stroke(cr);
+	}
+
 	if ( get_cursor_pos(fr, cursor_para, cursor_pos+cursor_trail,
 	                    &cx, &clow, &h) )
 	{