Cursor stuff

4 files changed, 155 insertions, 52 deletions

diff --git a/src/frame.c b/src/frame.c
index a541999..591dafd 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -523,3 +523,121 @@ void render_paragraph(cairo_t *cr, Paragraph *para, ImageStore *is,
 
 	}
 }
+
+
+size_t end_offset_of_para(struct frame *fr, int pn)
+{
+	int i;
+	size_t total = 0;
+	for ( i=0; i<fr->paras[pn]->n_runs; i++ ) {
+		total += fr->paras[pn]->runs[i].len_bytes;
+	}
+	return total;
+}
+
+
+/* Local x,y in paragraph -> text offset */
+static int 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),
+	                         pango_units_from_double(y), &idx, ptrail);
+	return idx;
+}
+
+
+int find_cursor(struct frame *fr, double x, double y,
+                int *ppara, int *ppos, int *ptrail)
+{
+	double pos = fr->pad_t;
+	int i;
+
+	for ( i=0; i<fr->n_paras; i++ ) {
+		double npos = pos + fr->paras[i]->height;
+		if ( npos > y ) {
+			*ppara = i;
+			if ( fr->paras[i]->type == PARA_TYPE_TEXT ) {
+				*ppos = text_para_pos(fr->paras[i], x-fr->pad_l,
+				                      y-pos, ptrail);
+			} else {
+				*ppos = 0;
+			}
+			return 0;
+		}
+		pos = npos;
+	}
+
+	/* Pretend it's in the last paragraph */
+	pos -= fr->paras[fr->n_paras-1]->height;
+	*ppara = fr->n_paras - 1;
+	*ppos = text_para_pos(fr->paras[i], x - fr->pad_l, y - pos, ptrail);
+	return 0;
+}
+
+
+int get_cursor_pos(struct frame *fr, int cursor_para, int cursor_pos,
+                   double *cx, double *cy, double *ch)
+{
+	Paragraph *para;
+	PangoRectangle rect;
+	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];
+
+	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);
+	return 0;
+}
+
+
+void cursor_moveh(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+                  signed int dir)
+{
+	Paragraph *para = fr->paras[*cpara];
+
+	if ( (*cpos+*ctrail == end_offset_of_para(fr, *cpara)) && (dir > 0) ) {
+		if ( *cpara < fr->n_paras-1 ) {
+			(*cpara)++;
+			*cpos = 0;
+			*ctrail = 0;
+			return;
+		} else {
+			/* Can't move any further */
+			return;
+		}
+	}
+
+	if ( (*cpos+*ctrail == 0) && (dir < 0) ) {
+		if ( *cpara > 0 ) {
+			(*cpara)--;
+			*cpos = end_offset_of_para(fr, *cpara) - 1;
+			*ctrail = 1;
+			return;
+		} else {
+			/* Can't move any further */
+			return;
+		}
+	}
+	pango_layout_move_cursor_visually(para->layout, 1, *cpos, *ctrail,
+	                                  dir, cpos, ctrail);
+}
+
+
+void cursor_movev(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+                  signed int dir)
+{
+}
diff --git a/src/frame.h b/src/frame.h
index b300c8d..39fe13f 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -125,4 +125,18 @@ extern void add_image_para(struct frame *fr, const char *filename,
 
 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);
+
+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,
+                         signed int dir);
+
+extern void cursor_movev(struct frame *fr, int *cpara, int *cpos, int *ctrail,
+                         signed int dir);
+
 #endif	/* FRAME_H */
diff --git a/src/sc_editor.c b/src/sc_editor.c
index 1658122..c61c51a 100644
--- a/src/sc_editor.c
+++ b/src/sc_editor.c
@@ -362,27 +362,6 @@ void sc_editor_delete_selected_frame(SCEditor *e)
 }
 
 
-static int find_cursor(struct frame *fr, double x, double y,
-                       int *ppara, int *ppos)
-{
-	*ppara = 0;
-	*ppos = 0;
-	return 0;
-}
-
-
-static void move_cursor_back(SCEditor *e)
-{
-	/* FIXME */
-}
-
-
-void advance_cursor(SCEditor *e)
-{
-	/* FIXME */
-}
-
-
 static gint destroy_sig(GtkWidget *window, SCEditor *e)
 {
 	return 0;
@@ -420,23 +399,19 @@ static void draw_editing_box(cairo_t *cr, struct frame *fr)
 }
 
 
-static void draw_caret(cairo_t *cr, struct frame *fr)
+static void draw_caret(cairo_t *cr, struct frame *fr, int cursor_para,
+                       size_t cursor_pos, int cursor_trail)
 {
-#if 0
-	double xposd, yposd, cx;
-	double clow, chigh;
-	PangoRectangle pos;
+	double cx, clow, chigh, h;
 	const double t = 1.8;
 
-	pango_layout_get_cursor_pos(o->layout,
-	                            o->insertion_point+o->insertion_trail,
-	                            &pos, NULL);
+	if ( get_cursor_pos(fr, cursor_para, cursor_pos+cursor_trail,
+	                    &cx, &clow, &h) )
+	{
+		return;
+	}
 
-	xposd = pos.x/PANGO_SCALE;
-	cx = o->base.x - o->offs_x + xposd;
-	yposd = pos.y/PANGO_SCALE;
-	clow = o->base.y - o->offs_y + yposd;
-	chigh = clow + (pos.height/PANGO_SCALE);
+	chigh = clow + h;
 
 	cairo_move_to(cr, cx, clow);
 	cairo_line_to(cr, cx, chigh);
@@ -454,7 +429,6 @@ static void draw_caret(cairo_t *cr, struct frame *fr)
 	cairo_set_source_rgb(cr, 0.86, 0.0, 0.0);
 	cairo_set_line_width(cr, 1.0);
 	cairo_stroke(cr);
-#endif
 }
 
 
@@ -488,7 +462,8 @@ static void draw_overlay(cairo_t *cr, SCEditor *e)
 			draw_resize_handle(cr, x+w-20.0, y+h-20.0);
 		}
 
-		draw_caret(cr, e->cursor_frame);
+		draw_caret(cr, e->cursor_frame, e->cursor_para, e->cursor_pos,
+		           e->cursor_trail);
 
 	}
 
@@ -561,16 +536,6 @@ static gboolean draw_sig(GtkWidget *da, cairo_t *cr, SCEditor *e)
 }
 
 
-static void move_cursor(SCEditor *e, signed int x, signed int y)
-{
-	if ( x > 0 ) {
-		advance_cursor(e);
-	} else {
-		move_cursor_back(e);
-	}
-}
-
-
 void insert_scblock(SCBlock *scblock, SCEditor *e)
 {
 #if 0
@@ -881,7 +846,8 @@ static gboolean button_press_sig(GtkWidget *da, GdkEventButton *event,
 
 				e->cursor_frame = clicked;
 				find_cursor(clicked, x-fr->x, y-fr->y,
-				            &e->cursor_para, &e->cursor_pos);
+				            &e->cursor_para, &e->cursor_pos,
+				            &e->cursor_trail);
 
 				e->start_corner_x = event->x - e->border_offs_x;
 				e->start_corner_y = event->y - e->border_offs_y;
@@ -914,7 +880,7 @@ static gboolean button_press_sig(GtkWidget *da, GdkEventButton *event,
 		e->selection = clicked;
 		e->cursor_frame = clicked;
 		find_cursor(clicked, x-clicked->x, y-clicked->y,
-		            &e->cursor_para, &e->cursor_pos);
+		            &e->cursor_para, &e->cursor_pos, &e->cursor_trail);
 
 	}
 
@@ -1122,7 +1088,8 @@ static gboolean key_press_sig(GtkWidget *da, GdkEventKey *event,
 
 		case GDK_KEY_Left :
 		if ( e->selection != NULL ) {
-			move_cursor(e, -1, 0);
+			cursor_moveh(e->cursor_frame, &e->cursor_para,
+			            &e->cursor_pos, &e->cursor_trail, -1);
 			sc_editor_redraw(e);
 		}
 		claim = 1;
@@ -1130,7 +1097,8 @@ static gboolean key_press_sig(GtkWidget *da, GdkEventKey *event,
 
 		case GDK_KEY_Right :
 		if ( e->selection != NULL ) {
-			move_cursor(e, +1, 0);
+			cursor_moveh(e->cursor_frame, &e->cursor_para,
+			            &e->cursor_pos, &e->cursor_trail, +1);
 			sc_editor_redraw(e);
 		}
 		claim = 1;
@@ -1138,7 +1106,8 @@ static gboolean key_press_sig(GtkWidget *da, GdkEventKey *event,
 
 		case GDK_KEY_Up :
 		if ( e->selection != NULL ) {
-			move_cursor(e, 0, -1);
+			cursor_movev(e->cursor_frame, &e->cursor_para,
+			            &e->cursor_pos, &e->cursor_trail, -1);
 			sc_editor_redraw(e);
 		}
 		claim = 1;
@@ -1146,7 +1115,8 @@ static gboolean key_press_sig(GtkWidget *da, GdkEventKey *event,
 
 		case GDK_KEY_Down :
 		if ( e->selection != NULL ) {
-			move_cursor(e, 0, +1);
+			cursor_movev(e->cursor_frame, &e->cursor_para,
+			            &e->cursor_pos, &e->cursor_trail, +1);
 			sc_editor_redraw(e);
 		}
 		claim = 1;
diff --git a/src/sc_editor.h b/src/sc_editor.h
index 99afa50..eaa7f41 100644
--- a/src/sc_editor.h
+++ b/src/sc_editor.h
@@ -119,6 +119,7 @@ struct _sceditor
 	struct frame        *cursor_frame;
 	int                  cursor_para; /* paragraph index */
 	int                  cursor_pos;  /* character offset into paragraph */
+	int                  cursor_trail;
 
 	/* Border surrounding actual slide within drawingarea */
 	double               border_offs_x;