expo: Support object alignment

Add support for left, right and centred alignment for text, in the
horizontal dimension.

Also support top, bottom and centred in the vertical dimension, for the
text object as a whole.

Alignment is not yet implemented for images. It has no meaning for
menus. A textline object uses a text object internally, so alignment
is supported there.

Provide some documentation to explain how objects are positioned.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 102 insertions, 5 deletions

diff --git a/boot/scene.c b/boot/scene.c
index f971db9aab4..3091a9e0ab1 100644
--- a/boot/scene.c
+++ b/boot/scene.c
@@ -306,6 +306,30 @@ int scene_obj_set_bbox(struct scene *scn, uint id, int x0, int y0, int x1,
 	return 0;
 }
 
+int scene_obj_set_halign(struct scene *scn, uint id, enum scene_obj_align aln)
+{
+	struct scene_obj *obj;
+
+	obj = scene_obj_find(scn, id, SCENEOBJT_NONE);
+	if (!obj)
+		return log_msg_ret("osh", -ENOENT);
+	obj->horiz = aln;
+
+	return 0;
+}
+
+int scene_obj_set_valign(struct scene *scn, uint id, enum scene_obj_align aln)
+{
+	struct scene_obj *obj;
+
+	obj = scene_obj_find(scn, id, SCENEOBJT_NONE);
+	if (!obj)
+		return log_msg_ret("osv", -ENOENT);
+	obj->vert = aln;
+
+	return 0;
+}
+
 int scene_obj_set_hide(struct scene *scn, uint id, bool hide)
 {
 	int ret;
@@ -331,6 +355,44 @@ int scene_obj_flag_clrset(struct scene *scn, uint id, uint clr, uint set)
 	return 0;
 }
 
+static void handle_alignment(enum scene_obj_align horiz,
+			     enum scene_obj_align vert,
+			     struct scene_obj_bbox *bbox,
+			     struct scene_obj_dims *dims,
+			     int xsize, int ysize,
+			     struct scene_obj_offset *offset)
+{
+	int width, height;
+
+	width = bbox->x1 - bbox->x0;
+	height = bbox->y1 - bbox->y0;
+
+	switch (horiz) {
+	case SCENEOA_CENTRE:
+		offset->xofs = (width - dims->x) / 2;
+		break;
+	case SCENEOA_RIGHT:
+		offset->xofs = width - dims->x;
+		break;
+	case SCENEOA_LEFT:
+		offset->xofs = 0;
+		break;
+	}
+
+	switch (vert) {
+	case SCENEOA_CENTRE:
+		offset->yofs = (height - dims->y) / 2;
+		break;
+	case SCENEOA_BOTTOM:
+		offset->yofs = height - dims->y;
+		break;
+	case SCENEOA_TOP:
+	default:
+		offset->yofs = 0;
+		break;
+	}
+}
+
 int scene_obj_get_hw(struct scene *scn, uint id, int *widthp)
 {
 	struct scene_obj *obj;
@@ -445,10 +507,12 @@ static int scene_txt_render(struct expo *exp, struct udevice *dev,
 			    struct scene_txt_generic *gen, int x, int y,
 			    int menu_inset)
 {
-	const struct vidconsole_mline *mline;
+	const struct vidconsole_mline *mline, *last;
 	struct video_priv *vid_priv;
 	struct vidconsole_colour old;
 	enum colour_idx fore, back;
+	struct scene_obj_dims dims;
+	struct scene_obj_bbox bbox;
 	const char *str;
 	int ret;
 
@@ -482,13 +546,33 @@ static int scene_txt_render(struct expo *exp, struct udevice *dev,
 				obj->bbox.y1, vid_priv->colour_bg);
 	}
 
-	if (!gen->lines.count) {
+	mline = alist_get(&gen->lines, 0, typeof(*mline));
+	last = alist_get(&gen->lines, gen->lines.count - 1, typeof(*mline));
+	if (mline)
+		dims.y = last->bbox.y1 - mline->bbox.y0;
+	bbox.y0 = obj->bbox.y0;
+	bbox.y1 = obj->bbox.y1;
+
+	if (!mline) {
 		vidconsole_set_cursor_pos(cons, x, y);
 		vidconsole_put_string(cons, str);
 	}
+
 	alist_for_each(mline, &gen->lines) {
-		vidconsole_set_cursor_pos(cons, x + mline->bbox.x0,
-					  y + mline->bbox.y0);
+		struct scene_obj_offset offset;
+
+		bbox.x0 = obj->bbox.x0;
+		bbox.x1 = obj->bbox.x1;
+		dims.x = mline->bbox.x1 - mline->bbox.x0;
+		handle_alignment(obj->horiz, obj->vert, &bbox, &dims,
+				 obj->bbox.x1 - obj->bbox.x0,
+				 obj->bbox.y1 - obj->bbox.y0, &offset);
+
+		x = obj->bbox.x0 + offset.xofs;
+		y = obj->bbox.y0 + offset.yofs + mline->bbox.y0;
+		if (y > bbox.y1)
+			break;	/* clip this line and any following */
+		vidconsole_set_cursor_pos(cons, x, y);
 		vidconsole_put_stringn(cons, str + mline->start, mline->len);
 	}
 	if (obj->flags & SCENEOF_POINT)
@@ -515,7 +599,7 @@ static int scene_obj_render(struct scene_obj *obj, bool text_mode)
 	int x, y, ret;
 
 	y = obj->bbox.y0;
-	x = obj->bbox.x0;
+	x = obj->bbox.x0 + obj->ofs.xofs;
 	vid_priv = dev_get_uclass_priv(dev);
 
 	switch (obj->type) {
@@ -626,14 +710,27 @@ int scene_calc_arrange(struct scene *scn, struct expo_arrange_info *arr)
 int scene_arrange(struct scene *scn)
 {
 	struct expo_arrange_info arr;
+	int xsize = 0, ysize = 0;
 	struct scene_obj *obj;
+	struct udevice *dev;
 	int ret;
 
+	dev = scn->expo->display;
+	if (dev) {
+		struct video_priv *priv = dev_get_uclass_priv(dev);
+
+		xsize = priv->xsize;
+		ysize = priv->ysize;
+	}
+
 	ret = scene_calc_arrange(scn, &arr);
 	if (ret < 0)
 		return log_msg_ret("arr", ret);
 
 	list_for_each_entry(obj, &scn->obj_head, sibling) {
+		handle_alignment(obj->horiz, obj->vert, &obj->bbox, &obj->dims,
+				 xsize, ysize, &obj->ofs);
+
 		switch (obj->type) {
 		case SCENEOBJT_NONE:
 		case SCENEOBJT_IMAGE: