workspaces: when cycling through desktops RTL languages shift right too much. about labwc

[01micko]

This is a weird bug. I put a hack in osd.c and workspaces.c printing x to file (the cairo x coordinate for text position) and here's the result:

68 [en - wkspces]
68
68
68
68
68
68
68
258 [en - osd]
258
66 [ar - wkspces]
66
66
66
66
66
66
256 [ar - osd]
256
256

The font extents were like so 84 [en] and 87 [ar] in both osd.c and workspaces.c so there is no error in the math. I didn't expect so but I did suspect maybe something weird was happening in font_width().

I think somehow in workspaces.c the logic maybe out?

[Consolatis]

Hm.. yeah, I think there is a bug in the calculation of the available width; we do set the width available to pango to the whole available space rather than just the space required for the text, clamped by the whole available width.

That should usually not be an issue but in this case of a RTL setting it means that pango will in fact use all the available width as it starts the text on the right rather than our pre-calculated center offset.

This might fix it:

diff --git a/src/workspaces.c b/src/workspaces.c
index e7707c5f..c8b1ac2c 100644
--- a/src/workspaces.c
+++ b/src/workspaces.c
@@ -118,18 +118,21 @@ _osd_update(struct server *server)
 		/* Text */
 		set_cairo_color(cairo, server->theme->osd_label_text_color);
 		PangoLayout *layout = pango_cairo_create_layout(cairo);
-		pango_layout_set_width(layout, (width - 2 * margin) * PANGO_SCALE);
 		pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
 
-		PangoFontDescription *desc = font_to_pango_desc(&rc.font_osd);
-		pango_layout_set_font_description(layout, desc);
 
 		/* Center workspace indicator on the x axis */
-		x = font_width(&rc.font_osd, server->workspace_current->name);
-		x = (width - x) / 2;
+		int req_width = font_width(&rc.font_osd, server->workspace_current->name);
+		if (req_width > width - 2 * margin) {
+			req_width = width - 2 * margin;
+		}
+		x = (width - req_width) / 2;
 		cairo_move_to(cairo, x, margin * 2 + rect_height);
+
+		PangoFontDescription *desc = font_to_pango_desc(&rc.font_osd);
 		//pango_font_description_set_weight(desc, PANGO_WEIGHT_BOLD);
 		pango_layout_set_font_description(layout, desc);
+		pango_layout_set_width(layout, req_width * PANGO_SCALE);
 		pango_font_description_free(desc);
 		pango_layout_set_text(layout, server->workspace_current->name, -1);
 		pango_cairo_show_layout(cairo, layout);

[01micko]

Nice!