draw_rectangle_gradient() for the progressbar widget; + fg_full option

Adds an optional additional foreground color option to a bar: fg_full = <color>

A value of 0 represents the fg-color, and a value of 100 (a full graph) the
fg_full-color.

Example:

progressbar xy
{
  bar { fg = "#111155" fg_full = "#3333cc"  bg = "#000000" bordercolor = "#4444cc"}
  ....
}

Signed-off-by: Julien Danjou <julien@danjou.info>

common/configopts.c

@@ -152,6 +152,7 @@ cfg_opt_t widget_graph_opts[] =
 cfg_opt_t widget_progressbar_bar_opts[] =
 {
     CFG_STR((char *) "fg", (char *) NULL, CFGF_NONE),
+    CFG_STR((char *) "fg_full", (char *) NULL, CFGF_NONE),
     CFG_STR((char *) "bg", (char *) NULL, CFGF_NONE),
     CFG_STR((char *) "bordercolor", (char *) NULL, CFGF_NONE),
     CFG_END()

common/draw.c

@@ -151,9 +151,42 @@ draw_rectangle(DrawCtx *ctx, Area geometry, Bool filled, XColor color)
         cairo_fill(ctx->cr);
     }
     else
+    {
         cairo_rectangle(ctx->cr, geometry.x + 1, geometry.y, geometry.width - 1, geometry.height - 1);
+        cairo_stroke(ctx->cr);
+    }
+}
 
-    cairo_stroke(ctx->cr);
+/* 'fullwidth' represents a full color-pattern range */
+void
+draw_rectangle_gradient(DrawCtx *ctx, Area geometry, int fullwidth, Bool filled,
+                        XColor color, XColor color_full)
+{
+    cairo_pattern_t *pat;
+
+    cairo_set_antialias(ctx->cr, CAIRO_ANTIALIAS_NONE);
+    cairo_set_line_width(ctx->cr, 1.0);
+
+    pat = cairo_pattern_create_linear(geometry.x, geometry.y, geometry.x + fullwidth, geometry.y);
+    cairo_pattern_add_color_stop_rgb(pat, 0, color.red / 65535.0,
+                                     color.green / 65535.0, color.blue / 65535.0);
+    cairo_pattern_add_color_stop_rgb(pat, 1, color_full.red / 65535.0,
+                                     color_full.green / 65535.0, color_full.blue / 65535.0);
+
+    cairo_set_source(ctx->cr, pat);
+
+    if(filled)
+    {
+        cairo_rectangle(ctx->cr, geometry.x, geometry.y, geometry.width, geometry.height);
+        cairo_fill(ctx->cr);
+    }
+    else
+    {
+        cairo_rectangle(ctx->cr, geometry.x + 1, geometry.y, geometry.width - 1, geometry.height - 1);
+        cairo_set_source(ctx->cr, pat);
+    }
+
+    cairo_pattern_destroy(pat);
 }
 
 /* draw_graph functions */

common/draw.h

@@ -95,6 +95,7 @@ void draw_context_delete(DrawCtx *);
 
 void draw_text(DrawCtx *, Area, Alignment, int, XftFont *, const char *, XColor fg, XColor bg);
 void draw_rectangle(DrawCtx *, Area, Bool, XColor);
+void draw_rectangle_gradient(DrawCtx *, Area, int, Bool, XColor, XColor);
 
 void draw_graph_setup(DrawCtx *);
 void draw_graph(DrawCtx *, int, int, int, int *, int *, int, XColor);

widgets/progressbar.c

@@ -42,6 +42,8 @@ typedef struct
     float height;
     /** Foreground color */
     XColor *fg;
+    /** Foreground color when bar is full */
+    XColor *fg_full;
     /** Background color */
     XColor *bg;
     /** Border color */
@@ -92,7 +94,7 @@ progressbar_draw(Widget *widget, DrawCtx *ctx, int offset,
             rectangle.y = margin_top + 1;
             rectangle.width = pwidth;
             rectangle.height = pb_height - 2;
-            draw_rectangle(ctx, rectangle, True, d->fg[i]);
+            draw_rectangle_gradient(ctx, rectangle, width - 2, True, d->fg[i], d->fg_full[i]);
         }
 
         if(width - 2 - pwidth > 0) /* not filled area */
@@ -152,8 +154,9 @@ progressbar_new(Statusbar *statusbar, cfg_t *config)
         return w;
     }
 
-    d->bg = p_new(XColor, d->bars);
     d->fg = p_new(XColor, d->bars);
+    d->fg_full = p_new(XColor, d->bars);
+    d->bg = p_new(XColor, d->bars);
     d->bordercolor = p_new(XColor, d->bars);
     d->percent = p_new(int, d->bars);
 
@@ -166,6 +169,11 @@ progressbar_new(Statusbar *statusbar, cfg_t *config)
         else
             d->fg[i] = globalconf.screens[statusbar->screen].colors_normal[ColFG];
 
+        if((color = cfg_getstr(cfg, "fg_full")))
+            d->fg_full[i] = draw_color_new(globalconf.display, phys_screen, color);
+        else
+            d->fg_full[i] = d->fg[i];
+
         if((color = cfg_getstr(cfg, "bg")))
             d->bg[i] = draw_color_new(globalconf.display, phys_screen, color);
         else