Re: Themable colors

[Matthias Clasen <mclasen redhat com>]

On Thu, 2005-03-31 at 10:50 +0400, Nickolay V. Shmyrev wrote:
> Well, you've almost convinced me :)
> 
> Isn't it better than have API for colors similar to stock icons API:
> 
> struct GtkStockColorItem;
> 
> gtk_stock_color_items_add
> gtk_stock_color_items_add_static
> gtk_stock_color_item_free
> gtk_stock_color_item_list_ids
> gtk_stock_color_lookup
> 
> and add to GtkGC's api.
> 
> gtk_gc_get_from_stock
> 
> also it is possible and useful to make public gtk_style_shade function as
> 
> gtk_color_shade (GtkColor *color, gdouble shade)
> 
> 
> and define a lot of stock colors:
> 
> GTK_STOCK_COLOR_ERROR         /* RED */
> GTK_STOCK_COLOR_WARNING       /* YELLOW */
> GTK_STOCK_COLOR_NORMAL        /* GREEN */
> GTK_STOCK_COLOR_HIGHLIGHT     /* BLUE */
> 
> and so on for all HIG palette. Note that there are definitely should be about 
> 8 items with just numbers, as Soren stated, useful for graphs, charts.
> 
> GTK_STOCK_COLOR_ITEM_1
> GTK_STOCK_COLOR_ITEM_2
> GTK_STOCK_COLOR_ITEM_3
> GTK_STOCK_COLOR_ITEM_4
> 
> 
> application could add it's own stock colors and theme authors could modify it just like stock icons

Some important points that need to be adressed are:

- We want to be able to write a simple "color setting" control. How does
that work ? Is there a Setting containing a palette, ie essentially a
map from color names to rgb triplets ? 

- How can themes adapt to the user-selected stock colors ? Do we add new
rc file syntax like fg[NORMAL] = stock-color("foreground") ?

- Do themes need to be able to derive new colors from the stock colors ?
If yes, how ? Do we parse color expressions like 
  fg[NORMAL] = lerp(0.5, stock-color("foreground"), #ff00ff) ?

- How can themes mark themselves as being "recolorable" ? (We probably
want to disable the color setting control if the theme uses fixed
colors)

Matthias