Currently the window shadows are being configured in two places. In xfwm4 using options: /general/shadow_delta_{x|y|width|height} ={-3,-3,0,0} and in respective settings in the themes. There are a couple of problems with them: 1. The default settings yield almost symmetric shadows, which does not match most (all?) of the Gtk themes, which assume top-left lighting when rendering gui elements. 2. If these setting are overrode in the theme (BTW, I think that most general purpose themes should do it, yet they do), the user cannot change these setting using above options because the theme takes precedence over xfwm4 settings. My proposal is to: 1. Adjust the defaults (I found that {-10, -10, 0, 0} looks good - treat these values as reference, not a suggestion). 2. Remove these settings from most themes, unless they _really_ need to redefine them. 3. Make the user-set value of the above parameters override the theme settings. This is perhaps desired for all other user-settable options as well.
Created attachment 4151 Screenshot of a window with shadow settings {-8, -8, 0, 0} (slightly less offset than mentioned in the first comment).
Created attachment 4152 Screenshot of a window with default xfwm4 shadow settings {-3, -3, 0, 0}
Created attachment 4153 Screenshot of a window with moheli theme shadow settings {1, 1, 1, 4}
Created attachment 4154 Screenshot with different x and y offsets {-5, -8, 0, 0}
Just to state that in advance: I agree with the wish for consistency in shadows, but I think it's hard to achieve. I think that having the user-settings override the theme-settings is a sane wish (at least it makes sense to me), but I'd like to add that it's not exactly easy for users to modify their xfwm-shadow-settings – at least I don't expect normal users to fiddle with the settings-editor or xfconf in the cli. I'm not sure I can agree with the claim that "most themes assume top-left lighting when rendering gui elements". At least none of mine do. In fact to me it seems that most themes I used set the light source to come straight from the top – this seems to be the default in the murrine engine by the way (when shadows are added underneath buttons etc.) Same goes for the Aurora engine and I can't really remember seeing shadows – at least not the way they're drawn underneath the window – in the xfce-engine. With the mist-engine it seems that they set the light-source from left-top, but it's a very bulky 3D effect, nothing I would call a shadow in the strict sense. Especially not something I would say conflicts with xfwm-shadows, because the look fundamentally different. Right, so all that above was just written from my experience, but I hope I can back up most of it with evidence if you disagree :)
Fair point about the light direction in the themes. Indeed the theme in screenshots I've uploaded seems to use top-down lighting. I wouldn't mind having the default shadow below the window without (or with only very slight) horizontal offset - that would be still much better than the current setup. The themes *should* be able to override the default xfwm4 settings if they *need* it for consistent lighting, but I think that with right defaults that would be more an exception than a rule. Finally, IMHO any user settings should take precedence over the defaults but as with any settings, it's better to ship good defaults than bother users with changing them. If the defaults satisfied "99+%" of the users then we could assume that the remaining ones will be able to tweak the settings using a settings editor or to make their own theme. I wouldn't bother adding a GUI for it, in fact exposing "99+%" of the users to additional knobs could have a negative impact on usability.
I think the main problem is that you can never say what a consistent combination of Gtk and Xfwm theme is, because the user can decide to combine whatever. So to some extent it's also up to the user to get a sane setup (and up to the packagers in distros to provide a sane default combination). I would second the shadow being somewhat underneath the windows, in fact it's what I have set in my Xfwm theme (Greybird). With respect to icons I wanted to add that those also have the lightsource on top, at least Tango and Gnome do. (Newer themes like elementary and Faenza follow that same policy.) So that's another argument for having the shadow-offset slightly below the window. Agreed, no GUI for shadow-config of Xfwm4, that would be far over the top.
Any agreement or at least consensus reached here?... in the form a patch, would be even better... :)
I agree that removing the shadow-settings from most xfwm4 themes might make sense and to have a good default value (and to let user-set options override them). Unfortunately I won't be able to provide a patch for that. Andrzej? Think I've expressed my thoughts on the default light situation at length, but not sure that was enough to reach a consensus :)
(In reply to comment #10) > I agree that removing the shadow-settings from most xfwm4 themes might make > sense and to have a good default value (and to let user-set options override > them). Unfortunately I won't be able to provide a patch for that. Andrzej? Well to this I disagree. The theme must be allowed to set the shadows, some themes have shapes that require the shadow offset to be adjusted or else it looks just displaced. > Think I've expressed my thoughts on the default light situation at length, > but not sure that was enough to reach a consensus :) Without a consensus I am fairly happy with status quo.
"Consensus" is a bit too much to ask for in this matter. Here is my (fairly minimal yet "good enough") proposal: - change the default settings so that the shadow doesn't go significantly beyond the upper edge of the window (I find it problematic for menus and inconsistent with lighting in *most* themes). No preference about the x offset (either 0 or shifted very slightly to the right is OK to me). - go over four themes shipped with xfwm4 and remove shadow settings unless they are necessary for consistency reasons. If change is required, make it minimal (e.g. only change x offset). I'm now working on a patch but it really is just a bunch of config changes. What I'm planing to use by default is: shadow_delta_height=0 shadow_delta_width=-5 shadow_delta_x=-6 <- very slight 1px x offset shadow_delta_y=-10 shadow_opacity=50
Created attachment 4315 A patch (based on comment #12). Note: changing default options will not affect users upgrading from previous Xfce versions.
I guess this isn't important enough to us anymore because we didn't follow up for 8 years :)