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> What complexity? What is a wl_registry_listener and why do I need it? What is a simple XGetImage() equivalent on Wayland? On Xlib function names at least giv

by sprash 6y ago

> What complexity? What is a wl_registry_listener and why do I need it? What is a simple XGetImage() equivalent on Wayland? On Xlib function names at least give you an idea about what they are supposed to be doing. > Also, how often do you write gui apps without any framework? As soon as you have a Toolkit you don't need Wayland anymore. Windows then are just additional nodes in the object tree. There was even a demonstration of GTK applications running in a framebuffer without X11 way before Wayland even existed. If Wayland can only be used sanely with toolkits it indeed is completely pointless.

kaba0 6y ago
It was some time ago I looked into it, but wl_registry_listener registers a callback for when the compositor “declares” what protocol extensions it supports. This is painfully missing from X, but this makes Wayland much more modular/extensibly. Wayland’s abstraction is basically a buffer. The client simply creates a buffer either in shared memory, or directly on the GPU and then passes the compositor a handle to the buffer. That’s it. Also, it is sort of ingenious to compare the two — the XLib is a higher level lib than libwayland. There is absolutely no reason why someone could not create a wrapper for this — although I again ask, how often does one create an only X/only Wayland window without a framework.
cycloptic 6y ago
Wayland doesn't have the equivalent of XGetImage for various reasons, but screen capture applications can use the ScreenCast flatpak portal to select window sources: https://flatpak.github.io/xdg-desktop-portal/portal-docs.html#gdbus-method-org-freedesktop-portal-ScreenCast.SelectSources https://flatpak.github.io/xdg-desktop-portal/portal-docs.htm... I am not sure what you mean by Wayland can only be used sanely with toolkits, any GUI usually need a toolkit or some equivalent, even under X. if you are not using a pre-existing toolkit and are writing your own routines to draw buttons and text boxes and such, that would be implementing your own toolkit.

by sprash 6y ago

kaba0 6y ago

It was some time ago I looked into it, but wl_registry_listener registers a callback for when the compositor “declares” what protocol extensions it supports. This is painfully missing from X, but this makes Wayland much more modular/extensibly. Wayland’s abstraction is basically a buffer. The client simply creates a buffer either in shared memory, or directly on the GPU and then passes the compositor a handle to the buffer. That’s it. Also, it is sort of ingenious to compare the two — the XLib is a higher level lib than libwayland. There is absolutely no reason why someone could not create a wrapper for this — although I again ask, how often does one create an only X/only Wayland window without a framework.

cycloptic 6y ago

Wayland doesn't have the equivalent of XGetImage for various reasons, but screen capture applications can use the ScreenCast flatpak portal to select window sources: https://flatpak.github.io/xdg-desktop-portal/portal-docs.html#gdbus-method-org-freedesktop-portal-ScreenCast.SelectSources https://flatpak.github.io/xdg-desktop-portal/portal-docs.htm... I am not sure what you mean by Wayland can only be used sanely with toolkits, any GUI usually need a toolkit or some equivalent, even under X. if you are not using a pre-existing toolkit and are writing your own routines to draw buttons and text boxes and such, that would be implementing your own toolkit.