Category: Wayland

  • January 19, 2018 - Chris Michael

    EFL Multiple Output Support with Wayland

    Supporting multiple outputs is something most of us take for granted in the world of X11 because the Xorg team has had years to implement and perfect support for multiple outputs. While we have all enjoyed the fruits of their labor, this has not been the case for Wayland. There are two primary types of multiple output configurations that are relevant: cloned and extended outputs. Cloned Outputs Cloned output mode is the one that most people are familiar with. This means that the contents of the primary output will be duplicated on any additional outputs that are enabled.  If you have ever hot plugged an external monitor into your Windows laptop, then you have seen this mode in action. Extended Outputs Extended output mode is somewhat less common, yet still very important. In this mode, the desktop is extended to span across multiple outputs, while the primary output retains sole […]

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  • December 22, 2017 - Chris Michael

    EFL: Enabling Wayland Output Rotation

    The Enlightenment Foundation Libraries have long supported the ability to do output rotation when running under X11 utilizing the XRandR (resize and rotate) extension. This functionality is exposed to the user by way of the Ecore_X library which provides API function calls that can be used to rotate a given output. Wayland While this functionality has been inside EFL for a long time, the ability to rotate an output while running under the Enlightenment Wayland Compositor has not been possible. This is due, in part, to the fact that the Wayland protocol does not provide any form of RandR extension. Normally this would have proved a challenge when implementing output rotation inside the Enlightnement Wayland compositor, however EFL already has the ability to do this. Software-Based Rotation EFL’s Ecore_Evas library, which is used as the base of the Enlightenment Compositor canvas, has the ability to perform software-based rotation. This means […]

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  • December 21, 2017 - Derek Foreman

    The Wayland Zombie Apocalypse is Near

    Quite some time ago I received a report of a nasty Wayland bug: under certain circumstances a Wayland event was being delivered with an incorrect file descriptor. The reporter dug deeper and determined the root cause of this; it wasn’t good. When a client deletes a Wayland object, there might still be protocol events coming from the compositor destined for it (as a contrived example, I delete my keyboard object because I’m done processing keys for the day, but the user is still typing…). Once the compositor receives the delete request it knows it can’t send any more events, but due to the asynchronous nature of Wayland, there could still be some unprocessed events in the buffer destined for the recently deleted object. The Zombie Scourge This is handled by making the deleted object into a zombie, rather, THE zombie, as there is a singleton zombie object in the client […]

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  • One of the most heinous visual artifacts modern displays are capable of is tearing, on the desktop, there are two major potential sources of this: A compositor redraw during screen refresh – this leads to global artifacts such as application windows breaking up while being repositioned. Applications redrawing while the compositor is reading their content – the contents of a single window will be displayed in an indeterminate state. Under X, application redraws are tricky to do without tearing because content can be updated at any chosen time with no clear feedback as to when the compositor will read it. EFL uses some clever tricks to this end (check out the state of the art X redraw timing for yourself), but it’s difficult to get right in all cases. For a lot of people this just works, or they’re not sensitive to the issue when it doesn’t. Wayland Does Application […]

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  • November 3, 2017 - Mike Blumenkrantz

    New Features in Enlightenment 22

    The E22 development cycle has been underway for over a year, and it has included over 1,500 patches to address nearly 200 tickets on our issue tracker. With this has come a number of new features and improvements. Greatly Improved Wayland Support The majority of development for this cycle has gone towards improving Wayland support. This covers, but is not limited to: adding support for xdg-shell v6, pointer constraints, and relative pointer motion protocols. These additions improve XWayland support and increase stability across all components running under Wayland. Continued Improvements to New Gadget Infrastructure As previous posts have indicated, a lot of work is being done in this area. The goal is to create a more robust infrastructure with a simpler and more intuitive EFL-based API, moving away from the legacy “gadcon” interface, which has its own API and currently only functions due to mountains of gadget-specific workarounds that make […]

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  • October 5, 2017 - Mike Blumenkrantz

    How to Create an EFL Gadget Sandbox

    The new gadget API and infrastructure for Enlightenment continue to undergo heavy development. In addition to improving and extending the base gadget UI, work has recently begun on creating a gadget provider with the new API to provide sandboxing and allow gadgets to be written as regular applications that don’t have or require access to compositor internals. The primary enabler of the new sandboxing system is the efl-wl compositor widget. This allows the compositor to launch applications in isolation, and also provides the ability to add protocol extensions for only that specific instance of the compositor widget. Using these features, it becomes possible to add gadget-specific protocols and utilities on the compositor side that are passed through transparently to the client gadget application. Currently, there is one base protocol in use: the e-gadget protocol, which looks like this:

    The purpose of this is to mimic the gadget API. Applications […]

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  • Wayland: there have been many blog posts, articles, and news items about the new Linux display protocol. There have been developers working to extend the protocol for new and extremely helpful use cases, but new frontiers continue to be explored: putting a multiseat Wayland compositor into a toolkit widget. Due to Wayland’s philosophy of “build your own compositor,” there is no de-facto implementation of a Wayland display server that is analogous to Xorg for X11. Wayland implementations are written using the libwayland server API, and this is flexible enough to be used even in the case of a widget. Overall, the only noteworthy difference between putting a compositor in a widget and a normal nested compositor is that the output size is set to the size of the widget instead of the size of the window. With this in mind, a compositor widget can be manipulated just like any other […]

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  • Recent development in Enlightenment’s Wayland compositor has focused on implementing cross-desktop protocols and improving stability. One of the recently handled protocol series has been relative and constrained pointers. Relative pointer motion is a method for providing pointer movement deltas directly to applications. This is useful for a number of cases, though the easiest to imagine might be first person shooter games. In this case, the application receives movement deltas, allowing the player to endlessly scroll the screen in one direction without hitting the boundaries of the screen. Under Enlightenment, this is handled in different ways depending on the output backend being used. For backends using libinput, e.g., DRM, it’s possible to get relative motion deltas directly from the events and then emit them for compositor use. Other backends, however, such as nested Wayland compositors, have no access to libinput’s hardware events. In this case, Enlightenment must manually calculate the deltas […]

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  • February 2, 2017 - Derek Foreman

    A Curious Wayland Bug

    Enlightenment has a slightly unconventional architecture. For many of its internal dialogues (settings, the file manager, etc.) it uses what we call “internal windows.” These are simply regular toolkit windows that use regular rendering back-ends; in the good ol’ days, this meant a connection to the X server which resulted in a render to a standard X window. In this scenario, the compositor gets the result back the same way as all X client windows, and it composites all internal and external windows together. Under Wayland, things get a bit scarier because now the compositor is the display server. Enlightenment makes a Wayland connection to itself; this gives us all manner of game winning capabilities we never had before. For example, let’s say the internal window wants to sleep and wait for a reply from the compositor (such as a released buffer to render the next frame into). We deadlock and fall down […]

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  • While there are some developers who are familiar with using Ecore_Evas to create a canvas for applications, we often find that new EFL users face some confusion when first trying to create an application. This article aims to provide a simple example of how to create your first EFL Wayland application. For those not familiar with the Ecore_Evas library, it is a set of functions that make it easy to tie together Ecore’s main loop and input handling to Evas; as such, it’s a natural base for EFL applications. While this combination makes it easy to create the basic aspects all applications need, for normal applications (those that use buttons, checkboxes and layouts) one should consider using Elementary. Ecore_Evas is extremely well suited for applications that are not based on widgets. It has a main loop that delivers events, does basic window handling, and leaves all of the drawing up […]

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