From: Po Lu Date: Sun, 2 Jun 2024 08:17:34 +0000 (+0800) Subject: Document a GDK misdesign interfering with touch screens and menus X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=5e19f449d7430bb944ad793f1845dbe76d3fd139;p=emacs.git Document a GDK misdesign interfering with touch screens and menus * etc/PROBLEMS (Runtime problems specific to PGTK): Document a misdesign preventing menus from being displayed in response to touch screen events. (cherry picked from commit 50c4feb13246f1f82efd761dd13d31d5474cffa0) --- diff --git a/etc/PROBLEMS b/etc/PROBLEMS index da861ebe6e7..085ed4d0532 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -3512,6 +3512,22 @@ Compose key to stop working. On X Windows, users should not use Emacs configured with PGTK, since this and many other problems do not exist on the regular X builds. +** On occasion, menus cannot be activated by touch screen events. + +Menus might not be displayed after a mode-line item, or another command +that produces a menu, is activated by touch screen events. This is the +product of several bugs or misdesigns in the GDK Wayland backend which +cannot be circumvented by Emacs. Specifically, Wayland denies clients +that cannot provide a sufficiently recent event serial number the +ability to display pop-up windows, but GDK only considers the serial +numbers of touch screen events when their touch sequences remain active, +and, as touch screen activity is not registered by Emacs until after the +toolkit's delivery of touch sequences completes, by the time +`x-popup-menu' is called, the only eligible event serials are those of +the last keyboard event and the last mouse event, which will not suffice +if Wayland has received pop-up or drag-and-drop requests from other +clients since their generation. + * Runtime problems specific to Android ** Text displayed in the default monospace font looks horrible.