svghmi/widget_back.ysl2
author Edouard Tisserant <edouard.tisserant@gmail.com>
Wed, 05 Oct 2022 16:10:17 +0200
branchwxPython4
changeset 3617 c3aae4c95bc1
parent 3241 fe945f1f48b7
child 3653 d5ff60e906b0
permissions -rw-r--r--
Runtime: work around 1s delay added when using twisted reactor's callLater.

Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).

While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython
// widget_back.ysl2

widget_desc("Back") {
    longdesc
    ||
    Back widget brings focus back to previous page in history when clicked.
    ||

    shortdesc > Jump to previous page
}

// TODO: use es6
widget_class("Back")
    ||
        on_click(evt) {
            if(jump_history.length > 1){
               jump_history.pop();
               let [page_name, index] = jump_history.pop();
               switch_page(page_name, index);
            }
        }
        init() {
            this.element.setAttribute("onclick", "hmi_widgets['"+this.element_id+"'].on_click(evt)");
        }
    ||