Fix exception when canvas becomes null because of window resize, and avoid useless parameter+condition in GetLogicalDC

Preliminary support for WxPython 4.1.0. Needs more testing. Grid selection/focus seems broken, and probably many other bugs hidden in dialogs and editors.

Merge SVGHMI in default

Close SVGHMI branch

Copy description when DnD variables from Globals in resources and configuration variable panels to POUs. Also prevent making exception in case some other DropSource wouldn't provide description.

SVGHMI: Allow toggling fulscreen mode my right click or long press.

Xenomai runtime: fixed bugs introduced in e3db472b0dfb (RT->nRT wakeup) + other small typos

IDE: systematically log command when launching process (was not showing in case of LOCAL:// runtime being launched)

Win32 runtime: fix build with gcc 9.3.0 from msys2

Runtime+SVGHMI: Add generic wakeup of threads from PLC thread to windows implementation of plc_main.c. Also added nRT_reschedule to abstract sched_yield.

Runtime+SVGHMI: Added a generic way to wakeup non-real-time threads from real-time PLC thread. Replace SVGHMI specific calls in Linux and Xenomai implementations of plc_main.c. Fixed xenomai build, xeno-config making problems with --no-auto-init argument.

Runtime: Better handling of nested strings in spawn_subprocess commandline parsing

IDE: Fixed use of RingBuffers in variable traces graphs when switching to 2D trend graph.

IDE: On windows, align better "reset to default" button in CTN config panel.

SVGHMI: Fix detection of library without instance and instances without library. Added one more widget in the widget library. Renamed "view_name" in "name" in commands substitutions.

SVGHMI: Fix missing "OnWatchdog" in XSD, accidentally deleted in earlier commit.

IDE: Add a "undo" button for each field in CTN config panel to reset to default value.

SVGHMI: detect watchdog abuse (more than one HMI instance with watchdog) at build time

SVGHMI: code refactoring allowing more in depth customization for substitution on start/stop/restart commands, and default SVG choice.

Runtime: more robust loading of Wamp config, specially in case config file was corrupted.

SVGHMI: add arguments to pass to ressource factory when attaching rerssource to svghmi root

SVGHMI: fix typo in slider widget

Runtime: Handle errors in user's python code more gracefully : make exceptions and allow repair.

SVGHMI: Fixed halting problem when there is no session opened.

SVGHMI: Widget lib: small doc fix.

SVGHMI: DnD UI: Use widget's short description, initially forgoten.

SVGHMI: Fixed typo on session manager unregister, leading to wrong count of sessions and then exceptions when creating more session than allowed in protocol options. Also added more safety check in protocol in case session would be missing.

SVGHMI: set some boundaries for watchdog timings and max connection count.

SVGHMI: update generated xslt

SVGHMI: fixed bug introduced in 7bdb766c2a4d, typo breaking meter widget

SVGHMI: default library path, default page when starting a SVGHMI project, error page when no SVG present

SVGHMI: finished multiclient support. Still needs more testing.

SVGHMI: Fixed iterator in session manager. Getting closer to working multiclient, to be continued.

SVGHMI: Fixing last commit's multiclient implementation, in case of watchdog. To be continued, since multiclient still fail...

SVGHMI: Implemented multiserver+multiclient, but only tested with single client and single server for now. To be continued...

SVGHMI: More configuration parameters : network interface, TCP port, URL path and watchdog enabling.

SVGHMI: Added a way to distinguish watchdog-enabled HMI from multi-client HMI in URL.

SVGHMI: Prepare accepting multiple clients on multiple HMI: Use POULibrary new capability to add variables to PLC Configuration. Now heartbeat and HMI tree root are added by the library part of SVGHMI, and not by each instance.

IDE: Allow POU Libraries to inject PLC Configurations globals during build.

SVGHMI: DnD UI: Add hint instructing user to Drag HMI tree items to text field.

SVGHMI: update generated XSLT files

SVGHMI: DnD UI: Fix SVG gen that was dropping widget name and making XSLTExceptions plus some UX enhancements.

removed useless import

SVGHMI: DnD UI: SVG for DnD now generated again based on paths and args entries filled by user.

merge

SVGHMI: UI: added prefill of arguments according to values in widget instance in library. Also added library's widget instance description to description field.

IDE: Fixed variable traces graphs RingBuffers. Removed an apparently useless wxCallAfter in trend graph that was leading to pydeadobject exception on wxGTK when double-clicking.

IDE: Cleaned up some useless tests in variable trace data handling code, changed from bare numpy arrays to RingBuffers inorder to avoid RAM outage and crash after long tracing session.

IDE: Log: Prevent crash when display progress on empty log.

merge

Copy description when DnD variables from CodeFile CTN to POUs

SVGHMI: fix exception when stored widget library path does not exist anymore

SVGHMI: added checking of widget literal argument in DnD UI according to type given in widget description

SVGHMI: UI Updates validity indicator when DnD HMI tree node in text field, according to node type

SVGHMI: Fixed typo in last commit

merged