This implementation is based on the implementation in MantidPlot.
A C++-based executor has been added that can execute Python code
with the option of installing a trace function to update
a progress marker on a given editor window.

The old implementation attempted to chunk up the script into
the smallest executable blocks and mark each of these as when
they were executed. There were 2 issues:
  - the chunking of the scripts was error prone as it actually
    requires a good knowledge of how Python internally handles
    indentation etc. It was fairly easy to break and future
    internal updates to Python would have required unknown changes.
  - the progress reporting resolution was far poorer than MantidPlot
    as the actual line being executed was not reported but inferred
    by what block was being executed giving a false sense of progress
    through a script.

Also corrects the line endings on the prefixed header
and fixes so that Toggle Whitespace shows line endings in workbench

This fixes an error when saving a script that contains unicode
characters. The io module gives a Python 2/3 compatible way of writing
to a file using utf8.

re #27072

Add completions for the modules if they are imported in the script.

Re-factor 'get_function_spec' and 'generate_call_tips' out of the
CodeCompleter class and into standalone functions.

New CodeCompleter class contains the logic for populating QScintilla's
completion API. It's CodeCompleter.update_completion_api is called
whenever a script is successfully run.

Re #24818

Add unit tests for class

re #24849

It was moved to `mantidqt.widgets.embedded_find_replace_dialog.presenter.visible`
but I never deleted this variable.

re #24849

re #25115

Martyn Gigg authored 6 years ago and Gigg, Martyn Anthony committed 6 years ago

Refs #24743

If the user is being prompted to save files (option in the settings)
then the prompt has the final decision whether to save or discard.

If the user is NOT being prompted, then pressing File>Save Script or
CTRL+S will force save, this has 2 outcomes:
- Code editor contents already exist in a file, in which case the
file is just saved
- Code editor is a `New Tab`, in which case the user is prompted to select
where to save.
- If a code editor is closed via `X` or middle mouse click, the file is
just discarded without notice.

Added "previous" button
Next/Previous now have icons
Made layout tighter
Added X to close
Added find/replace in Editor menu
Added Escape to close find, only works if Find/Replace has focus
Added Enter to search next, Shift+Enter to search previous,
only works if Find/Replace has focus

Replace magic numbers in PythonFileInterpreter's replace
tab/spaces functions with variable

Also enable C++ exceptions, and their messages, to be passed to
Python via sip when using clear_key_binding function.

Clearing an unbound keyboard shortcut in Scintilla would cause a
segfault. This has been addressed and now an error is raised
instead.

Remove redundant import in ScriptEditor.cpp and redundant enum in
_common.sip.
Add docstring for clearKeyBinding method in ScriptEditor class.

Block commenting can now be done with shortcut "Ctrl+/" that used
to be overridden by a QScintilla shortcut.
Some error catching still needs to be performed in the
"clear_key_binding" method in PythonFileInterpreter.

Also some clearer commenting in 'toggle_comment' method