Using the PythonScript plugin to automate N++

PeterJones

Just as an aside from @Alan-Kilborn’s excellent example of using an exception to bomb out: he handled the exception in main() – and that’s probably Python best-practice, and the right way to show it in an example that others follow

But just so that you know: if you ever forget to handle an exception, the PythonScript plugin will be forgiving, and won’t exit Notepad++ for you. It will show the traceback for the exception, and will relinquish control back to Notepad++. You’ll have a nice red message

raise Exception()

And if you want additional information in your exception printout, you can add it as a text argument when you raise the exception

raise Exception("extra text")

Or, using Alan’s Exit_exception() sub-class, the name of the class becomes an indicator of what kind of exception it was:

But however you call the exception: after seeing such a red error, you will then want to fix your script so that it won’t happen again.

And if you want a clean exit – it’s not an “error”, just a way to leave a deep subroutine early – then handling that clean-exit-exception in main() is the Right Thing To Do™

TL;DR summary

Catching exceptions at some point is Python best-practice, but if you miss catching one, the PythonScript plugin will not exit Notepad++. Thus, if you want to exit a script early or promptly, raising an exception is a much better choice than using notepad.runPluginCommand('Python Script', 'Stop Script') to push the menu button for you

Alan Kilborn

I just noticed that we dealt with the topic of “early return” from a PythonScript before, HERE. That time, the simple return-from-main() technique satisfied the petitioner. :-)

TBugReporter

This post is deleted!

TBugReporter

Is there any way that the PythonScript plugin can determine the size and position of the N++ window?

Ekopalypse

@TBugReporter

as an example

import ctypes
from ctypes import wintypes

rect = wintypes.RECT()

user32 = ctypes.WinDLL("user32")
hwnd = user32.FindWindowW(u"Notepad++", None)
user32.GetWindowRect(hwnd, ctypes.byref(rect))
print("position = ({},{})".format(rect.top, rect.left))
print("width = {}".format(rect.right - rect.left))
print("height = {}".format(rect.bottom - rect.top))

Be careful though, these are the outputs for my main and secondary monitor for example

position = (0,459)
width = 1079
height = 1087

>>> 
position = (-440,1912)
width = 1096
height = 1936

and when you start making more and more C interop calls, do yourself a favor and create your own startup.py script (you create it like any other script, but just call it startup.py. It should be stored alongside your other scripts so that it doesn’t conflict with the startup.py that comes with PS by default)

and do something like this

from win_api import FindWindow, FindWindowEx
notepad.hwnd = FindWindow(u'Notepad++', None)
editor1.hwnd = FindWindowEx(notepad.hwnd, None, u"Scintilla", None)
editor2.hwnd = FindWindowEx(notepad.hwnd, editor1.hwnd, u"Scintilla", None)

win_api is another file that contains all your C type declarations.
Just a suggestion.

Alan Kilborn

@Ekopalypse said in Using the PythonScript plugin to automate N++:

FindWindow(u’Notepad++', None)

If you have multiple instances of Notepad++ running, is this guaranteed to find the one that the script code is executing within?

Ekopalypse

@Alan-Kilborn

normaly yes - but 100% guaranteed - I assume no.

Alan Kilborn

@Ekopalypse said in Using the PythonScript plugin to automate N++:

normaly yes - but 100% guaranteed - I assume no.

I asked because I have some more complicated code to find the correct N++, and I was wondering if it was necessary. I’ll keep it. :-)

Ekopalypse

@Alan-Kilborn

It would be nice if PS would provide this, I know there is an open issue …

Alan Kilborn

@Ekopalypse said in Using the PythonScript plugin to automate N++:

would be nice if PS would provide this, I know there is an open issue

Yes, HERE, but from the comment HERE the primary person maintaining PS seemed to have no clue as to why it would be valuable. :-(

TBugReporter

@Alan-Kilborn said in Using the PythonScript plugin to automate N++:

I have some more complicated code to find the correct N++

Would you mind sharing?

dinkumoil

@Alan-Kilborn said in Using the PythonScript plugin to automate N++:

the primary person maintaining PS seemed to have no clue as to why it would be valuable

PythonScript plugin v3.0.15 should contain that feature. See change log 3.0.14 to 3.0.15, commit 2c178d8 from 2022-11-21.

Ekopalypse

@dinkumoil

As far as I understand, this was only implemented for the console and is probably why the issue is still open.

dinkumoil

@Ekopalypse

this was only implemented for the console

Seems like you are right. At least the names of the files changed in the commit I mentioned above indicate that. I’ve missed that, sorry.

Alan Kilborn

@TBugReporter said in Using the PythonScript plugin to automate N++:

Would you mind sharing?

Here’s NppHwnd.py:

# -*- coding: utf-8 -*-
from __future__ import print_function

from ctypes import (WinDLL, WINFUNCTYPE, create_unicode_buffer, byref)
from ctypes.wintypes import (BOOL, HWND, LPARAM, DWORD)

def find_npp_hwnd():

    user32 = WinDLL('user32')
    kernel32 = WinDLL('kernel32')

    WNDENUMPROC = WINFUNCTYPE(BOOL, HWND, LPARAM)

    our_pid = kernel32.GetCurrentProcessId()
    dw_process_id = DWORD()

    ubuff_size = 1024
    ubuffer = create_unicode_buffer(ubuff_size)

    notepad.hwnd = 0

    def foreach_window_to_find_npp(hwnd, __):
        if user32.IsWindowVisible(hwnd):  # maybe the check for being visible is not necessary?
            text_length = user32.GetWindowTextLengthW(hwnd)
            if 0 < text_length < ubuff_size:
                user32.GetWindowTextW(hwnd, ubuffer, text_length + 1)
                if u'- Notepad++' in ubuffer.value:
                    user32.GetWindowThreadProcessId(hwnd, byref(dw_process_id))
                    if dw_process_id.value == our_pid:
                        notepad.hwnd = hwnd
                        return False  # stop enumerating
        return True  # continue enumerating

    user32.EnumWindows(WNDENUMPROC(foreach_window_to_find_npp), 0)  # enumerate Desktop windows

    print('notepad.hwnd:', notepad.hwnd)

find_npp_hwnd()

Note that this script, like the original line of @Ekopalypse code ( notepad.hwnd = FindWindow(u'Notepad++', None) ), adds the hwnd member to the pre-existing notepad object.

Perhaps some explanation is in order: This script finds desktop windows with - Notepad++ in their titlebar. Since N++ always has this string of characters in its titlebar, it can be located in this manner. If there happens to be multiple instances of Notepad++ running, multiple windows will be located because they will all have the string in the titlebar – how to tell them apart? This script compares the process id of the located window to see if it is the same id as that under which the script is running; if so then we know we’ve located the desired N++ window.

TBugReporter

@Alan-Kilborn
I’m sorry, but I’m still having trouble with exception handling; when Tk is involved, it seems to eat the exception itself instead of passing it up to Python. Some sample code:

# -*- coding: utf-8 -*-
from Npp import MESSAGEBOXFLAGS

def main():

    print("Program started")
    tk_ok = False
    try:                                                    # see if we can do pretty dialogs
        import Tkinter as tk
        import qq                                           # DEBUG:  bogus name to force error triggering
        tk_ok = True
        print("Found tk")                                   # DEBUG
    except ImportError as e:                                # if not, tell user
        user_response = notepad.messageBox(
            ("Unable to import Tcl/Tk libraries.\n\n" + e.message), 
            "Missing Library",
            MESSAGEBOXFLAGS.OKCANCEL | MESSAGEBOXFLAGS.ICONWARNING)
        if user_response == MESSAGEBOXFLAGS.RESULTCANCEL:
            print("RESULTCANCEL loading Tkinter")           # DEBUG
            raise KeyboardInterrupt                         # closest exception to this condition
            while True:                                     # DEBUG:  wait for stop to happen
                print("Should have stopped!")
        elif user_response == MESSAGEBOXFLAGS.RESULTOK:
            print("RESULTOK loading Tkinter")               # DEBUG

    if tk_ok:
        my_dlg_bx = tk.Tk()

        def btn_cncl_action():
            print("Program CANCELLED")
            my_dlg_bx.destroy()
            raise KeyboardInterrupt                         # BUG:  doesn't work like above
            while True:                                     # DEBUG:  wait for stop to happen
                print("Should have stopped!")
        btn_cncl     = tk.Button     (
            my_dlg_bx,
            command     = btn_cncl_action,
            text        = "Cancel",
            width       = 10,
                                     )
        btn_cncl.pack    (padx   = 10,
                          pady   = 10,
                          side   = tk.RIGHT
                         )

        my_dlg_bx.attributes("-toolwindow", True)
        my_dlg_bx.attributes("-topmost", True)
        my_dlg_bx.resizable(width = False, height = False)
        my_dlg_bx.title("My Custom Dialog Box")
        my_dlg_bx.mainloop()
    # end "if tk_ok"

    print("Program should NOT get here if user clicks Cancel button")
    # do main program stuff here

    print("Program ended")                                  # DEBUG

main()

This code does as I expect - so long as the exception is in the testing for Tk. Comment out import qq, let Tk create and display “My Custom Dialog Box”, and click on its “Cancel” button, and a similar traceback appears in the console - but preceded by Exception in Tkinter callback. What can I do to get these exceptions both treated the same way? (And yes, I do realize that this sample code does nothing to actually catch the exception; I wanted to be sure it wasn’t my code that was eating it.)

And on a (probably) unrelated note, why is the “Plugins Admin” version of PythonScript so old? There are probably lots of people using it that don’t realize how outdated it is. Plus, I imagine it makes it more difficult to assist users when they’re likely not using the same version that you are.

Alan Kilborn

@TBugReporter said in Using the PythonScript plugin to automate N++:

I’m still having trouble with exception handling

General Python exception handling questions are off-topic for this forum.

why is the “Plugins Admin” version of PythonScript so old?

If I look at it, it shows the current version. Maybe you could be more specific in this question, like exactly what you see and why you think it is old?

TBugReporter

@Alan-Kilborn said in Using the PythonScript plugin to automate N++:

General Python exception handling questions are off-topic for this forum.

Yeah, but every time I try asking somewhere else they say “Old Python versions are off topic here”.
Head Bang Emoji

Maybe you could be more specific in this question, like exactly what you see and why you think it is old?

old Python.png

PeterJones

@TBugReporter,.

Yeah, but every time I try asking somewhere else they say “Old Python versions are off topic here”.

The overflowing stack of code writers don’t have such a restriction that I know of.

You complained to us about an old version of PythonScript in Plugins Admin, but the screenshot highlights that you’re actually wondering about the old version of the Python interpreter that’s part of PythonScript Plugin.

PythonScript is currently developing a Python 3 version of PythonScript Plugin, which is available for download in the PythonScript repository… But since it’s a huge project, it’s still considered alpha/beta and thus not in Plugins Admin yet. But that doesn’t stop you from installing it manually.

Alan Kilborn

@TBugReporter

every time I try asking somewhere else they say “Old Python versions are off topic here”.

It’s probably because instead of asking a pointed question, you just dump out a lot of code like you did above. Probably nobody wants to debug your code for you, so they come up with an excuse. Gosh, even I didn’t want to look at that Tkinter junk–ugh. Sorry, I just don’t personally feel that Tkinter is good enough for, well, any use whatsoever.

Exception handling in Python isn’t really specific to “older” Pythons. It seems that if you’re asking a general question about it in another forum, no one is going to say to you something about the age of your Python. But…you have to ask a reasonable question, and maybe you’re not to that stage yet.

why is the “Plugins Admin” version of PythonScript so old?

PythonScript 2.0 is NOT “old”. It may use a Python interpreter that is deemed “old”, but it does so for a reasonable reason. Python 2 and Python 3 differ in one huge way: How they treat strings. Python 2 doesn’t support unicode very well. Python 3 does. Because Notepad++ supports non-unicode encodings and always has, Python 2 is a great choice via PythonScript 2.0. If one isn’t going to use non-unicode encodings, then PythonScript 3.0 is probably the better choice. If the PythonScript developers figure out how to handle non-unicode encodings well in a Python 3 environment (that doesn’t like them), then PythonScript 2 could be phased out in favor of PythonScript 3.

I imagine it makes it more difficult to assist users when they’re likely not using the same version that you are.

Occasionally this is true. The “recommended” version is PS 2.0 and that’s what I use, but sometimes the scripts I share have some deficiency relating to unicode. One that comes to mind is a script that would open a filename in a text file, and that filename happened to include unicode characters. It was only a slight script adjustment, but I seem to recall the poster that complained about it went kind of nuts. Ah, well.