Python / Lua Script: Detect if a modifier is pressed when running a script

Claudia Frank

not 100% sure what you want to achieve but my regex tester script
may give you an idea what needs to be done to capture key presses. Check Hook class.

About the bug, where is the script stored?

Cheers
Claudia

Yaron

Hello again,

BTW, there seems to be a bug in Python Script: if you press Ctrl when running a script, the “File not found. Create it?” message is displayed.

Correction: Ctrl+left-click opens the file instead of running the script.
If the file name is Hebrew, it can not be found and hence the message.

Yaron

Hello Claudia,

Thanks for replying. I do appreciate it.

I’d like to have a slightly different behavior in case Alt is pressed.
I’ll have a look in your script.

And the bug is actually a problem in handling the Hebrew file name.

Best regards.

Yaron

Hello Claudia,

After a quick look in your script:
Is using ctypes the only way to detect if a modifier was pressed?
Can’t it be achieved with some keys module?

And allow me to clarify:
I want to know if a modifier was pressed when starting the script. NOT when it’s already running.

Thanks again.
BR

Claudia Frank

Hi Yaron,

no, unfortunately neither scintilla nor notepad provide a keyup/keydown event which could be
consumed.
The only way, I know, is using ctypes and I think python modules which would offer this would also
call win api to get the events.

And allow me to clarify:
I want to know if a modifier was pressed when starting the script. NOT when it’s already running.

So you need to have the keyboard logger registered within startup.py ;-)

Cheers
Claudia

Yaron

Hello Claudia,

Thank you for the detailed explanation. I appreciate it.

So you need to have the keyboard logger registered within startup.py

I haven’t thoroughly learned the script yet.

If I have a bool altPressed in startup.py, I’d need to set it to false on Alt-UP only after some timeout. Is that correct?

BR

Claudia Frank

Yaron,
in your case, if I understand it correctly, I would use

    if msg in [WM_KEYDOWN, WM_SYSKEYDOWN]:

to set the boolean true and

    elif msg in [WM_KEYUP,WM_SYSKEYUP]:

to set it to false

and you need to handle the cases when alt together with other modifiers is pressed.

Cheers
Claudia

Claudia Frank

@Yaron

Detecting a right-click would be better (i.e. execute the script on both left/right-click and detect the button).

sorry, I missed this one.
So you do have defined a button in the toolbar, correct?
And when clicking with left mouse = normal run but when clicking with right mouse then advanced run?

Cheers
Claudia

Yaron

If I have a bool altPressed in startup.py, I’d need to set it to false on Alt-UP only after some timeout. Is that correct?

Or setting it to false only in the altDependentScript.
I’ll think about it.

You’ve been very helpful as always. :)
Thank you very much.

BR

Claudia Frank

Yaron, in case you want to get the mouse clicks see here.

Cheers and good night
Claudia

Yaron

Hello again Claudia,

Detecting a right-click would be better (i.e. execute the script on both left/right-click and detect the button).
…
sorry, I missed this one.
So you do have defined a button in the toolbar, correct?
And when clicking with left mouse = normal run but when clicking with right mouse then advanced run?

That’s correct.

in case you want to get the mouse clicks see here.

Getting the specific command/button position would be too much. :)

Thanks again. Highly appreciated.

Good night.

dail

As far as LuaScript goes you’d probably be alot more limited as you have to use what Scintilla/Notepad++ provides which you can catch double clicks and get the modifier keys but don’t think there’s a way to distinguish between left or right click. You could also register the same function with more than one keyboard shortcut, such as “F5”, “Ctrl+F5”, “Alt+F5”, etc…but this is not ideal.

Python gives more possibilities as far as interacting with the OS so this is probably your better option depending what you need exactly.

Yaron

Hello @dail,

Thank you for the additional info. I appreciate it.

If I understand it correctly, SCN_DOUBLECLICK is only relevant to the editor.
Double-click could have been useful, but I need it for a command or a toolbar button.

And thanks again for the great Lua Script plugin.
BTW, Ctrl+left-click to open the file instead of running the script could be a nice addition to Lua Script.
What do you think?

BR

dail

but I need it for a command or a toolbar button.

Oh! Now I see what you are doing. In this case PythonScript is your best option.

Ctrl+left-click to open the file instead of running the script could be a nice addition to Lua Script.

Honestly I don’t even know if would be possible. Since individual functions are registered instead of files, there is nothing that associates where a function is defined.

Yaron

Hello @dail,

Oh! Now I see what you are doing. In this case PythonScript is your best option.

A simple example for what I meant:
A script TypeLetter types a letter in the editor. Using Customize Toolbar, I’ve assigned a toolbar button to the script.
I want it to normally type A but if Alt is down when pressing the toolbar button type B.

Claudia’s suggestion is a good option, but I think I’d have to use some timeout.
Using another script Toggle TypeLetter Mode is another option which should work well in Lua Script too.

Since individual functions are registered instead of files…

I didn’t think about that. :)

Thanks again.
BR

Claudia Frank

Hello Yaron

a quick script about what I meant with mouse click capture.

In one script you intercept the window proc (needs to be called first, startup.py might be good choice)

from ctypes import windll, byref, wintypes, WINFUNCTYPE, Structure, sizeof

WndProcType = WINFUNCTYPE(wintypes.LONG,
                          wintypes.HWND,
                          wintypes.UINT,
                          wintypes.WPARAM,
                          wintypes.LPARAM)
GWL_WNDPROC = -4

WNDENUMPROC = WINFUNCTYPE(wintypes.BOOL,
                          wintypes.HWND,
                          wintypes.LPARAM)


_g = globals()
CAPTURE_MOUSE_CLICK = _g.get('CAPTURE_MOUSE_CLICK', False)
OLD_WND_PROC = _g.get('OLD_WND_PROC', None)
LEFT_MOUSE_CLICK_MOD = False

class Hook():

    def EnumCallback(self, hwnd, lparam):
        curr_class = (wintypes.WCHAR * 256)()
        windll.user32.GetClassNameW(hwnd, curr_class, 256)
        if curr_class.value.lower() == 'toolbarwindow32':
            self.toolbar_handle = hwnd
            return False
        return True

    def __init__(self):
        self.toolbar_handle = None
        parent = windll.user32.FindWindowA('Notepad++',None)
        windll.user32.EnumChildWindows(parent, WNDENUMPROC(self.EnumCallback), 0)

        self.oldWndProc = None

        self.SHIFT_PRESSED = False
        self.CTRL_PRESSED = False
        self.ALT_PRESSED = False

    def register(self):
        if self.toolbar_handle:
            self.new_wnd_proc = WndProcType(self.sciWndProc)
            windll.kernel32.SetLastError(0)
            self.oldWndProc = windll.user32.SetWindowLongA(self.toolbar_handle, GWL_WNDPROC, self.new_wnd_proc)

            if self.oldWndProc:
                global OLD_WND_PROC
                OLD_WND_PROC = self.oldWndProc
            else:
                _err = 'GetLastError:{}'.format(windll.kernel32.GetLastError())
                notepad.messageBox('Could not register hook:\n{}\n'.format(_err) +
                                    'Shortcuts won\'t work',
                                    'Register Hook Failure', 0)
        else:
            console.write('no toolbar_handle found')

    def unregister(self):
        if OLD_WND_PROC:
            self.oldWndProc = OLD_WND_PROC
            windll.kernel32.SetLastError(0)
            dummy = windll.user32.SetWindowLongA(self.toolbar_handle, GWL_WNDPROC, self.oldWndProc)
            if not dummy:
                _err = 'GetLastError:{}'.format(windll.kernel32.GetLastError())
                notepad.messageBox('Could not unregister hook:\n{}\n'.format(_err) +
                                    'It is recommended to save data and restart npp to prevent data loss',
                                    'Unregister Hook Failure', 0)

        else:
            console.write('ERROR no saved window proc found')

    def sciWndProc(self, hWnd, msg, wParam, lParam):
        if msg == 0x0201: # WM_LBUTTONDOWN
            global LEFT_MOUSE_CLICK_MOD
            if wParam == 5: # 0x0001 LButton + 0x0004 Shift
                console.write('left mouse click while holding shift\n')
                LEFT_MOUSE_CLICK_MOD = True
            else:
                console.write('left mouse click\n')
                LEFT_MOUSE_CLICK_MOD = False

        return windll.user32.CallWindowProcA (self.oldWndProc, hWnd, msg, wParam, lParam)

# -----------------------------------------------------------------------------
_hook = Hook()
if not CAPTURE_MOUSE_CLICK:
    _hook.register()
    CAPTURE_MOUSE_CLICK = True
    console.write('registered')
else:
    _hook.unregister()
    CAPTURE_MOUSE_CLICK = False
    console.write('unregistered')

in another script something like

import datetime
print datetime.datetime.now()
print 'LEFT_MOUSE_CLICK_MOD:{}'.format(LEFT_MOUSE_CLICK_MOD)

The first script gets the handle of the toolbar and hooks it message queue.
Once you click a button the global variable is set and the second script gets executed.

Cheers
Claudia

Yaron

Hello Claudia,

Sorry for the late reply. I was not by my PC.
And thank you for the beautiful script. I appreciate your kindness.

Now that you capture both the click and the modifier, there’s no need to use timeout and it works like a charm.

Two follow-up questions with your permission:

Customize Toolbar inserts a separator on pressing Shift and left-clicking a toolbar button.
Which module should I import in order to use GetKeyState() and detect Alt?
The little programming experience I have is from Firefox.
In that browser adding a right-click functionality to a toolbar button is done as follows:

Get A specific toolbar button object.
Add a click listener to that button and assign your own action to right-click.

I suppose this procedure would be more complex in NPP.

Actually you can replace in your script

if wParam == 5: # 0x0001 LButton + 0x0004 Shift

with

if wParam == 3: # 0x0001 LButton + 0x0002 MK_RBUTTON

and then if you hold the right button down and left-click - you can execute the script in “alternative mode”.

Another simple (and not as elegant) way to run a script in two modes:
In startup (py or lua) add testScriptDefaultMode = True.
Create a script Toggle TestScript Default Mode containing two lines:

global testScriptDefaultMode 
testScriptDefaultMode = not testScriptDefaultMode

In TestScript check if testScriptDefaultMode:.

Assign a simple shortcut (e.g. Alt+Spacebar) to Toggle TestScript Default Mode and use it to quickly toggle the modes…

Thanks again.
Have a nice weekend.

Claudia Frank

@Yaron

Customize Toolbar inserts a separator on pressing Shift and left-clicking a toolbar button.
Which module should I import in order to use GetKeyState() and detect Alt?

The function is also called GetKeyState and is in user32.dll.
You need to provide the virtual key code to get the state, so something like

alt_state = windll.user32.GetKeyState(0x12)

but using wine, I was not able to press alt and do left click with mouse.
Would be interesting to see if this works on Windows.

The little programming experience I have is from Firefox.
In that browser adding a right-click functionality to a toolbar button is done as follows:
Get A specific toolbar button object.
Add a click listener to that button and assign your own action to right-click.
I suppose this procedure would be more complex in NPP.

I think so too. Out of my mind, you would need to find notepad++ window handle,
enumerate child windows to get toolbar, enumerate toolbar child windows to get
the button in question (not sure how to identify), register a function which hooks into
buttons message queue and I don’t know what happens if another program accesses toolbar
to modify (or add/delete) a button?? I’m pretty sure it can be done but I’m not convinced
it should be done.

Another possible solution to run script in alternate mode would be to use a
inputbox (prompt method) ;-) (also not as elegant but most painless version) :-D

Cheers
Claudia

Yaron

Hello Claudia,

The function is also called GetKeyState and is in user32.dll.

Great. Thank you.

but using wine, I was not able to press alt and do left click with mouse.
Would be interesting to see if this works on Windows.

alt_state = windll.user32.GetKeyState(0x12)
if alt_state < 0:

Works perfectly.

Out of my mind, you would need to find notepad++ window handle…

Your confirmation that this is indeed rather complex is important.

Another possible solution to run script in alternate mode would be to use a
inputbox

So I have multiple choices now. :)
Being a “mouse-oriented” user, your script detecting if the right button was down when left-clicking would probably fit me best.

Thanks again for your time and clever ideas. I do appreciate it.
BR

Scott Sumner

@Yaron and @Claudia-Frank

Oftentimes I find myself writing a Pythonscript that either acts on text above the caret or below the caret. So I need a way to tell it which way to go. An input box would work, but it slows down one’s “workflow”. Often it is an alternate but related keypress (e.g. F10 runs functionality above the caret, Shift+F10 for below the caret) that I want to use. So what I’ve been doing is having 3 scripts, one “common” one, and two others. The two others are tied to F10 and Shift+F10, and call the common script, telling it the direction.

So I just wanna say that this thread has gotten me thinking about how to do this cleaner; haven’t done anything about it yet, but definitely thinkin’… :-D