Backspace Unindents

dinkumoil

Yeah, this is one of the oddities in Npp. To users, the program pretends most of its settings are global to all documents. But internally every document/text buffer has its own set of preferences. I’m fighting with this in all my plugins.

I ended up with writing a buffer management, that remembers if a certain setting has been adopted by a text buffer. When a buffer is activated the first time, I do all configuration for this new buffer and store its id in a list. When a buffer is activated the next time, I will find it in the list and avoid doing any configuration. I do that mostly because of keeping Npp performant.

During development of the text buffer management I discovered some Npp quirks that I had to deal with. For example when a user moves a buffer from one view to the other it may get another buffer id.

You can have a look to the code of e.g. my AutoCodpage plugin to get some insights. The relevant code is in file Main.pas.

Ekopalypse

@dinkumoil said in Backspace Unindents:

I ended up with writing a buffer management … I discovered some Npp quirks…

In such a case we could also add a property to the document, can’t we?
Should resolve these kind of quirks. Might be a bit slower but maybe
more reliable.

dinkumoil

@Ekopalypse said in Backspace Unindents:

In such a case we could also add a property to the document, can’t we?

I’ve never tried this technique but it seems that a property is global for a certain Scintilla window, but one Scintilla windows hosts many text buffers (the document tabs). Thus I’m not sure if this feature can be used for a text buffer management.

Ekopalypse

as I understand it is a document property. Let me give it a quick try.

Ekopalypse

@dinkumoil
Yes, should work as it is bind to the document.
Script used to test:

from Npp import editor

editor.setProperty('secret_text','blablabla')
print(editor.getProperty('secret_text'))

dinkumoil

@Ekopalypse

I don’t know the Python API for Npp. The editor object represents a single text buffer? Or an instance of Scintilla?

Ekopalypse

@dinkumoil

editor is an scintilla instance but the property is set on document level.

dinkumoil

@Ekopalypse

Hmm, which document? The active one?

Ekopalypse

@dinkumoil

yes if editor is used. And in case editor1 or 2 is used, then the
current viewable document.

dinkumoil

@Ekopalypse

OK, then it’s worth to try using Scintilla’s properties for a text buffer management. But as I have a working system I will not change it. But I’m interested in knowing how that approach works.

Ekopalypse

Never change a running system!!! :-D

Ekopalypse

@dinkumoil

just a quick test

from Npp import editor1, notepad

def loop_files():
    for file in notepad.getFiles():
        notepad.activateFile(file[0])
        print(f'file: {file}')
        print(f'  secret_text:{editor1.getProperty("secret_text")}')

loop_files()
notepad.activateFile('new 3')
editor1.setProperty('secret_text', 'blablabla')
loop_files()

returned

file: ('new 1', 44120304, 0, 0)
  secret_text:
file: ('new 2', 112914256, 1, 0)
  secret_text:
file: ('new 3', 112915984, 2, 0)
  secret_text:
file: ('new 4', 112916416, 3, 0)
  secret_text:
file: ('new 5', 112915552, 4, 0)
  secret_text:
file: ('new 6', 112916848, 0, 1)
  secret_text:
file: ('new 1', 44120304, 0, 0)
  secret_text:
file: ('new 2', 112914256, 1, 0)
  secret_text:
file: ('new 3', 112915984, 2, 0)
  secret_text:blablabla
file: ('new 4', 112916416, 3, 0)
  secret_text:
file: ('new 5', 112915552, 4, 0)
  secret_text:
file: ('new 6', 112916848, 0, 1)
  secret_text:

Btw. setting and reading the value takes about ~20 microseconds each for python.

Alan Kilborn

@Ekopalypse @dinkumoil

FYI, SCI_GETPROPERTY and SCI_SETPROPERTY are put to good use by @Claudia-Frank in the File Specific word wrap (vs. global enable) discussion thread, specifically, THIS POSTING.

Alan Kilborn

@Michael-Vincent said in Backspace Unindents:

In a previous thread I mentioned I started using backspace unindents

THIS POSTING must be that reference to a previous thread.

Alan Kilborn

So for anybody interested, I turned the addition of the backspace-unindent capability into a PythonScript.

I put it in a BackspaceUnindents.py file:

from Npp import editor, notepad, NOTIFICATION

class BackspaceUnindents(object):

    def __init__(self):
        self.activated = True
        notepad.callback(self.callback_for_bufferactivated, [NOTIFICATION.BUFFERACTIVATED])
        self.callback_for_bufferactivated(None)  # set it for the currently active document

    def callback_for_bufferactivated(self, args):
        # this document property won't automatically be applied to newly created tabs; adjust for that:
        editor.setBackSpaceUnIndents(self.activated)

    def is_activated(self): return self.activated

    def set_activated(self, b):
        self.activated = b
        self.callback_for_bufferactivated(None)

if __name__ == '__main__':

    try:
        backspace_unindents
    except NameError:
        backspace_unindents = BackspaceUnindents()
        notepad.messageBox('BackspaceUnindents installed and activated')
    else:
        if backspace_unindents.is_activated():
            backspace_unindents.set_activated(False)
            notepad.messageBox('BackspaceUnindents deactivated')
        else:
            backspace_unindents.set_activated(True)
            notepad.messageBox('BackspaceUnindents activated')

I set mine to run from startup.py as follows:

import BackspaceUnindents
backspace_unindents = BackspaceUnindents.BackspaceUnindents()

but it can be run manually with or without that. Run it once to turn it on, run again to turn off.

guy038

Hi, @alan-kilborn, @ekopalypse, @michael-vincent and All,

Alan, Just tried your BackspaceUnindents.py with no difference seen between the two states, although the script seems to work nice ?!

Did I clearly understand what’s for ? I mean, from the link below :

https://www.scintilla.org/ScintillaDoc.html#SCI_SETBACKSPACEUNINDENTS

I supposed that the Python script alternatively change the behaviour of the Backspace key :

By default or when the BackspaceUnindents process is deactivated, a hit on the Backspace key deletes the previous indentation
When the BackspaceUnindents process is activated, a hit on the Backspace key simply moves the caret to the previous indentation location

Am I right about it ? What I miss, there ?

Best Regards

guy038

Alan Kilborn

@guy038

Hmmm, not sure.

For me, without the script or with it deactivated, on a line that contains only lots of space characters and the caret right before the line ending, pressing Backspace repeatedly will remove one space at a time.

With the script active, in the same situation, the Backspace key will remove 4 spaces with each press (I have my tabs setting to insert 4 spaces per tab), assuming I started with a number of spaces evenly divisible by 4.

I suppose, if one has tab set to insert tab characters, backspacing those out of existence will work the same either with the script of without it.

astrosofista

@Alan-Kilborn, @guy038 and All

Haven’t read all this thread, but in case you want to make a comparation, the Extended Settings plugin provides a similar feature. Works fine, by the way.

Cheers.

Alan Kilborn

@astrosofista

the Extended Settings plugin provides a similar feature

Sure; I’m actually quite surprised no one earlier in the thread mentioned that.
If I used Extended Settings plugin, I’d like to think I would have mentioned it.
At the time the plugin came out, I already had most of its functionality, thru scripts.

I even had a backspace-unindenter script (different from the one above); not realizing that Scintilla provided the function, my script did it manually and was tied to the Backspace key binding.
(In some ways I liked my earlier script better than Scintilla’s function!)

guy038

Hello @alan-kilborn and All,

OK ! When doing tests, the TAB key was set to write a four positions TAB character and I principally did tests with leading tab chars ! But never mind, now, I understood the whole thing :

First, from the Scintilla documentation, I saw that there a similar message to BackspaceUnindents, which is TabIndents. Note that, by default Notepad++ starts with the TabIndents message activated and with the BackspaceUnindents message deactivated !

So, I created an other python script, called TabIndents.py, in order to activate/deactivate the TabIndents message. I get absolutely no credit because it’s just a copy/paste of the Alan’s script !

from Npp import editor, notepad, NOTIFICATION

class TabIndents(object):

    def __init__(self):
        self.activated = True
        notepad.callback(self.callback_for_bufferactivated, [NOTIFICATION.BUFFERACTIVATED])
        self.callback_for_bufferactivated(None)  # set it for the currently active document

    def callback_for_bufferactivated(self, args):
        # this document property won't automatically be applied to newly created tabs; adjust for that:
        editor.setTabIndents(self.activated)

    def is_activated(self): return self.activated

    def set_activated(self, b):
        self.activated = b
        self.callback_for_bufferactivated(None)

if __name__ == '__main__':

    try:
        tab_indents
    except NameError:
        tab_indents = TabIndents()
        notepad.messageBox('TabIndents installed and activated')
    else:
        if tab_indents.is_activated():
            tab_indents.set_activated(False)
            notepad.messageBox('TabIndents deactivated')
        else:
            tab_indents.set_activated(True)
            notepad.messageBox('TabIndents activated')

Then I played around, with a sample line of mixed TAB and SPACE chars, both, in the leading part and further on, between usual characters :

Activating / deactivating the TabIndents.py and/or the BaskspaceUnindents.py messages
Choosing, either, 1 TAB char of 4 positions long OR 4 SPACE chars, when you hit the TAB key, for language normal, in Preferences... > Language > Tab Settings > normal
Moving caret within the leading blank chars OR in subsequents blanks ranges, further on, in current line

And, here is, below, a summary of my observations :

Regarding the BACKSPACE key behaviour :

If caret within the leading blank range of chars AND BackspaceUnindents message activated [ NEW backspace behaviour ] :
- If setting TAB to 4 SPACE chars, a hit on the BACKSPACE key :
  - Deletes previous char(s) to get the previous indentation level
  - Normalizes all preceding blank chars, till beginning of line, to SPACE chars
  - Moves the caret after the last leading SPACE char
- If setting TAB to 1 TABchar of 4 positions long, a hit on the BACKSPACE key :
  - Deletes previous char(s) to get the previous indentation level
  - Normalizes all preceding blank chars, till beginning of line, to TAB chars
  - Moves the caret after the last leading TAB char
If caret outside the leading blank range of chars OR BackspaceUnindents message deactivated OR by DEFAULT, a hit on the BACKSPACE key :
- Deletes previous char to get the correct or previous indentation level
- Leave the caret at current position

Regarding the TAB key behaviour :

If caret outside the leading blank range of chars, whatever the status of the TabIndents message :
- When setting TAB to 4 SPACE chars, a hit on the TAB key :
  - Adds up to 4 SPACE char(s) to get the next indentation level
  - Leave the caret right after these added SPACE char(s)
- When setting TAB to a 1 TAB of 4 positions long , a hit on the TAB key :
  - Adds a TAB char to get the next indentation level
  - Leave the caret right after the added TAB char
If caret within the leading blank range of chars :
- If the TabIndents message is activated OR by DEFAULT :
  - When setting TAB to 4 SPACE chars, a hit on the TAB key :
    - Adds up to 4 SPACE char(s) to get the next indentation level
    - Normalizes all preceding blank chars, till beginning of line, to SPACE chars
    - Moves the caret after the last leading SPACE char
  - When setting TAB to a 1 TAB of 4 positions long , a hit on the TAB key :
    - Adds a TAB char to get the next indentation level
    - Normalizes all preceding blank chars, till beginning of line, to TAB chars
    - Moves the caret after the last leading TAB char
- If the TabIndents message is deactivated [ NEW tab behaviour ] :
  - When setting TAB to 4 SPACE chars, a hit on the TAB key :
    - Adds up to 4 SPACE char(s) to get the next indentation level
    - Leave the caret right after these added SPACE char(s)
  - When setting TAB to a 1 TAB of 4 positions long , a hit on the TAB key :
    - Adds a TAB char to get the next indentation level
    - Leave the caret right after the added TAB char

Best Regards,

guy038