Fix RTL inverse horizontal arrow key movement

[Ashfaaq18]

Fix #8553, Fix #7678 and Fix #9730

Before the fix:

After the fix:

[mere-human]

Since it seems like a problem in Scintilla code you better submit your fix directly to Scintilla project.
So we won't have problems with merging.

[Yaron10]

@Ashfaaq18,

I've been using SCI_ASSIGNCMDKEY in case IDM_EDIT_RTL (NppCommands.cpp).
Your solution seems better. 👍

---

I'd be glad if you could have a look at #8520 and #8730.

Thank you.

[Ashfaaq18]

@mere-human, referring to this RTL issue ticket in the scintilla project https://sourceforge.net/p/scintilla/bugs/1590/, it seems like they've already fixed and closed it. Nevertheless, Ill still try to replicate the problem in that project. If I do encounter it, ill apply this fix and open a PR there.

And @Yaron10, yeah sure. Ill take a quick look at it.

[donho]

@Ashfaaq18

it seems like they've already fixed and closed it.

It has been fixed in v4.1.0, according Scintilla author. However, the Scintilla used by Notepad++ is v4.4.6.
I'm not sure if it's a regression in Scintilla, or Scintilla is misused in Notepad++ for causing this bug. If it's the 2nd case, it would be better to fix it in the layer of Notepad++.

Nevertheless, Ill still try to replicate the problem in that project. If I do encounter it, ill apply this fix and open a PR there.

Yes, it sounds good - thank you. I'm gonna keep this PR opened until the situation of this issue is more clear.

[donho]

@Yaron10

I've been using SCI_ASSIGNCMDKEY in case IDM_EDIT_RTL (NppCommands.cpp).

Do you build your Notepad++ or you use the script for it?
Could you pass your list of key for binding so I may find a way to do it in IDM_EDIT_RTL ?

Your solution seems better. 👍

If Scintilla were maintained by Notepad++, it would be a better solution.
But then there are also DELETE key and DELETEBACK.

[Yaron10]

@donho,

I'm using the following code in NppCommands.cpp.

case IDM_EDIT_RTL:
case IDM_EDIT_LTR:
{
	bool toRTL = id == IDM_EDIT_RTL, isRTL = _pEditView->isTextDirectionRTL();
	if ((toRTL && isRTL) || (!toRTL && !isRTL))
	{
		::MessageBeep(MB_OK);
		break;
	}

	_pEditView->changeTextDirection(toRTL);
	_pNonEditView->changeTextDirection(toRTL);

	// Wrap then !wrap to fix problem of mirror characters
	bool isWraped = _pEditView->isWrap();
	_pEditView->wrap(!isWraped);
	_pEditView->wrap(isWraped);

	_pNonEditView->wrap(!isWraped);
	_pNonEditView->wrap(isWraped);

	if (toRTL)
	{
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT, SCI_CHARLEFT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_SHIFT << 16), SCI_CHARLEFTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARLEFTRECTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_CTRL << 16), SCI_WORDLEFT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDLEFTEXTEND);

		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT, SCI_CHARRIGHT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_SHIFT << 16), SCI_CHARRIGHTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARRIGHTRECTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_CTRL << 16), SCI_WORDRIGHT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDRIGHTEXTEND);

		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT, SCI_CHARLEFT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_SHIFT << 16), SCI_CHARLEFTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARLEFTRECTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_CTRL << 16), SCI_WORDLEFT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDLEFTEXTEND);

		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT, SCI_CHARRIGHT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_SHIFT << 16), SCI_CHARRIGHTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARRIGHTRECTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_CTRL << 16), SCI_WORDRIGHT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDRIGHTEXTEND);
	}
	else
	{
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT, SCI_CHARRIGHT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_SHIFT << 16), SCI_CHARRIGHTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARRIGHTRECTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_CTRL << 16), SCI_WORDRIGHT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDRIGHTEXTEND);

		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT, SCI_CHARLEFT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_SHIFT << 16), SCI_CHARLEFTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARLEFTRECTEXTEND);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_CTRL << 16), SCI_WORDLEFT);
		_pEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDLEFTEXTEND);

		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT, SCI_CHARRIGHT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_SHIFT << 16), SCI_CHARRIGHTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARRIGHTRECTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + (SCMOD_CTRL << 16), SCI_WORDRIGHT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_RIGHT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDRIGHTEXTEND);

		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT, SCI_CHARLEFT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_SHIFT << 16), SCI_CHARLEFTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_ALT) << 16), SCI_CHARLEFTRECTEXTEND);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + (SCMOD_CTRL << 16), SCI_WORDLEFT);
		_pNonEditView->execute(SCI_ASSIGNCMDKEY, SCK_LEFT + ((SCMOD_SHIFT + SCMOD_CTRL) << 16), SCI_WORDLEFTEXTEND);
	}

	if (_pDocMap)
	{
		_pDocMap->changeTextDirection(toRTL);
	}
}
break;

---

NOTE:

1. I use NPP RTL but I have both views defaulted to LTR.
   With NPP original behavior, the keys would need to be re-assigned on startup as well.
2. For my personal use I prefer to apply the direction-change to both views.
3. You might want to shorten the code by using a function.
4. DELETE and DELETEBACK work as expected in both directions. - No need to change anything.

[donho]

It has been fixed in v4.1.0, according Scintilla author. However, the Scintilla used by Notepad++ is v4.4.6.
I'm not sure if it's a regression in Scintilla, or Scintilla is misused in Notepad++ for causing this bug. If it's the 2nd case, it would be better to fix it in the layer of Notepad++.

After checking the source code, I realized that Notepad++ R2L feature was done before the similar feature implemented in Scintilla - R2L feature in Notepad++ has been implemented by using Windows system's R2L capacity, but not using the bi_directional text implementation Scintilla SCI_SETBIDIRECTIONAL. That's why Neil (Scintilla author) has confirmed that has been fixed, but the fix is not in Notepad++.

The wired thing is, I have tested in the latest release of Notepad3, there is also the same caret inverse moving bug in RTL mode, but I didn't check Notepad3's code for this part.

I have also tried Scintilla native SCI_SETBIDIRECTIONAL, without success. So I took the solution of @Yaron10 and improved it as the PR #10963, which for me it's a better solution, comparing to the one of modifying Scintilla component which is not maintained by this project.