Script editor: Convert indentation on paste

[akien-mga]

This is implemented as an editor setting (opt-out), and only for the
script editor (though it's implemented in TextEdit which handles the
paste).

Based on the indent type and size from the editor settings, it will
convert tabs to the expected number of spaces, or spaces to tabs. In
the latter case, it aims to guess the number of spaces used as indent
size in the clipboard.

Fixes #19285.

---

The implementation is not perfect yet, and likely a bit naive, as my knowledge of the String API is a bit rusty and I didn't pause long to think about what would be the most efficient algorithm. Any feedback/suggestions are welcome.

I've noticed a slight issue with the selection cursor when doing undo, but haven't investigated yet.
Edit: Doesn't seem related to this PR, the same bug happens with the option disabled.

I would also have liked the reformatting to happen as a second undoable complex operation (so paste first without changes, then apply changes, and you undo in two steps), but I'm not sure how to do it easily.

[akien-mga]

This part of #19285 is not implemented BTW:

the code context: when pasting code in an already-indented block, the whole paste block should be re-indented accordingly.

[Paulb23]

Is it normal for other editors to detect space indent size, rather then using its own configuration? Both QT Creator and Sublime text don't seem to?
If not, I would suggest converting the existing methods in CodeTextEditor into text_edit with start / end line arguments (defaulting to the entire script), calling it after pasting.

Regardless, the setting will have to be created as a property of text_edit (defaulting to false), so it can be driven by CodeTextEditor, otherwise it will affect all text_edits in the editor, such as those in the inspector.

I've also seen this kind of paste separated into two shortcuts, a paste and a "paste with/without formatting", as an alternative to creating a setting.

In addition, there is an indent_using_spaces bool to detect whether it should be using spaces.
If it's true a string string called space_indent is padded with the number of spaces, so no need to recalculate these.

[akien-mga]

Is it normal for other editors to detect space indent size, rather then using its own configuration? Both QT Creator and Sublime text don't seem to?

I tested with Kate, and it seems to detect indent size. The feature would quite limited otherwise IMO, as if you're pasting code indented with 6-spaces in a project with 4-space wide tab indentation, the expected behavior would be that 6 spaces become tabs, not only 4 of them with 2 spaces remaining. Similarly, if the code being pasted is indented with 8-spaces, I don't want 2 tabs per level.

I tested this in Kate (6-spaces indentation):

void some_method() {
      if (true) {
            print_line("Hello world");
      }
}

When pasting to a file configured to use tabs, it properly converts the 6 spaces to a tab, regardless of the configured tab width (4 or 8 chars).

Kate is actually more clever than what I implemented here, as it manages to perfectly handle this mess:

void some_method() {
      if (true) {
            print_line("Hello world");
      }
    return;
}

void some_method() {
        if (true)
                print_line("Hello world");
             return;
}

It properly indents everything with tabs based on the language semantics.

Edit: So actually Kate likely doesn't try to figure out the indentation size by parsing the code, it just uses the language semantics to reflow everything as it ought to be. So since we don't do that, maybe we shouldn't try to figure things out and just stick to the configured indent width as QtCreator does.

I tried QtCreator, and indeed it seems more limited, it only handles its configured indent width, and only when saving the file, not on paste.

I've also seen this kind of paste separated into two shortcuts, a paste and a "paste with/without formatting", as an alternative to creating a setting.

Indeed, we could default to converting on paste, and add a "Paste with original formatting" context menu option.

I'll have a look at making the architecture changes requested.

[akien-mga]

Edit: So actually Kate likely doesn't try to figure out the indentation size by parsing the code, it just uses the language semantics to reflow everything as it ought to be. So since we don't do that, maybe we shouldn't try to figure things out and just stick to the configured indent width as QtCreator does.

Given the above, I think you're correct that we should likely not try to figure this out ourselves.

And then,

If not, I would suggest converting the existing methods in CodeTextEditor into text_edit with start / end line arguments (defaulting to the entire script), calling it after pasting.

Does sound like a better approach, reusing the methods called for text_editor/indent/convert_indent_on_save.

[akien-mga]

@Paulb23 I did a quick test reusing CodeEditor's methods to convert indentation on paste, and add an option to paste with original formatting. Currently it converts the whole script, I have yet to look into saving the position before paste and use it to convert only the pasted code.

The context menu "Paste" works fine, but the problem is that the Ctrl+V shortcut triggers TextEdit's paste, and not ScriptTextEditor's... Not sure how to fix that.

diff --git a/editor/plugins/script_text_editor.cpp b/editor/plugins/script_text_editor.cpp
index 07303da2f..6869c76ab 100644
--- a/editor/plugins/script_text_editor.cpp
+++ b/editor/plugins/script_text_editor.cpp
@@ -1028,6 +1028,17 @@ void ScriptTextEditor::_edit_option(int p_op) {
 		} break;
 		case EDIT_PASTE: {
 
+			tx->paste();
+			// Convert clipboard indentation to match configured indent style
+			if (use_space_indentation) {
+				convert_indent_to_spaces();
+			} else {
+				convert_indent_to_tabs();
+			}
+			tx->call_deferred("grab_focus");
+		} break;
+		case EDIT_PASTE_ORIGINAL_INDENT: {
+
 			tx->paste();
 			tx->call_deferred("grab_focus");
 		} break;
@@ -1627,6 +1638,7 @@ void ScriptTextEditor::_make_context_menu(bool p_selection, bool p_color, bool p
 	}
 
 	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/paste"), EDIT_PASTE);
+	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/paste_original_indent"), EDIT_PASTE_ORIGINAL_INDENT);
 	context_menu->add_separator();
 	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/select_all"), EDIT_SELECT_ALL);
 	context_menu->add_shortcut(ED_GET_SHORTCUT("script_text_editor/undo"), EDIT_UNDO);
@@ -1661,6 +1673,7 @@ void ScriptTextEditor::_make_context_menu(bool p_selection, bool p_color, bool p
 ScriptTextEditor::ScriptTextEditor() {
 
 	theme_loaded = false;
+	use_space_indentation = EditorSettings::get_singleton()->get("text_editor/indent/type");
 
 	VSplitContainer *editor_box = memnew(VSplitContainer);
 	add_child(editor_box);
@@ -1725,6 +1738,7 @@ ScriptTextEditor::ScriptTextEditor() {
 	edit_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/cut"), EDIT_CUT);
 	edit_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/copy"), EDIT_COPY);
 	edit_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/paste"), EDIT_PASTE);
+	edit_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/paste_original_indent"), EDIT_PASTE_ORIGINAL_INDENT);
 	edit_menu->get_popup()->add_separator();
 	edit_menu->get_popup()->add_shortcut(ED_GET_SHORTCUT("script_text_editor/select_all"), EDIT_SELECT_ALL);
 	edit_menu->get_popup()->add_separator();
@@ -1843,6 +1857,7 @@ void ScriptTextEditor::register_editor() {
 	ED_SHORTCUT("script_text_editor/cut", TTR("Cut"), KEY_MASK_CMD | KEY_X);
 	ED_SHORTCUT("script_text_editor/copy", TTR("Copy"), KEY_MASK_CMD | KEY_C);
 	ED_SHORTCUT("script_text_editor/paste", TTR("Paste"), KEY_MASK_CMD | KEY_V);
+	ED_SHORTCUT("script_text_editor/paste_original_indent", TTR("Paste with Original Indent"), KEY_MASK_CMD | KEY_MASK_SHIFT | KEY_V);
 	ED_SHORTCUT("script_text_editor/select_all", TTR("Select All"), KEY_MASK_CMD | KEY_A);
 	ED_SHORTCUT("script_text_editor/move_up", TTR("Move Up"), KEY_MASK_ALT | KEY_UP);
 	ED_SHORTCUT("script_text_editor/move_down", TTR("Move Down"), KEY_MASK_ALT | KEY_DOWN);
diff --git a/editor/plugins/script_text_editor.h b/editor/plugins/script_text_editor.h
index 4dbade472..a01a41bd5 100644
--- a/editor/plugins/script_text_editor.h
+++ b/editor/plugins/script_text_editor.h
@@ -96,6 +96,7 @@ class ScriptTextEditor : public ScriptEditorBase {
 	} colors_cache;
 
 	bool theme_loaded;
+	bool use_space_indentation;
 
 	enum {
 		EDIT_UNDO,
@@ -103,6 +104,7 @@ class ScriptTextEditor : public ScriptEditorBase {
 		EDIT_CUT,
 		EDIT_COPY,
 		EDIT_PASTE,
+		EDIT_PASTE_ORIGINAL_INDENT,
 		EDIT_SELECT_ALL,
 		EDIT_COMPLETE,
 		EDIT_AUTO_INDENT,

[akien-mga]

I did a quick test reusing CodeEditor's methods to convert indentation on paste, and add an option to paste with original formatting. Currently it converts the whole script, I have yet to look into saving the position before paste and use it to convert only the pasted code.

I pushed an update commit which implements this properly, adding optional arguments to the convert_indent* methods for the start and end line indices.

The context menu "Paste" works fine, but the problem is that the Ctrl+V shortcut triggers TextEdit's paste, and not ScriptTextEditor's... Not sure how to fix that.

That's still unsolved though, and needs to be before this can be merged.

I guess it's not TextEdit's shortcut which gets triggered, but the fact that it has many hardcoded hotkeys in its input processing. I'm not sure how to solve that. There's definitely some duplication between menu entries and hardcoded hotkeys in TextEdit... maybe we could drop the hardcoded ones and keep only those registered by the contextual menu?

Related to #31183.

[Paulb23]

Besides the one comment below it looks okay to me. I don't know if it would be better calling it "paste unformatted" rather then "paste original indent", to make it easier to potentially add more functionally such as trimming whitespace?

Might also be worth adding it to the shader and text editors.

As for the shortcut, the easiest way is to handle it before text_edit by processing it in inside of _input (This was done for a few shortcuts inside of CodeTextEditor). Otherwise you'd have to move everything into text_edit (see #12164) or have it emit a signal on paste and handle it from there.

Alternatively, as you say have build a way to disable it, but that's way out of scope.

[Paulb23]

Needs to be set under update_settings else it won't update if the setting is changed.

[aaronfranke]

@akien-mga What's the status of this PR? It needs to be rebased.

[akien-mga]

I'm struggling to find time to work on this, so closing for now. It's salvageable, anyone feel free to pick it up and adapt it to the 4.0 script editor architecture while addressing the above feedback.