Add duplication feature

[varshith257]

/claim #201
Closes #201

[manuq]

@varshith257 this doesn't work for me. The scripts have parse errors. See the failed checks above and see how to setup pre-commit checks in the README. Here is the output I get while loading the project from your branch:

Godot Engine v4.3.stable.flathub (c) 2007-present Juan Linietsky, Ariel Manzur & Godot Contributors.
--- Debug adapter server started on port 6006 ---
--- GDScript language server started on port 6005 ---
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "copy_picked_block_and_drag".
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "block_picked".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "connect_block_canvas_signals".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "reconnect_block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/main_panel.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/entry_block/entry_block.gd:3 - Parse Error: Could not resolve super class inheritance from "StatementBlock".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/entry_block/entry_block.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/utilities/background/background.gd:14 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/background/background.gd:61 - Parse Error: Could not resolve external class member "get_parent_block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/utilities/background/background.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.gd:29 - Parse Error: Used space character for indentation instead of tab as used before in the file.
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:9 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:9 - Parse Error: Cannot use simple "@export" annotation because the type of the initialized value can't be inferred.
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:23 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:24 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:25 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:44 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:52 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:62 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:62 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:79 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:38 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:88 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd:101 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/utilities/snap_point/snap_point.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd:38 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd:45 - Parse Error: Could not resolve external class member "get_parent_block".
  res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd:139 - Parse Error: Could not resolve external class member "block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/utilities/template_editor/template_editor.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/statement_block/statement_block.gd:3 - Parse Error: Could not resolve super class inheritance from "Block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/statement_block/statement_block.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/parameter_block/parameter_block.gd:3 - Parse Error: Could not resolve super class inheritance from "Block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/parameter_block/parameter_block.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/control_block/control_block.gd:3 - Parse Error: Could not resolve super class inheritance from "Block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/control_block/control_block.gd" with error "Parse error". (User)
  res://addons/block_code/ui/blocks/utilities/background/gutter.gd:8 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/blocks/utilities/background/gutter.gd:21 - Parse Error: Could not resolve external class member "get_parent_block".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/utilities/background/gutter.gd" with error "Parse error". (User)
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/block_code_node/block_code.gd:-1 - Compile Error: 
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "copy_picked_block_and_drag".
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "block_picked".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "connect_block_canvas_signals".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "reconnect_block".
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "copy_picked_block_and_drag".
  res://addons/block_code/ui/main_panel.gd:51 - Parse Error: Could not resolve external class member "block_picked".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "connect_block_canvas_signals".
  res://addons/block_code/ui/main_panel.gd:53 - Parse Error: Could not resolve external class member "reconnect_block".
  res://addons/block_code/inspector_plugin/block_script_inspector.gd:-1 - Compile Error: 
  res://addons/block_code/block_code_plugin.gd:-1 - Compile Error: 
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/block_code_plugin.gd" with error "Compilation failed". (User)
  res://addons/block_code/ui/picker/categories/variable_category/variable_category_display.gd:2 - Parse Error: Could not resolve class "res://addons/block_code/ui/picker/categories/block_category_display.gd".
  res://addons/block_code/ui/picker/categories/variable_category/variable_category_display.gd:2 - Parse Error: Could not resolve class "res://addons/block_code/ui/picker/categories/block_category_display.gd".
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/picker/categories/variable_category/variable_category_display.gd" with error "Parse error". (User)
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/block_editor_context.gd:-1 - Compile Error: 
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd:-1 - Compile Error: 
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/picker/categories/variable_category/create_variable_dialog.gd" with error "Compilation failed". (User)
  res://addons/block_code/block_code_plugin.gd:47 - Invalid access to property or key 'script_window_requested' on a base object of type 'MarginContainer (main_panel.gd)'.
  res://addons/block_code/block_code_plugin.gd:157 - Invalid call. Nonexistent function 'switch_block_code_node' in base 'MarginContainer (main_panel.gd)'.
  res://addons/block_code/ui/blocks/block/block.gd:163 - Parse Error: Used space character for indentation instead of tab as used before in the file.
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://addons/block_code/ui/blocks/block/block.gd" with error "Parse error". (User)
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:48 - Invalid assignment of property or key 'block_code_node' with value of type 'Node (BlockCode)' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/block_code_node/block_code.gd:36 - Invalid assignment of property or key 'script_inherits' with value of type 'String' on a base object of type 'Resource (BlockScriptSerialization)'.
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://tests/test_category_factory.gd:-1 - Compile Error: 
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://tests/test_category_factory.gd" with error "Parse error". (User)
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/code_generation/script_generator.gd:-1 - Compile Error: 
  res://addons/block_code/serialization/block_script_serialization.gd:56 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:74 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://addons/block_code/serialization/block_script_serialization.gd:68 - Parse Error: Could not parse global class "Block" from "res://addons/block_code/ui/blocks/block/block.gd".
  res://tests/test_code_generation.gd:-1 - Compile Error: 
  modules/gdscript/gdscript.cpp:2936 - Failed to load script "res://tests/test_code_generation.gd" with error "Parse error". (User)
  res://addons/block_code/block_code_plugin.gd:157 - Invalid call. Nonexistent function 'switch_block_code_node' in base 'MarginContainer (main_panel.gd)'.

[manuq]

The scripts have parse errors.

[varshith257]

@manuq Thanks for reviewing! I have formatted it with the same. Kindly review this PR and approve workflows

The compilation error occurred because var _block_canvas: Node was not initialized in block.gd.

Godot Engine v4.3.stable.official.77dcf97d8 - https://godotengine.org
OpenGL API 3.3.0 NVIDIA 546.80 - Compatibility - Using Device: NVIDIA - NVIDIA GeForce GTX 1650

Cleanly compiled

[varshith257]

@manuq Any reviews on it?

[manuq]

@varshith257 thanks for iterating on this. I see a bug when I try to delete from the menu: nothing happens and this is displayed in the output:

 res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.gd:91 - Invalid call. Nonexistent function 'confirm_delete' in base 'MarginContainer (StatementBlock)'.

Here is a recording:
Grabación de pantalla desde 2024-12-18 07-20-42.webm

[manuq]

@varshith257 sorry but I had to merge the other proposal #341 because it was ready, while yours had a bug. Even if yours came first.

[varshith257]

Thanks! @manuq