Fix InstructionTree and Block circular dependency

Since 4338632 there's been a circular dependency between InstructionTree
and Block that manifests as a script error due to a non-existent
resource in a seemingly unrelated object. Several components use
InstructionTree.TreeNode including Block, and prior to 4338632 there
were no references to any non-native classes. Split out the block tree
functions to a new BlockTreeUtil class so that InstructionTree no longer
contains references to Block.

Author: dbnicholson

addons/block_code/drag_manager/drag.gd

@@ -3,6 +3,7 @@ extends Control
 
 const Background = preload("res://addons/block_code/ui/blocks/utilities/background/background.gd")
 const BlockCanvas = preload("res://addons/block_code/ui/block_canvas/block_canvas.gd")
+const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
 const Types = preload("res://addons/block_code/types/types.gd")
@@ -143,7 +144,7 @@ func _snaps_to(node: Node) -> bool:
 			if _block_scope != top_block.get_entry_statement():
 				return false
 		elif top_block:
-			var tree_scope := InstructionTree.get_tree_scope(top_block)
+			var tree_scope := BlockTreeUtil.get_tree_scope(top_block)
 			if tree_scope != "" and _block_scope != tree_scope:
 				return false
 

addons/block_code/drag_manager/drag_manager.gd

@@ -5,6 +5,7 @@ signal block_dropped
 signal block_modified
 
 const BlockCanvas = preload("res://addons/block_code/ui/block_canvas/block_canvas.gd")
+const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
 const Drag = preload("res://addons/block_code/drag_manager/drag.gd")
 const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
 const Picker = preload("res://addons/block_code/ui/picker/picker.gd")
@@ -50,7 +51,7 @@ func drag_block(block: Block, copied_from: Block = null):
 
 	block.disconnect_signals()
 
-	var block_scope := InstructionTree.get_tree_scope(block)
+	var block_scope := BlockTreeUtil.get_tree_scope(block)
 	if block_scope != "":
 		_block_canvas.set_scope(block_scope)
 

addons/block_code/instruction_tree/instruction_tree.gd

@@ -56,80 +56,3 @@ static func generate_text_recursive(node: TreeNode, depth: int, out: PackedStrin
 
 	if node.next:
 		generate_text_recursive(node.next, depth, out)
-
-
-static func generate_script_from_nodes(nodes: Array[Node], bsd: BlockScriptData) -> String:
-	var entry_blocks_by_entry_statement: Dictionary = {}
-
-	for block in nodes:
-		if !(block is Block):
-			continue
-
-		if block is EntryBlock:
-			var entry_statement = block.get_entry_statement()
-			if not entry_blocks_by_entry_statement.has(entry_statement):
-				entry_blocks_by_entry_statement[entry_statement] = []
-			entry_blocks_by_entry_statement[entry_statement].append(block)
-
-	var script: String = ""
-
-	script += "extends %s\n\n" % bsd.script_inherits
-
-	for variable in bsd.variables:
-		script += "var %s: %s\n\n" % [variable.var_name, type_string(variable.var_type)]
-
-	script += "\n"
-
-	var init_func = TreeNode.new("func _init():")
-
-	for entry_statement in entry_blocks_by_entry_statement:
-		var entry_blocks: Array[EntryBlock]
-		entry_blocks.assign(entry_blocks_by_entry_statement[entry_statement])
-		script += _generate_script_from_entry_blocks(entry_statement, entry_blocks, init_func)
-
-	if init_func.children:
-		script += generate_text(init_func)
-
-	return script
-
-
-static func _generate_script_from_entry_blocks(entry_statement: String, entry_blocks: Array[EntryBlock], init_func: TreeNode) -> String:
-	var script = entry_statement + "\n"
-	var signal_node: TreeNode
-	var is_empty = true
-
-	IDHandler.reset()
-
-	for entry_block in entry_blocks:
-		var next_block := entry_block.bottom_snap.get_snapped_block()
-
-		if next_block != null:
-			var instruction_node: TreeNode = next_block.get_instruction_node()
-			var to_append := generate_text(instruction_node, 1)
-			script += to_append
-			script += "\n"
-			is_empty = false
-
-		if signal_node == null and entry_block.signal_name:
-			signal_node = TreeNode.new("{0}.connect(_on_{0})".format([entry_block.signal_name]))
-
-	if signal_node:
-		init_func.add_child(signal_node)
-
-	if is_empty:
-		script += "\tpass\n\n"
-
-	return script
-
-
-## Returns the scope of the first non-empty scope child block
-static func get_tree_scope(node: Node) -> String:
-	if node is Block:
-		if node.scope != "":
-			return node.scope
-
-	for c in node.get_children():
-		var scope := get_tree_scope(c)
-		if scope != "":
-			return scope
-	return ""

addons/block_code/ui/block_canvas/block_canvas.gd

@@ -2,6 +2,7 @@
 extends MarginContainer
 
 const BlockCodePlugin = preload("res://addons/block_code/block_code_plugin.gd")
+const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
 const DragManager = preload("res://addons/block_code/drag_manager/drag_manager.gd")
 const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
 const Util = preload("res://addons/block_code/ui/util.gd")
@@ -219,7 +220,7 @@ func set_scope(scope: String):
 			if scope == block.get_entry_statement():
 				valid = true
 		else:
-			var tree_scope := InstructionTree.get_tree_scope(block)
+			var tree_scope := BlockTreeUtil.get_tree_scope(block)
 			if tree_scope == "" or scope == tree_scope:
 				valid = true
 
@@ -321,4 +322,4 @@ func set_mouse_override(override: bool):
 
 func generate_script_from_current_window(bsd: BlockScriptData) -> String:
 	# TODO: implement multiple windows
-	return InstructionTree.generate_script_from_nodes(_window.get_children(), bsd)
+	return BlockTreeUtil.generate_script_from_nodes(_window.get_children(), bsd)

addons/block_code/ui/block_tree_util.gd

@@ -0,0 +1,80 @@
+extends Object
+
+const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
+
+
+static func generate_script_from_nodes(nodes: Array[Node], bsd: BlockScriptData) -> String:
+	var entry_blocks_by_entry_statement: Dictionary = {}
+
+	for block in nodes:
+		if !(block is Block):
+			continue
+
+		if block is EntryBlock:
+			var entry_statement = block.get_entry_statement()
+			if not entry_blocks_by_entry_statement.has(entry_statement):
+				entry_blocks_by_entry_statement[entry_statement] = []
+			entry_blocks_by_entry_statement[entry_statement].append(block)
+
+	var script: String = ""
+
+	script += "extends %s\n\n" % bsd.script_inherits
+
+	for variable in bsd.variables:
+		script += "var %s: %s\n\n" % [variable.var_name, type_string(variable.var_type)]
+
+	script += "\n"
+
+	var init_func = InstructionTree.TreeNode.new("func _init():")
+
+	for entry_statement in entry_blocks_by_entry_statement:
+		var entry_blocks: Array[EntryBlock]
+		entry_blocks.assign(entry_blocks_by_entry_statement[entry_statement])
+		script += _generate_script_from_entry_blocks(entry_statement, entry_blocks, init_func)
+
+	if init_func.children:
+		script += InstructionTree.generate_text(init_func)
+
+	return script
+
+
+static func _generate_script_from_entry_blocks(entry_statement: String, entry_blocks: Array[EntryBlock], init_func: InstructionTree.TreeNode) -> String:
+	var script = entry_statement + "\n"
+	var signal_node: InstructionTree.TreeNode
+	var is_empty = true
+
+	InstructionTree.IDHandler.reset()
+
+	for entry_block in entry_blocks:
+		var next_block := entry_block.bottom_snap.get_snapped_block()
+
+		if next_block != null:
+			var instruction_node: InstructionTree.TreeNode = next_block.get_instruction_node()
+			var to_append := InstructionTree.generate_text(instruction_node, 1)
+			script += to_append
+			script += "\n"
+			is_empty = false
+
+		if signal_node == null and entry_block.signal_name:
+			signal_node = InstructionTree.TreeNode.new("{0}.connect(_on_{0})".format([entry_block.signal_name]))
+
+	if signal_node:
+		init_func.add_child(signal_node)
+
+	if is_empty:
+		script += "\tpass\n\n"
+
+	return script
+
+
+## Returns the scope of the first non-empty scope child block
+static func get_tree_scope(node: Node) -> String:
+	if node is Block:
+		if node.scope != "":
+			return node.scope
+
+	for c in node.get_children():
+		var scope := get_tree_scope(c)
+		if scope != "":
+			return scope
+	return ""

tests/test_instruction_tree.gd

@@ -1,6 +1,7 @@
 extends GutTest
 ## Tests for InstructionTree
 
+const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
 const CategoryFactory = preload("res://addons/block_code/ui/picker/categories/category_factory.gd")
 const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
 
@@ -88,7 +89,7 @@ func test_tree_node_text():
 
 func test_script_no_nodes():
 	var bsd := BlockScriptData.new("Foo")
-	var script := InstructionTree.generate_script_from_nodes([], bsd)
+	var script := BlockTreeUtil.generate_script_from_nodes([], bsd)
 	assert_eq(
 		script,
 		(
@@ -105,7 +106,7 @@ func test_script_no_nodes():
 func test_script_no_entry_blocks():
 	var bsd := BlockScriptData.new("Foo")
 	var nodes: Array[Node] = [Node.new(), Node2D.new(), Control.new()]
-	var script := InstructionTree.generate_script_from_nodes(nodes, bsd)
+	var script := BlockTreeUtil.generate_script_from_nodes(nodes, bsd)
 	assert_eq(
 		script,
 		(
@@ -137,7 +138,7 @@ func test_basic_script():
 	assert_eq(ready_block.bottom_snap.get_snapped_block(), print_block)
 
 	var bsd := BlockScriptData.new("Node2D")
-	var script := InstructionTree.generate_script_from_nodes([ready_block], bsd)
+	var script := BlockTreeUtil.generate_script_from_nodes([ready_block], bsd)
 	assert_eq(
 		script,
 		(
@@ -165,7 +166,7 @@ func test_multiple_entry_script():
 	var ready_block_2: Block = dup_node(ready_block)
 
 	var bsd := BlockScriptData.new("Node2D")
-	var script := InstructionTree.generate_script_from_nodes([ready_block, ready_block_2], bsd)
+	var script := BlockTreeUtil.generate_script_from_nodes([ready_block, ready_block_2], bsd)
 	assert_eq(
 		script,
 		(
@@ -196,7 +197,7 @@ func test_signal_script():
 	entered_block.bottom_snap.snapped_block = print_block
 
 	var bsd := BlockScriptData.new("Area2D")
-	var script = InstructionTree.generate_script_from_nodes([entered_block], bsd)
+	var script = BlockTreeUtil.generate_script_from_nodes([entered_block], bsd)
 	assert_eq(
 		script,
 		(