Added scene palette addon

addons/scene_palette/components/scene_thumbnail/scene_drop.gd

@@ -0,0 +1,116 @@
+@tool
+extends Control
+
+const pp = 'ScenePalettePlugin: '  # prepended to printed messages
+const MOUSE_HOVER_SCALE_ADJUST = 0.05
+
+@onready var picture_point = %PicturePoint
+@onready var name_label = %NameLabel
+@onready var texture_rect: TextureRect = %TextureRect
+
+var _scene_path:String
+var instantiate_scene_preview:
+	set(value):
+		instantiate_scene_preview = value
+		# refresh the preview
+		if _scene_path:
+			set_scene(_scene_path)
+
+func adjust_scale(amt:float):
+	picture_point.scale = Vector2(amt, amt)
+
+func show_file_label(show:bool):
+	# setting text here instead of in set_scene seems to work better
+	name_label.text = _create_display_label(_scene_path)
+	name_label.visible = show
+
+func _create_display_label(path:String) -> String:
+	var display_label = path.split('.tscn')[0].split('/')[-1]
+	display_label = display_label.replace('_', ' ').replace('-', ' ')
+	return display_label
+
+func set_scene(path:String):
+	tooltip_text = path
+	_scene_path = path
+	var file_extension = path.split('.')[-1]
+	
+	for node in picture_point.get_children():
+		node.queue_free()
+	
+	match file_extension:
+		'png':
+			texture_rect.texture = load(_scene_path)
+		'tscn':
+			if instantiate_scene_preview:
+					var node:Node = load(_scene_path).instantiate()
+					if _scene_is_safe(node):
+						picture_point.add_child(node)
+						return
+			# if scene is not safe to instantiate, just keep a preview
+			_make_preview()
+		'obj':
+			_make_preview()
+
+func _make_preview():
+	var resource_previewer = EditorInterface.get_resource_previewer()
+	resource_previewer.queue_resource_preview(_scene_path, self, '_on_resource_preview', null)
+
+func _on_resource_preview(path:String, preview:Texture2D, thumbnail_preview:Texture2D, _user_data):
+	var texture_rect = TextureRect.new()
+	add_child(texture_rect)
+	texture_rect.texture = preview
+	hide()
+	show()
+
+## determine if scene is safe to instantiate as a preview
+func _scene_is_safe(scene:Node) -> bool:
+	# if scene is a Node then it can't be positioned within the panel and
+	# clip_contents does not work.
+	if not scene is Node2D:
+		print("%Not instantiating preview for %s because it is not a Node2D" %
+			[pp, scene.scene_file_path]
+			)
+		return false
+	# if scene contains a camera, the entire editor is repositioned
+	if _scene_contains_camera(scene):
+		print("%Not instantiating preview for %s because it contains a camera." %
+			[pp, scene.scene_file_path]
+			)
+		return false
+	return true
+
+func _scene_contains_camera(scene:Node) -> bool:
+	if scene is Camera2D:
+		return true
+	for node in scene.get_children():
+		var result:bool = _scene_contains_camera(node)
+		if result:
+			return result
+	return false
+
+## Mimics the data that would be provided if a file were dragged from the 
+## FileSystem browser
+func _make_file_data() -> Dictionary:
+	return {
+		'type': 'files',
+		'files': [_scene_path],
+		'from': ''
+	}
+
+func _make_drag_preview() -> Control:
+	var control:Control = Control.new()
+	if instantiate_scene_preview:
+		var scene = load(_scene_path).instantiate()
+		control.add_child(scene)
+	# TODO add an alternate image here
+	return control
+
+func _get_drag_data(at_position):
+	set_drag_preview(_make_drag_preview())
+	return _make_file_data()
+
+func _on_mouse_entered():
+	scale = Vector2.ONE + Vector2(MOUSE_HOVER_SCALE_ADJUST, MOUSE_HOVER_SCALE_ADJUST)
+
+func _on_mouse_exited():
+	scale = Vector2.ONE