Add process_mode property to PTY

Adds process_mode property to PTY which can be set to IDLE or PHYSICS.
Determines whether the PTY will be updated in the `_process()` or
`_physics_process()` step. Defaults to PHYSICS.

addons/godot_xterm/editor_plugins/terminal/editor_terminal.gd

@@ -4,7 +4,6 @@ extends "../../terminal.gd"
 signal exited(exit_code, signum)
 
 var editor_settings: EditorSettings
-var timer := Timer.new()
 
 onready var pty = $PTY
 
@@ -51,20 +50,6 @@ func _ready():
 	)
 	_native_terminal._update_theme()
 
-	# In editor _process is not called continuously unless the "Update Continuously"
-	# editor setting is enabled. This setting is disabled by default and uses 100%
-	# of one core when enabled, so best to leave it off and use a timer instead.
-	add_child(timer)
-	timer.wait_time = 0.025
-	timer.connect("timeout", self, "_poll")
-	timer.start()
-
-
-func _poll():
-	if pty and pty.has_method("get_master"):
-		pty.get_master().poll()
-		update()
-
 
 func _input(event):
 	if has_focus() and event is InputEventKey and event.is_pressed():

addons/godot_xterm/nodes/pty/pty_native.gd

@@ -9,6 +9,10 @@ func open(cols: int, rows: int):
 	return _not_implemented()
 
 
+func run_process(delta: float):
+	return _not_implemented()
+
+
 func resize(cols: int, rows: int):
 	return _not_implemented()
 

addons/godot_xterm/nodes/pty/unix/pty_unix.gd

@@ -91,6 +91,11 @@ func write(data) -> void:
 		_pipe.write(data)
 
 
+func run_process(_delta):
+	if _pipe:
+		_pipe.poll()
+
+
 func resize(cols: int, rows: int) -> void:
 	if cols <= 0 or rows <= 0 or cols == NAN or rows == NAN or cols == INF or rows == INF:
 		push_error("Resizing must be done using positive cols and rows.")
@@ -126,11 +131,6 @@ func _parse_env(env: Dictionary = {}) -> PoolStringArray:
 	return pairs
 
 
-func _process(_delta):
-	if _pipe:
-		_pipe.poll()
-
-
 func fork(
 	file: String = OS.get_environment("SHELL"),
 	args: PoolStringArray = PoolStringArray(),

addons/godot_xterm/pty.gd

@@ -23,6 +23,13 @@ const Signal = _PTYUnix.Signal
 signal data_received(data)
 signal exited(exit_code, signum)
 
+enum ProcessMode {
+	IDLE,
+	PHYSICS,
+}
+
+export(ProcessMode) var process_mode := ProcessMode.IDLE
+
 export(NodePath) var terminal_path := NodePath() setget set_terminal_path
 
 var _terminal: _Terminal = null setget _set_terminal
@@ -150,6 +157,16 @@ func get_master():
 	return _pty_native.get_master()
 
 
+func _process(delta: float):
+	if process_mode == ProcessMode.IDLE:
+		_pty_native.run_process(delta)
+
+
+func _physics_process(delta: float):
+	if process_mode == ProcessMode.PHYSICS:
+		_pty_native.run_process(delta)
+
+
 func _on_pty_native_data_received(data):
 	emit_signal("data_received", data)
 

addons/godot_xterm/terminal.gd

@@ -82,6 +82,7 @@ func write(data) -> void:
 
 	# Will be cleared when _flush() is called after VisualServer emits the "frame_pre_draw" signal.
 	_buffer.push_back(data)
+	update()  # Queue the CanvasItem for updates. Ensures VisualServer will draw a frame, otherwise it might not.
 
 
 func _flush():

test/mocks/mock_pty_native.gd

@@ -0,0 +1,9 @@
+extends "res://addons/godot_xterm/nodes/pty/pty_native.gd"
+
+
+func write(data):
+	emit_signal("data_received", data)
+
+
+func run_process(_delta: float):
+	pass

test/unit/pty.test.gd

@@ -1,27 +1,38 @@
 extends "res://addons/gut/test.gd"
 
 
-class MockPTY:
-	extends "res://addons/godot_xterm/nodes/pty/pty_native.gd"
-
-	func write(data):
-		emit_signal("data_received", data)
-
-
 class BaseTest:
 	extends "res://addons/gut/test.gd"
 	const PTY := preload("res://addons/godot_xterm/pty.gd")
+	const MockPTYPath := "res://test/mocks/mock_pty_native.gd"
+	const MockPTY := preload(MockPTYPath)
 
 	var pty: PTY
 	var mock_pty_native: MockPTY
 
 	func before_each():
 		pty = add_child_autofree(PTY.new())
-		mock_pty_native = autofree(MockPTY.new())
+		mock_pty_native = autofree(double(MockPTYPath).new())
 		pty._pty_native = mock_pty_native
 		watch_signals(mock_pty_native)
 
 
+class TestProcessMode:
+	extends BaseTest
+
+	func test_updates_only_during_idle_time():
+		pty.process_mode = PTY.ProcessMode.IDLE
+		for _i in range(4):
+			yield(get_tree(), "idle_frame")
+		assert_between(get_call_count(mock_pty_native, "run_process"), 3, 4)
+
+	func test_updates_only_during_physics_step():
+		pty.process_mode = PTY.ProcessMode.PHYSICS
+		for _i in range(4):
+			yield(get_tree(), "physics_frame")
+		assert_between(get_call_count(mock_pty_native, "run_process"), 3, 4)
+
+
 class TestPTYInterfaceGodotXterm2_0_0:
 	extends BaseTest
 	# Test that PTY class conforms to the GodotXterm 2.0.0 specification published at: