Prevent loss of focus on Tab/Arrow key press

Prevents Terminal losing focus when in a scene with other inputs and
the Tab or Arrow keys are pressed.

Fixes #51.

addons/godot_xterm/terminal.gd

@@ -184,6 +184,10 @@ func _gui_input(event):
 		):
 			_native_terminal.sb_reset()
 
+		# Prevent focus changing to other inputs when pressing Tab or Arrow keys.
+		if event.scancode in [KEY_LEFT, KEY_UP, KEY_RIGHT, KEY_DOWN, KEY_TAB]:
+			accept_event()
+
 	_handle_mouse_wheel(event)
 	_handle_selection(event)
 

test/scenes/multiple_inputs.tscn

@@ -0,0 +1,50 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://addons/godot_xterm/terminal.gd" type="Script" id=1]
+
+[node name="HBoxContainer" type="HBoxContainer"]
+anchor_right = 1.0
+anchor_bottom = 1.0
+
+[node name="HBoxContainer" type="HBoxContainer" parent="."]
+margin_right = 1024.0
+margin_bottom = 600.0
+size_flags_horizontal = 3
+
+[node name="TextEdit" type="TextEdit" parent="HBoxContainer"]
+margin_right = 338.0
+margin_bottom = 600.0
+size_flags_horizontal = 3
+
+[node name="VBoxContainer" type="VBoxContainer" parent="HBoxContainer"]
+margin_left = 342.0
+margin_right = 681.0
+margin_bottom = 600.0
+size_flags_horizontal = 3
+
+[node name="TextEdit3" type="TextEdit" parent="HBoxContainer/VBoxContainer"]
+margin_right = 339.0
+margin_bottom = 197.0
+size_flags_vertical = 3
+
+[node name="Terminal" type="Control" parent="HBoxContainer/VBoxContainer"]
+margin_top = 201.0
+margin_right = 339.0
+margin_bottom = 398.0
+focus_mode = 2
+size_flags_vertical = 3
+script = ExtResource( 1 )
+
+[node name="TextEdit2" type="TextEdit" parent="HBoxContainer/VBoxContainer"]
+margin_top = 402.0
+margin_right = 339.0
+margin_bottom = 600.0
+size_flags_vertical = 3
+
+[node name="TextEdit2" type="TextEdit" parent="HBoxContainer"]
+margin_left = 685.0
+margin_right = 1024.0
+margin_bottom = 600.0
+size_flags_horizontal = 3
+
+[connection signal="data_sent" from="HBoxContainer/VBoxContainer/Terminal" to="HBoxContainer/VBoxContainer/Terminal" method="write"]

test/unit/terminal.test.gd

@@ -31,3 +31,45 @@ func test_bell_cooldown() -> void:
 	term.write("\a")
 	yield(yield_to(term, "bell", 5), YIELD)
 	assert_signal_emit_count(term, "bell", 2)
+
+
+class TestMultipleInputs:
+	# Tests for when Terminal is around other input nodes and arrow keys or TAB
+	# key is pressed. Focus should not change to other inputs when pressing these
+	# keys (same behaviour as TextEdit node).
+	# See: https://github.com/lihop/godot-xterm/issues/51
+	extends "res://addons/gut/test.gd"
+
+	const KEYS := {
+		KEY_LEFT = KEY_LEFT,
+		KEY_UP = KEY_UP,
+		KEY_RIGHT = KEY_RIGHT,
+		KEY_DOWN = KEY_DOWN,
+		KEY_TAB = KEY_TAB,
+	}
+
+	var terminal: Control
+
+	func press_key(scancode: int, unicode := 0) -> void:
+		var key_down = InputEventKey.new()
+		key_down.scancode = scancode
+		key_down.pressed = true
+		Input.parse_input_event(key_down)
+		yield(get_tree().create_timer(0.1), "timeout")
+		var key_up = InputEventKey.new()
+		key_up.scancode = scancode
+		key_up.pressed = false
+		Input.parse_input_event(key_up)
+
+	func before_each():
+		var scene := preload("../scenes/multiple_inputs.tscn").instance()
+		add_child_autofree(scene)
+		terminal = scene.find_node("Terminal")
+		terminal.grab_focus()
+
+	func test_terminal_keeps_focus_when_certain_keys_pressed():
+		for key in KEYS.keys():
+			press_key(KEYS[key])
+			assert_true(
+				terminal.has_focus(), "Terminal should still have focus after %s is pressed." % key
+			)