Initial commit

Half-baked state. Most of the UI is mostly done, but the integration
with Grist (or any other data provider) is still missing.

addons/onscreenkeyboard/keyboard_button.gd

@@ -0,0 +1,67 @@
+extends Button
+
+var key_data
+
+signal released
+signal down
+
+var icon_tex_rect
+
+func _enter_tree():
+	pass
+
+func _ready():
+	pass # Replace with function body.
+
+func _init(_key_data):
+	key_data = _key_data
+	button_down.connect(_on_button_down)
+	button_up.connect(_on_button_up)
+	item_rect_changed.connect(_on_item_rect_changed)
+
+	size_flags_horizontal = SIZE_EXPAND_FILL
+	size_flags_vertical = SIZE_EXPAND_FILL
+
+	focus_mode = FOCUS_NONE
+
+	if key_data.has("display"):
+		text = key_data.get("display")
+
+	if key_data.has("stretch-ratio"):
+		size_flags_stretch_ratio = key_data.get("stretch-ratio")
+
+
+func set_icon_color(color):
+	if icon_tex_rect != null:
+		icon_tex_rect.modulate = color
+
+
+func set_icon(texture):
+	icon_tex_rect = TextureRect.new()
+	icon_tex_rect.ignore_texture_size = true
+	icon_tex_rect.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
+	icon_tex_rect.texture = texture
+	add_child(icon_tex_rect)
+
+
+func change_uppercase(value):
+	if value:
+		if key_data.has("display-uppercase"):
+			text = key_data.get("display-uppercase")
+	else:
+		if key_data.has("display"):
+			text = key_data.get("display")
+
+
+func _on_item_rect_changed():
+	if icon_tex_rect != null:
+		icon_tex_rect.size = size
+
+
+func _on_button_up():
+	released.emit(key_data)
+	release_focus()
+
+
+func _on_button_down():
+	down.emit(key_data)