add simple checkbox component

druid/base/checkbox.lua

@@ -0,0 +1,44 @@
+--- Druid checkbox component
+-- @module base.checkbox
+
+local helper = require("druid.helper")
+
+local M = {}
+
+
+local function state_animate(node, state)
+	local target = state and 1 or 0
+	gui.animate(node, "color.w", target, gui.EASING_OUTSINE, 0.1)
+end
+
+
+function M.set_state(self, state, is_silence)
+	if self.state == state then
+		return
+	end
+
+	self.state = state
+	state_animate(self.node, state)
+
+	if not is_silence and self.callback then
+		self.callback(self.parent.parent, state)
+	end
+end
+
+
+-- TODO: pass self as first parameter
+local function on_click(context, self)
+	M.set_state(self, not self.state)
+end
+
+
+function M.init(self, node, callback, click_node)
+	self.node = helper.get_node(node)
+	self.click_node = helper.get_node(click_node)
+	self.callback = callback
+	self.button = self.parent:new_button(self.click_node or self.node, on_click, self)
+	M.set_state(self, false, true)
+end
+
+
+return M

druid/druid.lua

@@ -22,6 +22,7 @@ M.comps = {
 	progress = require("druid.base.progress"),
 	grid = require("druid.base.grid"),
 	scroll = require("druid.base.scroll"),
+	checkbox = require("druid.base.checkbox"),
 
 	progress_rich = require("druid.rich.progress_rich"),
 }

example/kenney/page/main.lua

@@ -62,6 +62,16 @@ local function setup_grid(self)
 end
 
 
+local function setup_checkbox(self)
+	self.druid:new_checkbox("radio1/check", nil, "radio1/back")
+	self.druid:new_checkbox("radio2/check", nil, "radio2/back")
+	self.druid:new_checkbox("radio3/check", nil, "radio3/back")
+	self.druid:new_checkbox("checkbox1/check", nil, "checkbox1/back")
+	self.druid:new_checkbox("checkbox2/check", nil, "checkbox2/back")
+	self.druid:new_checkbox("checkbox3/check", nil, "checkbox3/back")
+end
+
+
 local function setup_timer(self)
 	self.timer = self.druid:new_timer("timer", 300, 0, empty_callback)
 end
@@ -85,6 +95,7 @@ function M.setup_page(self)
 	setup_progress(self)
 	setup_grid(self)
 	setup_timer(self)
+	setup_checkbox(self)
 	setup_scroll(self)
 	setup_back_handler(self)
 end