Godot自定义控件样式语法解析-编程知识

前言

本篇原始文章写于2023年8月7日，存储在我的语雀文档中。但是语雀分享有诸多不便，为了让更多Godoter更轻松的搜到和看到，就转过来了。
这个项目我上传了Github，后续会贴上链接。

概述

Godot控件体系存在的问题之一就是样式无法用纯文本形式简洁而清晰的定义，一切都要靠主题编辑器或检视器面板那一套手动的东西。4.x提供了一些样式属性和方法，但仍然算不上简洁。

在样式定义方面，前端的CSS样式表可谓是最佳实践之一。

如果能够以类似CSS一样的纯文本形式解析和控制Godot的控件样式，那么样式定义就能更轻松。

基于这样的想法，笔者尝试建立了一个类CSS样式的样式书写和解析机制。让使用者可以基于一个简单的导出变量，用纯文本的方式定义控件的样式。

样式解析函数库

ConfigFile提供了一个名叫parse() 的方法，可以将符合ConfigFile风格和书写规则的字符串直接解析到ConfigFile实例。进而可以使用其提供的方法便捷的遍历节、键和值。

基于此我创建了一个名为Sty的静态函数库。
下面是初期的一个效果，已经可以解析按钮多个状态下的一些简单样式。

# ========================================================
# 名称：Sty
# 类型：静态函数库
# 简介：用于解析和应用控件样式
# 作者：巽星石
# Godot版本：4.1.1-stable (official)
# 创建时间：2023-08-07 23:11:57
# 最后修改时间：2023-08-07 23:11:57
# ========================================================
class_name Sty# 样式解析
static func parse_style(ctl:Control,style_str:String):var cfg = ConfigFile.new()var err = cfg.parse(style_str.replace(":","=\"").replace(";","\""))if err == OK: # 解析成功for section in cfg.get_sections():for key in cfg.get_section_keys(section):var val = cfg.get_value(section,key)match key:"font_size":pass"color":match section:"normal":ctl.add_theme_color_override("font_color",Color(val))"hover","pressed","disabled","focus":ctl.add_theme_color_override("font_%s_color" % section,Color(val))"bg_color":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)stylebox.bg_color = Color(val)"radius":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.corner_radius_top_left = int(vals[0])stylebox.corner_radius_top_right = int(vals[1])stylebox.corner_radius_bottom_left = int(vals[2])stylebox.corner_radius_bottom_right = int(vals[3])"border_width":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.border_width_left = int(vals[0])stylebox.border_width_top = int(vals[1])stylebox.border_width_right = int(vals[2])stylebox.border_width_bottom = int(vals[3])"border_color":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)stylebox.border_color = Color(val)"padding":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.content_margin_left = int(vals[0])stylebox.content_margin_top = int(vals[1])stylebox.content_margin_right = int(vals[2])stylebox.content_margin_bottom = int(vals[3])"margin":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.expand_margin_left = int(vals[0])stylebox.expand_margin_top = int(vals[1])stylebox.expand_margin_right = int(vals[2])stylebox.expand_margin_bottom = int(vals[3])"shadow_color":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)stylebox.shadow_color = Color(val)"shadow_size":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)stylebox.shadow_size = int(val)"shadow_offset":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.shadow_offset = Vector2(float(vals[0]),float(vals[1]))"skew":match section:"normal","hover","pressed","disabled","focus":var stylebox:StyleBoxFlat = get_stylebox(ctl,section)var vals = val.split(",")stylebox.skew = Vector2(float(vals[0]),float(vals[1]))# 获取控件对应名称的样式盒
static func get_stylebox(ctl:Control,name:String) -> StyleBoxFlat:var stylebox:StyleBoxFlatif ctl.has_theme_stylebox_override(name):stylebox = ctl.get_theme_stylebox(name)else:stylebox= StyleBoxFlat.new()ctl.add_theme_stylebox_override(name, stylebox)return stylebox

实际使用

为普通节点添加style属性

我们创建一个UI场景，添加一个Button。
在这里插入图片描述

为Button添加如下代码：

@tool
extends Button@export_multiline var style:String = "":set(val):style = valSty.parse_style(self,val)

接着我们在检视器面板的style变量中，定义如下的样式：

[normal]
font_size :64;
color:#FF4400;
bg_color:yellow;
radius:55,5,56,45;
skew:0.1,0;
border_width:5,2,5,2;
border_color:#444;
[disable]
color:#00FF00;
[hover]
color:#00FF00;
bg_color:#ccc;
radius:55,5,5,45;