refactor(界面重构): 支持三种主题

internal/webview/webview_theme.go

@@ -0,0 +1,130 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !js || !wasm
+
+package webview
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/xiaoqidun/guigo"
+	webuiassets "github.com/xiaoqidun/ofdgo/assets/webui"
+)
+
+// applicationTheme 保存应用主题偏好及最后一次解析的系统外观
+type applicationTheme struct {
+	Mode string `json:"mode"`
+	Dark bool   `json:"dark"`
+}
+
+// themeColors 返回应用对应外观的原生标题栏配色
+// 入参: dark 是否使用深色
+// 返回: guigo.TitleBarColors 标题栏配色
+func themeColors(dark bool) guigo.TitleBarColors {
+	if dark {
+		return guigo.TitleBarColors{Background: "#20272b", Foreground: "#e0e7eb", InactiveBackground: "#242b30", InactiveForeground: "#9aa8b1"}
+	}
+	return guigo.TitleBarColors{Background: "#e8edee", Foreground: "#263238", InactiveBackground: "#eef1f3", InactiveForeground: "#728087"}
+}
+
+// loadTheme 在创建窗口前读取用户目录中的主题偏好
+// 返回: error 读取或解析错误
+func (h *Host) loadTheme() error {
+	h.theme = applicationTheme{Mode: "system"}
+	data, err := os.ReadFile(h.themePath)
+	if os.IsNotExist(err) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	if err := json.Unmarshal(data, &h.theme); err != nil {
+		return err
+	}
+	return h.theme.validate()
+}
+
+// validate 检查应用主题及解析后的配色是否一致
+// 返回: error 偏好错误
+func (a applicationTheme) validate() error {
+	if a.Mode != "system" && a.Mode != "light" && a.Mode != "dark" {
+		return fmt.Errorf("主题无效")
+	}
+	if a.Mode == "light" && a.Dark || a.Mode == "dark" && !a.Dark {
+		return fmt.Errorf("主题配色无效")
+	}
+	return nil
+}
+
+// themeIndex 在页面首次绘制前提供当前主题偏好
+// 返回: []byte 页面内容, error 资源读取错误
+func (h *Host) themeIndex() ([]byte, error) {
+	data, err := webuiassets.NativeFS.ReadFile("index.html")
+	if err != nil {
+		return nil, err
+	}
+	h.themeMu.Lock()
+	mode := h.theme.Mode
+	h.themeMu.Unlock()
+	if mode == "" {
+		mode = "system"
+	}
+	return bytes.Replace(data, []byte(`<html lang="zh-CN">`), []byte(`<html lang="zh-CN" data-theme-mode="`+mode+`">`), 1), nil
+}
+
+// setTheme 串行保存应用偏好并同步当前窗口配色
+// 入参: value 已解析的主题偏好
+// 返回: error 校验、持久化或窗口更新错误
+func (h *Host) setTheme(value applicationTheme) error {
+	if err := value.validate(); err != nil {
+		return err
+	}
+	h.themeMu.Lock()
+	defer h.themeMu.Unlock()
+	h.mu.Lock()
+	window := h.window
+	h.mu.Unlock()
+	if window == nil {
+		return fmt.Errorf("窗口尚未就绪")
+	}
+	if h.theme != value {
+		data, err := json.Marshal(value)
+		if err != nil {
+			return err
+		}
+		file, err := os.CreateTemp(filepath.Dir(h.themePath), "appearance-*")
+		if err != nil {
+			return err
+		}
+		defer os.Remove(file.Name())
+		_, writeErr := file.Write(data)
+		closeErr := file.Close()
+		if writeErr != nil {
+			return writeErr
+		}
+		if closeErr != nil {
+			return closeErr
+		}
+		if err := os.Rename(file.Name(), h.themePath); err != nil {
+			return err
+		}
+		h.theme = value
+	}
+	return window.SetTitleBarColors(themeColors(value.Dark))
+}