LayerManager.h

// =============================================================================
//  LayerManager.h  ── 图层管理器声明
//  放置在画布左侧，显示所有曲线图层
// =============================================================================
#pragma once
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <windows.h>
#include <string>
#include <vector>

class Canvas;

class LayerManager
{
public:
    LayerManager(HWND parent, Canvas* canvas);
    ~LayerManager();

    void Resize(int x, int y, int w, int h);
    void UpdateFromCanvas();

    HWND GetHWND() const { return m_hwnd; }

private:
    static LRESULT CALLBACK PanelProc(HWND, UINT, WPARAM, LPARAM);
    LRESULT HandleMsg(UINT, WPARAM, LPARAM);

    void CreateControls();
    void LayoutControls(int w, int h);

    // 图层项区域计算
    int GetItemY(int index) const;
    int GetItemCount() const;
    int HitTestItem(int mouseY) const;
    int HitTestIcon(int mouseX, int mouseY, int itemIdx) const;
    // 返回值: 0=visibility, 1=lock, -1=无

    HWND    m_hwnd   = nullptr;
    HWND    m_parent = nullptr;
    Canvas* m_canvas = nullptr;

    // 控件
    HWND m_titleLabel   = nullptr;
    HWND m_addBtn       = nullptr;
    HWND m_delBtn       = nullptr;
    HWND m_upBtn        = nullptr;
    HWND m_downBtn      = nullptr;

    // 主题色
    HBRUSH m_bgBrush     = nullptr;
    HBRUSH m_selBrush    = nullptr;
    HBRUSH m_itemBgBrush = nullptr;
    HFONT  m_font        = nullptr;
    HFONT  m_smallFont   = nullptr;

    // 布局基准常量（实际运行时由 g_dpiScale 缩放）
    // 设计基准: ITEM_H=32, ICON_SIZE=20, COLOR_SQ=16, BTN_H=26
};