1。kicad启动：

single_top.cpp
启动函数：
1。

IMPLEMENT_APP( APP_SINGLE_TOP )

2。

PGM_SINGLE_TOP::OnPgmInit()

3。

PGM_BASE::InitPgm

2。kicad参数

grid参数定义：

struct GRID_SETTINGS
{
    bool axes_enabled;
    std::vector<wxString> sizes;
    wxString user_grid_x;
    wxString user_grid_y;
    int last_size_idx;
    int fast_grid_1;
    int fast_grid_2;
    double line_width;
    double min_spacing;
    bool show;
    int style;
    int snap;
};

grid参数配置文件：
kicad.json
symbol_editor.json
eeschema.json

 "window": {
    "cursor": {
      "always_show_cursor": true,
      "fullscreen_cursor": false
    },
    "display": 0,
    "grid": {
      "axes_enabled": false,
      "fast_grid_1": 1,
      "fast_grid_2": 2,
      "last_size": 0,
      "line_width": 1.0,
      "min_spacing": 10.0,
      "show": true,
      "snap": 0,
      "style": 0,
      "user_grid_x": "10 mil",
      "user_grid_y": "10 mil"
    },

2.1 启动时设置grid参数：

APP_SETTINGS_BASE::addParamsForWindow（）

中设置参数：

 m_params.emplace_back( new PARAM<int>( aJsonPath + ".grid.last_size",
            &aWindow->grid.last_size_idx, defaultGridIdx ) );

    m_params.emplace_back( new PARAM<int>( aJsonPath + ".grid.fast_grid_1",
            &aWindow->grid.fast_grid_1, defaultGridIdx ) );

    m_params.emplace_back( new PARAM<int>( aJsonPath + ".grid.fast_grid_2",
            &aWindow->grid.fast_grid_2, defaultGridIdx + 1 ) );

APP_SETTINGS_BASE::migrateWindowConfig（）
   ret &= fromLegacy<int>(  aCfg, aFrame + "_LastGridSize",        gridPath + ".last_size" );

    ret &= fromLegacy<int>(  aCfg, aFrame + "FastGrid1",            gridPath + ".fast_grid_1" );
    ret &= fromLegacy<int>(  aCfg, aFrame + "FastGrid2",            gridPath + ".fast_grid_2" );

2.2启动的时候调用onGridchange事件

2.3 使用时，鼠标右键–>Grid,切换grid

调用OnGrid（）函数：

int COMMON_TOOLS::GridPreset( int idx )
{
    int& currentGrid = m_toolMgr->GetSettings()->m_Window.grid.last_size_idx;

    currentGrid = std::max( 0, std::min( idx, (int) m_grids.size() - 1 ) );

    return OnGridChanged();
}

启动GridPreset事件：

 m_toolManager->RunAction( ACTIONS::gridPreset, true, static_cast<intptr_t>( idx ) );

3.Tools工具栏打开symbol editor