【学写LibreCAD】1 LibreCAD主程序

一、源码

• 头文件：

#ifndef MAIN_H
#define MAIN_H#include<QStringList>#define STR(x)   #x
#define XSTR(x)  STR(x)/*** @brief handleArgs* @param argc cli argument counter from main()* @param argv cli arguments from main()* @param argClean a list of indices to be ignored* @return*/
QStringList handleArgs(int argc, char** argv, const QList<int>& argClean);/*** @brief LCReleaseLabel return a label for the current release based on LC_VERSION in src.pro* @return "Release Candidate" - if LC_VERSION contains rc;*         "BETA" - if LC_VERSION contains beta*         "ALPHA" - if LC_VERSION contains alpha*/
QString LCReleaseLabel();#endif

程序文件：

#include <clocale>#include <QApplication>
#include <QByteArray>
#include <QDebug>
#include <QFileInfo>
#include <QMessageBox>
#include <QPainter>
#include <QPixmap>
#include <QSettings>
#include <QSplashScreen>#include "console_dxf2pdf.h"
#include "console_dxf2png.h"
#include "lc_application.h"
#include "main.h"
#include "qc_applicationwindow.h"
#include "qg_dlginitial.h"
#include "rs_debug.h"
#include "rs_fontlist.h"
#include "rs_patternlist.h"
#include "rs_settings.h"
#include "rs_system.h"namespace{void restoreWindowGeometry(QC_ApplicationWindow& appWin, QSettings& settings);
// update splash for alpha/beta names)void updateSplash(const std::unique_ptr<QSplashScreen>& splash);
}
/*** Main. 创建应用程序窗口。*/// fixme - sand - refactor and split to several specialized functions
int main(int argc, char** argv){QT_REQUIRE_VERSION(argc, argv, "5.2.1"); //确保 LibreCAD 在 Qt 5.2.1 或更高版本上运行//检查前两个参数，以决定我们是要将librecad作为控制台dxf2pdf还是dxf2png工具运行。在Linux上，我们可以创建一个指向librecad可执行文件的链接，并将其命名为dxf2pdf。因此，我们可以运行以下任一操作：//librecad dxf2pdf[选项]...//或者只是：dxf2pdf[选项]...for (int i = 0; i < qMin(argc, 2); i++) {QString arg(argv[i]);if (i == 0) {arg = QFileInfo(QFile::decodeName(argv[i])).baseName();}if (arg.compare("dxf2pdf") == 0) {return console_dxf2pdf(argc, argv);}if (arg.compare("dxf2png") == 0 || arg == "dxf2svg") {return console_dxf2png(argc, argv);}}RS_DEBUG->setLevel(RS_Debug::D_WARNING);LC_Application app(argc, argv);QCoreApplication::setOrganizationName("LibreCAD");QCoreApplication::setApplicationName("LibreCAD");QCoreApplication::setApplicationVersion(XSTR(LC_VERSION));RS_Settings::init(app.organizationName(), app.applicationName());QGuiApplication::setDesktopFileName("librecad.desktop");QSettings settings; // fixme - direct invocation of settingsbool first_load = settings.value("Startup/FirstLoad", 1).toBool();const QString lpDebugSwitch0("-d"),lpDebugSwitch1("--debug") ;const QString help0("-h"), help1("--help");bool allowOptions=true;QList<int> argClean;for (int i=0; i<argc; i++){QString argstr(argv[i]);if(allowOptions&&QString::compare("--", argstr)==0){allowOptions=false;continue;}if (allowOptions && (help0.compare(argstr, Qt::CaseInsensitive)==0 ||help1.compare(argstr, Qt::CaseInsensitive)==0 )){qDebug()<<"Usage: librecad [command] <options> <dxf file>";qDebug()<<"";qDebug()<<"Commands:";qDebug()<<"";qDebug()<<"  dxf2pdf\tRun librecad as console dxf2pdf tool. Use -h for help.";qDebug()<<"  dxf2png\tRun librecad as console dxf2png tool. Use -h for help.";qDebug()<<"  dxf2svg\tRun librecad as console dxf2svg tool. Use -h for help.";qDebug()<<"";qDebug()<<"Options:";qDebug()<<"";qDebug()<<"  -h, --help\tdisplay this message";qDebug()<<"  -d, --debug <level>";qDebug()<<"";RS_DEBUG->print( RS_Debug::D_NOTHING, "possible debug levels:");RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Nothing", RS_Debug::D_NOTHING);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Critical", RS_Debug::D_CRITICAL);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Error", RS_Debug::D_ERROR);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Warning", RS_Debug::D_WARNING);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Notice", RS_Debug::D_NOTICE);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Informational", RS_Debug::D_INFORMATIONAL);RS_DEBUG->print( RS_Debug::D_NOTHING, "    %d Debugging", RS_Debug::D_DEBUGGING);exit(0);}if (allowOptions&& (argstr.startsWith(lpDebugSwitch0, Qt::CaseInsensitive) ||argstr.startsWith(lpDebugSwitch1, Qt::CaseInsensitive) )){argClean<<i;// to control the level of debugging output use --debug with level 0-6, e.g. --debug3// for a list of debug levels use --debug?// if no level follows, the debugging level is setargstr.remove(QRegularExpression("^"+lpDebugSwitch0));argstr.remove(QRegularExpression("^"+lpDebugSwitch1));char level;if(argstr.size()==0){if(i+1<argc){if(QRegularExpression(R"(\d*)").match(argv[i+1]).hasMatch()){++i;qDebug()<<"reading "<<argv[i]<<" as debugging level";level=argv[i][0];argClean<<i;} else {level = '3';}}else {level = '3'; //default to D_WARNING}}else {level = argstr.toStdString()[0];}switch(level){case '?' : {RS_DEBUG->print(RS_Debug::D_NOTHING, "possible debug levels:");RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Nothing", RS_Debug::D_NOTHING);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Critical", RS_Debug::D_CRITICAL);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Error", RS_Debug::D_ERROR);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Warning", RS_Debug::D_WARNING);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Notice", RS_Debug::D_NOTICE);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Informational", RS_Debug::D_INFORMATIONAL);RS_DEBUG->print(RS_Debug::D_NOTHING, "    %d Debugging", RS_Debug::D_DEBUGGING);return 0;}case '0' + RS_Debug::D_NOTHING : {RS_DEBUG->setLevel(RS_Debug::D_NOTHING);break;}case '0' + RS_Debug::D_CRITICAL : {RS_DEBUG->setLevel(RS_Debug::D_CRITICAL);break;}case '0' + RS_Debug::D_ERROR : {RS_DEBUG->setLevel(RS_Debug::D_ERROR);break;}case '0' + RS_Debug::D_WARNING : {RS_DEBUG->setLevel(RS_Debug::D_WARNING);break;}case '0' + RS_Debug::D_NOTICE : {RS_DEBUG->setLevel(RS_Debug::D_NOTICE);break;}case '0' + RS_Debug::D_INFORMATIONAL : {RS_DEBUG->setLevel(RS_Debug::D_INFORMATIONAL);break;}case '0' + RS_Debug::D_DEBUGGING : {RS_DEBUG->setLevel(RS_Debug::D_DEBUGGING);break;}default : {RS_DEBUG->setLevel(RS_Debug::D_DEBUGGING);break;}}}}RS_DEBUG->print("param 0: %s", argv[0]);QFileInfo prgInfo( QFile::decodeName(argv[0]) );QString prgDir(prgInfo.absolutePath());RS_SYSTEM->init(app.applicationName(), app.applicationVersion(), XSTR(QC_APPDIR), prgDir);// parse command line arguments that might not need a launched program:QStringList fileList = handleArgs(argc, argv, argClean);QString unit = settings.value("Defaults/Unit", "Invalid").toString();// show initial config dialog:if (first_load){RS_DEBUG->print("main: show initial config dialog..");QG_DlgInitial di(nullptr);QPixmap pxm(":/main/intro_librecad.png");di.setPixmap(pxm);if (di.exec()) {unit = LC_GET_ONE_STR("Defaults", "Unit", "None");}RS_DEBUG->print("main: show initial config dialog: OK");}auto splash = std::make_unique<QSplashScreen>();bool show_splash = settings.value("Startup/ShowSplash", 1).toBool();if (show_splash){updateSplash(splash);app.processEvents();RS_DEBUG->print("main: splashscreen: OK");}RS_DEBUG->print("main: init fontlist..");RS_FONTLIST->init();RS_DEBUG->print("main: init fontlist: OK");RS_DEBUG->print("main: init patternlist..");RS_PATTERNLIST->init();RS_DEBUG->print("main: init patternlist: OK");RS_DEBUG->print("main: loading translation..");settings.beginGroup("Appearance");QString lang = settings.value("Language", "en").toString();QString langCmd = settings.value("LanguageCmd", "en").toString();settings.endGroup();RS_SYSTEM->loadTranslation(lang, langCmd);RS_DEBUG->print("main: loading translation: OK");RS_DEBUG->print("main: creating main window..");QC_ApplicationWindow& appWin = *QC_ApplicationWindow::getAppWindow();
#ifdef Q_OS_MACapp.installEventFilter(&appWin);
#endifRS_DEBUG->print("main: setting caption");appWin.setWindowTitle(app.applicationName());RS_DEBUG->print("main: show main window");settings.beginGroup("Defaults");if( !settings.contains("UseQtFileOpenDialog")) {
#ifdef Q_OS_LINUX// on Linux don't use native file dialog// because of case insensitive filters (issue #791)settings.setValue("UseQtFileOpenDialog", QVariant(1));
#elsesettings.setValue("UseQtFileOpenDialog", QVariant(0));
#endif}settings.endGroup();if (!first_load) {restoreWindowGeometry(appWin, settings);}bool maximize = settings.value("Startup/Maximize", 0).toBool();if (maximize || first_load) {appWin.showMaximized();}else {appWin.show();}RS_DEBUG->print("main: set focus");appWin.setFocus();RS_DEBUG->print("main: creating main window: OK");if (show_splash){RS_DEBUG->print("main: updating splash");splash->raise();splash->showMessage(QObject::tr("Loading..."),Qt::AlignRight|Qt::AlignBottom, Qt::black);RS_DEBUG->print("main: processing events");qApp->processEvents();RS_DEBUG->print("main: updating splash: OK");}// Set LC_NUMERIC so that entering numeric values uses . as the decimal separatorsetlocale(LC_NUMERIC, "C");RS_DEBUG->print("main: loading files..");
#ifdef Q_OS_MAC// get the file list from LC_ApplicationfileList << app.fileList();
#endif// reopen files that we open during last close of application// we'll reopen them if no explicit files to open are provided in command linebool reopenLastFiles;QString lastFiles;QString activeFile;LC_GROUP("Startup");{reopenLastFiles = LC_GET_BOOL("OpenLastOpenedFiles");lastFiles = LC_GET_STR("LastOpenFilesList", "");activeFile = LC_GET_STR("LastOpenFilesActive", "");bool checkForNewVersion = LC_GET_BOOL("CheckForNewVersions", true);if (reopenLastFiles && fileList.isEmpty() && !lastFiles.isEmpty()) {foreach(const QString &filename, lastFiles.split(";")) {if (!filename.isEmpty() && QFileInfo::exists(filename))fileList << filename;}}bool files_loaded = false;for (QStringList::Iterator it = fileList.begin(); it != fileList.end(); ++it) {if (show_splash) {splash->showMessage(QObject::tr("Loading File %1..").arg(QDir::toNativeSeparators(*it)),Qt::AlignRight | Qt::AlignBottom, Qt::black);qApp->processEvents();}appWin.slotFileOpen(*it);files_loaded = true;}if (reopenLastFiles) {appWin.activateWindowWithFile(activeFile);}RS_DEBUG->print("main: loading files: OK");if (!files_loaded) {appWin.slotFileNewNew();}if (show_splash) {splash->finish(&appWin);splash.release();}if (checkForNewVersion) {appWin.checkForNewVersion();}}LC_GROUP_END();if (first_load)settings.setValue("Startup/FirstLoad", 0);RS_DEBUG->print("main: entering Qt event loop");QCoreApplication::processEvents();int return_code = app.exec();RS_DEBUG->print("main: exited Qt event loop");// Destroy the singletonQC_ApplicationWindow::getAppWindow().reset();return return_code;
}/*** Handles command line arguments that might not require a GUI.** @return list of files to load on startup.*/
QStringList handleArgs(int argc, char** argv, const QList<int>& argClean){RS_DEBUG->print("main: handling args..");QStringList ret;bool doexit = false;for (int i=1; i<argc; i++)    {if(argClean.indexOf(i)>=0) continue;if (!QString(argv[i]).startsWith("-")){QString fname = QDir::toNativeSeparators(QFileInfo(QFile::decodeName(argv[i])).absoluteFilePath());ret.append(fname);}else if (QString(argv[i])=="--exit"){doexit = true;}}if (doexit)    {exit(0);}RS_DEBUG->print("main: handling args: OK");return ret;
}QString LCReleaseLabel(){QString version{XSTR(LC_VERSION)};QString label;const std::map<QString, QString> labelMap = {{"rc", QObject::tr("Release Candidate")},{"beta", QObject::tr("BETA")},{"alpha", QObject::tr("ALPHA")}};for (const auto& [key, value]: labelMap) {if (version.contains(key, Qt::CaseInsensitive)) {label=value;break;}}return label;
}namespace {void restoreWindowGeometry(QC_ApplicationWindow& appWin, QSettings& settings){settings.beginGroup("Geometry");auto geometryB64 = settings.value("/WindowGeometry").toString().toUtf8();auto geometry = QByteArray::fromBase64(geometryB64, QByteArray::Base64Encoding);if (!geometry.isEmpty()) {appWin.restoreGeometry(geometry);} else {// fallbackint windowWidth = settings.value("WindowWidth", 1024).toInt();int windowHeight = settings.value("WindowHeight", 1024).toInt();int windowX = settings.value("WindowX", 32).toInt();int windowY = settings.value("WindowY", 32).toInt();appWin.resize(windowWidth, windowHeight);appWin.move(windowX, windowY);}settings.endGroup();}// Update Splash image to show "ALPHA", "BETA", and "Release Candidate"
QPixmap getSplashImage(const std::unique_ptr<QSplashScreen>& splash, const QString& label);
// Update Splash Screenvoid updateSplash(const std::unique_ptr<QSplashScreen>& splash){if (splash == nullptr)return;QString label = LCReleaseLabel();if (label.isEmpty())return;QPixmap splashImage = getSplashImage(splash, label);splash->setPixmap(splashImage);splash->setAttribute(Qt::WA_DeleteOnClose);splash->show();splash->showMessage(QObject::tr("Loading.."),Qt::AlignRight|Qt::AlignBottom, Qt::black);}// Update Splash image to show "ALPHA", "BETA", and "Release Candidate"QPixmap getSplashImage(const std::unique_ptr<QSplashScreen>& splash, const QString& label){if (splash == nullptr)return {};QPixmap pixmapSplash(":/main/splash_librecad.png");QPainter painter(&pixmapSplash);const double factorX = pixmapSplash.width()/542.;const double factorY = pixmapSplash.height()/337.;painter.setPen(QColor(255, 0, 0, 128));QRectF labelRect{QPointF{280.*factorX, 130.*factorY}, QPointF{480.*factorX, 170.*factorY}};QFont font;font.setPixelSize(int(labelRect.height()) - 2);painter.setFont(font);painter.drawText(labelRect,Qt::AlignRight, label);return pixmapSplash;}
}

二、代码介绍

1. Qt 版本检查

QT_REQUIRE_VERSION(argc, argv, "5.2.1");

确保应用程序运行在 Qt 5.2.1 或更高版本上。

2. 控制台模式检测

for (int i = 0; i < qMin(argc, 2); i++) {// 检查是否为 dxf2pdf/dxf2png 命令if (arg.compare("dxf2pdf") == 0) return console_dxf2pdf(...);if (arg.compare("dxf2png") == 0) return console_dxf2png(...);
}

检测是否以命令行工具模式运行，用于文件格式转换（如 PDF/PNG/SVG）。

3. 应用程序初始化

LC_Application app(argc, argv);
QCoreApplication::setOrganizationName("LibreCAD");
// ... 其他应用程序设置 ...
RS_Settings::init(...);

• 创建 Qt 应用程序对象。

• 设置组织和应用程序的元数据。

• 初始化持久化设置系统。

4. 命令行参数处理

QStringList fileList = handleArgs(argc, argv, argClean);

处理以下参数：

• 调试级别控制（-d/–debug）。
• 帮助信息输出（-h/–help）。
• 要打开的文件路径。
• 特殊命令（如 --exit）。

5. 首次运行配置

if (first_load) {QG_DlgInitial di(nullptr);// 显示初始配置对话框
}

• 如果是第一次运行，显示初始设置对话框。
• 设置默认单位和其他基本偏好。

6. 启动画面设置

auto splash = std::make_unique<QSplashScreen>();
updateSplash(splash); // 添加版本标签（如 ALPHA/BETA 等）

• 创建并自定义启动画面。
• 使用 getSplashImage() 添加版本标签。

7. 资源初始化

RS_FONTLIST->init();  // 字体
RS_PATTERNLIST->init(); // 图案
RS_SYSTEM->loadTranslation(...); // 本地化

• 加载 CAD 所需的资源。
• 设置多语言支持。

8. 主窗口创建

QC_ApplicationWindow& appWin = *QC_ApplicationWindow::getAppWindow();
restoreWindowGeometry(appWin, settings);

• 使用单例模式创建主应用程序窗口。
• 从设置中恢复窗口的几何状态。

9. 文件处理

// 如果配置了，重新打开上次的文件
if (reopenLastFiles) fileList = lastFiles.split(";"); // 加载命令行指定的文件
for (QString file : fileList) appWin.slotFileOpen(file);

• 处理命令行指定的文件以及“重新打开上次文件”的功能。
• 如果没有指定文件，则创建新文档。

10. 事件循环与清理

int return_code = app.exec();
// ... 清理 ...
return return_code;

• 启动 Qt 事件循环。
• 在退出时进行适当的清理。
• 在关闭时保存设置。

关键架构特性

1. 单例模式：用于主应用程序窗口（QC_ApplicationWindow::getAppWindow()）。
2. 工厂模式：用于字体和图案资源的初始化。
3. 命令分发：同时支持 GUI 和命令行模式。
4. 持久化：使用 QSettings 保存窗口几何状态和偏好设置。
5. 国际化：通过翻译文件支持多语言。

重要的辅助函数

1. handleArgs()：处理命令行参数。
2. restoreWindowGeometry()：从设置中恢复窗口状态。
3. updateSplash()：自定义启动画面，添加版本信息。
4. LCReleaseLabel()：确定版本类型（如 Alpha/Beta 等）。

总结

这段代码展示了一个成熟的 Qt 应用程序结构，具有清晰的职责分离：

• 初始化：应用程序和资源的初始化。
• 资源管理：字体、图案和本地化资源的加载。
• UI 设置：主窗口和启动画面的创建与配置。
• 命令行处理：支持命令行模式和文件加载。
  通过良好的架构设计和模块化实现，LibreCAD 的主程序能够高效地处理多种运行场景，并为用户提供一致的使用体验。