Polish the Qt plugin wizard

- Add overrides for pure virtual base class functions
- Modernize C++ in the generated code
- Do not build into the Qt installation directory by default
- Rename misleading "Qt4Plugin" enum
- Remove Qt 4 compatibility code
- Remove some excess newlines

Fixes: QTCREATORBUG-21207
Change-Id: I50641eddf9084ef3eb8199684aec639c5e5d71fc
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/qmakeprojectmanager/wizards/libraryparameters.cpp

@@ -27,6 +27,7 @@
 #include "librarywizarddialog.h"
 
 #include <utils/codegeneration.h>
+#include <utils/qtcassert.h>
 
 #include <QTextStream>
 #include <QStringList>
@@ -35,7 +36,6 @@ namespace QmakeProjectManager {
 namespace Internal {
 
 void LibraryParameters::generateCode(QtProjectParameters:: Type t,
-                                     const QString &projectTarget,
                                      const QString &headerName,
                                      const QString &sharedHeader,
                                      const QString &exportMacro,
@@ -75,7 +75,9 @@ void LibraryParameters::generateCode(QtProjectParameters:: Type t,
     const QString namespaceIndent = Utils::writeOpeningNameSpaces(namespaceList, indent, headerStr);
 
     // Class declaraction
-    headerStr << '\n' << namespaceIndent << "class ";
+    if (!namespaceIndent.isEmpty())
+        headerStr << '\n';
+    headerStr << namespaceIndent << "class ";
     if (t == QtProjectParameters::SharedLibrary && !exportMacro.isEmpty())
         headerStr << exportMacro << ' ';
 
@@ -85,30 +87,37 @@ void LibraryParameters::generateCode(QtProjectParameters:: Type t,
     headerStr << "\n{\n";
 
     // Is this a QObject (plugin)
-    const bool inheritsQObject = t == QtProjectParameters::Qt4Plugin;
+    const bool inheritsQObject = t == QtProjectParameters::QtPlugin;
     if (inheritsQObject)
         headerStr << namespaceIndent << indent << "Q_OBJECT\n";
-    if (t == QtProjectParameters::Qt4Plugin) { // Write Qt 5 plugin meta data.
+    if (t == QtProjectParameters::QtPlugin) { // Write Qt plugin meta data.
         const QString qt5InterfaceName = LibraryWizardDialog::pluginInterface(baseClassName);
-        if (!qt5InterfaceName.isEmpty()) {
+        QTC_CHECK(!qt5InterfaceName.isEmpty());
-            headerStr << "#if QT_VERSION >= 0x050000\n"
+        headerStr << namespaceIndent << indent << "Q_PLUGIN_METADATA(IID \""
-                      << namespaceIndent << indent << "Q_PLUGIN_METADATA(IID \""
+                  << qt5InterfaceName << '"';
-                      << qt5InterfaceName << '"';
+        QTC_CHECK(!pluginJsonFileName.isEmpty());
-            if (!pluginJsonFileName.isEmpty())
+        headerStr << " FILE \"" << pluginJsonFileName << '"';
-                headerStr << " FILE \"" << pluginJsonFileName << '"';
+        headerStr << ")\n";
-            headerStr << ")\n#endif // QT_VERSION >= 0x050000\n";
-        }
     }
 
     headerStr << namespaceIndent << "\npublic:\n";
-    if (inheritsQObject)
+    if (inheritsQObject) {
-        headerStr << namespaceIndent << indent << unqualifiedClassName << "(QObject *parent = 0);\n";
+        headerStr << namespaceIndent << indent << "explicit " << unqualifiedClassName
-    else
+                  << "(QObject *parent = nullptr);\n";
+    } else {
         headerStr << namespaceIndent << indent << unqualifiedClassName << "();\n";
-    headerStr << namespaceIndent << "};\n\n";
+    }
+    if (!pureVirtualSignatures.empty()) {
+        headerStr << "\nprivate:\n";
+        for (const QString &signature : pureVirtualSignatures)
+            headerStr << namespaceIndent << indent << signature << " override;\n";
+    }
+    headerStr << namespaceIndent << "};\n";
+    if (!namespaceIndent.isEmpty())
+        headerStr << '\n';
     Utils::writeClosingNameSpaces(namespaceList, indent, headerStr);
     if (!usePragmaOnce)
-        headerStr <<  "#endif // " << guard << '\n';
+        headerStr <<  "\n#endif // " << guard << '\n';
 
     /// 2) Source
     QTextStream sourceStr(source);
@@ -117,8 +126,11 @@ void LibraryParameters::generateCode(QtProjectParameters:: Type t,
     sourceStr << '\n';
 
     Utils::writeOpeningNameSpaces(namespaceList, indent, sourceStr);
+    if (!namespaceIndent.isEmpty())
+        sourceStr << '\n';
+
     // Constructor
-    sourceStr << '\n' << namespaceIndent << unqualifiedClassName << "::" << unqualifiedClassName;
+    sourceStr << namespaceIndent << unqualifiedClassName << "::" << unqualifiedClassName;
     if (inheritsQObject) {
          sourceStr << "(QObject *parent) :\n"
                    << namespaceIndent << indent << baseClassName << "(parent)\n";
@@ -126,14 +138,26 @@ void LibraryParameters::generateCode(QtProjectParameters:: Type t,
         sourceStr << "()\n";
     }
     sourceStr << namespaceIndent << "{\n" << namespaceIndent <<  "}\n";
+    for (const QString &signature : pureVirtualSignatures) {
+        const int parenIndex = signature.indexOf('(');
+        QTC_ASSERT(parenIndex != -1, continue);
+        int nameIndex = -1;
+        for (int i = parenIndex - 1; i > 0; --i) {
+            if (!signature.at(i).isLetterOrNumber()) {
+                nameIndex = i + 1;
+                break;
+            }
+        }
+        QTC_ASSERT(nameIndex != -1, continue);
+        sourceStr << '\n' << namespaceIndent << signature.left(nameIndex);
+        if (signature.at(nameIndex - 1) != ' ')
+            sourceStr << ' ';
+        sourceStr << unqualifiedClassName << "::" << signature.mid(nameIndex) << '\n';
+        sourceStr << namespaceIndent << "{\n" << indent
+                  << "static_assert(false, \"You need to implement this function\");\n}\n";
+    }
 
     Utils::writeClosingNameSpaces(namespaceList, indent, sourceStr);
-
-    if (t == QtProjectParameters::Qt4Plugin) { // Qt 4 plugin export
-        sourceStr << "\n#if QT_VERSION < 0x050000\n"
-                  << "Q_EXPORT_PLUGIN2(" << projectTarget << ", " << className << ")\n"
-                  << "#endif // QT_VERSION < 0x050000\n";
-    }
 }
 
 QString  LibraryParameters::generateSharedHeader(const QString &globalHeaderFileName,

src/plugins/qmakeprojectmanager/wizards/libraryparameters.h

@@ -27,7 +27,7 @@
 
 #include "qtprojectparameters.h"
 
-#include <QString>
+#include <QStringList>
 
 namespace QmakeProjectManager {
 namespace Internal {
@@ -38,7 +38,6 @@ struct LibraryParameters {
 
     // generate class
     void generateCode(QtProjectParameters:: Type t,
-                      const QString &projectTarget,
                       const QString &headerName,
                       const QString &sharedHeader,
                       const QString &exportMacro,
@@ -58,6 +57,7 @@ struct LibraryParameters {
     QString baseClassName;
     QString sourceFileName;
     QString headerFileName;
+    QStringList pureVirtualSignatures;
 };
 
 } // namespace Internal

src/plugins/qmakeprojectmanager/wizards/librarywizard.cpp

@@ -63,12 +63,15 @@ Core::BaseFileWizard *LibraryWizard::create(QWidget *parent, const Core::WizardD
     return dialog;
 }
 
-static void writeLinuxProFile(QTextStream &str)
+static void writeLinuxProFile(QTextStream &str, const QtProjectParameters &params)
 {
     str << "\n"
-           "unix {\n"
+           "unix {\n";
-           "    target.path = /usr/lib\n"
+    if (!params.targetDirectory.isEmpty())
-           "    INSTALLS += target\n"
+        str << "    target.path = " << params.targetDirectory << '\n';
+    else
+        str << "    target.path = /usr/lib\n";
+    str << "    INSTALLS += target\n"
            "}\n";
 }
 
@@ -94,7 +97,7 @@ Core::GeneratedFiles LibraryWizard::generateFiles(const QWizard *w,
     const QString headerFileName = Utils::FileName::fromString(headerFileFullName).fileName();
     QString pluginJsonFileFullName;
     QString pluginJsonFileName;
-    if (projectParams.type == QtProjectParameters::Qt4Plugin) {
+    if (projectParams.type == QtProjectParameters::QtPlugin) {
         pluginJsonFileFullName = buildFileName(projectPath, projectParams.fileName, QLatin1String("json"));
         pluginJsonFileName = Utils::FileName::fromString(pluginJsonFileFullName).fileName();
     }
@@ -114,7 +117,7 @@ Core::GeneratedFiles LibraryWizard::generateFiles(const QWizard *w,
 
     // Generate code
     QString headerContents, sourceContents;
-    params.generateCode(projectParams.type, projectParams.fileName,  headerFileName,
+    params.generateCode(projectParams.type, headerFileName,
                         globalHeaderFileName, sharedLibExportMacro, pluginJsonFileName,
                         /* indentation*/ 4, usePragmaOnce, &headerContents, &sourceContents);
 
@@ -141,7 +144,7 @@ Core::GeneratedFiles LibraryWizard::generateFiles(const QWizard *w,
             proStr << " \\\n        " << globalHeaderFileName << " \n";
         if (!pluginJsonFileName.isEmpty())
             proStr << "\nDISTFILES += " << pluginJsonFileName << " \n";
-        writeLinuxProFile(proStr);
+        writeLinuxProFile(proStr, projectParams);
     }
     profile.setContents(profileContents);
     rc.push_back(profile);

src/plugins/qmakeprojectmanager/wizards/librarywizarddialog.cpp

@@ -44,27 +44,38 @@ namespace Internal {
 struct PluginBaseClasses {
     const char *name;
     const char *module;
+    QStringList pureVirtuals;
+
     // blank separated list or 0
     const char *dependentModules;
     const char *targetDirectory;
     const char *pluginInterface;
 };
+using QSL = QStringList;
 
 static const PluginBaseClasses pluginBaseClasses[] =
 {
-    {"QAccessiblePlugin", "QtGui", "QtCore", "accessible", "QAccessibleFactoryInterface"},
+    {"QAccessiblePlugin", "QtGui",
-    {"QDecorationPlugin", "QtGui", "QtCore", nullptr, nullptr}, // Qt 4 only.
+     QSL{"QAccessibleInterface * create(const QString &key, QObject *object)"},
-    {"QGenericPlugin", "QtGui", "QtCore", "generic", "QGenericPluginFactoryInterface"},
+     "QtCore", "accessible", "QAccessibleFactoryInterface"},
-    {"QIconEnginePluginV2", "QtGui", "QtCore", "imageformats", nullptr}, // Qt 4 only.
+    {"QGenericPlugin", "QtGui", QSL{"QObject *create(const QString &name, const QString &spec)"},
-    {"QIconEnginePlugin", "QtGui", "QtCore", "imageformats", "QIconEngineFactoryInterface"},
+     "QtCore", "generic", "QGenericPluginFactoryInterface"},
-    {"QImageIOPlugin", "QtGui", "QtCore", "imageformats",  "QImageIOHandlerFactoryInterface"},
+    {"QIconEnginePlugin", "QtGui", QSL{"QIconEngine *create(const QString &filename)"},
-    {"QScriptExtensionPlugin", "QtScript", "QtCore", nullptr, "QScriptExtensionInterface"},
+     "QtCore", "imageformats", "QIconEngineFactoryInterface"},
-    {"QSqlDriverPlugin", "QtSql", "QtCore", "sqldrivers", "QSqlDriverFactoryInterface"},
+    {"QImageIOPlugin", "QtGui",
-    {"QStylePlugin", "QtGui", "QtCore", "styles", "QStyleFactoryInterface"},
+     QSL{"QImageIOPlugin::Capabilities capabilities(QIODevice *device, const QByteArray &format) const",
-    {"QTextCodecPlugin", "QtCore", nullptr, "codecs", nullptr} // Qt 4 only.
+          "QImageIOHandler *create(QIODevice *device, const QByteArray &format) const"},
+     "QtCore", "imageformats",  "QImageIOHandlerFactoryInterface"},
+    {"QScriptExtensionPlugin", "QtScript",
+     QSL{"void initialize(const QString &key, QScriptEngine *engine)", "QStringList keys() const"},
+     "QtCore", nullptr, "QScriptExtensionInterface"},
+    {"QSqlDriverPlugin", "QtSql", QSL{"QSqlDriver *create(const QString &key)"},
+     "QtCore", "sqldrivers", "QSqlDriverFactoryInterface"},
+    {"QStylePlugin", "QtWidgets", QSL{"QStyle *create(const QString &key)"},
+     "QtCore", "styles", "QStyleFactoryInterface"},
 };
 
-enum { defaultPluginBaseClass = 2 };
+enum { defaultPluginBaseClass = 1 };
 
 static const PluginBaseClasses *findPluginBaseClass(const QString &name)
 {
@@ -114,7 +125,7 @@ LibraryIntroPage::LibraryIntroPage(QWidget *parent) :
     m_typeCombo->addItem(LibraryWizardDialog::tr("Statically Linked Library"),
                          QVariant(QtProjectParameters::StaticLibrary));
     m_typeCombo->addItem(LibraryWizardDialog::tr("Qt Plugin"),
-                         QVariant(QtProjectParameters::Qt4Plugin));
+                         QVariant(QtProjectParameters::QtPlugin));
     insertControl(0, new QLabel(LibraryWizardDialog::tr("Type")), m_typeCombo);
 }
 
@@ -197,7 +208,7 @@ bool LibraryWizardDialog::isModulesPageSkipped() const
 {
     // When leaving the intro or target page, the modules page is skipped
     // in the case of a plugin since it knows its dependencies by itself.
-    return type() == QtProjectParameters::Qt4Plugin;
+    return type() == QtProjectParameters::QtPlugin;
 }
 
 int LibraryWizardDialog::skipModulesPageIfNeeded() const
@@ -249,7 +260,7 @@ QtProjectParameters LibraryWizardDialog::parameters() const
     rc.type = type();
     rc.fileName = projectName();
     rc.path = path();
-    if (rc.type == QtProjectParameters::Qt4Plugin) {
+    if (rc.type == QtProjectParameters::QtPlugin) {
         // Plugin: Dependencies & Target directory
         if (const PluginBaseClasses *plb = findPluginBaseClass(m_filesPage->baseClassName())) {
             rc.selectedModules = pluginDependencies(plb);
@@ -277,7 +288,7 @@ void LibraryWizardDialog::slotCurrentIdChanged(int id)
 void LibraryWizardDialog::setupFilesPage()
 {
     switch (type()) {
-    case QtProjectParameters::Qt4Plugin:
+    case QtProjectParameters::QtPlugin:
         if (!m_pluginBaseClassesInitialized) {
             if (debugLibWizard)
                 qDebug("initializing for plugins");
@@ -309,8 +320,15 @@ LibraryParameters LibraryWizardDialog::libraryParameters() const
 {
     LibraryParameters rc;
     rc.className = m_filesPage->className();
-    rc.baseClassName = type() == QtProjectParameters::Qt4Plugin ?
+    if (type() == QtProjectParameters::QtPlugin)  {
-                       m_filesPage->baseClassName() : QString();
+        rc.baseClassName = m_filesPage->baseClassName();
+        for (const PluginBaseClasses &c : pluginBaseClasses) {
+            if (QLatin1String(c.name) == rc.baseClassName) {
+                rc.pureVirtualSignatures = c.pureVirtuals;
+                break;
+            }
+        }
+    }
     rc.sourceFileName = m_filesPage->sourceFileName();
     rc.headerFileName = m_filesPage->headerFileName();
     return rc;

src/plugins/qmakeprojectmanager/wizards/qtprojectparameters.cpp

@@ -100,14 +100,14 @@ void QtProjectParameters::writeProFile(QTextStream &str) const
     case SharedLibrary:
         str << "TEMPLATE = lib\n\nDEFINES += " << libraryMacro(fileName) << '\n';
         break;
-    case Qt4Plugin:
+    case QtPlugin:
         str << "TEMPLATE = lib\nCONFIG += plugin\n";
         break;
     default:
         break;
     }
 
-    if (!targetDirectory.isEmpty())
+    if (!targetDirectory.isEmpty() && !targetDirectory.contains("QT_INSTALL_"))
         str << "\nDESTDIR = " << targetDirectory << '\n';
 
     if (qtVersionSupport != SupportQt4Only) {

src/plugins/qmakeprojectmanager/wizards/qtprojectparameters.h

@@ -42,7 +42,7 @@ QString createMacro(const QString &name, const QString &suffix);
 // write a .pro-file section.
 
 struct QtProjectParameters {
-    enum Type { ConsoleApp, GuiApp, StaticLibrary, SharedLibrary, Qt4Plugin, EmptyProject };
+    enum Type { ConsoleApp, GuiApp, StaticLibrary, SharedLibrary, QtPlugin, EmptyProject };
     enum QtVersionSupport { SupportQt4And5, SupportQt4Only, SupportQt5Only };
     enum Flags { WidgetsRequiredFlag = 0x1 };