plugin-support: make header-only, expose as public API

Issue: #151

Some global namespace macros are now prefixed with "OPENTRACK_" to avoid
namespace clashes.

This header is now safe to include in third-party projects.

1 files changed, 247 insertions, 0 deletions

diff --git a/opentrack/plugin-support.hpp b/opentrack/plugin-support.hpp
new file mode 100644
index 00000000..bc07c106
--- /dev/null
+++ b/opentrack/plugin-support.hpp
@@ -0,0 +1,247 @@
+#pragma once
+
+/* Copyright (c) 2015 Stanislaw Halik
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#include "plugin-api.hpp"
+#include "options.hpp"
+
+#include <QWidget>
+#include <QDebug>
+#include <QString>
+#include <QLibrary>
+#include <QFrame>
+#include <QList>
+
+#include <cstdio>
+#include <cinttypes>
+#include <iostream>
+
+#include <QCoreApplication>
+#include <QFile>
+#include <QDir>
+#include <QList>
+#include <QStringList>
+
+#ifndef _WIN32
+#   include <dlfcn.h>
+#endif
+
+#if defined(__APPLE__)
+#   define OPENTRACK_SONAME "dylib"
+#elif defined(_WIN32)
+#   define OPENTRACK_SONAME "dll"
+#else
+#   define OPENTRACK_SONAME "so"
+#endif
+
+#include <iostream>
+
+#ifdef _MSC_VER
+#   error "No support for MSVC anymore"
+#else
+#   define OPENTRACK_LIB_PREFIX "lib"
+#endif
+
+
+extern "C" typedef void* (*OPENTRACK_CTOR_FUNPTR)(void);
+extern "C" typedef Metadata* (*OPENTRACK_METADATA_FUNPTR)(void);
+
+struct dylib {
+    enum Type { Filter, Tracker, Protocol };
+    
+    dylib(const QString& filename, Type t) :
+        type(t),
+        filename(filename),
+        Dialog(nullptr),
+        Constructor(nullptr),
+        Meta(nullptr),
+        handle(nullptr)
+    {
+        // otherwise dlopen opens the calling executable
+        if (filename.size() == 0)
+            return;
+    
+#if defined(_WIN32)
+        QString fullPath = QCoreApplication::applicationDirPath() + "/" + this->filename;
+        handle = new QLibrary(fullPath);
+    
+        struct _foo {
+            static bool die(QLibrary*& l, bool failp)
+            {
+                if (failp)
+                {
+                    qDebug() << "failed" << l->errorString();
+                    delete l;
+                    l = nullptr;
+                }
+                return failp;
+            }
+        };
+    
+        if (_foo::die(handle, !handle->load()))
+            return;
+    
+        Dialog = (OPENTRACK_CTOR_FUNPTR) handle->resolve("GetDialog");
+        if (_foo::die(handle, !Dialog))
+            return;
+    
+        Constructor = (OPENTRACK_CTOR_FUNPTR) handle->resolve("GetConstructor");
+        if (_foo::die(handle, !Constructor))
+            return;
+    
+        Meta = (OPENTRACK_METADATA_FUNPTR) handle->resolve("GetMetadata");
+        if (_foo::die(handle, !Meta))
+            return;
+#else
+        QByteArray latin1 = QFile::encodeName(filename);
+        handle = dlopen(latin1.constData(),
+#   if defined(__APPLE__)
+                    RTLD_LOCAL|RTLD_FIRST|RTLD_NOW
+#   else
+                    RTLD_NOW|RTLD_GLOBAL|RTLD_NODELETE
+#   endif
+                        );
+    
+        struct _foo {
+            static bool err(void*& handle)
+            {
+                const char* err = dlerror();
+                if (err)
+                {
+                    fprintf(stderr, "Error, ignoring: %s\n", err);
+                    fflush(stderr);
+                    dlclose(handle);
+                    handle = nullptr;
+                    return true;
+                }
+                return false;
+            }
+        };
+    
+        if (handle)
+        {
+            if (_foo::err(handle))
+                return;
+            Dialog = (OPENTRACK_CTOR_FUNPTR) dlsym(handle, "GetDialog");
+            if (_foo::err(handle))
+                return;
+            Constructor = (OPENTRACK_CTOR_FUNPTR) dlsym(handle, "GetConstructor");
+            if (_foo::err(handle))
+                return;
+            Meta = (OPENTRACK_METADATA_FUNPTR) dlsym(handle, "GetMetadata");
+            if (_foo::err(handle))
+                return;
+        } else {
+            (void) _foo::err(handle);
+        }
+#endif
+    
+        auto m = mem<Metadata>(Meta());
+    
+        icon = m->icon();
+        name = m->name();
+    }
+    ~dylib()
+    {
+#if defined(_WIN32)
+        if (handle)
+            delete handle;
+#else
+        if (handle)
+            (void) dlclose(handle);
+#endif
+    }
+    
+    static QList<mem<dylib>> enum_libraries()
+    {
+        const char* filters_n[] = { "opentrack-filter-*.",
+                                    "opentrack-tracker-*.",
+                                    "opentrack-proto-*."
+                                  };
+        const Type filters_t[] = { Filter, Tracker, Protocol };
+    
+        QDir settingsDir( QCoreApplication::applicationDirPath() );
+    
+        QList<mem<dylib>> ret;
+    
+        for (int i = 0; i < 3; i++)
+        {
+            QString filter = filters_n[i];
+            auto t = filters_t[i];
+            QStringList filenames = settingsDir.entryList(QStringList { OPENTRACK_LIB_PREFIX + filter + OPENTRACK_SONAME },
+                                                          QDir::Files,
+                                                          QDir::Name);
+            for (int i = 0; i < filenames.size(); i++) {
+                QIcon icon;
+                QString longName;
+                QString str = filenames.at(i);
+                auto lib = std::make_shared<dylib>(str, t);
+                qDebug() << "Loading" << str;
+                std::cout.flush();
+                if (!get_metadata(lib, longName, icon))
+                    continue;
+                ret.push_back(lib);
+            }
+        }
+    
+        return ret;
+    }
+    
+    Type type;
+    QString filename;
+    
+    QIcon icon;
+    QString name;
+    
+    OPENTRACK_CTOR_FUNPTR Dialog;
+    OPENTRACK_CTOR_FUNPTR Constructor;
+    OPENTRACK_METADATA_FUNPTR Meta;
+private:
+#if defined(_WIN32)
+    QLibrary* handle;
+#else
+    void* handle;
+#endif
+    
+    static bool get_metadata(mem<dylib> lib, QString& name, QIcon& icon)
+    {
+        Metadata* meta;
+        if (!lib->Meta || ((meta = lib->Meta()), !meta))
+            return false;
+        name = meta->name();
+        icon = meta->icon();
+        delete meta;
+        return true;
+    }
+};
+
+struct Modules {
+    Modules() :
+        module_list(dylib::enum_libraries()),
+        filter_modules(filter(dylib::Filter)),
+        tracker_modules(filter(dylib::Tracker)),
+        protocol_modules(filter(dylib::Protocol))
+    {}
+    QList<mem<dylib>>& filters() { return filter_modules; }
+    QList<mem<dylib>>& trackers() { return tracker_modules; }
+    QList<mem<dylib>>& protocols() { return protocol_modules; }
+private:
+    QList<mem<dylib>> module_list;
+    QList<mem<dylib>> filter_modules;
+    QList<mem<dylib>> tracker_modules;
+    QList<mem<dylib>> protocol_modules;
+    
+    QList<mem<dylib>> filter(dylib::Type t)
+    {
+        QList<mem<dylib>> ret;
+        for (auto x : module_list)
+            if (x->type == t)
+                ret.push_back(x);
+        return ret;
+    }
+};