修复 加载应用程序信息时随机崩溃

这个问题就是因为在异步操作时直接修改GUI，导致事件发生时GUI与异步加载线程不同步导致程序崩溃。将所有加载操作已移至
SpkAppInfoLoaderThread，在其需要操作GUI时阻塞该工作线程并发射信号让主线程操作GUI，以解决该问题。

workerthreads.cpp

@@ -0,0 +1,152 @@
+
+#include <QProcess>
+#include <QDir>
+#include <QFile>
+#include <QJsonDocument>
+#include "workerthreads.h"
+#include "widget.h"
+
+void SpkAppInfoLoaderThread::run()
+{
+    emit requestResetUi();
+
+    QProcess get_json;
+    QString urladdress, deatils, more, packagename, appweb;
+    QDir dir("/tmp");
+    bool isInstalled;
+    dir.mkdir("spark-store");
+    QDir::setCurrent("/tmp/spark-store");
+
+    get_json.start("curl -o app.json " + targetUrl.toString());
+    if(waitDownload(get_json) == -1)
+        return;
+    if(get_json.exitCode())
+    {
+        Widget::sendNotification(tr("Failed to download app info. Please check internet connection."));
+    }
+
+    QFile app_json("app.json");
+    if(app_json.open(QIODevice::ReadOnly)){
+        // 成功得到json文件
+        QByteArray json_array = app_json.readAll();
+        // 将路径转化为相应源的下载路径
+        urladdress = targetUrl.toString().left(targetUrl.toString().length()-8);
+        QStringList downloadurl=urladdress.split("/");
+
+        QString deburl = serverUrl;
+        deburl = deburl.left(urladdress.length()-1);
+        urladdress = "https://cdn.jsdelivr.net/gh/Jerrywang959/jsonpng@master/"; // 使用图片专用服务器请保留这行，删除后将使用源服务器
+        urladdress = urladdress.left(urladdress.length()-1);
+
+        for (int i=3;i<downloadurl.size();i++) {
+            urladdress+="/"+downloadurl[i];
+            deburl+="/"+downloadurl[i];
+        }
+
+        // 路径转化完成
+        QJsonObject json= QJsonDocument::fromJson(json_array).object();
+        QString appName = json["Name"].toString();
+        QUrl fileUrl = deburl + json["Filename"].toString();
+
+        // 软件信息加载
+        QString details;
+        details = tr("PkgName: ") + json["Pkgname"].toString()+"\n";
+        details += tr("Version: ") + json["Version"].toString()+"\n";
+        if(json["Author"].toString() != "" && json["Author"].toString() != " "){
+            details += tr("Author: ") + json["Author"].toString() + "\n";
+        }
+
+        if(json["Website"].toString() != "" && json["Website"].toString() != " "){
+            details += tr("Official Site: ") + json["Website"].toString() + "\n";
+            //ui->pushButton_website->show(); move to setinfo slot
+            appweb=json["Website"].toString();
+        }
+        details+=tr("Contributor: ")+json["Contributor"].toString()+"\n";
+        details+=tr("Update Time: ")+json["Update"].toString()+"\n";
+        details+=tr("Installed Size: ")+json["Size"].toString()+"\n";
+        more = json["More"].toString();
+
+        QProcess isInstall;
+        packagename = json["Pkgname"].toString();
+        isInstall.start("dpkg -s "+json["Pkgname"].toString());
+        isInstall.waitForFinished();
+        int error=QString::fromStdString(isInstall.readAllStandardError().toStdString()).length();
+        if(error==0)
+            isInstalled = true;
+        else
+            isInstalled = false;
+
+        emit requestSetAppInformation(&appName, &details, &more, &appweb, &packagename, &fileUrl, isInstalled);
+
+        //tag加载
+        QString tags=json["Tags"].toString();
+        QStringList tagList=tags.split(";");
+        emit requestSetTags(&tagList);
+
+        // 图标加载
+        get_json.start("curl -o icon.png "+urladdress+"icon.png");
+        if(waitDownload(get_json) == -1)
+            return;
+        if(!get_json.exitCode()) {
+            QPixmap appicon("icon.png");
+            emit finishedIconLoad(&appicon);
+        }
+        else
+            Widget::sendNotification(tr("Failed to load application icon."));
+
+
+        // 截图展示加载
+        QPixmap screenshotCache[5];
+        for (int i = 0; i < 5; i++) {
+            QString cmd = "curl -o screen_"+QString::number(i+1)+".png "+urladdress+"screen_"+QString::number(i+1)+".png";
+            get_json.start(cmd);
+            if(waitDownload(get_json) == -1)
+                return;
+            bool s = screenshotCache[i].load(QString(TMP_PATH) + "/screen_"+QString::number(i+1)+".png");
+            if(s){
+                emit finishedScreenshotLoad(&screenshotCache[i], i);
+            }else{
+                emit finishedScreenshotLoad(nullptr, i);
+                QFile::remove("screen_"+QString::number(i+1)+".png");
+                break;
+            }
+        }
+        emit finishAllLoading();
+    }
+
+}
+
+void SpkAppInfoLoaderThread::setUrl(const QUrl &url)
+{
+    targetUrl = url;
+}
+
+void SpkAppInfoLoaderThread::setServer(const QString &server)
+{
+    serverUrl = server;
+}
+
+void SpkAppInfoLoaderThread::downloadFinished(int exitcode, QProcess::ExitStatus status)
+{
+    Q_UNUSED(exitcode);
+    Q_UNUSED(status);
+    qDebug() << "Finish one download";
+    finishedDownload = true;
+}
+
+int SpkAppInfoLoaderThread::waitDownload(QProcess& downloader)
+{
+    while(!downloader.waitForFinished(100))
+    {
+        if(downloader.state() == QProcess::NotRunning)
+            return -1;
+        if(this->isInterruptionRequested())
+        {
+            downloader.terminate();
+            downloader.waitForFinished(-1);
+            qDebug() << "Appinfo loader thread was forcefully terminated";
+            return -1;
+        }
+    }
+    return 0;
+}