export: call tool process asynchronously

src/dialog/vexportdialog.cpp

@@ -133,6 +133,8 @@ void VExportDialog::setupUI()
                 if (m_inExport) {
                     // Just cancel the export. Do not exit.
                     m_askedToStop = true;
+                    m_exporter->setAskedToStop(true);
+                    appendLogLine(tr("Cancelling the export..."));
                 } else {
                     QDialog::reject();
                 }
@@ -489,6 +491,7 @@ void VExportDialog::startExport()
     m_exportBtn->setEnabled(false);
     m_proBar->show();
     m_askedToStop = false;
+    m_exporter->setAskedToStop(false);
     m_inExport = true;
 
     QString outputFolder = QDir::cleanPath(QDir(getOutputDirectory()).absolutePath());
@@ -579,6 +582,11 @@ void VExportDialog::startExport()
 
         s_opt.m_format = ExportFormat::OnePDF;
 
+        if (m_askedToStop) {
+            ret = 0;
+            goto exit;
+        }
+
         Q_ASSERT(ret == files.size());
         if (!files.isEmpty()) {
             ret = doExportPDFAllInOne(files, s_opt, outputFolder, &msg);
@@ -611,6 +619,7 @@ exit:
     if (m_askedToStop) {
         appendLogLine(tr("User cancelled the export. Aborted!"));
         m_askedToStop = false;
+        m_exporter->setAskedToStop(false);
     }
 
     if (!msg.isEmpty()) {

src/vexporter.cpp

@@ -7,6 +7,8 @@
 #include <QRegExp>
 #include <QProcess>
 #include <QTemporaryDir>
+#include <QScopedPointer>
+#include <QCoreApplication>
 
 #include "vconfigmanager.h"
 #include "vfile.h"
@@ -25,7 +27,8 @@ extern VWebUtils *g_webUtils;
 VExporter::VExporter(QWidget *p_parent)
     : QObject(p_parent),
       m_webViewer(NULL),
-      m_state(ExportState::Idle)
+      m_state(ExportState::Idle),
+      m_askedToStop(false)
 {
 }
 
@@ -666,8 +669,12 @@ bool VExporter::htmlsToPDFViaWK(const QList<QString> &p_htmlFiles,
     QString cmd = p_opt.m_wkPath + " " + combineArgs(args);
     emit outputLog(cmd);
     qDebug() << "wkhtmltopdf cmd:" << cmd;
-    int ret = QProcess::execute(p_opt.m_wkPath, args);
+    int ret = startProcess(p_opt.m_wkPath, args);
     qDebug() << "wkhtmltopdf returned" << ret;
+    if (m_askedToStop) {
+        return ret == 0;
+    }
+
     switch (ret) {
     case -2:
         VUtils::addErrMsg(p_errMsg, tr("Fail to start wkhtmltopdf (%1).").arg(cmd));
@@ -695,3 +702,77 @@ int VExporter::exportPDFInOne(const QList<QString> &p_htmlFiles,
 
     return p_htmlFiles.size();
 }
+
+int VExporter::startProcess(const QString &p_program, const QStringList &p_args)
+{
+    int ret = 0;
+    QScopedPointer<QProcess> process(new QProcess(this));
+    process->start(p_program, p_args);
+    bool finished = false;
+    bool started = false;
+    while (true) {
+        QProcess::ProcessError err = process->error();
+        if (err == QProcess::FailedToStart
+            || err == QProcess::Crashed) {
+            emit outputLog(tr("QProcess error %1.").arg(err));
+            if (err == QProcess::FailedToStart) {
+                ret = -2;
+            } else {
+                ret = -1;
+            }
+
+            break;
+        }
+
+        if (started) {
+            if (process->state() == QProcess::NotRunning) {
+                finished = true;
+            }
+        } else {
+            if (process->state() != QProcess::NotRunning) {
+                started = true;
+            }
+        }
+
+        if (process->waitForFinished(500)) {
+            // Finished.
+            finished = true;
+        }
+
+        QByteArray outBa = process->readAllStandardOutput();
+        QByteArray errBa = process->readAllStandardError();
+        QString msg;
+        if (!outBa.isEmpty()) {
+            msg += QString::fromLocal8Bit(outBa);
+        }
+
+        if (!errBa.isEmpty()) {
+            msg += QString::fromLocal8Bit(errBa);
+        }
+
+        if (!msg.isEmpty()) {
+            emit outputLog(msg);
+        }
+
+        if (finished) {
+            QProcess::ExitStatus sta = process->exitStatus();
+            if (sta == QProcess::CrashExit) {
+                ret = -1;
+                break;
+            }
+
+            ret = process->exitCode();
+            break;
+        }
+
+        QCoreApplication::processEvents();
+
+        if (m_askedToStop) {
+            process->kill();
+            ret = -1;
+            break;
+        }
+    }
+
+    return ret;
+}

src/vexporter.h

@@ -36,6 +36,8 @@ public:
                        const QString &p_outputFile,
                        QString *p_errMsg = NULL);
 
+    void setAskedToStop(bool p_askedToStop);
+
 signals:
     // Request to output log.
     void outputLog(const QString &p_log);
@@ -107,6 +109,8 @@ private:
 
     void prepareWKArguments(const ExportPDFOption &p_opt);
 
+    int startProcess(const QString &p_program, const QStringList &p_args);
+
     // Fix @p_html's resources like url("...") with "file" or "qrc" schema.
     // Copy the resource to @p_folder and fix the url string.
     static bool fixStyleResources(const QString &p_folder,
@@ -144,6 +148,8 @@ private:
 
     // Arguments for wkhtmltopdf.
     QStringList m_wkArgs;
+
+    bool m_askedToStop;
 };
 
 inline void VExporter::clearNoteState()
@@ -161,4 +167,8 @@ inline bool VExporter::isNoteStateFailed() const
     return m_noteState & NoteState::Failed;
 }
 
+inline void VExporter::setAskedToStop(bool p_askedToStop)
+{
+    m_askedToStop = p_askedToStop;
+}
 #endif // VEXPORTER_H