Progress bar for windows taskbar button

PdfForQtLib/PdfForQtLib.pro

@@ -46,6 +46,7 @@ SOURCES += \
     sources/pdfdocument.cpp \
     sources/pdfdocumentreader.cpp \
     sources/pdfpattern.cpp \
+    sources/pdfprogress.cpp \
     sources/pdfsecurityhandler.cpp \
     sources/pdfutils.cpp \
     sources/pdfxreftable.cpp \
@@ -80,6 +81,7 @@ HEADERS += \
     sources/pdfdocument.h \
     sources/pdfdocumentreader.h \
     sources/pdfpattern.h \
+    sources/pdfprogress.h \
     sources/pdfsecurityhandler.h \
     sources/pdfxreftable.h \
     sources/pdfflatmap.h \

PdfForQtLib/sources/pdfdocumentreader.cpp

@@ -33,9 +33,10 @@
 namespace pdf
 {
 
-PDFDocumentReader::PDFDocumentReader(const std::function<QString(bool*)>& getPasswordCallback) :
+PDFDocumentReader::PDFDocumentReader(PDFProgress* progress, const std::function<QString(bool*)>& getPasswordCallback) :
     m_result(Result::OK),
-    m_getPasswordCallback(getPasswordCallback)
+    m_getPasswordCallback(getPasswordCallback),
+    m_progress(progress)
 {
 
 }
@@ -253,6 +254,8 @@ PDFDocument PDFDocumentReader::readFromBuffer(const QByteArray& buffer)
                     PDFParsingContext context(objectFetcher);
                     PDFObject object = getObject(&context, entry.offset, entry.reference);
 
+                    progressStep();
+
                     QMutexLocker lock(&m_mutex);
                     objects[entry.reference.objectNumber] = PDFObjectStorage::Entry(entry.reference.generation, object);
                 }
@@ -266,7 +269,9 @@ PDFDocument PDFDocumentReader::readFromBuffer(const QByteArray& buffer)
         };
 
         // Now, we are ready to scan all objects
+        progressStart(occupiedEntries.size());
         std::for_each(std::execution::parallel_policy(), occupiedEntries.cbegin(), occupiedEntries.cend(), processEntry);
+        progressFinish();
 
         if (m_result != Result::OK)
         {
@@ -351,8 +356,10 @@ PDFDocument PDFDocumentReader::readFromBuffer(const QByteArray& buffer)
         // decipher object streams here. 4) must be handled in the security handler.
         if (securityHandler->getMode() != EncryptionMode::None)
         {
-            auto decryptEntry = [encryptObjectReference, &securityHandler, &objects](const PDFXRefTable::Entry& entry)
+            auto decryptEntry = [this, encryptObjectReference, &securityHandler, &objects](const PDFXRefTable::Entry& entry)
             {
+                progressStep();
+
                 if (encryptObjectReference.objectNumber != 0 && encryptObjectReference == entry.reference)
                 {
                     // 2) - Encrypt dictionary
@@ -362,7 +369,9 @@ PDFDocument PDFDocumentReader::readFromBuffer(const QByteArray& buffer)
                 objects[entry.reference.objectNumber].object = securityHandler->decryptObject(objects[entry.reference.objectNumber].object, entry.reference);
             };
 
+            progressStart(occupiedEntries.size());
             std::for_each(std::execution::parallel_policy(), occupiedEntries.cbegin(), occupiedEntries.cend(), decryptEntry);
+            progressFinish();
         }
 
         // ------------------------------------------------------------------------------------------
@@ -520,4 +529,28 @@ int PDFDocumentReader::findFromEnd(const char* what, const QByteArray& byteArray
     return FIND_NOT_FOUND_RESULT;
 }
 
+void PDFDocumentReader::progressStart(size_t stepCount)
+{
+    if (m_progress)
+    {
+        m_progress->start(stepCount);
+    }
+}
+
+void PDFDocumentReader::progressStep()
+{
+    if (m_progress)
+    {
+        m_progress->step();
+    }
+}
+
+void PDFDocumentReader::progressFinish()
+{
+    if (m_progress)
+    {
+        m_progress->finish();
+    }
+}
+
 }   // namespace pdf

PdfForQtLib/sources/pdfdocumentreader.h

@@ -21,6 +21,7 @@
 
 #include "pdfglobal.h"
 #include "pdfdocument.h"
+#include "pdfprogress.h"
 
 #include <QtCore>
 #include <QIODevice>
@@ -36,7 +37,7 @@ class PDFFORQTLIBSHARED_EXPORT PDFDocumentReader
     Q_DECLARE_TR_FUNCTIONS(pdf::PDFDocumentReader)
 
 public:
-    explicit PDFDocumentReader(const std::function<QString(bool*)>& getPasswordCallback);
+    explicit PDFDocumentReader(PDFProgress* progress, const std::function<QString(bool*)>& getPasswordCallback);
 
     constexpr inline PDFDocumentReader(const PDFDocumentReader&) = delete;
     constexpr inline PDFDocumentReader(PDFDocumentReader&&) = delete;
@@ -86,6 +87,10 @@ private:
     /// \returns Position of string, or FIND_NOT_FOUND_RESULT
     int findFromEnd(const char* what, const QByteArray& byteArray, int limit);
 
+    void progressStart(size_t stepCount);
+    void progressStep();
+    void progressFinish();
+
     /// Mutex for access to variables of this reader from more threads
     /// (providing thread safety)
     QMutex m_mutex;
@@ -101,6 +106,9 @@ private:
 
     /// Callback to obtain password from the user
     std::function<QString(bool*)> m_getPasswordCallback;
+
+    /// Progress indicator
+    PDFProgress* m_progress;
 };
 
 }   // namespace pdf

PdfForQtLib/sources/pdfprogress.cpp

@@ -0,0 +1,60 @@
+//    Copyright (C) 2019 Jakub Melka
+//
+//    This file is part of PdfForQt.
+//
+//    PdfForQt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    PdfForQt is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDFForQt.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "pdfprogress.h"
+
+namespace pdf
+{
+
+void PDFProgress::start(size_t stepCount)
+{
+    Q_ASSERT(stepCount > 0);
+
+    m_currentStep = 0;
+    m_stepCount = stepCount;
+    m_percentage = 0;
+
+    emit progressStarted();
+}
+
+void PDFProgress::step()
+{
+    // Atomically increment by one. We must add + 1 to the current step,
+    // because fetch_add will return old value. Then we must test, if percentage
+    // has been changed.
+    size_t currentStep = m_currentStep.fetch_add(1) + 1;
+
+    int newPercentage = int((size_t(100) * currentStep) / m_stepCount);
+    int oldPercentage = m_percentage.load(std::memory_order_acquire);
+    bool emitSignal = oldPercentage < newPercentage;
+    do
+    {
+        emitSignal = oldPercentage < newPercentage;
+    } while (oldPercentage < newPercentage && !m_percentage.compare_exchange_weak(oldPercentage, newPercentage, std::memory_order_release, std::memory_order_relaxed));
+
+    if (emitSignal)
+    {
+        progressStep(newPercentage);
+    }
+}
+
+void PDFProgress::finish()
+{
+    emit progressFinished();
+}
+
+} // namespace pdf

PdfForQtLib/sources/pdfprogress.h

@@ -0,0 +1,54 @@
+//    Copyright (C) 2019 Jakub Melka
+//
+//    This file is part of PdfForQt.
+//
+//    PdfForQt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    PdfForQt is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDFForQt.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef PDFPROGRESS_H
+#define PDFPROGRESS_H
+
+#include "pdfglobal.h"
+
+#include <QObject>
+
+#include <atomic>
+
+namespace pdf
+{
+
+class PDFFORQTLIBSHARED_EXPORT PDFProgress : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit PDFProgress(QObject* parent) : QObject(parent) { }
+
+    void start(size_t stepCount);
+    void step();
+    void finish();
+
+signals:
+    void progressStarted();
+    void progressStep(int percentage);
+    void progressFinished();
+
+private:
+    std::atomic<size_t> m_currentStep = 0;
+    std::atomic<size_t> m_stepCount = 0;
+    std::atomic<int> m_percentage = 0;
+};
+
+}   // namespace pdf
+
+#endif // PDFPROGRESS_H

PdfForQtViewer/PdfForQtViewer.pro

@@ -4,7 +4,7 @@
 #
 #-------------------------------------------------
 
-QT       += core gui
+QT       += core gui winextras
 
 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 

PdfForQtViewer/pdfviewermainwindow.cpp

@@ -61,10 +61,16 @@ PDFViewerMainWindow::PDFViewerMainWindow(QWidget *parent) :
     m_pageNumberSpinBox(nullptr),
     m_pageNumberLabel(nullptr),
     m_pageZoomSpinBox(nullptr),
-    m_isLoadingUI(false)
+    m_isLoadingUI(false),
+    m_progress(new pdf::PDFProgress(this)),
+    m_taskbarButton(new QWinTaskbarButton(this)),
+    m_progressTaskbarIndicator(nullptr)
 {
     ui->setupUi(this);
 
+    // Initialize task bar progress
+    m_progressTaskbarIndicator = m_taskbarButton->progress();
+
     // Initialize shortcuts
     ui->actionOpen->setShortcut(QKeySequence::Open);
     ui->actionClose->setShortcut(QKeySequence::Close);
@@ -164,6 +170,9 @@ PDFViewerMainWindow::PDFViewerMainWindow(QWidget *parent) :
     connect(m_pdfWidget->getDrawWidgetProxy(), &pdf::PDFDrawWidgetProxy::pageLayoutChanged, this, &PDFViewerMainWindow::onPageLayoutChanged);
     connect(m_pdfWidget, &pdf::PDFWidget::pageRenderingErrorsChanged, this, &PDFViewerMainWindow::onPageRenderingErrorsChanged, Qt::QueuedConnection);
     connect(m_settings, &PDFViewerSettings::settingsChanged, this, &PDFViewerMainWindow::onViewerSettingsChanged);
+    connect(m_progress, &pdf::PDFProgress::progressStarted, this, &PDFViewerMainWindow::onProgressStarted);
+    connect(m_progress, &pdf::PDFProgress::progressStep, this, &PDFViewerMainWindow::onProgressStep);
+    connect(m_progress, &pdf::PDFProgress::progressFinished, this, &PDFViewerMainWindow::onProgressFinished);
 
     updatePageLayoutActions();
     updateUI(true);
@@ -242,6 +251,23 @@ void PDFViewerMainWindow::onPageZoomSpinboxEditingFinished()
     m_pdfWidget->getDrawWidgetProxy()->zoom(m_pageZoomSpinBox->value() / 100.0);
 }
 
+void PDFViewerMainWindow::onProgressStarted()
+{
+    m_progressTaskbarIndicator->setRange(0, 100);
+    m_progressTaskbarIndicator->reset();
+    m_progressTaskbarIndicator->show();
+}
+
+void PDFViewerMainWindow::onProgressStep(int percentage)
+{
+    m_progressTaskbarIndicator->setValue(percentage);
+}
+
+void PDFViewerMainWindow::onProgressFinished()
+{
+    m_progressTaskbarIndicator->hide();
+}
+
 void PDFViewerMainWindow::readSettings()
 {
     QSettings settings(QSettings::IniFormat, QSettings::UserScope, QCoreApplication::organizationName(), QCoreApplication::applicationName());
@@ -403,7 +429,7 @@ void PDFViewerMainWindow::openDocument(const QString& fileName)
 
     // Try to open a new document
     QApplication::setOverrideCursor(Qt::WaitCursor);
-    pdf::PDFDocumentReader reader(qMove(getPasswordCallback));
+    pdf::PDFDocumentReader reader(m_progress, qMove(getPasswordCallback));
     pdf::PDFDocument document = reader.readFromFile(fileName);
     QApplication::restoreOverrideCursor();
 
@@ -497,6 +523,12 @@ void PDFViewerMainWindow::closeEvent(QCloseEvent* event)
     event->accept();
 }
 
+void PDFViewerMainWindow::showEvent(QShowEvent* event)
+{
+    Q_UNUSED(event);
+    m_taskbarButton->setWindow(windowHandle());
+}
+
 void PDFViewerMainWindow::on_actionPageLayoutSinglePage_triggered()
 {
     setPageLayout(pdf::PageLayout::SinglePage);

PdfForQtViewer/pdfviewermainwindow.h

@@ -20,12 +20,14 @@
 
 #include "pdfcatalog.h"
 #include "pdfrenderer.h"
-
+#include "pdfprogress.h"
 #include "pdfviewersettings.h"
 
 #include <QTreeView>
 #include <QMainWindow>
 #include <QSharedPointer>
+#include <QWinTaskbarButton>
+#include <QWinTaskbarProgress>
 
 class QLabel;
 class QSpinBox;
@@ -56,6 +58,7 @@ public:
     virtual ~PDFViewerMainWindow() override;
 
     virtual void closeEvent(QCloseEvent* event) override;
+    virtual void showEvent(QShowEvent* event) override;
 
 private slots:
     void on_actionPageLayoutSinglePage_triggered();
@@ -77,6 +80,10 @@ private:
     void onPageNumberSpinboxEditingFinished();
     void onPageZoomSpinboxEditingFinished();
 
+    void onProgressStarted();
+    void onProgressStep(int percentage);
+    void onProgressFinished();
+
     void readSettings();
     void writeSettings();
 
@@ -111,6 +118,9 @@ private:
     QLabel* m_pageNumberLabel;
     QDoubleSpinBox* m_pageZoomSpinBox;
     bool m_isLoadingUI;
+    pdf::PDFProgress* m_progress;
+    QWinTaskbarButton* m_taskbarButton;
+    QWinTaskbarProgress* m_progressTaskbarIndicator;
 };
 
 }   // namespace pdfviewer