paging for pdfpreviews

gui/mainwindow.cpp

@@ -21,9 +21,10 @@ MainWindow::MainWindow(QWidget *parent) :
 	ui(new Ui::MainWindow)
 {
 	ui->setupUi(this);
+	QSettings settings;
 
 	db = QSqlDatabase::addDatabase("QSQLITE");
-    db.setDatabaseName(QSettings().value("dbpath").toString());
+	db.setDatabaseName(settings.value("dbpath").toString());
 	if(!db.open())
 	{
 		qDebug() << "failed to open database";
@@ -35,8 +36,9 @@ MainWindow::MainWindow(QWidget *parent) :
 	ui->statusBar->addWidget(ui->lblSearchResults);
 	ui->statusBar->addWidget(ui->pdfProcessBar);
 	ui->pdfProcessBar->hide();
-    QSettings settings;
 	ui->comboScale->setCurrentText(settings.value("currentScale").toString());
+	pdfPreviewsPerPage = settings.value("pdfPreviewsPerPage", 20).toInt();
+	ui->spinPdfPreviewPage->setMinimum(1);
 }
 
 void MainWindow::connectSignals()
@@ -63,13 +65,20 @@ void MainWindow::connectSignals()
 	connect(ui->treeResultsList, &QTreeWidget::customContextMenuRequested, this, &MainWindow::showSearchResultsContextMenu);
 	connect(ui->tabWidget, &QTabWidget::currentChanged, this, &MainWindow::tabChanged);
 	connect(ui->comboScale, qOverload<const QString &>(&QComboBox::currentIndexChanged), this, &MainWindow::comboScaleChanged);
+	connect(ui->spinPdfPreviewPage, qOverload<int>(&QSpinBox::valueChanged), this, &MainWindow::spinPdfPreviewPageValueChanged);
+
+}
+
+void MainWindow::spinPdfPreviewPageValueChanged(int val)
+{
+	makePdfPreview(val);
 }
 
 void MainWindow::comboScaleChanged(QString text)
 {
 	QSettings scaleSetting;
 	scaleSetting.setValue("currentScale", ui->comboScale->currentText());
-    makePdfPreview();
+	makePdfPreview(ui->spinPdfPreviewPage->value());
 }
 bool MainWindow::pdfTabActive()
 {
@@ -102,7 +111,7 @@ void MainWindow::tabChanged()
 	{
 		if(pdfDirty)
 		{
-            makePdfPreview();
+			makePdfPreview(ui->spinPdfPreviewPage->value());
 		}
 		ui->pdfProcessBar->show();
 	}
@@ -190,14 +199,19 @@ void MainWindow::handleSearchResults(const QVector<SearchResult> &results)
 	ui->treeResultsList->resizeColumnToContents(0);
 	ui->treeResultsList->resizeColumnToContents(1);
 	pdfDirty = ! this->pdfSearchResults.empty();
+
+	int numpages = ceil(static_cast<double>(this->pdfSearchResults.size()) / pdfPreviewsPerPage);
+	ui->spinPdfPreviewPage->setMinimum(1);
+	ui->spinPdfPreviewPage->setMaximum(numpages);
+	ui->spinPdfPreviewPage->setValue(1);
 	if(pdfTabActive() && pdfDirty)
 	{
-       makePdfPreview();
+		makePdfPreview(1);
 	}
 
 }
 
-void MainWindow::makePdfPreview()
+void MainWindow::makePdfPreview(int page)
 {
 
 	this->pdfWorkerWatcher.cancel();
@@ -233,7 +247,9 @@ void MainWindow::makePdfPreview()
 		}
 	}
 	PdfWorker worker;
-   this->pdfWorkerWatcher.setFuture(worker.generatePreviews(this->pdfSearchResults, wordsToHighlight, scaleText.toInt() / 100.));
+	int end = pdfPreviewsPerPage;
+	int begin = page * pdfPreviewsPerPage - pdfPreviewsPerPage;
+	this->pdfWorkerWatcher.setFuture(worker.generatePreviews(this->pdfSearchResults.mid(begin, end), wordsToHighlight, scaleText.toInt() / 100.));
 	ui->pdfProcessBar->setMaximum(this->pdfWorkerWatcher.progressMaximum());
 	ui->pdfProcessBar->setMinimum(this->pdfWorkerWatcher.progressMinimum());
 
@@ -274,3 +290,4 @@ MainWindow::~MainWindow()
 {
 	delete ui;
 }
+

gui/mainwindow.h

@@ -34,13 +34,14 @@ private:
     void add(QString path, unsigned int page);
     QVector<SearchResult> pdfSearchResults;
     void connectSignals();
-    void makePdfPreview();
+	void makePdfPreview(int page);
     bool pdfTabActive();
     void keyPressEvent(QKeyEvent *event) override;
     unsigned int processedPdfPreviews;
     void handleSearchResults(const QVector<SearchResult> &results);
     void handleSearchError(QString error);
     QSSQuery currentQuery;
+	int pdfPreviewsPerPage;
 private slots:
     void lineEditReturnPressed();
     void treeSearchItemActivated(QTreeWidgetItem *item, int i);
@@ -48,7 +49,7 @@ private slots:
     void tabChanged();
     void pdfPreviewReceived(PdfPreview preview);
     void comboScaleChanged(QString text);
-
+	void spinPdfPreviewPageValueChanged(int val);
 };
 
 #endif // MAINWINDOW_H

gui/mainwindow.ui

@@ -148,6 +148,26 @@
             </property>
            </spacer>
           </item>
+          <item>
+           <widget class="QLabel" name="lblPdfPreviewPage">
+            <property name="text">
+             <string>Page:</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QSpinBox" name="spinPdfPreviewPage">
+            <property name="buttonSymbols">
+             <enum>QAbstractSpinBox::PlusMinus</enum>
+            </property>
+            <property name="accelerated">
+             <bool>false</bool>
+            </property>
+            <property name="showGroupSeparator" stdset="0">
+             <bool>false</bool>
+            </property>
+           </widget>
+          </item>
          </layout>
         </item>
        </layout>