Printing support #1525: plot printing using preview dialog

Add shortcut and entry in context menu for printing a plot.
sqlitebrowser · Sep 29, 2018 · 79983e2 · 79983e2
1 parent e771662
commit 79983e2
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Showing 2 changed files with 41 additions and 1 deletion.
diff --git a/src/PlotDock.cpp b/src/PlotDock.cpp
@@ -5,6 +5,9 @@
 #include "FileDialog.h"
 #include "MainWindow.h"     // Just for BrowseDataTableSettings, not for the actual main window class
 
+#include <QPrinter>
+#include <QPrintPreviewDialog>
+
 PlotDock::PlotDock(QWidget* parent)
     : QDialog(parent),
       ui(new Ui::PlotDock),
@@ -40,18 +43,28 @@ PlotDock::PlotDock(QWidget* parent)
     QShortcut* shortcutCopy = new QShortcut(QKeySequence::Copy, ui->plotWidget, nullptr, nullptr, Qt::WidgetShortcut);
     connect(shortcutCopy, SIGNAL(activated()), this, SLOT(copy()));
 
+    QShortcut* shortcutPrint = new QShortcut(QKeySequence::Print, ui->plotWidget, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(shortcutPrint, &QShortcut::activated, this, &PlotDock::openPrintDialog);
+
     ui->plotWidget->setContextMenuPolicy(Qt::CustomContextMenu);
 
     // Set up context menu
     m_contextMenu = new QMenu(this);
+
     QAction* copyAction = new QAction(QIcon(":/icons/copy"), tr("Copy"), m_contextMenu);
     copyAction->setShortcut(shortcutCopy->key());
     m_contextMenu->addAction(copyAction);
-
     connect(copyAction, &QAction::triggered, [&]() {
        copy();
     });
 
+    QAction* printAction = new QAction(QIcon(":/icons/print"), tr("Print..."), m_contextMenu);
+    printAction->setShortcut(shortcutPrint->key());
+    m_contextMenu->addAction(printAction);
+    connect(printAction, &QAction::triggered, [&]() {
+       openPrintDialog();
+    });
+
     QAction* showLegendAction = new QAction(tr("Show legend"), m_contextMenu);
     showLegendAction->setCheckable(true);
     m_contextMenu->addAction(showLegendAction);
@@ -851,3 +864,27 @@ void PlotDock::reject()
     // dock go away
     return;
 }
+
+void PlotDock::openPrintDialog()
+{
+    QPrinter printer;
+    QPrintPreviewDialog previewDialog(&printer, this);
+    connect(&previewDialog, &QPrintPreviewDialog::paintRequested, this, &PlotDock::renderPlot);
+    previewDialog.exec();
+}
+
+void PlotDock::renderPlot(QPrinter* printer)
+{
+    QCPPainter painter(printer);
+    QRectF pageRect = printer->pageRect(QPrinter::DevicePixel);
+
+    int plotWidth = ui->plotWidget->viewport().width();
+    int plotHeight = ui->plotWidget->viewport().height();
+    double scale = pageRect.width()/(double)plotWidth;
+
+    painter.setMode(QCPPainter::pmVectorized);
+    painter.setMode(QCPPainter::pmNoCaching);
+
+    painter.scale(scale, scale);
+    ui->plotWidget->toPainter(&painter, plotWidth, plotHeight);
+}
diff --git a/src/PlotDock.h b/src/PlotDock.h
@@ -7,6 +7,7 @@
 
 class SqliteTableModel;
 class QTreeWidgetItem;
+class QPrinter;
 struct BrowseDataTableSettings;
 
 namespace Ui {
@@ -110,6 +111,8 @@ private slots:
     void copy();
     void toggleLegendVisible(bool visible);
     void toggleStackedBars(bool stacked);
+    void openPrintDialog();
+    void renderPlot(QPrinter* printer);
 };
 
 #endif