DocPage Organizer: Preview image painting

Pdf4QtDocPageOrganizer/mainwindow.cpp

@@ -33,6 +33,7 @@
 #include <QToolBar>
 #include <QDesktopServices>
 #include <QImageReader>
+#include <QPixmapCache>
 
 namespace pdfdocpage
 {
@@ -345,6 +346,7 @@ void MainWindow::performOperation(Operation operation)
         case Operation::Clear:
         {
             m_model->clear();
+            QPixmapCache::clear();
             break;
         }
         case Operation::CloneSelection:

Pdf4QtDocPageOrganizer/pageitemdelegate.cpp

@@ -19,8 +19,10 @@
 #include "pageitemmodel.h"
 #include "pdfwidgetutils.h"
 #include "pdfpainterutils.h"
+#include "pdfrenderer.h"
 
 #include <QPainter>
+#include <QPixmapCache>
 
 namespace pdfdocpage
 {
@@ -62,9 +64,18 @@ void PageItemDelegate::paint(QPainter* painter, const QStyleOptionViewItem& opti
         QSize pageImageSize = rotatedPageSize.scaled(pageBoundingRect.size(), Qt::KeepAspectRatio).toSize();
         QRect pageImageRect(pageBoundingRect.topLeft() + QPoint((pageBoundingRect.width() - pageImageSize.width()) / 2, (pageBoundingRect.height() - pageImageSize.height()) / 2), pageImageSize);
 
-        painter->setPen(QPen(Qt::black));
         painter->setBrush(Qt::white);
         painter->drawRect(pageImageRect);
+
+        QPixmap pageImagePixmap = getPageImagePixmap(item, pageImageRect);
+        if (!pageImagePixmap.isNull())
+        {
+            painter->drawPixmap(pageImageRect, pageImagePixmap);
+        }
+
+        painter->setPen(QPen(Qt::black));
+        painter->setBrush(Qt::NoBrush);
+        painter->drawRect(pageImageRect);
     }
 
     int textOffset = pageBoundingRect.bottom() + verticalSpacing;
@@ -122,4 +133,73 @@ void PageItemDelegate::setPageImageSize(QSize pageImageSize)
     }
 }
 
+QPixmap PageItemDelegate::getPageImagePixmap(const PageGroupItem* item, QRect rect) const
+{
+    QPixmap pixmap;
+
+    Q_ASSERT(item);
+    if (item->groups.empty())
+    {
+        return pixmap;
+    }
+
+    const PageGroupItem::GroupItem& groupItem = item->groups.front();
+    if (groupItem.pageType == PT_Empty)
+    {
+        return pixmap;
+    }
+
+    // Jakub Melka: generate key and see, if pixmap is not cached
+    QString key = QString("%1#%2#%3#%4#%5@%6x%7").arg(groupItem.documentIndex).arg(groupItem.imageIndex).arg(int(groupItem.pageAdditionalRotation)).arg(groupItem.pageIndex).arg(groupItem.pageType).arg(rect.width()).arg(rect.height());
+
+    if (!QPixmapCache::find(key, &pixmap))
+    {
+        // We must draw the pixmap
+        pixmap = QPixmap(rect.width(), rect.height());
+        pixmap.fill(Qt::transparent);
+
+        switch (groupItem.pageType)
+        {
+            case pdfdocpage::PT_DocumentPage:
+                break;
+
+            case pdfdocpage::PT_Image:
+            {
+                const auto& images = m_model->getImages();
+                auto it = images.find(groupItem.imageIndex);
+                if (it != images.cend())
+                {
+                    const QImage& image = it->second.image;
+                    if (!image.isNull())
+                    {
+                        QRect drawRect(QPoint(0, 0), rect.size());
+                        QRect mediaBox(QPoint(0, 0), image.size());
+                        QMatrix matrix = pdf::PDFRenderer::createMediaBoxToDevicePointMatrix(mediaBox, drawRect, groupItem.pageAdditionalRotation);
+
+                        QPainter painter(&pixmap);
+                        painter.setWorldMatrixEnabled(true);
+                        painter.setWorldMatrix(matrix);
+                        painter.translate(0, mediaBox.height());
+                        painter.scale(1.0, -1.0);
+                        painter.drawImage(0, 0, image);
+                    }
+                }
+                break;
+            }
+
+            case pdfdocpage::PT_Empty:
+                Q_ASSERT(false);
+                break;
+
+            default:
+                Q_ASSERT(false);
+                break;
+        }
+
+        QPixmapCache::insert(key, pixmap);
+    }
+
+    return pixmap;
+}
+
 }   // namespace pdfdocpage

Pdf4QtDocPageOrganizer/pageitemdelegate.h

@@ -24,6 +24,7 @@ namespace pdfdocpage
 {
 
 class PageItemModel;
+struct PageGroupItem;
 
 class PageItemDelegate : public QAbstractItemDelegate
 {
@@ -46,6 +47,8 @@ private:
     static constexpr int getVerticalSpacing() { return 5; }
     static constexpr int getHorizontalSpacing() { return 5; }
 
+    QPixmap getPageImagePixmap(const PageGroupItem* item, QRect rect) const;
+
     PageItemModel* m_model;
     QSize m_pageImageSize;
 };

Pdf4QtLib/sources/pdfrenderer.cpp

@@ -48,12 +48,22 @@ PDFRenderer::PDFRenderer(const PDFDocument* document,
     Q_ASSERT(document);
 }
 
-QMatrix PDFRenderer::createPagePointToDevicePointMatrix(const PDFPage* page, const QRectF& rectangle)
+QMatrix PDFRenderer::createPagePointToDevicePointMatrix(const PDFPage* page,
+                                                        const QRectF& rectangle,
+                                                        PageRotation extraRotation)
 {
-    QRectF mediaBox = page->getRotatedMediaBox();
+    PageRotation pageRotation = getPageRotationCombined(page->getPageRotation(), extraRotation);
+    QRectF mediaBox = page->getRotatedBox(page->getMediaBox(), pageRotation);
 
+    return createMediaBoxToDevicePointMatrix(mediaBox, rectangle, pageRotation);
+}
+
+QMatrix PDFRenderer::createMediaBoxToDevicePointMatrix(const QRectF& mediaBox,
+                                                       const QRectF& rectangle,
+                                                       PageRotation rotation)
+{
     QMatrix matrix;
-    switch (page->getPageRotation())
+    switch (rotation)
     {
         case PageRotation::None:
         {

Pdf4QtLib/sources/pdfrenderer.h

@@ -97,7 +97,18 @@ public:
     /// from page's media box to the target rectangle.
     /// \param page Page, for which we want to create matrix
     /// \param rectangle Page rectangle, to which is page media box transformed
-    static QMatrix createPagePointToDevicePointMatrix(const PDFPage* page, const QRectF& rectangle);
+    /// \param extraRotation Extra rotation applied to the page rotation
+    static QMatrix createPagePointToDevicePointMatrix(const PDFPage* page,
+                                                      const QRectF& rectangle,
+                                                      PageRotation extraRotation = PageRotation::None);
+
+    /// Creates media box to device point matrix for the given media box.
+    /// \param mediaBox Media box
+    /// \param rectangle Page rectangle, to which is page media box transformed
+    /// \param rotation Rotation
+    static QMatrix createMediaBoxToDevicePointMatrix(const QRectF& mediaBox,
+                                                     const QRectF& rectangle,
+                                                     PageRotation rotation);
 
     /// Returns default renderer features
     static constexpr Features getDefaultFeatures() { return Features(Antialiasing | TextAntialiasing | ClipToCropBox | DisplayAnnotations); }