Changes the UI interface so that only the current page is rendered on screen at a time. This has significant memory benefits for large PDF files. This also implements a least-recently used cache of tunable size, which improves responsiveness if you're hopping between two specific pages.

1 files changed, 129 insertions, 114 deletions

diff --git a/src-qt5/desktop-utils/lumina-pdf/PrintWidget.cpp b/src-qt5/desktop-utils/lumina-pdf/PrintWidget.cpp
index d6597705..95a32c02 100644
--- a/src-qt5/desktop-utils/lumina-pdf/PrintWidget.cpp
+++ b/src-qt5/desktop-utils/lumina-pdf/PrintWidget.cpp
@@ -1,23 +1,27 @@
 #include "PrintWidget.h"
-#include <QPushButton>
 #include <QGraphicsProxyWidget>
+#include <QPushButton>
 
-PrintWidget::PrintWidget(Renderer *backend, QWidget *parent) : 
-  QGraphicsView(parent), scene(0), curPage(1), viewMode(SinglePageView), 
-  zoomMode(FitInView), zoomFactor(1), initialized(false), fitting(true), BACKEND(backend) {
+PrintWidget::PrintWidget(Renderer *backend, QWidget *parent)
+    : QGraphicsView(parent), scene(0), curPage(1), viewMode(SinglePageView),
+      zoomMode(FitInView), zoomFactor(1), initialized(false), fitting(true),
+      BACKEND(backend) {
 
   this->setMouseTracking(true);
-  QList<QWidget*> children = this->findChildren<QWidget*>("",Qt::FindChildrenRecursively);
-  for(int i=0; i<children.length(); i++){
+  QList<QWidget *> children =
+      this->findChildren<QWidget *>("", Qt::FindChildrenRecursively);
+  for (int i = 0; i < children.length(); i++) {
     children[i]->setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(children[i], SIGNAL(customContextMenuRequested(const QPoint&)), this, SIGNAL(customContextMenuRequested(const QPoint&)) );
+    QObject::connect(children[i],
+                     SIGNAL(customContextMenuRequested(const QPoint &)), this,
+                     SIGNAL(customContextMenuRequested(const QPoint &)));
   }
   this->setInteractive(false);
   this->setDragMode(QGraphicsView::ScrollHandDrag);
   this->setViewportUpdateMode(QGraphicsView::SmartViewportUpdate);
   this->setFocusPolicy(Qt::NoFocus);
-  QObject::connect(this->verticalScrollBar(), SIGNAL(valueChanged(int)),
-                   this, SLOT(updateCurrentPage()));
+  QObject::connect(this->verticalScrollBar(), SIGNAL(valueChanged(int)), this,
+                   SLOT(updateCurrentPage()));
   QObject::connect(this, SIGNAL(resized()), this, SLOT(fit()));
 
   scene = new QGraphicsScene(this);
@@ -31,24 +35,24 @@ PrintWidget::PrintWidget(Renderer *backend, QWidget *parent) :
 }
 
 PrintWidget::~PrintWidget() {
-  for (int i = 0; i < pages.size(); i++){
+  for (int i = 0; i < pages.size(); i++) {
     scene->removeItem(pages.at(i));
   }
   qDeleteAll(pages);
-  pages.clear(); 
+  pages.clear();
   scene->deleteLater();
 }
 
-//Public Slots
+// Public Slots
 
 void PrintWidget::fitView() {
   setZoomMode(FitInView);
-  setCurrentPage(publicPageNum); //Make sure we stay on the same page
+  setCurrentPage(curPage); // Make sure we stay on the same page
 }
 
 void PrintWidget::fitToWidth() {
   setZoomMode(FitToWidth);
-  setCurrentPage(publicPageNum); //Make sure we stay on the same page
+  setCurrentPage(curPage); // Make sure we stay on the same page
 }
 
 void PrintWidget::setZoomMode(ZoomMode mode) {
@@ -57,17 +61,11 @@ void PrintWidget::setZoomMode(ZoomMode mode) {
   fit(true);
 }
 
-void PrintWidget::setAllPagesViewMode() {
-  setViewMode(AllPagesView);
-}
+void PrintWidget::setAllPagesViewMode() { setViewMode(AllPagesView); }
 
-void PrintWidget::setSinglePageViewMode() {
-  setViewMode(SinglePageView);
-}
+void PrintWidget::setSinglePageViewMode() { setViewMode(SinglePageView); }
 
-void PrintWidget::setFacingPagesViewMode() {
-  setViewMode(FacingPagesView);
-}
+void PrintWidget::setFacingPagesViewMode() { setViewMode(FacingPagesView); }
 
 void PrintWidget::setViewMode(ViewMode mode) {
   viewMode = mode;
@@ -94,7 +92,7 @@ void PrintWidget::zoomOut(double factor) {
   fitting = false;
   zoomMode = CustomZoom;
   zoomFactor *= factor;
-  this->scale(1/factor, 1/factor);
+  this->scale(1 / factor, 1 / factor);
 }
 
 void PrintWidget::updatePreview() {
@@ -104,48 +102,48 @@ void PrintWidget::updatePreview() {
 }
 
 void PrintWidget::setVisible(bool visible) {
-  if(visible and !initialized)
+  if (visible and !initialized)
     updatePreview();
   QGraphicsView::setVisible(visible);
 }
 
 void PrintWidget::setCurrentPage(int pageNumber) {
-  if(pageNumber < 0 || pageNumber > (pages.count()+1) ){ return; }
-  publicPageNum = pageNumber; //publicly requested page number (+/- 1 from actual page range)
-  emit currentPageChanged();
-  if(pageNumber < 1 || pageNumber > pages.count())
-    return;
+
   int lastPage = curPage;
-  curPage = pageNumber;
+  curPage = std::max(1, std::min(pageNumber, BACKEND->numPages()));
 
-  if (lastPage != curPage && lastPage > 0 && lastPage <= pages.count()) {
+  /* if (lastPage != curPage && lastPage > 0 && lastPage <= pages.count()) {
     if (zoomMode != FitInView) {
       QScrollBar *hsc = this->horizontalScrollBar();
       QScrollBar *vsc = this->verticalScrollBar();
-      QPointF pt = this->transform().map(pages.at(curPage-1)->pos());
+      QPointF pt = this->transform().map(pages.at(curPage - 1)->pos());
       vsc->setValue(int(pt.y()) - 10);
       hsc->setValue(int(pt.x()) - 10);
     } else {
-      this->centerOn(pages.at(curPage-1));
+      this->centerOn(pages.at(curPage - 1));
     }
-  }
+  } */
 
-  //qDebug() << "Page Set";
+  if (lastPage != curPage)
+    updatePreview();
+
+  qDebug() << "Current page set to " << pageNumber << "\n";
 }
 
 void PrintWidget::highlightText(TextData *text) {
-  //Creates a rectangle around the text if the text has not already been highlighted
-  //qDebug() << "Page:" << text->page() << "Loc:" << text->loc();
-  if(!text->highlighted() && !text->loc().isNull()) {
+  // Creates a rectangle around the text if the text has not already been
+  // highlighted qDebug() << "Page:" << text->page() << "Loc:" << text->loc();
+  if (!text->highlighted() && !text->loc().isNull()) {
     int degrees = BACKEND->rotatedDegrees();
-    //qDebug() << "Degrees:" << degrees;
-    //Shows the text's location on a non-rotated page
+    // qDebug() << "Degrees:" << degrees;
+    // Shows the text's location on a non-rotated page
     QRectF rect = text->loc();
-    //Rotates the rectangle by the page's center and gets the right calculation for text's new location
-    if(degrees != 0) {
-      QSize center = BACKEND->imageHash(text->page()-1).size()/2;
+    // Rotates the rectangle by the page's center and gets the right calculation
+    // for text's new location
+    if (degrees != 0) {
+      QSize center = BACKEND->imageSize(text->page() - 1) / 2;
 
-      if(degrees == 90 or degrees == 270)
+      if (degrees == 90 or degrees == 270)
         center.transpose();
 
       double cx = center.width(), cy = center.height();
@@ -153,24 +151,24 @@ void PrintWidget::highlightText(TextData *text) {
       QMatrix matrix;
       matrix.rotate(BACKEND->rotatedDegrees());
       rect = matrix.mapRect(rect);
-      if(BACKEND->rotatedDegrees() == 180)
+      if (BACKEND->rotatedDegrees() == 180)
         rect.adjust(cx, cy, cx, cy);
       else
         rect.adjust(cy, cx, cy, cx);
     }
 
-    //qDebug() << "Post Degrees:" << rect;
-    //Moves the rectangle onto the right page
+    // qDebug() << "Post Degrees:" << rect;
+    // Moves the rectangle onto the right page
     double pageHeight = 0;
-    for(int i = 0; i < text->page() - 1; i++)
+    for (int i = 0; i < text->page() - 1; i++)
       pageHeight += pages.at(i)->boundingRect().height();
 
-    //qDebug() << "PageHeight:" << pageHeight;
+    // qDebug() << "PageHeight:" << pageHeight;
 
     rect.moveTop(rect.y() + pageHeight);
 
-    //qDebug() << "Final Rect:" << rect;
-    //Transparent yellow for the highlight box
+    // qDebug() << "Final Rect:" << rect;
+    // Transparent yellow for the highlight box
     QBrush highlightFill(QColor(255, 255, 177, 100));
     QPen highlightOutline(QColor(255, 255, 100, 125));
     scene->addRect(rect, highlightOutline, highlightFill);
@@ -179,15 +177,17 @@ void PrintWidget::highlightText(TextData *text) {
   goToPosition(text->page(), text->loc().x(), text->loc().y());
 }
 
-//Private functions
+// Private functions
 
 void PrintWidget::generatePreview() {
   populateScene(); // i.e. setPreviewPrintedPictures() e.l.
   layoutPages();
-  curPage = qBound(1, curPage, pages.count());
+  // curPage = qBound(1, curPage, pages.count());
   publicPageNum = curPage;
   emit currentPageChanged();
-  if (fitting){ fit(); }
+  if (fitting) {
+    fit();
+  }
 }
 
 void PrintWidget::layoutPages() {
@@ -197,17 +197,18 @@ void PrintWidget::layoutPages() {
 
   int numPagePlaces = numPages;
   int cols = 1; // singleMode and default
-  QSize pageSize = BACKEND->imageHash(curPage-1).size();
+  QSize pageSize = BACKEND->imageSize(curPage);
   if (viewMode == AllPagesView) {
-    cols = pageSize.width() > pageSize.height() ? qFloor(qSqrt(numPages)) : qCeil(qSqrt(numPages));
-    cols += cols % 2;  // Nicer with an even number of cols
+    cols = pageSize.width() > pageSize.height() ? qFloor(qSqrt(numPages))
+                                                : qCeil(qSqrt(numPages));
+    cols += cols % 2; // Nicer with an even number of cols
   } else if (viewMode == FacingPagesView) {
     cols = 2;
     numPagePlaces += 1;
   }
   int rows = qCeil(double(numPagePlaces) / cols);
 
-  int pageNum = 0; 
+  int pageNum = 0;
   QList<double> rowMaxList;
   for (int i = 0; i < rows && pageNum < numPages; i++) {
     double rowMax = 0;
@@ -215,11 +216,11 @@ void PrintWidget::layoutPages() {
       double itemWidth = 0, itemHeight = 0;
       double pageHeight = pages.at(pageNum)->boundingRect().height();
 
-      for(int k = cols * (pageNum / cols); k < pageNum; k++)
+      for (int k = cols * (pageNum / cols); k < pageNum; k++)
         itemWidth += pages.at(k)->boundingRect().width();
 
-      foreach(double size, rowMaxList)
-        itemHeight += size;  
+      foreach (double size, rowMaxList)
+        itemHeight += size;
 
       pages.at(pageNum)->setPos(QPointF(itemWidth, itemHeight));
       pageNum++;
@@ -228,46 +229,47 @@ void PrintWidget::layoutPages() {
     rowMaxList.push_back(rowMax);
   }
   scene->setSceneRect(scene->itemsBoundingRect());
-  //qDebug() << "Finished Page Layout";
+  // qDebug() << "Finished Page Layout";
 }
 
-void PrintWidget::populateScene()
-{
-  for (int i = 0; i < pages.size(); i++){
-    scene->removeItem(pages.at(i));
-  }
-  qDeleteAll(pages);
+void PrintWidget::populateScene() {
+  // qDeleteAll(scene->items().begin(), scene->items().end());
+  scene->clear();
+  // qDeleteAll(pages.begin(), pages.end());
   pages.clear();
   links.clear();
   annots.clear();
-  int numPages = BACKEND->numPages();
-  if(BACKEND->hashSize() < numPages){ return; } //nothing to show yet
+  // int numPages = BACKEND->numPages();
+  if (!BACKEND->isDoneLoading()) {
+    qDebug() << "populateScene() called while backend still loading.\n";
+    return;
+  } // nothing to show yet
 
-  for (int i = 0; i < numPages; i++) {
+  for (int i = curPage; i < curPage + 1; i++) {
     QImage pagePicture = BACKEND->imageHash(i);
     QSize paperSize = pagePicture.size();
-    QList<QGraphicsItem*> linkLocations;
-    QList<QGraphicsItem*> annotLocations;
+    QList<QGraphicsItem *> linkLocations;
+    QList<QGraphicsItem *> annotLocations;
 
-    if(pagePicture.isNull()) {
+    if (pagePicture.isNull()) {
       qDebug() << "NULL IMAGE ON PAGE " << i;
       continue;
     }
 
-    PageItem* item = new PageItem(i+1, pagePicture, paperSize, BACKEND);
+    PageItem *item = new PageItem(i + 1, pagePicture, paperSize, BACKEND);
     scene->addItem(item);
     pages.append(item);
 
-    if(BACKEND->supportsExtraFeatures()) {
-      for(int k = 0; k < BACKEND->linkSize(i); k++) {
+    if (BACKEND->supportsExtraFeatures()) {
+      for (int k = 0; k < BACKEND->linkSize(i); k++) {
         LinkItem *lItem = new LinkItem(item, BACKEND->linkList(i, k));
         lItem->setOpacity(0.1);
         linkLocations.append(lItem);
       }
-      //qDebug() << "Creating annotations for:" <<  i;
-      for(int k = 0; k < BACKEND->annotSize(i); k++) {
-        Annotation *annot = BACKEND->annotList(i, k); 
-        if(annot->getType() == 14) {
+      // qDebug() << "Creating annotations for:" <<  i;
+      for (int k = 0; k < BACKEND->annotSize(i); k++) {
+        Annotation *annot = BACKEND->annotList(i, k);
+        if (annot->getType() == 14) {
           InkItem *iItem = new InkItem(item, annot);
           annotLocations.append(iItem);
         }
@@ -278,31 +280,38 @@ void PrintWidget::populateScene()
         annotLocations.append(aZone);
       }
 
-      for(int k = 0; k < BACKEND->widgetSize(i); k++) {
+      for (int k = 0; k < BACKEND->widgetSize(i); k++) {
         Widget *widget = BACKEND->widgetList(i, k);
         int type = widget->getWidgetType();
         QRectF loc = widget->getLocation();
         QString text = widget->getCurrentText();
-        if(type == 0) {
+        switch (type) {
+        case 0: {
           QPushButton *button = new QPushButton(widget->getCurrentText());
           button->setGeometry(loc.toRect());
           button->setText(text);
           QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget(item);
           proxy->setWidget(button);
-        }else if(type == 1) {
+        } break;
+        case 1: {
 
-        }else if(type == 2) {
+        } break;
+        case 2: {
 
-        }else if(type == 3) {
+        } break;
+        case 3: {
 
-        }else if(type == 4) {
+        } break;
+        case 4: {
 
-        }else if(type == 5) {
+        } break;
+        case 5: {
 
-        }else if(type == 6) {
+        } break;
+        case 6: {
 
-        }else {
-          qDebug() << "INVALID WIDGET";
+        } break;
+        default: { qDebug() << "INVALID WIDGET"; }
         }
       }
       links.insert(i, linkLocations);
@@ -311,7 +320,7 @@ void PrintWidget::populateScene()
   }
 }
 
-//Private Slots
+// Private Slots
 void PrintWidget::updateCurrentPage() {
   if (viewMode == AllPagesView)
     return;
@@ -326,12 +335,16 @@ void PrintWidget::updateCurrentPage() {
 
 int PrintWidget::calcCurrentPage() {
   int maxArea = 0;
+
+  return curPage;
+
   int newPage = curPage;
   QRect viewRect = this->viewport()->rect();
-  QList<QGraphicsItem*> items = this->items(viewRect);
-  for (int i=0; i<items.size(); ++i) {
-    PageItem* pg = static_cast<PageItem*>(items.at(i));
-    QRect overlap = this->mapFromScene(pg->sceneBoundingRect()).boundingRect() & viewRect;
+  QList<QGraphicsItem *> items = this->items(viewRect);
+  for (int i = 0; i < items.size(); ++i) {
+    PageItem *pg = static_cast<PageItem *>(items.at(i));
+    QRect overlap =
+        this->mapFromScene(pg->sceneBoundingRect()).boundingRect() & viewRect;
     int area = overlap.width() * overlap.height();
     if (area > maxArea) {
       maxArea = area;
@@ -352,9 +365,10 @@ void PrintWidget::fit(bool doFitting) {
   if (doFitting && fitting) {
     QRect viewRect = this->viewport()->rect();
     if (zoomMode == FitInView) {
-      QList<QGraphicsItem*> containedItems = this->items(viewRect, Qt::ContainsItemBoundingRect);
-      foreach(QGraphicsItem* item, containedItems) {
-        PageItem* pg = static_cast<PageItem*>(item);
+      QList<QGraphicsItem *> containedItems =
+          this->items(viewRect, Qt::ContainsItemBoundingRect);
+      foreach (QGraphicsItem *item, containedItems) {
+        PageItem *pg = static_cast<PageItem *>(item);
         if (pg->pageNumber() == curPage)
           return;
       }
@@ -365,7 +379,7 @@ void PrintWidget::fit(bool doFitting) {
       curPage = newPage;
   }
 
-  QRectF target = pages.at(curPage-1)->sceneBoundingRect();
+  QRectF target = pages.at(curPage - 1)->sceneBoundingRect();
   if (viewMode == FacingPagesView) {
     if (curPage % 2)
       target.setLeft(target.left() - target.width());
@@ -381,7 +395,8 @@ void PrintWidget::fit(bool doFitting) {
     t.scale(scale, scale);
     this->setTransform(t);
     if (doFitting && fitting) {
-      QRectF viewSceneRect = this->viewportTransform().mapRect(this->viewport()->rect());
+      QRectF viewSceneRect =
+          this->viewportTransform().mapRect(this->viewport()->rect());
       viewSceneRect.moveTop(target.top());
       this->ensureVisible(viewSceneRect); // Nah...
     }
@@ -398,29 +413,29 @@ void PrintWidget::fit(bool doFitting) {
 }
 
 void PrintWidget::goToPosition(int pagenum, float x, float y) {
-  //qDebug() << "Page:" << pagenum << "X:" << x << "Y:" << y;
+  // qDebug() << "Page:" << pagenum << "X:" << x << "Y:" << y;
   setCurrentPage(pagenum);
-  
+
   QScrollBar *hsc = this->horizontalScrollBar();
   QScrollBar *vsc = this->verticalScrollBar();
-  QPointF pt = this->transform().map(pages.at(pagenum-1)->pos());
-  int secondPagenum = pagenum < pages.size() ? pagenum : pagenum-2;
+  QPointF pt = this->transform().map(pages.at(pagenum - 1)->pos());
+  int secondPagenum = pagenum < pages.size() ? pagenum : pagenum - 2;
   QPointF pt2 = this->transform().map(pages.at(secondPagenum)->pos());
-  double realHeight = pages.at(pagenum-1)->boundingRect().height();
+  double realHeight = pages.at(pagenum - 1)->boundingRect().height();
   double virtualHeight = qAbs(pt2.y() - pt.y());
 
-  //qDebug() << "Real:" << realHeight << "Virtual:" << virtualHeight;
+  // qDebug() << "Real:" << realHeight << "Virtual:" << virtualHeight;
 
-  int yConv = int(pt.y() + y*(virtualHeight/realHeight)) - 30;
-  int xConv = int(pt.x() + x*(virtualHeight/realHeight)) - 30;
+  int yConv = int(pt.y() + y * (virtualHeight / realHeight)) - 30;
+  int xConv = int(pt.x() + x * (virtualHeight / realHeight)) - 30;
 
-  //qDebug() << "newX:" << xConv << "newY:" << yConv;
+  // qDebug() << "newX:" << xConv << "newY:" << yConv;
 
-  if(yConv > vsc->maximum())
+  if (yConv > vsc->maximum())
     vsc->triggerAction(QAbstractSlider::SliderToMaximum);
-  else if(y != 0)
+  else if (y != 0)
     vsc->setValue(yConv);
 
-  if(x != 0)
+  if (x != 0)
     hsc->setValue(xConv);
 }