Page navigation and zoom

PdfForQtLib/sources/pdfdrawspacecontroller.cpp

@@ -93,6 +93,27 @@ PDFDrawSpaceController::LayoutItems PDFDrawSpaceController::getLayoutItems(size_
     return result;
 }
 
+PDFDrawSpaceController::LayoutItem PDFDrawSpaceController::getLayoutItemForPage(PDFInteger pageIndex) const
+{
+    LayoutItem result;
+
+    if (pageIndex >= 0 && pageIndex < static_cast<PDFInteger>(m_layoutItems.size()) && m_layoutItems[pageIndex].pageIndex == pageIndex)
+    {
+        result = m_layoutItems[pageIndex];
+    }
+
+    if (!result.isValid())
+    {
+        auto it = std::find_if(m_layoutItems.cbegin(), m_layoutItems.cend(), [pageIndex](const LayoutItem& item) { return item.pageIndex == pageIndex; });
+        if (it != m_layoutItems.cend())
+        {
+            result = *it;
+        }
+    }
+
+    return result;
+}
+
 void PDFDrawSpaceController::recalculate()
 {
     if (!m_document)
@@ -713,6 +734,25 @@ void PDFDrawWidgetProxy::zoom(PDFReal zoom)
     }
 }
 
+void PDFDrawWidgetProxy::goToPage(PDFInteger pageIndex)
+{
+    PDFDrawSpaceController::LayoutItem layoutItem = m_controller->getLayoutItemForPage(pageIndex);
+
+    if (layoutItem.isValid())
+    {
+        // We have found our page, navigate onto it
+        if (isBlockMode())
+        {
+            setBlockIndex(layoutItem.blockIndex);
+        }
+        else
+        {
+            QRect rect = fromDeviceSpace(layoutItem.pageRectMM).toRect();
+            setVerticalOffset(-rect.top() - m_layout.blockRect.top());
+        }
+    }
+}
+
 void PDFDrawWidgetProxy::setPageLayout(PageLayout pageLayout)
 {
     if (getPageLayout() != pageLayout)

PdfForQtLib/sources/pdfdrawspacecontroller.h

@@ -76,6 +76,8 @@ public:
         constexpr inline explicit LayoutItem(PDFInteger blockIndex, PDFInteger pageIndex, PageRotation rotation, const QRectF& pageRectMM) :
             blockIndex(blockIndex), pageIndex(pageIndex), pageRotation(rotation), pageRectMM(pageRectMM) { }
 
+        bool isValid() const { return pageIndex != -1; }
+
         PDFInteger blockIndex;
         PDFInteger pageIndex;
         PageRotation pageRotation;
@@ -89,6 +91,11 @@ public:
     /// \param blockIndex Index of the block
     LayoutItems getLayoutItems(size_t blockIndex) const;
 
+    /// Returns layout for single page. If page index is invalid,
+    /// or page layout cannot be found, then invalid layout item is returned.
+    /// \param pageIndex Page index
+    LayoutItem getLayoutItemForPage(PDFInteger pageIndex) const;
+
     /// Returns the document
     const PDFDocument* getDocument() const { return m_document; }
 
@@ -190,6 +197,10 @@ public:
     /// \param zoom New zoom
     void zoom(PDFReal zoom);
 
+    /// Go to the specified page
+    /// \param pageIndex Page to scroll to
+    void goToPage(PDFInteger pageIndex);
+
     /// Returns current zoom from widget space to device space. So, for example 2.00 corresponds to 200% zoom,
     /// and each 1 cm of widget area corresponds to 0.5 cm of the device space area.
     PDFReal getZoom() const { return m_zoom; }