/// <summary>
/// Determine the visible page range
/// </summary>
/// <returns></returns>
private PageRange FindVisibleRange()
{
// Find a visible page,
int visiblePage = FindVisiblePage();
if (visiblePage <= 0)
{
AppEventSource.Log.Warn("ViewerPage: No visible page found.");
return new PageRange(1, 1);
}
// Find the pages that are currently visible
PageRange range = new PageRange(visiblePage, visiblePage);
// Find the first visible page
for (int i = 1; i <= pageCount; i++)
{
if (!IsPageVisible(visiblePage - i))
{
range.first = visiblePage - i + 1;
break;
}
}
// Find the last visible page
for (int i = 1; i <= pageCount; i++)
{
if (!IsPageVisible(visiblePage + i))
{
range.last = visiblePage + i - 1;
break;
}
}
return range;
}
/// <summary>
/// This method is not used.
/// </summary>
private void SetMinZoomFactor()
{
if (!this.fileLoaded) return;
// Store current zoom factor
double factor = scrollViewer.ZoomFactor;
// Update visible page range
this._visiblePageRange = FindVisibleRange();
// Find the max page height and width in the visible pages
double maxHeight = 0;
double maxWidth = 0;
for (int i = this.VisiblePageRange.first; i <= this.VisiblePageRange.last; i++)
{
Image image = (Image)this.imagePanel.FindName(PREFIX_PAGE + i.ToString());
if (image.ActualHeight > maxHeight) maxHeight = image.ActualHeight;
if (image.ActualWidth > maxWidth) maxWidth = image.MaxWidth;
}
// Recalculate min zoom factor
double hZoomFactor = (this.scrollViewer.ActualHeight - SCROLLBAR_WIDTH
- 2 * (PAGE_IMAGE_MARGIN + imagePanel.Margin.Top)) / maxHeight;
double wZoomFactor = (this.scrollViewer.ActualWidth - SCROLLBAR_WIDTH
- 2 * (PAGE_IMAGE_MARGIN + imagePanel.Margin.Left)) / maxWidth;
if (hZoomFactor < 0.1)
{
hZoomFactor = 0.1;
AppEventSource.Log.Debug("ViewerPage: Minimum vertical zoom factor is too small");
}
if (wZoomFactor < 0.1)
{
wZoomFactor = 0.1;
AppEventSource.Log.Debug("ViewerPage: Minimum horizontal zoom factor is too small");
}
this.scrollViewer.MinZoomFactor = (float)Math.Min(hZoomFactor, wZoomFactor);
// Recalculate offsets if zoom level changed
if (this.scrollViewer.MinZoomFactor > factor)
{
factor = this.scrollViewer.MinZoomFactor / factor;
scrollViewer.ChangeView(factor * scrollViewer.HorizontalOffset,
factor * scrollViewer.VerticalOffset, scrollViewer.ZoomFactor, true);
AppEventSource.Log.Debug("ViewerPage: zoom factor changed, offsets recalculated.");
}
}
/// <summary>
/// Prepare a range of pages to be displayed. Visiable pages and buffer pages (before/after the visible pages)
/// are added to a queue for rendering. Other pages are added to the recycle queue so that memeory will be release
/// when the a page is removed later.
/// </summary>
/// <param name="range"></param>
private void PreparePages(PageRange range)
{
// Add invisible pages to recycle list
for (int i = inkingPageRange.first - SIZE_PAGE_BUFFER; i <= inkingPageRange.last + SIZE_PAGE_BUFFER; i++)
{
if ((i < range.first - SIZE_PAGE_BUFFER || i > range.last + SIZE_PAGE_BUFFER)
&& i > 0 && i <= pageCount)
this.recyclePagesQueue.Enqueue(i);
}
// Update inking range
this.inkingPageRange = range;
// Clear render page queue
this.renderPagesQueue.Clear();
// Add visible pages to queue
for (int i = range.first; i <= range.last; i++)
{
if (i > 0 && i <= pageCount)
renderPagesQueue.Enqueue(i);
}
// Add buffer pages to queue
for (int i = range.first - SIZE_PAGE_BUFFER; i <= range.last + SIZE_PAGE_BUFFER; i++)
{
if (i > 0 && i <= pageCount && !renderPagesQueue.Contains(i))
renderPagesQueue.Enqueue(i);
}
// Start rendering pages
if (!this.isRenderingPage)
RenderPages();
}
private async void FinishInitialization()
{
this.fullScreenCover.Visibility = Visibility.Collapsed;
this.imagePanel.UpdateLayout();
// Load viewer state
await LoadViewerState();
RestoreViewerState();
// Load inking
inkManager = await InkingManager.InitializeInking(dataFolder);
// Make sure about the visible page range
this._visiblePageRange = FindVisibleRange();
this.fileLoaded = true;
this.fileLoadingWatch.Stop();
RefreshViewer();
AppEventSource.Log.Info("ViewerPage: Finished Preparing the file in " + fileLoadingWatch.Elapsed.TotalSeconds.ToString());
this.zoomOutGrid.ItemsSource = pageThumbnails;
this.recycleTimer.Start();
}
private void InitializeZoomInView()
{
this.imagePanel.Children.Clear();
this.imagePanel.UpdateLayout();
this.inkingPageRange = new PageRange();
this._visiblePageRange = new PageRange();
this._viewerKey = new Guid();
this.pageCount = 0;
this.inkCanvasList = new List<int>();
this.renderedPages = new List<int>();
this.recyclePagesQueue = new Queue<int>();
this.renderPagesQueue = new Queue<int>();
this.isRenderingPage = false;
this.inkProcessMode = InkInputProcessingMode.Inking;
this.recycleTimer.Stop();
this.fullScreenCover.Visibility = Visibility.Visible;
this.fullScreenMessage.Text = DEFAULT_FULL_SCREEN_MSG;
this.pageNumberTextBlock.Text = "";
this.filenameTextBlock.Text = "";
this.imagePanel.Orientation = Orientation.Vertical;
this.semanticZoom.IsZoomedInViewActive = true;
ClearViewModeToggleBtn();
this.VerticalViewBtn.IsChecked = true;
this.pageThumbnails = null;
if (NavigationPage.Current != null) NavigationPage.Current.InitializeViewBtn();
AppEventSource.Log.Debug("ViewerPage: Viewer panel and settings initialized.");
}
private void scrollViewer_ViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
{
// Determine visible page range
this._visiblePageRange = FindVisibleRange();
// Show page number
this.pageNumberTextBlock.Text = this.VisiblePageRange.ToString() + " / " + this.pageCount.ToString();
// Show zoom level
this.zoomFactorTextBlock.Text = ((int)(this.scrollViewer.ZoomFactor * 100)).ToString() + "%";
// Show information grid
this.infoGrid.Opacity = INFO_GRID_OPACITY;
// The following code acts like a filter to prevent the timer ticking too frequently
if (fileLoaded && !e.IsIntermediate)
{
refreshTimer.Stop();
refreshTimer.Start();
pageNumberTextTimer.Stop();
pageNumberTextTimer.Start();
}
}
public static ViewerState SaveViewerState(string futureAccessToken, ScrollViewer scrollViewer, StackPanel imagePanel, PageRange visibleRange)
{
ViewerState viewerState = new ViewerState(futureAccessToken)
{
hOffset = scrollViewer.HorizontalOffset,
vOffset = scrollViewer.VerticalOffset,
zFactor = scrollViewer.ZoomFactor,
panelWidth = imagePanel.ActualWidth,
panelHeight = imagePanel.ActualHeight,
visibleRange = visibleRange,
lastViewed = DateTime.Now
};
if (imagePanel.Orientation == Orientation.Horizontal)
{
viewerState.isHorizontalView = true;
}
return(viewerState);
}
