Request for Enhanced Touch Experience

Question

Hello everyone, I've been using PDFViewer and encountered a few issues that I need help with:

1. When using touch input, pinch-to-zoom gestures on a PDF often cause the application to crash. This issue doesn't occur when using a mouse.

2. Deleting ink annotations while using touch input leads to the app crashing. Here are the specific steps to reproduce the issue:
   1. Click the "Open PDF" button and open any PDF file.
   2. (Optional) Pinch-to-zoom the PDF using touch input.
   3. Click "Ink Annotation" and draw any ink annotation.
   4. Check the "Delete Annotation" checkbox.
   5. Select and delete a few ink annotations.
   6. At this point, the app may crash immediately, or the ink annotations may be removed but the selection box remains. Clicking on another ink annotation will then cause the app to crash.

3. When printing a PDF, if I don't choose "Silent Print," a dialog box will pop up. In this dialog box, there is an option called "Print to File." When I check this box, another "Save As" dialog appears. I would like to set the filename in this dialog to the value of PrinterSettings.DocumentName, but I don't know how to do this. I would appreciate your help.

4. I would like to automatically save a PDF with ink annotations when a user leaves the page. Is there a way to determine if ink annotations exist on a PDF?

Attachment: Syncfusion_PDF_6ac9a105.zip

Manigandan Shanmugam · Accepted Answer

We
have included the fix for this issue “Selection is not disabled when we
delete ink annotation using touch interaction” fix in our latest weekly
release (22.2.7).Please
use the below link to download our latest NuGet,

Nuget Link:https://www.nuget.org/packages/Syncfusion.PdfViewer.WPF/22.2.7Feedback Link:https://www.syncfusion.com/feedback/45230/selection-is-not-disabled-when-we-delete-ink-annotation-using-touch-interaction

Manigandan Shanmugam · Answer

Rhyme,

1. When using touch input, pinch-to-zoom gestures
  on a PDF often cause the application to crash. This issue doesn't occur when
  using a mouse.

We are not able to
  reproduce the reported issue on our end with the provided details. We have
  attached a video which we tried to reproduce the reported issue. We request
  you to kindly share the document that you have used, Syncfusion NuGet version
  and the detailed replication steps. This will help us to investigate further
  on this.

2. Deleting ink annotations while using touch input
  leads to the app crashing. Here are the specific steps to reproduce the
  issue:
     1. Click the "Open PDF" button and open
  any PDF file.
     2. (Optional) Pinch-to-zoom the PDF using touch
  input.
     3. Click "Ink Annotation" and draw any
  ink annotation.
     4. Check the "Delete Annotation"
  checkbox.
     5. Select and delete a few ink annotations.
     6. At this point, the app may crash immediately, or
  the ink annotations may be removed but the selection box remains. Clicking on
  another ink annotation will then cause the app to crash.

With the provided
  details, the reported issue “Selection is not disabled when we delete ink
  annotation using touch interaction” can be reproduced on our end. We will
  analyze and update the further details on July 12, 2023.

3. When printing a PDF, if I don't choose "Silent Print," a
  dialog box will pop up. In this dialog box, there is an option called
  "Print to File." When I check this box, another "Save As"
  dialog appears. I would like to set the filename in this dialog to the value
  of PrinterSettings.DocumentName, but I don't know how to do this. I would
  appreciate your help.

In our WPF PDF Viewer, as
  we are using the MSDN print internally, we can’t be able to set the document
  name in the save as dialog box as it was handled by the `Microsoft Print To PDF`
  printer. This was the default behavior of the `Microsoft Print To PDF` printer.
  You can also check this behavior while printing in adobe and chrome.

4. I would like to
  automatically save a PDF with ink annotations when a user leaves the page.

We can save the PDF document,
  when we leave the page with making any changes on the ink annotation, this
  can be achieved by using PdfViewer_InkAnnotationChanged
  event. Please find
  the attached link about the ink annotation changed event. Also, we have
  attached the code snippet for your reference.

private void PdfViewer_InkAnnotationChanged(object sender,
    InkAnnotationChangedEventArgs e)
            {
                MemoryStream stream = new MemoryStream();

pdfViewer.LoadedDocument.Save(stream);
     
                pdfViewer.Load(stream);
           
    }

Is there a way to determine if ink annotations exist on a PDF?

Yes, we can find the whether
  the ink annotation is present in the pdf document or not by using the
  following code snippet in the PdfViewer_DocumentLoaded
  event.

private void PdfViewer_DocumentLoaded(object sender,
    EventArgs args)
            {
                bool
    isinkPresent = false;
     
                for (int i = 0; i < pdfViewer.LoadedDocument.Pages.Count; i++)
                {
                    for (int j = 0; j <
    pdfViewer.LoadedDocument.Pages[i].Annotations.Count; j++)
                    {
                        if (pdfViewer.LoadedDocument.Pages[i].Annotations[j] is PdfLoadedInkAnnotation)
                        {
                            isinkPresent = true;
                        }
                    }
                }
           
    }

Attachment: Video_861d3708.zip

Rhyme · Answer

Hello Manigandan,Thank you for your response. Regarding the first issue, I admit that it's difficult to reproduce, and it seems to only occur on computers with insufficient memory. When I encounter this problem again, I will record a screencast and send it to you.As for the second issue, I look forward to your further analysis and resolution. I will continue to monitor the situation.Concerning the third issue, is it possible for me to call MSDN to print and set the document name in the "Save As" dialog box? If so, I would appreciate it if you could provide me with an example code.The other issues have been resolved, and I thank you for your assistance.

Manigandan Shanmugam · Answer

Hi Rhyme,

Thank you for
  your response. Regarding the first issue, I admit that it's difficult to reproduce,
  and it seems to only occur on computers with insufficient memory. When I
  encounter this problem again, I will record a screencast and send it to you.

Thanks for
  the update. If the issue was reproduced again on your end, please share the
  below mentioned details also with the recorded screencast.

System
  specifications.Syncfusion
  WPF Pdfviewer NuGet versionVisual
  studio version..NET\.NET
  Framework versionProject
  environment(32-bit/64-bit)Used
  document if it is document specific.Stack
  trace if any.

As for the
  second issue, I look forward to your further analysis and resolution. I will
  continue to monitor the situation.

As we said
  earlier, we will update further details on July 12, 2023.

Concerning
  the third issue, is it possible for me to call MSDN to print and set the
  document name in the "Save As" dialog box? If so, I would
  appreciate it if you could provide me with an example code.

The DocumentName property of the printer settings is used
  to pass information about the document name of the print document.
  Additionally, since the "Microsoft print to pdf" printer receives
  the printed document information and shows its own save as dialogue, we can't
  customize the dialogue box's file name.

Krithika Ganesan · Answer

We have confirmed the issue “Selection is not disabled when we
delete ink annotation using touch interaction" as a defect in our product and we will include the fix
into our upcoming weekly NuGet release on 25th July 2023. Please use the below feedback link to track the status
of the reported bug.https://www.syncfusion.com/feedback/45230/selection-is-not-disabled-when-we-delete-ink-annotation-using-touch-interaction Note: If you require a patch for the reported issue in any of our
Essential Studio Main or SP release version, then kindly let us know the
version, so that we can provide a patch in that version based on our SLA
policy. Disclaimer: “Inclusion of this solution in the weekly
release may change due to other factors including but not limited to QA checks
and works reprioritization.”

Rhyme · Answer

Hello Krithika,I'm glad to hear that you're willing to address the issue I've encountered. Additionally, I've noticed that the lock annotation feature doesn't seem to work as expected; perhaps I'm doing something wrong. Here are the steps I've followed:Open any PDFSelect the Ink Annotation tool and create an annotationChoose Locked Annotation; at this point, the annotation should be lockedHowever, I can still select and move the annotationAttachment: Syncfusion_PDF_6ae52de9.zip

Manigandan Shanmugam · Answer

Hi
Rhyme,We
have investigated the reported issue with the sample you have provided. This
was occur due to sample level code, in which IsChecked property of the
"delete" annotation checkbox was used instead of the "lock"
annotation checkbox. Please find below modified code snippet and also attached
a modified sample for your reference.

var isLocked =
  LockedAnnotation.IsChecked == true;

Attachment: Syncfusion_PDF_6ae52de9_9242d56a.zip

Rhyme · Answer

Hello, Manigandan. Thank you for your response. I have used the attachment provided in your reply, but it seems that the issue of being able to select and move the ink is still present. Could this be due to my own mistake?

Krithika Ganesan · Answer

Hi Rhyme,When we update default
annotation settings it will work for annotation, which are going to add but it
won’t work for existing annotations in the loaded document. In order to achieve
your requirement, to lock all ink annotations present in the document. We can
set lock property for the selected annotation using  annotation change
event. Please find the below code snippet and sample, which will set lock
property of  any of the selected ink annotations based on the checkbox value.

private void
  PdfSyncfusionDocument_InkAnnotationChanged(object sender,
  InkAnnotationChangedEventArgs e)
  {
       if (e.Action ==
  AnnotationChangedAction.Select && DeleteAnnotation.IsChecked == true)
       {
          
   SyncfusionSingle.Instance.PdfSyncfusionDocument.DeleteAnnotation(e.Name,
  e.PageNumber);
       }
       else if (e.Action ==
  AnnotationChangedAction.Select)
       {
           
  e.Settings.IsLocked = LockedAnnotation.IsChecked == true;
       }
  }

Attachment: Sample_53daf5bf.zip

Rhyme · Answer

Hello, Krithika. Thank you for your prompt response. The added comments can now be fixed in place. I have another query. Is it possible to make the ink not selectable (without a selection box) and then revert it back to a selectable state after unlocking?

Manigandan Shanmugam · Answer

Hi Rhyme,

As per
your requirement, we have analysed and determined that we are not able to
disable the selection of annotations using the locked feature in WPF PdfViewer.
However, we have created a workaround sample to achieve your requirement to
disable the selection of annotations by using the flatten property of the
PdfLoaded document, which is attached below for your reference. 
In this sample, when we checked the locked annotation
check box, we were flattening all the annotations present in the document.
While flattening the annotations, they were drawn as a graphic, so we couldn't
select or modify them. And when we unselect the locked annotation check box, we
reload the original documents, which are already saved. Also, we have handled
saving the newly added annotations to the original documents, which were added
at the time of flattening.Attachment: sample_7545f1d6.zip

Rhyme · Answer

Thank you, Manigandan. I used the sample code you provided and found that locking and unlocking causes ink strokes to be lost. Since I cannot disable comment selection using the lock feature in the WPF PdfViewer, I will make some adjustments on my end to prevent the program from crashing.

Additionally, I'd like to mention that when annotations are selected during touchscreen operations, occasionally the PDF is unable to zoom in or out even if the user clicks on a blank area next to the annotation. If possible, please assist in resolving this issue.

Rajavignesh BalaSankar · Answer

Rhyme, please find the details for your queries in the
below table.

I used the sample code you provided and found that
  locking and unlocking causes ink strokes to be lost. Since I cannot disable
  comment selection using the lock feature in the WPF PdfViewer, I will make
  some adjustments on my end to prevent the program from crashing.

As we said earlier, the lock feature of WPF PdfViewer
  disables only the property changes and the selection won’t be disabled. The
  ink stroke was removed as we have missed to maintain the original document
  properly. We have modified the sample and attached below for your reference.

Additionally, I'd like to mention that when annotations
  are selected during touchscreen operations, occasionally the PDF is unable to
  zoom in or out even if the user clicks on a blank area next to the
  annotation. If possible, please assist in resolving this issue.

Since, this was a new query, we have splitted this one as
  a new forum to avoid misunderstanding. Please follow this query in the below
  mentioned forum link,
  https://forumassist.syncfusion.com/183537

Attachment: Sample_53daf5bf_39a021b2.zip

Rhyme · Answer

Hello Manigandan,As I mentioned before, there has been an issue where the pinch-to-zoom gesture causes the application to crash.I had one of my colleagues assist in confirming this issue. Interestingly, he didn't come across any crashes related to the pinch-to-zoom gesture. Instead, he discovered that occasionally a null reference exception occurs when opening a PDF.I must apologize, as my colleague does not have development experience and is not particularly proficient at computer operations. He can only review the application's logs when an error occurs. According to the log information, it appears that the null reference is caused by UpdateOffset.I've captured the relevant error information in a screenshot. If there are any points that require further clarification, I'll provide as much assistance as I can.

Manigandan Shanmugam · Answer

Hi Rhyme,We are unable the reproduce the
reported issue on our end. We suspect that the reported issue occurred with the
specific PDF document used. If it is possible for you to share the PDF
document which you have used to reproduce the reported issue and it will
be helpful for us to reproduce the problem on our end.

Krithika Ganesan · Answer

Hi Rhyme,2023 Volume 2 SP Release has been planned for this week,
so we will not be having a weekly release this week (July 25, 2023).
So, we have created the patch fix in the version 22.1.34.The reported issue “Selection is not disabled when we delete ink annotation
using touch interaction" has been fixed and the patch for this fix can be
downloaded from the following location. We have created the patch with
essential studio version 22.1.34.Recommended approach - exe will perform automatic configuration. Please find the patch setup from below location: https://syncfusion.com/Installs/support/patch/22.1.34/1571619/F183376/SyncfusionPatch_22.1.34_1571619_7252023060356128_F183376.exeAdvanced approach – use only if you have specific needs and
can directly replace existing assemblies for your build environment. Please find the patch assemblies alone from below location:https://syncfusion.com/Installs/support/patch/22.1.34/1571619/F183376/SyncfusionPatch_22.1.34_1571619_7252023060356128_F183376.zipNuget:https://syncfusion.com/Installs/support/patch/22.1.34/1571619/F183376/SyncfusionNuget_22.1.34_1571619_7252023060356128_F183376.zipAssembly Version: 22.1.34Installation Directions : This patch should replace the files
“Syncfusion.Pdf.Base,Syncfusion.PdfViewer.WPF” under the following
folder. $system drive:\ Files\Syncfusion\Essential Studio\$Version #
\precompiledassemblies\$Version#\4.6 Eg : $system drive:\Program Files\Syncfusion\Essential
Studio\9.3.0.61\precompiledassemblies\9.3.0.61\4.0 To automatically run the Assembly Manager, please check the
Run assembly manager checkbox option while installing the patch. If this option
is unchecked, the patch will replace the assemblies in precompiled assemblies’
folder only. Then, you will have to manually copy and paste them to the
preferred location or you will have to run the Syncfusion Assembly Manager
application (available from the Syncfusion Dashboard, installed as a shortcut
in the Application menu) to re-install assemblies. Note : You can change how you receive bug fixes by navigating to the
following link and updating your preferences. https://www.syncfusion.com/support/directtrac/patchesDisclaimer : Please note that we have created this patch for
version 22.1.34 specifically to resolve the following issue(s) reported in
this/the forum(s). 183376If you have received other patches for the same version for
other products, please apply all patches in the order received. This fix
will be included in our upcoming weekly release which will be available in
August 2023.   Please find the feedback link below,https://www.syncfusion.com/feedback/45230/selection-is-not-disabled-when-we-delete-ink-annotation-using-touch-interaction

Rhyme · Answer

Dear Krithika,Thank you for your prompt response and for providing the patch fix for the reported issue. I appreciate your efforts in resolving this matter.However, I would like to inform you that I am currently using version 22.1.37. Could you please confirm whether this patch is compatible with the latest version or if I need to downgrade to version 22.1.34?Thank you for your assistance.

Manigandan Shanmugam · Answer

Rhyme, the patch creation is not supported in any weekly
NuGet version. As you are using weekly NuGet version 22.1.37, We will include
this fix in our weekly NuGet package, which will be available on August 1st
week.

Rhyme · Answer

Thanks for your help, Manigandan. I'll be waiting for next week's release.

Rhyme · Answer

Thank youI can't wait to update and test it out in my project. It's always reassuring to see such responsive and efficient support from the development team.

Swetha Srikumar · Answer

Thanks for the feedback.Please let us know if you need any assistance.