Add PDF printing functionality to editor components

Enabled PDF printing in `SenderPdfImageEditor` and `SenderPdfImageEditorToolbar`. Added `CanPrintPdf` property to determine print availability and a new `OnPrintPdfAsync` method for handling print logic via JavaScript interop. Updated the toolbar with a "Print" button that triggers the print functionality.

Implemented the `printDataUrlPdf` function in `envelope-editor.js` to handle printing from a data URL. This function creates an iframe, loads the PDF, and invokes the browser's print functionality with proper cleanup of resources.

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditor.razor

@@ -25,7 +25,9 @@
                                         ZoomIn="OnZoomInAsync"
                                         SetZoomPercent="OnSetZoomPercentAsync"
                                         CanDownloadPdf="@CanDownloadPdf"
-                                        DownloadPdf="OnDownloadPdfAsync" />
+                                        CanPrintPdf="@CanPrintPdf"
+                                        DownloadPdf="OnDownloadPdfAsync"
+                                        PrintPdf="OnPrintPdfAsync" />
         </div>
     }
 
@@ -150,6 +152,7 @@
     private const int MaxZoomPercent = 300;
     private const int ZoomStepPercent = 5;
     private bool CanDownloadPdf => !string.IsNullOrWhiteSpace(PdfDataUrl);
+    private bool CanPrintPdf => !string.IsNullOrWhiteSpace(PdfDataUrl);
 
     private static string GetFieldStyle(SenderPdfFieldOverlay field, double pageWidthPt, double pageHeightPt)
     {
@@ -397,6 +400,17 @@
             "application/pdf");
     }
 
+    private async Task OnPrintPdfAsync()
+    {
+        if (string.IsNullOrWhiteSpace(PdfDataUrl))
+            return;
+
+        await JSRuntime.InvokeVoidAsync(
+            "envelopeEditor.printDataUrlPdf",
+            PdfDataUrl,
+            "application/pdf");
+    }
+
     private void OnEditorMouseUp(MouseEventArgs args)
     {
         _draggedFieldIndex = null;

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/PdfEditor/SenderPdfImageEditorToolbar.razor

@@ -86,7 +86,7 @@
     </div>
 
     <div class="sender-image-toolbar__group sender-image-toolbar__group--actions" role="group" aria-label="Document actions">
-        <button type="button" class="sender-image-toolbar__icon-btn" title="Print" disabled>
+        <button type="button" class="sender-image-toolbar__icon-btn" title="Print" disabled="@(!CanPrintPdf)" @onclick="PrintPdfAsync">
             <svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" viewBox="0 0 24 24" fill="none" aria-hidden="true">
                 <path d="M7 9V4H17V9" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
                 <rect x="5" y="9" width="14" height="8" rx="2" stroke="currentColor" stroke-width="2" />
@@ -150,9 +150,15 @@
     [Parameter]
     public bool CanDownloadPdf { get; set; }
 
+    [Parameter]
+    public bool CanPrintPdf { get; set; }
+
     [Parameter]
     public EventCallback DownloadPdf { get; set; }
 
+    [Parameter]
+    public EventCallback PrintPdf { get; set; }
+
     private int CurrentPageDisplay => CurrentPage > 0 ? CurrentPage : 0;
     private int TotalPagesDisplay => TotalPages > 0 ? TotalPages : 0;
     private int ZoomPercentDisplay => ZoomPercent > 0 ? ZoomPercent : 100;
@@ -238,4 +244,10 @@
         if (DownloadPdf.HasDelegate)
             await DownloadPdf.InvokeAsync();
     }
+
+    private async Task PrintPdfAsync()
+    {
+        if (PrintPdf.HasDelegate)
+            await PrintPdf.InvokeAsync();
+    }
 }

EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/js/envelope-editor.js

@@ -243,5 +243,82 @@ window.envelopeEditor = {
         host.appendChild(link);
         link.click();
         host.removeChild(link);
+    },
+
+    printDataUrlPdf: async function (dataUrl, mimeType) {
+        if (!dataUrl || typeof dataUrl !== 'string') {
+            return;
+        }
+
+        let objectUrl = null;
+        let printSrc = dataUrl;
+
+        if (dataUrl.startsWith('data:')) {
+            try {
+                const response = await fetch(dataUrl);
+                const blob = await response.blob();
+                objectUrl = URL.createObjectURL(blob);
+                printSrc = objectUrl;
+            } catch {
+                printSrc = dataUrl;
+            }
+        }
+
+        const frame = document.createElement('iframe');
+        frame.style.position = 'fixed';
+        frame.style.right = '0';
+        frame.style.bottom = '0';
+        frame.style.width = '0';
+        frame.style.height = '0';
+        frame.style.border = '0';
+        frame.setAttribute('aria-hidden', 'true');
+
+        const host = document.body || document.documentElement;
+        host.appendChild(frame);
+
+        let cleaned = false;
+        const cleanup = function () {
+            if (cleaned) {
+                return;
+            }
+
+            cleaned = true;
+
+            if (frame.parentNode) {
+                frame.parentNode.removeChild(frame);
+            }
+
+            if (objectUrl) {
+                URL.revokeObjectURL(objectUrl);
+                objectUrl = null;
+            }
+        };
+
+        frame.onload = function () {
+            try {
+                const frameWindow = frame.contentWindow;
+                if (!frameWindow) {
+                    cleanup();
+                    return;
+                }
+
+                frameWindow.addEventListener('afterprint', function () {
+                    window.setTimeout(cleanup, 250);
+                }, { once: true });
+
+                window.addEventListener('focus', function () {
+                    window.setTimeout(cleanup, 1500);
+                }, { once: true });
+
+                frameWindow.focus();
+                frameWindow.print();
+            } catch {
+                cleanup();
+            }
+        };
+
+        frame.src = printSrc;
+
+        window.setTimeout(cleanup, 120000);
     }
 };