From 0daf51c340718429774ef93a2be47dcf5242c297 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 23 Dec 2020 11:13:43 +0100
Subject: [PATCH] [Scripting] Try to ensure that the `WillPrint`/`DidPrint`
 respectively `DidSave` events are always dispatched

Note that currently the `DidSave` event is not *guaranteed* to actually be dispatched if there's any errors during saving, which is easily fixed by simply moving it to occur in the `finally`-handler in `PDFViewerApplication.save` method.

For the `WillPrint`/`DidPrint` events, things are unfortunately more complicated. Currently these events will *only* be dispatched iff the printing request comes from within the viewer itself (e.g. by the user clicking on the "Print" toolbar button), however printing can be triggered in a few additional ways:
 - In the GENERIC viewer:
   - By the <kbd>Ctrl</kbd>+<kbd>P</kbd> keyboard shortcut.
 - In the MOZCENTRAL viewer, i.e. the Firefox built-in viewer:
   - By the <kbd>Ctrl</kbd>+<kbd>P</kbd> keyboard shortcut.
   - By the "Print" item, as found in either the Firefox "Hamburger menu" or in the browser-window menu.

In either of the cases described above, no `WillPrint`/`DidPrint` events will be dispatched. In order to *guarantee* that things work in the general case, we thus have to move the `dispatchEventInSandbox` calls to the "beforeprint"/"afterprint" event handlers instead.
---
 web/app.js | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/web/app.js b/web/app.js
index c2ddd2b48..6040dc854 100644
--- a/web/app.js
+++ b/web/app.js
@@ -1047,16 +1047,16 @@ const PDFViewerApplication = {
       .then(data => {
         const blob = new Blob([data], { type: "application/pdf" });
         downloadManager.download(blob, url, filename, sourceEventType);
-
-        this._scriptingInstance?.scripting.dispatchEventInSandbox({
-          id: "doc",
-          name: "DidSave",
-        });
       })
       .catch(() => {
         this.download({ sourceEventType });
       })
       .finally(() => {
+        this._scriptingInstance?.scripting.dispatchEventInSandbox({
+          id: "doc",
+          name: "DidSave",
+        });
+
         this._saveInProgress = false;
       });
   },
@@ -1967,6 +1967,11 @@ const PDFViewerApplication = {
   },
 
   beforePrint() {
+    this._scriptingInstance?.scripting.dispatchEventInSandbox({
+      id: "doc",
+      name: "WillPrint",
+    });
+
     if (this.printService) {
       // There is no way to suppress beforePrint/afterPrint events,
       // but PDFPrintService may generate double events -- this will ignore
@@ -2028,6 +2033,11 @@ const PDFViewerApplication = {
   },
 
   afterPrint() {
+    this._scriptingInstance?.scripting.dispatchEventInSandbox({
+      id: "doc",
+      name: "DidPrint",
+    });
+
     if (this.printService) {
       this.printService.destroy();
       this.printService = null;
@@ -2060,17 +2070,7 @@ const PDFViewerApplication = {
     if (!this.supportsPrinting) {
       return;
     }
-    this._scriptingInstance?.scripting.dispatchEventInSandbox({
-      id: "doc",
-      name: "WillPrint",
-    });
-
     window.print();
-
-    this._scriptingInstance?.scripting.dispatchEventInSandbox({
-      id: "doc",
-      name: "DidPrint",
-    });
   },
 
   bindEvents() {