[UnifiedPDF] When an incremental PDF completes its load, blank pages are still visible

[smfr]

7208a15

[UnifiedPDF] When an incremental PDF completes its load, blank pages are still visible
https://bugs.webkit.org/show_bug.cgi?id=273917
rdar://127713604

Reviewed by Tim Horton.

While loading an incremental PDF (potentially over a slow network connection), nothing
currently triggers repaints, so we never show pages as they load, nor do we repaint all
the pages when the load completes. This can leave you with blank pages until you scroll
or zoom.

Fix by hooking up some virtual functions on the plugin to give UnifiedPDFPlugin a way
to know when incremental loads progress, finish or cancel. While progressing, fire
a repeating timer every 1s to trigger repaints (we currently can't know which pages
become valid based on data ranges). Also trigger a repaint when the load completes.
This repaints use the coverage rect to only invalidate visible pages.

* Source/WebKit/WebProcess/Plugins/PDF/PDFPluginBase.h:
(WebKit::PDFPluginBase::incrementalLoadingDidProgress):
(WebKit::PDFPluginBase::incrementalLoadingDidCancel):
(WebKit::PDFPluginBase::incrementalLoadingDidFinish):
* Source/WebKit/WebProcess/Plugins/PDF/PDFPluginBase.mm:
(WebKit::PDFPluginBase::streamDidReceiveData):
(WebKit::PDFPluginBase::streamDidFinishLoading):
(WebKit::PDFPluginBase::streamDidFail):
(WebKit::PDFPluginBase::receivedNonLinearizedPDFSentinel):
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/AsyncPDFRenderer.mm:
(WebKit::AsyncPDFRenderer::coverageRectDidChange):
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/PDFDocumentLayout.h:
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/PDFDocumentLayout.mm:
(WebKit::PDFDocumentLayout::contentsSize const):
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/UnifiedPDFPlugin.h:
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/UnifiedPDFPlugin.mm:
(WebKit::UnifiedPDFPlugin::installPDFDocument):
(WebKit::UnifiedPDFPlugin::incrementalLoadingDidProgress):
(WebKit::UnifiedPDFPlugin::incrementalLoadingDidCancel):
(WebKit::UnifiedPDFPlugin::incrementalLoadingDidFinish):
(WebKit::UnifiedPDFPlugin::updatePageBackgroundLayers):
(WebKit::UnifiedPDFPlugin::incrementalLoadingRepaintTimerFired):
(WebKit::UnifiedPDFPlugin::repaintForIncrementalLoad):
(WebKit::UnifiedPDFPlugin::paintContents):

Canonical link: https://commits.webkit.org/278597@main

d648943

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	🧪 ios-wk2-wpt		✅ 🛠 wpe-skia
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	🧪 mac-AS-debug-wk2	⏳ 🧪 gtk-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	⏳ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 717b2af)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt		✅ 🛠 wpe-skia
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
❌ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 41b1367)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	⏳ 🧪 wpe-wk2
🧪 webkitperl	🧪 ios-wk2	🧪 api-mac	🧪 api-wpe
	⏳ 🧪 ios-wk2-wpt		✅ 🛠 wpe-skia
	⏳ 🧪 api-ios	🧪 mac-wk2	✅ 🛠 gtk
	🛠 tv	🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	🛠 tv-sim	🧪 mac-wk2-stress	🧪 api-gtk
	🛠 watch
	🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash d648943)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	🧪 ios-wk2-wpt		✅ 🛠 wpe-skia
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	🧪 mac-AS-debug-wk2	⏳ 🧪 gtk-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	⏳ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 278597@main (7208a15): https://commits.webkit.org/278597@main

Reviewed commits have been landed. Closing PR #28318 and removing active labels.