EPUB: Can't swipe to scroll pages on some documents

[michalrentka]

Swiping to scroll doesn't seem to work on some documents. Tapping corners works fine. It's reproducible in the woodworking epub I shared with you before.

https://www.dropbox.com/scl/fi/t4af5wzq3i3o33rkf4ql1/IMG_1164.MOV?rlkey=q59mvmjd6uowxzcwqthhriy7n&dl=0

[AbeJellinek]

Just with the pencil, right?

[michalrentka]

Just with the pencil, right?

Yes, you're right. I didn't notice that initially, sorry.

[AbeJellinek]

See if that commit fixes it. If it doesn't, could you apply this patch

diff --git a/src/dom/epub/flow.ts b/src/dom/epub/flow.ts
index 46ddd033..4157e8f9 100644
--- a/src/dom/epub/flow.ts
+++ b/src/dom/epub/flow.ts
@@ -894,6 +894,7 @@ export class PaginatedFlow extends AbstractFlow {
 			}
 		}
 
+		console.log('Pointer down', event.clientX, event.clientY, event.pointerType, event.target);
 		this._touchDown = true;
 		this._touchStartX = event.clientX;
 		this._touchStartY = event.clientY;
@@ -906,6 +907,7 @@ export class PaginatedFlow extends AbstractFlow {
 				|| !this._iframeDocument.getSelection()!.isCollapsed) {
 			return;
 		}
+		console.log('Pointer move', event.clientX, event.clientY, event.pointerType, event.target);
 		let swipeAmount = (event.clientX - this._touchStartX) / PAGE_TURN_SWIPE_LENGTH_PX;
 		// If on the first/last page, clamp the CSS variable so the indicator doesn't expand all the way
 		if (swipeAmount < 0 && !this.canNavigateRight()) {
@@ -924,6 +926,7 @@ export class PaginatedFlow extends AbstractFlow {
 				|| !this._iframeDocument.getSelection()!.isCollapsed) {
 			return;
 		}
+		console.log('Pointer up', event.clientX, event.clientY, event.pointerType, event.target);
 		this._swipeIndicators.style.setProperty('--swipe-amount', '0');
 		this._touchDown = false;
 
@@ -964,6 +967,7 @@ export class PaginatedFlow extends AbstractFlow {
 			// No event.buttons check - "buttons" have now been released
 			return;
 		}
+		console.log('Pointer cancel', event.clientX, event.clientY, event.pointerType, event.target);
 		this._touchDown = false;
 		this._swipeIndicators.style.setProperty('--swipe-amount', '0');
 	};
@@ -986,6 +990,7 @@ export class PaginatedFlow extends AbstractFlow {
 	}, 100, { leading: true, trailing: false, maxWait: 400 });
 
 	private _handleSelectionChange = () => {
+		console.log('Selection change', this._iframeDocument.getSelection()!.isCollapsed, this._iframeDocument.getSelection()!.toString());
 		if (this._iframeDocument.getSelection()!.isCollapsed) {
 			return;
 		}

and connect via Safari devtools, reproduce the issue, and send me the output?

Thank you!

[michalrentka]

@AbeJellinek sorry it took me so long. It doesn't seem to work, here's the output when dragging from right to left from within text

And a longer drag from left to right starting outside of epub

And here's finger drag, the only difference seems to be pointer type

[AbeJellinek]

OK, @michalrentka, try after that commit?

[michalrentka]

@AbeJellinek well, it's a bit better, but still broken :). It's quite hard to describe, but it looks like if I move the pen slowly, it seems to register it properly more often (not 100% though, some slow drags still abort). If I move the pen quickly, it never seems to work. Also, it works better if I start dragging from side (outside of content), but it also worked when I started dragging from content a few times (maybe it doesn't work when I start dragging from text, but a few times I missed all text and dragged from inbetween).

Here's a video, maybe you'll notice something else: https://www.dropbox.com/scl/fi/v0dnn9jiu5740l48n4v6i/IMG_1503.mov?rlkey=ojp7wi6gsu90jc1e28msxz73t&dl=0