pdf.js Mobile: Long press on text produces just 2 handle bars without having any text selected

[Dima-Android]

[mrtcode]

@Dima-Android This is a tough issue because we use our custom, non-native selection layer. But in #226 I added artificial text handles on artificial touch and hold even. So please check it out and let me know if this works.

[Dima-Android]

When i long press on the text, the text gets selected and the fake handles appear and they look good! My custom popup with buttons also appear in the correct position.
The problem now is there is no way to drag left or right handle to extend selection. I tried both with mouse and finger, the moment i touch the handles selection disappears.
Also of the things that do work well - if i press the left mouse button and drag the mouse the text does get selected along the way.

[mrtcode]

Can you reproduce this issue if you open Reader view-dev directly in your browser on a mobile device? You can do that by listening view-dev on 0.0.0.0:3002, see the webpack config. I tried on iOS and moving handles seems to work, while my Android phone with Chrome seems to be too old to load the Reader View…

[Dima-Android]

Not on port 3002, but on port 3000, which is what is set in webpack config.
What i did is that i ran npm start on macbook and then on Android phone in Chrome i opened http://192.168.1.105:3000/dev/reader.html?type=pdf
Long pressing with finger on text doesn't do anything, I only feel haptic feedback from the phone as I long press but no text is selected nor handles appear. Single tap on text doesnt select text either(I mean it shouldn't but just FYI)
Connecting a mouse to the phone and double clicking on the text works and produces exactly same thing as it would do on desktop chrome - text is selected and popup appears.

That's on f7a50ff

Also did i do it right? What is view-dev?

[mrtcode]

You need to use npm run view-dev, because npm start, that you just tried, is for the whole reader, not for the mobile view.

[Dima-Android]

Alright, this time i tried with this
http://192.168.1.105:3001/view-dev/view.html?type=pdf
long press with finger on text does nothing, double click with the mouse selects text.

[mrtcode]

Are you sure you are testing that on #226?

[Dima-Android]

Sorry! Now that I've tested on #226 selection works well in Chrome!

Which means that when reader is displayed inside of our Android app's WebView something interferers with dragging the handle to extend selection...

I looked at what might be interfering with it on the Kotlin side, but I can't find it yet (I mean there are things like DragAnchors and we do intercept MotionEvent.ACTION_DOWN but we do not consume it, so it's propagated. Even when i comment out all of those interceptors the reader selection issue still remains). And also very same ReaderScreen is opened for both HTML/EPUB and PDF and for HTML/EPUB the selection and dragging works well.

Screen_recording_20260708_202548.mp4

[mrtcode]

OK, my coding agent put Reader with that PR into our Android app and ran it in an emulator. And this is what it found:

---

Suggested Android fix

The issue is in the Android app popup dismissal path.

When the PDF selection action menu is visible, touching a WebView selection handle is treated by Compose Popup as an outside click. That calls HtmlEpubActionMenuPopup.onDismissRequest, which currently calls viewModel.dismissActionMenu(). dismissActionMenu() then calls deselectText(), which runs:

window._view.selectAnnotations([]);

So the PDF selection is cleared immediately after the handle drag starts.

The fix should be to let popup outside-dismiss hide only the Android action menu, without clearing the reader selection:

// HtmlEpubActionMenuPopup.kt
val onDismiss: () -> Unit = {
    viewModel.dismissActionMenu(clearSelection = false)
}

// HtmlEpubReaderViewModel.kt
fun dismissActionMenu(clearSelection: Boolean = true) {
    updateState {
        copy(selectedTextParamsRects = null)
    }
    if (clearSelection) {
        viewModelScope.launch {
            htmlEpubReaderWebCallChainExecutor?.deselectText()
        }
    }
}

Explicit menu actions keep the old behavior because they still call dismissActionMenu() with the default clearSelection = true.

I also tried dismissOnClickOutside = false, but that is worse: a normal outside tap clears the reader selection while leaving the Compose action menu visible.

Validation from emulator:

• Handle drag no longer clears the selection:
  • bad clears after selection during drag: 0
  • drag ranges=0: 0
  • drag ranges=1: 214
• Normal outside tap still clears the selection and hides the menu.
• ./gradlew :app:assembleDevDebug passes.

[Dima-Android]

Well I be damned! The selection does work after applying suggested fixes! Thank you!

[mrtcode]

Now the question is regarding selection handles. They should probably look more Android-like, as currently I made them iOS-like. But does Android have more or less consistent handles across different devices and versions?

[Dima-Android]

I think they are pretty consistent across devices. The handles that are currently used by Reader for EPUB look pretty close to how they look in Chrome with only difference being the chrome's are dark blue.