Multiwindow / free mode support.

[pazos]

Mostly useful for ChromeOS or big tablets. Doesn't make much sense in a phone/e-ink device.

Android docs in https://developer.android.com/guide/topics/ui/multi-window.

Some notes:

1. ~~Resize when the app has a native window to draw. That happens on ChromeOS when we're resizing but not on Android. On android resizing needs to happen in onStart() or when we have focus back, not onConfigurationChanged()~~ No longer true since https://github.com/koreader/android-luajit-launcher/pull/257 (use APP_CMD_WINDOW_RESIZED instead)
2. Disable fullscreen layout while in multiwindow mode. ~~Also need to take constraints into account to calculate width and height (to avoid draw on top of the menu bar)~~
3. ~~width and height in multiwindow mode are calculated based on reported data by window.decorView. Current implementations of android.getScreenWidth() and android.getScreenHeight will return bogus values.~~ No longer relevant since we get the true values from surfaceChanged callback.

I will label as won't fix because I won't but PR are indeed very welcome.

[HoanPiTa]

I just wanna to read a book in 2 languages in a time.

[pazos]

I just wanna to read a book in 2 languages in a time.

I'm afraid you'll need another program. There're plenty of them in android and most should support multiple instances :)

[HoanPiTa]

I just wanna to read a book in 2 languages in a time.

I'm afraid you'll need another program. There're plenty of them in android and most should support multiple instances :) Yes. I am using Neo reader, moon reader for 2 book in a time. But i like koreader :((