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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
package org.mozilla.tv.firefox.webrender
import android.view.KeyEvent
import android.webkit.ValueCallback
import mozilla.components.concept.engine.EngineView
import org.mozilla.tv.firefox.MainActivity
import org.mozilla.tv.firefox.ext.backForwardList
import org.mozilla.tv.firefox.ext.checkYoutubeBack
import org.mozilla.tv.firefox.ext.handleYoutubeBack
import org.mozilla.tv.firefox.ext.isUriYouTubeTV
/**
* youtube/tv does not handle their back stack correctly. Going back in history visits redirects
* which do not alter the UI. Users must navigate back by pressing ESC. To deal with this,
* we remap BACK presses to ESC. When the top of YouTube's back stack is reached, or we are in
* an unexpected state, we back all the way out of YouTube.
*
* If YouTube guide-list element is focused or we are in an unexpected state:
* - Suppress the DOWN,BACK key event
* - Change the UP,BACK key event to go back in history before YouTube
* Else:
* - Dispatch ESC key event
*/
class YouTubeBackHandler(private val engineView: EngineView, private val activity: MainActivity) {
private val preYouTubeIndexHistory: MutableList<Int> = mutableListOf()
private var currentPreYouTubeIndex: Int? = null
fun onBackPressed() {
val backOrMoveFocus = ValueCallback<String> { shouldExitPage ->
if (shouldExitPage == "true") {
goBackBeforeYouTube()
} else {
// Esc will move focus within YouTube
activity.dispatchKeyEvent(KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_ESCAPE))
activity.dispatchKeyEvent(KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_ESCAPE))
}
}
engineView.checkYoutubeBack(backOrMoveFocus)
}
fun onUrlChanged(url: String) {
if (!url.isUriYouTubeTV) currentPreYouTubeIndex = null
else if (currentPreYouTubeIndex == null) {
// Store the current (pre-YouTube) backForwardIndex when the URL first changes to YouTube
currentPreYouTubeIndex = engineView.backForwardList.currentIndex
}
}
/**
* We only want to add indexes to the list that are a forward navigation from non-YouTube site
* to YouTube. If you hit back from a non-YouTube site to YouTube, we do not want to save the index
* of that non-YouTube site. The web history list is only updated after loading has completed,
* which is why this function is called from onLoadingStateChanged callback.
*/
fun onLoadComplete() {
// Don't store anything if we aren't navigating to YouTube
val preYouTubeIndex = currentPreYouTubeIndex ?: return
val navigationWasForward = preYouTubeIndex < engineView.backForwardList.currentIndex
if (navigationWasForward) {
preYouTubeIndexHistory.add(preYouTubeIndex)
}
}
fun goBackBeforeYouTube() = engineView.handleYoutubeBack(getIndexToGoBackTo())
private fun getIndexToGoBackTo(): Int {
return if (preYouTubeIndexHistory.isEmpty()) 0
else preYouTubeIndexHistory.removeAt(preYouTubeIndexHistory.lastIndex)
}
}