Mozilla EngineView Geckoview 渲染元素隐藏在工具栏后面

如何解决Mozilla EngineView Geckoview 渲染元素隐藏在工具栏后面

使用 android mozilla mobile android 组件构建浏览器。我有一个动态顶部工具栏和一个动态底部工具栏，覆盖 mozilla.components.concept.engine.EngineView（在幕后使用 Geckoview）。工具栏在引擎视图滚动时显示/隐藏。

问题是网页元素隐藏在本机工具栏后面。例如，youtube.com 主页具有基于 html 的动态顶部和底部工具栏，它们隐藏在我的本机工具栏后面。

mozilla.components.feature.session.behavior.EngineViewBottomBehavior 类更改操作方法告诉引擎视图在哪里放置元素。如果我的应用程序中有一个工具栏，这会起作用。例如，如果我只有一个顶部工具栏，则 topToolbarChangedAction() 设置垂直剪辑，而 youtube.com html 顶部工具栏位于我的本机工具栏下方。但是，当我有 2 个工具栏（底部和顶部）需要同时定位顶端和底端的 html 元素时，我不知道如何解决。下面是来自 mozilla 行为类的一段代码，它被调用如下

(getSwipeRefreshLayout().layoutParams as CoordinatorLayout.LayoutParams).behavior =
                EngineViewbrowserToolbarBehavior(
                    context,null,getSwipeRefreshLayout(),toolbarHeight,toolbarPosition
                )

https://github.com/mozilla-mobile/android-components/blob/master/components/feature/session/src/main/java/mozilla/components/feature/session/behavior/EngineViewBrowserToolbarBehavior.kt

  /**
 * A [CoordinatorLayout.Behavior] implementation that allows the [EngineView] to automatically
 * size itself in relation to the Y translation of the [browserToolbar].
 *
 * This is useful for dynamic [browserToolbar]s ensuring the web content is displayed immediately
 * below / above the toolbar even when that is animated.
 *
 * @param context [Context] used for varIoUs Android interactions
 * @param attrs XML set attributes configuring this
 * @param engineViewParent [nestedScrollingChild] parent of the [EngineView]
 * @param toolbarHeight size of [browserToolbar] when it is placed above the [EngineView]
 * @param whether the [browserToolbar] is placed above or below the [EngineView]
 */
class EngineViewbrowserToolbarBehavior(
    context: Context?,attrs: AttributeSet?,engineViewParent: View,toolbarHeight: Int,toolbarPosition: ToolbarPosition
) : CoordinatorLayout.Behavior<View>(context,attrs) {

    private val engineView = engineViewParent.findViewInHierarchy { it is EngineView } as EngineView?
    private var toolbarChangedAction: (Float) -> Unit?
    private val bottomToolbarChangedAction = { newToolbarTranslationY: Float ->
        engineView?.setVerticalClipping(-newToolbarTranslationY.toInt())
    }
    private val topToolbarChangedAction = { newToolbarTranslationY: Float ->
        // the top toolbar is translated upwards when collapsing-> all values received are 0 or negative
        engineView?.let {
            it.setVerticalClipping(newToolbarTranslationY.toInt())
            // Need to add the toolbarHeight to effectively place the engineView below the toolbar.
            engineViewParent.translationY = newToolbarTranslationY + toolbarHeight
        }
    }

    init {
        toolbarChangedAction = if (toolbarPosition == ToolbarPosition.TOP) {
            topToolbarChangedAction
        } else {
            bottomToolbarChangedAction
        }
    }

    @SuppressLint("LogUsage")
    override fun layoutDependsOn(parent: CoordinatorLayout,child: View,dependency: View): Boolean {
        // This package does not have access to "browserToolbar" ... so we are just checking the class name here since
        // we actually do not need anything from that class - we only need to identify the instance.
        // Right Now we do not have a component that has access to (concept/browser-toolbar and concept-engine).
        // Creating one just for this behavior is too excessive.
        if (dependency::class.java.simpleName == "browserToolbar") {
            return true
        }

        return super.layoutDependsOn(parent,child,dependency)
    }

    /**
     * Apply vertical clipping to [EngineView]. This requires [EngineViewbrowserToolbarBehavior] to be set
     * in/on the [EngineView] or its parent. Must be a direct descending child of [CoordinatorLayout].
     */
    override fun onDependentViewChanged(parent: CoordinatorLayout,dependency: View): Boolean {
        toolbarChangedAction.invoke(dependency.translationY)

        return true
    }
}

/**
 * Where the toolbar is placed on the screen.
 */
enum class ToolbarPosition {
    TOP,BottOM
}