Android笔记(十九)：WebView浏览器多标签页（多窗口）功能新的实现

效果图

基于android实现浏览器多标签页

背景

之前写过的文章——WebView+Fragment+ViewPager构建浏览器多标签页
虽然实现了多标签页的功能，但是有个弊端就是随着创建的标签页数量增加，viewpager的滑动会越来越卡。之前一直没有时间优化，最近尝试着优化了一下，对Dainty浏览器的多标签页功能抽取出来，进行改造。

思路

WebTabManager用于管理tab页面对象

class WebTabManager private constructor(){
    
    

    private object Holder{
    
    
        val instance = WebTabManager()
    }

    companion object Instance {
    
    
        var increaseKey = 0
        @JvmStatic
        fun getInstance(): WebTabManager{
    
    
            return Holder.instance
        }
    }

    private val cacheWebTab = LinkedList<WebBean>()

    fun divideAllWebView(){
    
    
        LogUtil.d("divideAllWebView: ${
      
      cacheWebTab.size}")
        for (wb in cacheWebTab){
    
    
            wb.webView.parent?.let {
    
    
                (it as ViewGroup).removeAllViews()
            }
        }
    }

    fun getCacheWebTab(): List<WebBean>{
    
    
        return cacheWebTab
    }

    fun addNewTab(): WebBean {
    
    
        val webView = CommonWebView(MutableContextWrapper(Dainty2Application.app))
        val wb = WebBean(increaseKey++, webView, "首页", ContextCompat.getDrawable(Dainty2Application.app, R.drawable.web_tab_icon_home), ContextCompat.getDrawable(Dainty2Application.app, R.drawable.ic_launcher_foreground))
        cacheWebTab.add(wb)
        return wb
    }

    fun joinWebTabToLast(key: Int){
    
    
        for (wb in cacheWebTab){
    
    
            if (wb.id == key){
    
    
                cacheWebTab.remove(wb)
                cacheWebTab.addLast(wb)
                break
            }
        }
    }

    fun updateLastTabTitle(tabTitle: String){
    
    
        val wb = cacheWebTab.last
        wb.tabTitle = tabTitle
    }

    fun updateLastTabIcon(tabIcon: Drawable){
    
    
        val wb = cacheWebTab.last
        wb.tabIcon = tabIcon
    }
}

tab页面对象，保存了webview对象，网页icon和标题，网页截图

data class WebBean(val id: Int, val webView: CommonWebView, var tabTitle: String,
                   var tabIcon: Drawable?, var picture: Drawable?)

用于获取网页截图

    fun catchWebView(context: Context){
    
    
        val capture = WebTabManager.getInstance().getCacheWebTab().last().webView
        capture.isDrawingCacheEnabled = true
        val bitmap = capture.drawingCache
        WebTabManager.getInstance().getCacheWebTab().last().picture = BitmapDrawable(context.resources, bitmap).current
    }

具体可参考：Dainty2