|
| 1 | +package com.haoge.easyandroid.easy |
| 2 | + |
| 3 | +import android.app.Activity |
| 4 | +import android.graphics.Canvas |
| 5 | +import android.graphics.drawable.BitmapDrawable |
| 6 | +import android.graphics.drawable.Drawable |
| 7 | +import android.os.AsyncTask |
| 8 | +import android.os.Build |
| 9 | +import android.text.Html |
| 10 | +import android.widget.TextView |
| 11 | +import com.bumptech.glide.Glide |
| 12 | +import com.haoge.easyandroid.EasyAndroid |
| 13 | +import java.lang.ref.WeakReference |
| 14 | + |
| 15 | +private typealias ImageGetterLoader = (String) -> Drawable? |
| 16 | +class EasyImageGetter:Html.ImageGetter { |
| 17 | + |
| 18 | + private var loader:ImageGetterLoader? = null |
| 19 | + private var placeHolder:Drawable? = null |
| 20 | + private var error:Drawable? = null |
| 21 | + private var container:TextView? = null |
| 22 | + private var tagHandler:Html.TagHandler? = null |
| 23 | + |
| 24 | + /** 设置图片在加载时的占位图*/ |
| 25 | + @Suppress("DEPRECATION") |
| 26 | + fun setPlaceHolder(placeHolder:Int): EasyImageGetter { |
| 27 | + this.placeHolder = EasyAndroid.getApplicationContext().resources.getDrawable(placeHolder) |
| 28 | + return this |
| 29 | + } |
| 30 | + |
| 31 | + /** 设置当图片加载失败时的占位图*/ |
| 32 | + @Suppress("DEPRECATION") |
| 33 | + fun setError(error:Int): EasyImageGetter { |
| 34 | + this.error = EasyAndroid.getApplicationContext().resources.getDrawable(error) |
| 35 | + return this |
| 36 | + } |
| 37 | + |
| 38 | + /** |
| 39 | + * 设置额外的加载器。将src数据解析为drawable进行展示。 |
| 40 | + * |
| 41 | + * 在解析过程中。若有设置此加载器，则将首先通过此加载器进行drawable创建。 |
| 42 | + * |
| 43 | + * 当此加载器所返回的drawable为null时。则将触发组件本身自带的加载方式(通过glide进行加载) |
| 44 | + */ |
| 45 | + fun setLoader(loader: ImageGetterLoader): EasyImageGetter { |
| 46 | + this.loader = loader |
| 47 | + return this |
| 48 | + } |
| 49 | + |
| 50 | + /** 参考[Html.TagHandler]*/ |
| 51 | + fun setTagHandler(handler: Html.TagHandler): EasyImageGetter { |
| 52 | + this.tagHandler = handler |
| 53 | + return this |
| 54 | + } |
| 55 | + |
| 56 | + override fun getDrawable(source: String?): Drawable { |
| 57 | + val drawable = FutureDrawable(placeHolder) |
| 58 | + InternalAsyncTask(error, drawable, loader, WeakReference<TextView>(container)).execute(source) |
| 59 | + return drawable |
| 60 | + } |
| 61 | + |
| 62 | + fun loadHtml(html:String, container: TextView) { |
| 63 | + this.container = container |
| 64 | + |
| 65 | + val spanned = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { |
| 66 | + Html.fromHtml(html, Html.FROM_HTML_MODE_LEGACY, this, tagHandler) |
| 67 | + } else { |
| 68 | + @Suppress("DEPRECATION") |
| 69 | + Html.fromHtml(html, this, tagHandler) |
| 70 | + } |
| 71 | + |
| 72 | + container.text = spanned |
| 73 | + } |
| 74 | + |
| 75 | + companion object { |
| 76 | + fun create():EasyImageGetter = EasyImageGetter() |
| 77 | + |
| 78 | + // 判断执行环境中是否包含有glide图片解析库 |
| 79 | + private val glideSupport = exist("com.bumptech.glide.Glide") |
| 80 | + private fun exist(name:String):Boolean = try{ |
| 81 | + Class.forName(name) |
| 82 | + true |
| 83 | + } catch (e:Exception) { |
| 84 | + false |
| 85 | + } |
| 86 | + } |
| 87 | + |
| 88 | + class InternalAsyncTask(private val error: Drawable?, |
| 89 | + private val drawable: FutureDrawable, |
| 90 | + private val loader: ImageGetterLoader?, |
| 91 | + private var container: WeakReference<TextView>): AsyncTask<String, Int, Drawable>() { |
| 92 | + |
| 93 | + override fun doInBackground(vararg params: String?): Drawable? { |
| 94 | + try { |
| 95 | + if (checkContextValid().not()) return null |
| 96 | + |
| 97 | + val url = params[0]?:throw RuntimeException("URL is null") |
| 98 | + // 先使用用户设置的loader进行加载 |
| 99 | + val result = loader?.invoke(url) |
| 100 | + if (result != null) return result |
| 101 | + // 当用户设置的loader加载失败时(返回null), 则使用内部机制进行drawable获取 |
| 102 | + if (glideSupport.not()) throw RuntimeException("Internal loader requires glide to load drawable!") |
| 103 | + val context = container.get()?.context?:throw RuntimeException("Fetch context failed from container") |
| 104 | + return Glide.with(context).load(url).submit().get() |
| 105 | + } catch (e:Exception) { |
| 106 | + e.printStackTrace() |
| 107 | + return null |
| 108 | + } |
| 109 | + } |
| 110 | + |
| 111 | + override fun onPostExecute(result: Drawable?) { |
| 112 | + if (checkContextValid().not()) return |
| 113 | + val textView = container.get()?:return |
| 114 | + |
| 115 | + val real = result?:error |
| 116 | + real?.let { drawable.apply(it) } |
| 117 | + textView.invalidate() |
| 118 | + textView.text = textView.text |
| 119 | + } |
| 120 | + |
| 121 | + // 从绑定的TextView中获取activity实例进行生命周期判断。避免页面销毁后还占用大量资源去进行load |
| 122 | + private fun checkContextValid():Boolean { |
| 123 | + val activity = (container.get()?.context?:return false) as? Activity ?: return false |
| 124 | + return !(activity.isFinishing || (Build.VERSION.SDK_INT >= 17 && activity.isDestroyed)) |
| 125 | + } |
| 126 | + } |
| 127 | + |
| 128 | + // 用于进行异步加载Drawable时的占位Drawable： |
| 129 | + @Suppress("DEPRECATION") |
| 130 | + class FutureDrawable(private val placeholder:Drawable?): BitmapDrawable() { |
| 131 | + |
| 132 | + private var drawable:Drawable? = null |
| 133 | + |
| 134 | + private fun setBounds(drawable:Drawable) { |
| 135 | + drawable.setBounds(0, 0, drawable.intrinsicWidth, drawable.intrinsicHeight) |
| 136 | + setBounds(0, 0, drawable.intrinsicWidth, drawable.intrinsicHeight) |
| 137 | + } |
| 138 | + |
| 139 | + fun apply(drawable: Drawable) { |
| 140 | + this.drawable = drawable |
| 141 | + setBounds(drawable) |
| 142 | + } |
| 143 | + |
| 144 | + override fun draw(canvas: Canvas?) { |
| 145 | + val real = drawable?:placeholder |
| 146 | + real?.draw(canvas) |
| 147 | + } |
| 148 | + |
| 149 | + init { |
| 150 | + placeholder?.let { setBounds(it) } |
| 151 | + } |
| 152 | + } |
| 153 | +} |
| 154 | + |
0 commit comments