AB_Converters 工具类详解
以上目前AB提供的converters包下的工具类。下面将逐一介绍。
介绍前提到 DependentObservable 。他可以实现类似自定义Converters的作用。文章末尾作解释。
【ADAPTER】:返回一个Adapter对象。
ADAPTER accepts only one argument, and it must be DynamicObject
需要使用DynamicObject对象作为其参数。ADAPTER({xxxxx,xxxx})；
java代码中可通过 gueei.binding.collections.Utility.getSimpleAdapter调用
@item template gueei.binding.viewAttributes.templates.Layout
@item source Object
@item @optional spinnerTemplate gueei.binding.viewAttributes.templates.Layout
@item @optional enable String child property that determines the enabled state of the item
@item @optional filter android.widget.Filter filter supplies to adapter
ADAPTER({template=@layout/list_item, source=Demos,enable=true})
【AFTERCOMMAND】:Trigger the provided animation after the command is executed. 当Command方法执行完后触发动画。
(This is NOT compatible with the newer Property-based animation) _mark 不适用newer Property-based animation。是指？？
@arg animationId integer, specify by "@anim/animation"
@arg command gueei.binding.Command
@arg @optional condition boolean
@return gueei.binding.viewAttributes.view.AnimationTrigger
binding:animation="AFTERCOMMAND(@anim/shake, CheckPassword, NOT(PasswordCorrect))"
【ALT_TEMPELATE】 交替布局。
binding:itemTemplate="ALT_TEMPLATE(
@layout/arraylist_item, @layout/arraylist_item1, @layout/arraylist_item2)"
@return gueei.binding.viewAttributes.templates.Layout
【AND】 逻辑与
AND(arg ...) 大于1个参数，全true为true。
【ARG】 Passing extra arguments to command. 传递额外参数给指定的方法。
binding:onItemClicked="ARG(ToggleItem, =id/lvItems.clickedItem)" ———— ARG(Command cmd,Object arg ...)
@return command gueei.binding.Command
在 Command 的 invoke(View, args) 方法中，新增的args参数会被作为最左边的参数被调用。
例如：默认情况下 绑定 binding:onChecked="Fire" 属性，对象的Command Fire 的回调是 invoke（View,Boolean）。
这时如果 使用ARGB—— binding:onChecked="ARGB(Fire,1,2)"。 则对应的回调 会是 invoke(View,Integer,Integer,Boolean)
【ARGB】 转化为RGB或者ARGB的色值。
@return integer Android color-coded Integer
RGB——ARGB(0,0,0)； ARGB——ARGB(255,0,255,0)
【CONCAT】 字符串连接，等同于java的concat方法。
CONCAT('str1 ','str2')
@return String
【EQUAL】 equal比较。注：如果两个参数都为空，则返回true。
EQUAL(conditon1,conditon2)
@return Boolean
【FALSE】 Constant that always return false. Takes no argument 。无参，始终返回false。_ binding:text="FASLE()"
【FORMAT】 类似于java中的String.format(formatstring, item...)
@arg formatString String _Java-styled format string
@arg str String _If supplied Object, it will call Object.toString()
@return android.text.Spanned formatted with HTML tags in string
目前尝试 。binding:text="FORMAT('123','%05d')" 界面显示 123.未出现预想的00123，而binding:text="FORMAT('123','test%05d')"。还是显示123
【HIGHLIGHT_SPAN】 all occurences in a given text with a span。
Param 0: TextInput 需要处理的Str
Param 1: Text to search 目标文本
Param 2: SpanCreatorCommand or SpanListCreatorCommand for creating the Spans 传递通过两种方式创建得到的SPAN 或 SPANS 的 List
@return list of Spans
详见com.gueei.demos.markupDemo.viewModels.TextViewSpan 示例。
【HTML】 按HTML风格 转化SPAN 显示（表述不确切）
/** * Concat, Styles and Convert HTML Charsequences into Styled Spanned. * * @usage str str ... * * @arg str String : If supplied Object, it will call Object.toString() * * @return android.text.Spanned : formatted with HTML tags in string */ public class HTML
binding:text="HTML(Title, ' ', '<sup>', Id, '</sup>')" _ id 以上标形式展示。
【IF_NULL】 逻辑判断
* @usage condition arg_if_null arg_if_not * * @arg condition boolean * @arg arg_if_null Object * @arg arg_if_not Object * * @return Object
【IF】 逻辑判断
* @usage condition arg_if_true arg_if_false * * @arg condition boolean * @arg arg_if_true Object * @arg arg_if_false Object * * @return boolean
【INJECT】 INJECT binding statements into layout templates. 给layout注入 binding 属性。
常用于对一些模版 layout 的部分效果进行变更。
/** * INJECT binding statements into layout templates. <br/> * Most probably those templates came from external libraries (e.g. android) that you cannot change <br/> * This is much more convenient than everytime you need to copy those standard templates. <br/> * <br/> * * The most common usage is on those templates for spinners, listviews (e.g. @android:layout/simple_list_item1). <br/> * Suppose We need to inject the statement to the textview (@android:id/textview1), then: <br/> * binding:itemTemplate="INJECT(@android:layout/simple_list_item1, { id=@android:id/textview1, attr='text', statement='Name' })" <br/> * Note it is possible to inject more than one attribute, for example you can change the color of the above mentioned text view too: <br/> * binding:itemTemplate="INJECT(@android:layout/simple_list_item1, { id=@android:id/textview1, attr='text', statement='Name' }, { id=@android:id/textview1, attr='backgroundColor', statement='ARGB(255,0,0)' })" <br/> * @usage layout params ... * * @arg layout gueei.binding.viewAttributes.templates.Layout Layout of the template-to-inject * @arg params DynamicObject * * @item id integer Android Id value of the widget * @item attr Attribute name of that widget * @item statement Binding Statement to be injected * * @return gueei.binding.viewAttributes.templates.Layout */
【IS_NOT_NULL】 return true if the argument is NOT null 。
binding:text ="IS_NOT_NULL(1)"
【ISNULL】 同上。
【ITEM_LAYOUT】 ITEM_LAYOUT this adapter is used for bindable linear layouts
binding:itemLayout="ITEM_LAYOUT('LayoutId')"
binding:itemPath="ITEM_LAYOUT(@layout/binablelinearlayout_item)"
【LEN】 Length of the given String, if provided is an object, object.toString().length() will be evaluated。测试指定对象长度，非String会强转
* @arg str String
*
* @return integer
【LOWER】 小写 binding:text="LOWER("LOVWERASD")"
【MENU】
/** * Use exclusively for contextMenu attribute * * @usage menu_xml_id model * * @arg menu_xml integer XML id of the context menu, e.g. @menu/context_menu * @arg model Object View model to bind to the menu, most probably it will be just "." * * @return gueei.binding.menu.ContextMenuBinder * * @author andy * */
【NOT】 逻辑非
* @arg arg boolean * * @return boolean
【NULL】 常量，永远返回null. --- NULL()
【OR】 逻辑或 操作。 只要有一个参数为 true，则结果为true。
【PROP】
/** * Dynamically evaluate the statement for the given view_model * * @usage view_model statement * * @arg view_model Object the Context to evaluate the statement * @arg statement String * * @return Object */
【ROW_CHILD】 this adapter is used for bindable table layouts
binding:rowChild="ROW_CHILD('Children','LayoutId','ColSpan')"
【SECTION】 Returns a Single Item Adapter (SingletonAdapter) for the given object.
/** * Returns a Single Item Adapter (SingletonAdapter) for the given object. <br/> * This is most useful as declaring header/footer templates for list views, or as divider to divide list in sections * * @usage object layout * @arg object Object * @arg layout gueei.binding.viewAttributes.templates.Layout * * @return Adapter * */
【SPAN】 返回List<SPAN>对象
/** * Span for text/editfields * * Param 0: TextInput * Param 1: Span or List of Spans * * @return list of Spans */
【STITCH】 就是将多个ADAPTER展示在一个listView中。
/** * STITCH multiple adapters to one adapter for used in List Views. <br/> * * @usage adapter adapter ... * @arg adapter android.widget.Adapter * * @return android.widget.Adapter */
【TAB】
【TRUE】 常量，永远返回true。 TRUE()
【TYPEFACE_FROM_ASSET】
/** * Get type face from asset folder * * @usage type_name * @arg type_name String Name of the typeface * * @return android.graphics.Typeface */
【UPPER】 大写。
DependentObservable is an Observable that `Observes` other observables, once any of those observables changes, it calculate its value accordingly; a Converter is the same as DependentObservable, only DependentObservable is readonly, a Converter can do reverse conversion.
Android-Binding supports custom Converters (along with some built-in) to declared in XML layout, first, we have to create a class extends from DependentObservable:
public class FormatDisplay extends DependentObservable<CharSequence> { public FormatDisplay(IObservable<?>[] dependents) { super(CharSequence.class, dependents); } @Override public CharSequence calculateValue(Object... args) throws Exception { Double display = (Double)args[0]; DecimalFormat format = new DecimalFormat(); format.applyPattern("#.######"); String output = format.format(display); if (output.length() <= 10) return output; format.applyPattern("0.########E00"); return format.format(display); } }
Now, we modify our layout to:
<TextView android:layout_width="fill_parent" android:layout_height="fill_parent" android:textSize="45dip" android:gravity="right|bottom" binding:text="com.gueei.tutorials.calculator.FormatDisplay(Display)" android:layout_weight="1"/>
