java - conditionally implement an interface -


so i'm trying animations in app , had way without using objectanimator , animatorlistener api 11. however, they're not smooth , robust doing animations using classes.

so made changes code in object's class check api level, objectanimator , animatorlistener stuff wouldn't called unless api level 11+.

the problem object implementing animatorlistener though functionality isn't being used in versions of code. think leading verifyerror on start of app because crashes on devices api level 10 , down.

is there way conditionally implement interface based on api level or different way achieve same thing?

thanks!

actually, ok if build against or higher sdk target, issue when code run on device missing classes higher sdk. others suggested, can go factory

public class factory {   public static <t> t getimplementation(){     if(<sdk_level_incompatible>){       return (t)new <package>.oldschoolanimator();     }else{       return (t)new <package>.superanimator();     }   } }   ... someimplementation impl = new factory().getimplementation(); ...

watchout, "someimplementation" has common super-type or interface of oldschoolanimator , superanimator classes! dont use "imports" implementation classes in factory, rather use full-qualified classnames.


Comments

Post a Comment

Popular posts from this blog

linux - xterm copying to CLIPBOARD using copy-selection causes automatic updating of CLIPBOARD upon mouse selection -

i've tried various ways coerce xterm (versions 285 , 292) copy selection clipboard clipboard whenever press ctrl-shift-c. promising way far has been, in ~/.xresources, put this: xterm*vt100.translations: #override \ ctrl shift <keypress> c: copy-selection(clipboard) \n\ ctrl shift <keypress> v: insert-selection(clipboard) ctrl-shift-v works perfectly, copying has nuance... if restart xterm, highlighting text puts things in primary clipboard; expected, proper, default behavior. if hit ctrl-shift-c, copies current selection clipboard clipboard. the bug, however, if highlight text after first time pressed ctrl-shift-c, you'll see highlighting copies both primary and clipboard. cannot figure out how stop xterm updating clipboard upon selection... , doesn't make sense me in first place. i said, @ specific point in time, copy selection clipboard... yet starts updating automatically upon selection after doing once... anyone have workaround...
Read more

c++ - qgraphicsview horizontal scrolling always has a vertical delta -

Image
i've subclassed qgraphicsview custom canvas used in cad application. i've reimplemented qgraphicsview::wheelevent check keyboard modifiers control key and, if control key pressed, zoom. i'm trying implement horizontal scroll when user holds shift , uses wheel. the problem i'm having horizontal scrolling always scrolls 0.279. not huge problem, hugely annoying , points else being wrong. so, here questions: is right way implement horizontal scrolling? if not, is? how eliminate delta of 0.279? thanks in advance. code , sample output below void myview::zoom(int delta) { double factor = pow(1.2, delta/abs(delta)); this->scale(factor, factor); } void myview::scrollhorizontal(int level) { qpointf center = maptoscene(viewport()->rect().center()); qdebug() << "center: " << center.x() << ", " << center.y(); centeron(qpointf(center.x() - level, center.y())); } void myview::wheelevent(qwheeleve...
Read more