TestAnimation2.dart

//Sample Code: Test Animation 2

import 'dart:html';
import 'dart:math';

import 'package:rikulo_ui/view.dart';
import 'package:rikulo_ui/gesture.dart';
import 'package:rikulo_ui/effect.dart';
import "package:rikulo_ui/html.dart";

View createCube(int size, String txt) {
  View v = new View();
  v.width = size;
  v.height = size;
  v.style.border = "2px solid #3D4C99";
  v.style.borderRadius = "10px";
  v.style.backgroundColor = "#5C73E5";
  v.style.userSelect = "none";
  v.style.zIndex = "10";
  
  TextView txtv = new TextView(txt);
  txtv.width = v.width;
  txtv.style.lineHeight = "${v.height}px";
  txtv.style.textAlign = "center";
  txtv.style.color = "#EEEEEE";
  txtv.style.fontFamily = "Arial";
  txtv.style.fontWeight = "bold";
  txtv.style.userSelect = "none";
  v.addChild(txtv);
  
  return v;
}

void main() {
  
  final View mainView = new View()..addToDocument();
  
  final View box = new Section();
  box.width = 500;
  box.height = 500;
  box.left = 48;
  box.top = 48;
  box.style.border = "2px dashed #CCCCCC";
  mainView.addChild(box);
  
  final View cube = createCube(100, "Drag Me");
  cube.left = 250;
  cube.top = 250;
  mainView.addChild(cube);
  
  Rectangle range = new Rectangle(50, 50, 446 - 50, 446 - 50);
  Element element = cube.node;
  final num deceleration = 0.0005;
  
  Motion motion;
  new Dragger(element, snap: (Point ppos, Point pos) => Points.snap(range, pos), 
  start: (DraggerState dstate) {
    if (motion != null)
      motion.stop();
    
  }, end: (DraggerState dstate) {
    final Point vel = dstate.elementVelocity;
    num speed = Points.norm(vel);
    if (speed == 0)
      return;
    Point unitv = Points.divide(vel, speed);
    Point pos = DomUtil.position(element);
    motion = new Motion(move: (MotionState mstate) {
      int elapsed = mstate.elapsedTime;
      pos = Points.snap(range, pos + (unitv * speed * elapsed));
      element.style.left = CssUtil.px(pos.x.toInt());
      element.style.top = CssUtil.px(pos.y.toInt());
      speed = max(0, speed - deceleration * elapsed);
      return speed > 0;
    })..run();
  });
  
}