ionic-framework/ionic/components/tap-click/activator.ts

import {raf} from '../../util/dom';


export class Activator {

  constructor(app, config) {
    this.app = app;
    this.active = [];
    this.clearStateTimeout = 180;
    this.clearAttempt = 0;
    this.activatedClass = config.setting('activatedClass') || 'activated';
    this.x = 0;
    this.y = 0;
  }

  downAction(targetEle, pointerX, pointerY, callback) {
    // the user just pressed down

    // remember where they pressed
    this.x = pointerX;
    this.y = pointerY;

    // remember this is the active element
    targetEle.classList.add(this.activatedClass);
    this.active.push(targetEle);
  }

  upAction() {
    // the user was pressing down, then just let up
    setTimeout(() => {
      this.clearState();
    }, this.clearStateTimeout);
  }

  clearState() {
    // all states should return to normal

    if ((!this.app.isEnabled() || this.app.isTransitioning()) && this.clearAttempt < 30) {
      // the app is actively disabled, so don't bother deactivating anything.
      // this makes it easier on the GPU so it doesn't have to redraw any
      // buttons during a transition. This will retry in XX milliseconds.
      ++this.clearAttempt;
      this.upAction();

    } else {
      // not actively transitioning, good to deactivate any elements
      this.deactivate();
      this.clearAttempt = 0;
    }
  }

  deactivate() {
    // remove the active class from all active elements
    for (let i = 0; i < this.active.length; i++) {
      this.active[i].classList.remove(this.activatedClass);
    }
    this.active = [];
  }

}