Pressure.js - 让你的网站支持 Force Touch一个支持 iOS Force Touch 的开源库，且

1. Installation

Pressure is really simple to install, you can use npm or bower, or head over to the github and download the repo itself. All you need is the pressure.min.js or the pressure.js file.

bower

bower install pressure --save

npm

npm install pressure --save

2. Setup

You can use pressure with browserify, debowerify, or anything that uses CommonJS to include packages. Pressure can be used normally if no module object exists.

// Regular
Pressure.set('#test', {
  change: function(force, event){
    console.log(force);
  }
});

// Browserify, Debowerify, CommonJS
var Pressure = require('pressure');

Pressure.set('#test', {
  change: function(force, event){
    console.log(force);
  }
});

3. Usage

Pressure has a really simple method signature. The first argument is the element(s) you are targeting and the second argument is an object with optional callback functions.

Click Me

// target all links
Pressure.set('a', {});

// pass in jQuery elements
var elements = $('.dogs');
Pressure.set(elements, {});

// pass in element list or single element
var elements2 = document.querySelectorAll('.cats');
Pressure.set(elements2, {});
var elements3 = document.getElementById('cat');
Pressure.set(elements3, {});

// element with the 'stuart' ID being selected and calling the 'change' callback
Pressure.set('#stuart', {
  change: function(force, event){
    // the force value is passed back as well as the full event
    this.innerHTML = force;
  }
});

Pro Tip: "force" is a value passed back by the "change" function and is a value from 0 to 1. On Mac it is converted from a 1 to 3 scale to a 0 to 1 scale so it can be used in a consistent manner.

This example uses all of the methods available to you in the callback object.

Pressure.set('#element', {
  start: function(){
    // this is called on force start
  },
  end: function(){
    // this is called on force end
  },
  startDeepPress: function(){
    // this is called on "force click" / "deep press", aka once the force is greater than 0.5
  },
  endDeepPress: function(){
    // this is called when the "force click" / "deep press" end
  },
  change: function(force, event){
    // this is called every time there is a change in pressure
  },
  unsupported: function(){
    // this is called once there is a touch on the element and the device or browser does not support Force or 3D touch
  }
});

4. Device Targeting

With Pressure, the standard Pressure.set() targets all devices, but you can target just 3D or Force touch seperaratly using Pressure.set3DTouch() and Pressure.setForceTouch().

Click Me On an iPhone 6s

Pressure.set3DTouch('#element-3d', {
  change: function(force, event){
    this.innerHTML = force + 'on an iphone';
  }
});

Click Me On a Mac with Force Touch

Pressure.setForceTouch('#element-force', {
  change: function(force, event){
    this.innerHTML = force + 'on a Mac';
  }
});

5. Helper

You can use Pressure.map() to map a value from one range of values to another. It takes 5 params: Pressure.map(inputValue, inputValueMin, inputValueMax, mapToMin, mapToMax); Here is a good write up on how this works in the Processing framework: Map Function

Pressure.set('#element', {
  change: function(force, event){
    // this takes the force, given that the force can range from 0 to 1, and maps that force value on a 100 to 200 range
    this.style.width = Pressure.map(force, 0, 1, 100, 200);
  }
});