Touch

Angular Bootstrap 5 Touch

This component allows you to improve the user experience on mobile touch screens by calling methods on the following custom events: pinch, swipe, tap, press, pan and rotate.

Note: Read the API tab to find all available options and advanced customization

Note: This method is intended only for users of mobile touch screens, so it won't work for the mouse or keyboard events.

Configuration

Step 1

Install hammerjs package.

npm install hammerjs

Step 2

Add HammerModule to your module imports.

import { HammerModule } from '@angular/platform-browser';
…
@NgModule ({
  ...
  imports: [HammerModule],
  ...
})

Step 3

Create HammerConfig and add it to the module providers.

import {
  BrowserModule,
  HammerGestureConfig,
  HammerModule,
  HAMMER_GESTURE_CONFIG,
} from '@angular/platform-browser';

...

@Injectable()
export class HammerConfig extends HammerGestureConfig {}

@NgModule ({
  ...
  imports: [HammerModule],
  providers: [
  {
    provide: HAMMER_GESTURE_CONFIG,
    useClass: HammerConfig,
  },
],
  ...
})

Press

Press calls the chosen method when the touch event on the element lasts longer than 250 milliseconds.

Hold the button to remove the mask from the image 

<div>
  <div class="bg-image">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div
      *ngIf="showMask"
      class="mask"
      style="background-color: rgba(0, 0, 0, 0.6)"
      id="remove-bg"
    >
      <div class="d-flex justify-content-center align-items-center h-100">
        <p id="press-text" class="text-white mb-0">
          Hold the button to remove the mask from the image
        </p>
      </div>
    </div>
  </div>
  <div class="my-3">
    <button type="button" class="btn btn-primary btn-press" (press)="onPress()">
      Tap & hold to show image
    </button>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  showMask = true;

  constructor() {}

  onPress() {
    this.showMask = false;
  }
}

Press duration

To change default press duration, override the press time value in HammerConfig

Hold the button for 5s to remove mask from the image 

<div>
  <div class="bg-image">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div
      *ngIf="showMask"
      class="mask"
      style="background-color: rgba(0, 0, 0, 0.6)"
      id="remove-bg"
    >
      <div class="d-flex justify-content-center align-items-center h-100">
        <p id="press-text" class="text-white mb-0">
          Hold the button for 5s to remove mask from the imag
        </p>
      </div>
    </div>
  </div>
  <div class="my-3">
    <button type="button" class="btn btn-primary btn-press" (press)="onPress()">
      Tap & hold to show image
    </button>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  showMask = true;

  constructor() {}

  onPress() {
    this.showMask = false;
  }
}
import {
  BrowserModule,
  HammerGestureConfig,
  HammerModule,
  HAMMER_GESTURE_CONFIG,
} from '@angular/platform-browser';

...

@Injectable()
export class HammerConfig extends HammerGestureConfig {
  overrides = {
    'press': { time: 5000 }
  }
}

@NgModule ({
  ...
  imports: [HammerModule],
  providers: [
  {
    provide: HAMMER_GESTURE_CONFIG,
    useClass: HammerConfig,
  },
],
  ...
})

Tap

The callback on tap event is called with an object containing origin field - the x and y coordinates of the user's touch.

Tap button to change a color

<div>
  <div class="bg-image">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div class="mask" [ngStyle]="{ 'background-color': background }" id="bg-tap">
      <div class="d-flex justify-content-center align-items-center h-100">
        <p class="text-white mb-0">Tap button to change a color</p>
      </div>
    </div>
  </div>
  <div class="my-3">
    <button type="button" class="btn btn-primary btn-tap" (tap)="onTap()">
      Tap to change a color
    </button>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  background = 'rgba(0, 0, 0, 0.6)';

  constructor() {}

  generateColor(): string {
    return `rgba(${this.getRandomNumber()},${this.getRandomNumber()},${this.getRandomNumber()},.4)`;
  }

  getRandomNumber(): number {
    return Math.floor(Math.random() * 255) + 1;
  }

  onTap() {
    this.background = this.generateColor();
  }
}

Double Tap

Set default taps to touch event.

Change background color with 2 taps

<div>
  <div class="bg-image">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div class="mask" [ngStyle]="{ 'background-color': background }" id="bg-tap">
      <div class="d-flex justify-content-center align-items-center h-100">
        <p class="text-white mb-0">Tap button to change a color</p>
      </div>
    </div>
  </div>
  <div class="my-3">
    <button type="button" class="btn btn-primary btn-tap" (doubleTap)="onTap()">
      Tap to change a color
    </button>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  background = 'rgba(0, 0, 0, 0.6)';

  constructor() {}

  generateColor(): string {
    return `rgba(${this.getRandomNumber()},${this.getRandomNumber()},${this.getRandomNumber()},.4)`;
  }

  getRandomNumber(): number {
    return Math.floor(Math.random() * 255) + 1;
  }

  onTap() {
    this.background = this.generateColor();
  }
}

Pan

The pan event is useful for dragging elements - every time the user moves a finger on the element to which the directive is attached to, the given method is being called with an argument consisting of two keys: x and y (the values corresponds to the horizontal and vertical translation). 

<div>
  <div class="bg-image" id="pan">
    <img
      [ngStyle]="{ transform: panTransform }"
      (panstart)="onPanStart()"
      (panmove)="onPanMove($event)"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
      id="img-pan"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  x = 0;
  y = 0;
  startX = 0;
  startY = 0;

  panTransform: string;

  constructor() {}

  onPanStart() {
    this.startX = this.x;
    this.startY = this.y;
  }

  onPanMove(event: any) {
    event.preventDefault();
    this.x = this.startX + event.deltaX;
    this.y = this.startY + event.deltaY;
    this.panTransform = this.getTransform(this.x, this.y);
  }

  getTransform(x: number, y: number): string {
    return `translate(${x}px, ${y}px)`;
  }
}

Pan Left

Pan with only left direction

<div>
  <div class="bg-image" id="pan">
    <img
      [ngStyle]="{ transform: panTransform }"
      (panstart)="onPanStart()"
      (panLeft)="onPanLeft($event)"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
      id="img-pan"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  x = 0;
  y = 0;
  startX = 0;
  startY = 0;
  panTransform: string;

  constructor() {}

  onPanStart() {
    this.startX = this.x;
    this.startY = this.y;
  }

  onPanLeft(event: any) {
    event.preventDefault();
    this.x = this.startX + event.deltaX;
    this.panTransform = this.getTransform(this.x, 0);
  }

  getTransform(x: number, y: number): string {
    return `translate(${x}px, ${y}px)`;
  }
}

Pan Right

Pan with only right direction

<div>
  <div class="bg-image" id="pan">
    <img
      [ngStyle]="{ transform: panTransform }"
      (panstart)="onPanStart()"
      (panRight)="onPanRight($event)"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
      id="img-pan"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  x = 0;
  y = 0;
  startX = 0;
  startY = 0;
  panTransform: string;

  constructor() {}

  onPanStart() {
    this.startX = this.x;
    this.startY = this.y;
  }

  onPanRight(event: any) {
    event.preventDefault();
    this.x = this.startX + event.deltaX;
    this.panTransform = this.getTransform(this.x, 0);
  }

  getTransform(x: number, y: number): string {
    return `translate(${x}px, ${y}px)`;
  }
}

Pan Up/Down

Pan with only up/down direction

<div>
  <div class="bg-image" id="pan">
    <img
      [ngStyle]="{ transform: panTransform }"
      (panstart)="onPanStart()"
      (panup)="onPanUp($event)"
      (pandown)="onPanDown($event)"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
      id="img-pan"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  x = 0;
  y = 0;
  startX = 0;
  startY = 0;
  panTransform: string;

  constructor() {}

  onPanStart() {
    this.startX = this.x;
    this.startY = this.y;
  }

  onPanUp(event: any) {
    event.preventDefault();
    this.y = this.startY + event.deltaY;
    this.panTransform = this.getTransform(0, this.y);
  }

  onPanDown(event: any) {
    event.preventDefault();
    this.y = this.startY + event.deltaY;
    this.panTransform = this.getTransform(0, this.y);
  }

  getTransform(x: number, y: number): string {
    return `translate(${x}px, ${y}px)`;
  }
}

Pinch

The pinch event calls the given method with an object containing two keys - ratio and origin. The first one it the ratio of the distance between user's fingers on touchend to the same distance on touchstart - it's particularly useful for scaling images. The second one, similarly as in doubleTap event, is a pair of coordinates indicating the middle point between the user's fingers. 

<div>
  <div class="bg-image" id="pan">
    <img
      [ngStyle]="{ transform: pinchTransform }"
      [ngStyle]="{ transformOrigin: pinchTransformOrigin }"
      (pinch)="onPinch($event)"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  pinchTransform: string;
  pinchTransformOrigin: string;

  constructor() {}

  onPinch(event: any) {
    this.pinchTransform = `scale(${event.ratio})`;
    this.pinchTransformOrigin = `translate(${event.origin.x}px, ${event.origin.y}px,)`;
  }
}

Swipe Left/Right

The swipe event comes with several modifiers (left, right, up, down) - each of them will ensure that event will fire only on swipe in that particular direction. If the directive is used without any modifier, the callback method will be called each time the swiping occurs, and the string indicating the direction will be passed as an argument.

This example shows example with left and right

Swipe Left-Right to change a color

<div>
  <div class="bg-image" (swiperight)="onSwipeRight()" (swipeleft)="onSwipeLeft()">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div
      class="mask"
      [ngStyle]="{ 'background-color': background }"
      id="swipe-left-right"
    >
      <div class="d-flex justify-content-center align-items-center h-100">
        <p class="text-white mb-0">Swipe Left-Right to change a color</p>
      </div>
    </div>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  background = 'rgba(0, 0, 0, 0.6)';

  constructor() {}

  generateColor(): string {
    return `rgba(${this.getRandomNumber()},${this.getRandomNumber()},${this.getRandomNumber()},.4)`;
  }

  getRandomNumber(): number {
    return Math.floor(Math.random() * 255) + 1;
  }

  onSwipeLeft() {
    this.background = this.generateColor();
  }

  onSwipeRight() {
    this.background = this.generateColor();
  }
}

Swipe Up/Down

In order to use (swipeup) and (swipedown) events, you need to enable all swipe directions in the HammerConfig.

Swipe Up-Down to change a color

<div>
  <div class="bg-image" (swipeup)="onSwipeUp()" (swipedown)="onSwipeDown()">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div
      class="mask"
      [ngStyle]="{ 'background-color': background }"
      id="swipe-left-right"
    >
      <div class="d-flex justify-content-center align-items-center h-100">
        <p class="text-white mb-0">Swipe Up-Down to change a color</p>
      </div>
    </div>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  background = 'rgba(0, 0, 0, 0.6)';

  constructor() {}

  generateColor(): string {
    return `rgba(${this.getRandomNumber()},${this.getRandomNumber()},${this.getRandomNumber()},.4)`;
  }

  getRandomNumber(): number {
    return Math.floor(Math.random() * 255) + 1;
  }

  onSwipeUp() {
    this.background = this.generateColor();
  }

  onSwipeDown() {
    this.background = this.generateColor();
  }
}
import {
  BrowserModule,
  HammerGestureConfig,
  HammerModule,
  HAMMER_GESTURE_CONFIG,
} from '@angular/platform-browser';
import hammer from 'hammerjs';

...

@Injectable()
export class HammerConfig extends HammerGestureConfig {
  overrides = {
    swipe: { direction: hammer.DIRECTION_ALL },
  };
}

@NgModule ({
  ...
  imports: [HammerModule],
  providers: [
  {
    provide: HAMMER_GESTURE_CONFIG,
    useClass: HammerConfig,
  },
],
  ...
})

Rotate

This example shows example with rotate

<div>
  <div class="bg-image">
    <img
      [ngStyle]="{ rotate: rotateTransform }"
      src="https://mdbootstrap.com/img/new/standard/city/053.webp"
      class="img-fluid"
      id="rotate"
      (rotate)="onRotate($event)"
    />
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  rotateTransform: string;

  constructor() {}

  onRotate(event: any) {
    this.rotateTransform = `rotate(${event.currentAngle}turn)`;
  }
}

Touch - API

Import

import {
  BrowserModule,
  HammerGestureConfig,
  HammerModule,
  HAMMER_GESTURE_CONFIG,
} from '@angular/platform-browser';
import hammer from 'hammerjs';

...

@Injectable()
export class HammerConfig extends HammerGestureConfig {
  overrides = {
    swipe: { direction: hammer.DIRECTION_ALL },
  };
}

@NgModule ({
  ...
  imports: [HammerModule],
  providers: [
  {
    provide: HAMMER_GESTURE_CONFIG,
    useClass: HammerConfig,
  },
],
  ...
})

Options

Tap

Name Type Default Description
interval number 500 Set interval to tap
time number 250 Set delays time to tap event
taps number 1 Set default value of number for taps
pointers number 1 Set default value of number for pointers

Press

Name Type Default Description
time number 250 Set time delays to take tap
pointers number 1 Set default value of number for pointers

Swipe

Name Type Default Description
threshold number 10 Set distance bettwen when event fires
direction string all Set direction to swipe. Available options: all, right, left, top, up.

Rotate

Name Type Default Description
angle number 0 Set started angle to rotate.
pointers number 2 Set default value of number for pointers

Pan

Name Type Default Description
threshold number 20 Set distance bettwen when event fires
direction string all Set direction to pan. Available options: all, right, left, top, up.
pointers number 1 Set default value of number for pointers

Pinch

Name Type Default Description
pointers number 2 Option for tap event, set duration to how long it takes to take a tap
threshold number 10 Set distance bettwen when event fires

Outputs

Name Type Description
tap EventEmitter<void> This event fires tap touch funcionality.
press EventEmitter<void> This event fires press touch funcionality.
pan EventEmitter<void> This event fires pan touch funcionality.
pinch EventEmitter<void> This event fires pinch touch funcionality.
swipe EventEmitter<void> This event fires swipe touch funcionality.
rotate EventEmitter<void> This event fires rotate touch funcionality. 
<div>
  <div class="bg-image">
    <img src="https://mdbootstrap.com/img/new/standard/city/053.webp" class="img-fluid" />
    <div
      *ngIf="showMask"
      class="mask"
      style="background-color: rgba(0, 0, 0, 0.6)"
      id="remove-bg"
    >
      <div class="d-flex justify-content-center align-items-center h-100">
        <p id="press-text" class="text-white mb-0">
          Hold the button to remove the mask from the image
        </p>
      </div>
    </div>
  </div>
  <div class="my-3">
    <button type="button" class="btn btn-primary btn-press" (press)="onPress()">
      Tap & hold to show image
    </button>
  </div>
</div>
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  showMask = true;

  onPress() {
    console.log('pressed')
    this.showMask = false;
  }
}