Breakpoints

The token BREAKPOINTS is an injection token in ngx-layout that is used to build a Provider for a raw list of breakpoints.

import {
  BreakPointRegistry,
  BREAKPOINTS,
  DEFAULT_BREAKPOINTS,
} from '@ngbracket/ngx-layout';
import { MatchMedia } from 'projects/libs/flex-layout/core/match-media';

export const BreakPointsProvider = {
  provide: BREAKPOINTS,
  useValue: DEFAULT_BREAKPOINTS,
};

export const appConfig: ApplicationConfig = {
  providers: [
    BreakPointsProvider, // Supports developer overrides of list of known breakpoints
    // BreakPointRegistry,      // Registry of known/used BreakPoint(s)
    // MatchMedia,              // Low-level service to publish observables w/ window.matchMedia()
    // MediaMonitor,            // MediaQuery monitor service observes all known breakpoints
    // ObservableMediaProvider  // easy subscription injectable `media$` matchMedia observable
  ],
};

This provider is used to return a list to all known BreakPoint(s) and, in turn, this list is used internally to register mediaQueries and announce mediaQuery activations.

Custom BreakPoints

Using the BREAKPOINT (note: singular) InjectionToken, developers can add custom breakpoints or easily override existing breakpoints.

For example to add mediaQueries that activate when printing:

custom-breakpoints.ts

import { BREAKPOINT } from '@ngbracket/ngx-layout';

const PRINT_BREAKPOINTS = [
  {
    alias: 'xs.print',
    suffix: 'XsPrint',
    mediaQuery: 'screen and (max-width: 297px)',
    overlapping: false,
  },
];

export const CustomBreakPointsProvider = {
  provide: BREAKPOINT,
  useValue: PRINT_BREAKPOINTS,
  multi: true,
};

app.config.ts

import { CustomBreakPointsProvider } from './custom-breakpoints.ts';

export const appConfig: ApplicationConfig = {
  providers: providers: [
    CustomBreakPointsProvider, // Adds breakpoints for 'print' mediaQueries
  ],
};

With the above changes, when printing on mobile-sized viewports the xs.print mediaQuery will activate. Please note that the provider is a multi-provider, meaning it can be provided multiple times and in a variety of presentations. The type signature of BREAKPOINT is the following:

BREAKPOINT = InjectionToken<BreakPoint|BreakPoint[]>

Thus, you can use the token to segment which breakpoints you provide and in which order. For instance, you can provide all print breakpoints in an array called PRINT_BREAKPOINTS and then all mobile breakpoints in another array called MOBILE_BREAKPOINTS. You can also simply provide one additional breakpoint if that's all you need.

Disabling the default breakpoints

To disable the default breakpoints, you simply provide the new DISABLE_DEFAULT_BREAKPOINTS token as follows:

import {DISABLE_DEFAULT_BREAKPOINTS} from '@ngbracket/ngx-layout';

{provide: DISABLE_DEFAULT_BREAKPOINTS, useValue: true}

The default value for this breakpoint is false

Adding the orientation breakpoints

The orientation breakpoints are a set of breakpoints that detect when a device is in portrait or landscape mode. Ngx-layout has a set of these that conform to the Material Design spec built-in to the library. They can be found in the ORIENTATION_BREAKPOINTS InjectionToken. To have these added to the default breakpoints, you can provide the token ADD_ORIENTATION_BREAKPOINTS to your app as follows:

import {ADD_ORIENTATION_BREAKPOINTS} from '@ngbracket/ngx-layout';

{provide: ADD_ORIENTATION_BREAKPOINTS, useValue: true}

The default value for this breakpoint is false

Custom Breakpoints and Directives

It must be noted that simply registering custom breakpoints will not automatically mean that ngx-layout API will support those as selectors.

In the above example the custom Breakpoint has been registered, but HTML selectors for xs.print` will not work automatically. Consider the scenario below where some content should be hidden while printing and other content has different layouts while printing:

<section
    class="main"
    fxShow
    fxHide.xs.print="true">
 ...
</section>

<footer
    fxLayout="row"
    fxLayout.xs.print="column">
 ...
</section>

Notice the use of 'xs.print' alias in the selectors above To enable these custom, responsive selectors, developers must extend the ShowHideDirective and the LayoutDirective as follows.

import { Directive, ElementRef, Input, Renderer2 } from '@angular/core';
import {
  ShowHideDirective,
  MediaMonitor,
  negativeOf,
} from '@ngbracket/ngx-layout';
@Directive({ selector: `[fxHide.xs.print]` })
export class CustomShowHideDirective extends ShowHideDirective {
  constructor(monitor: MediaMonitor, elRef: ElementRef, renderer: Renderer2) {
    super(monitor, elRef, renderer);
  }
  @Input('fxHide.xs.print') set hideXs(val) {
    this._cacheInput('showXsPrint', negativeOf(val));
  }
}