bug(mat-button-toggle): letter-spacing not the same as mat-button

[leomayer]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

14

Description

The new mat-button use a letter-spacing which is calculated as 1.25px with the default settings. To be more precise:

var(--mdc-typography-button-letter-spacing, .0892857143em)

whereas the variable --mdc-typography-button-letter-spacing is undefined.

For the toggle-button the letter-spacing is used from the user agent stylesheet which is set to normal.

Reproduction

Steps to reproduce:

1. Inspect the HTML-code of https://material.angular.io/components/button-toggle/overview
2. https://material.angular.io/components/button/overview

Expected Behavior

At least that the letter-spacing is consistent over the components.

Additionally I would have expected the same spacing for similar types.

According to the Material 3 specs there is no additional letter-spacing set: https://m3.material.io/components/buttons/specs

Actual Behavior

Width is set 1.25px

Environment

Angular CLI: 15.1.3
Node: 19.5.0 (Unsupported)
Package Manager: npm 9.3.1
OS: linux x64

Angular: 15.1.2
... animations, cdk, common, compiler, compiler-cli, core, forms
... localize, material, material-moment-adapter
... platform-browser, platform-browser-dynamic, router

Package Version

@angular-devkit/architect 0.1501.3
@angular-devkit/build-angular 15.1.3
@angular-devkit/core 15.1.3
@angular-devkit/schematics 15.1.3
@angular/cli 15.1.3
@schematics/angular 15.1.3
rxjs 7.8.0
typescript 4.9.5

[amysorto]

Currently the styling of button-toggle and button are a bit different. The button toggle material specs shows only the buttons with icons and no text.

Regardless if they should look the same or not, button-toggle should probably set letter-spacing from the typography.

[seerj30]

Any updates on this?