The zooming API makes makes it easier to supports zooming in applications.
Zooming is done by increasing/decreasing FlatLaf scale factor (see UIScale.getUserScaleFactor())
and increasing/decreasing default font size.

Note:

• This PR only offers API. You need to implement zooming UI for your application yourself.
• Only standard Swing components are zoomed.
  Custom components need to use UIScale.scale(int) to zoom their UI.

Use FlatLaf Demo to test it:

with 120% zoom:

Usage

Set zoom factor

if( UIScale.setZoomFactor( 1.2f ) )
    FlatLaf.updateUI();

UI needs to be updated if zoom factor has changed.
If you set zoom factor before any UI components are created, then FlatLaf.updateUI() is not necessary.

Increase zoom factor / Zoom In

if( UIScale.zoomIn() )
    FlatLaf.updateUI();

This increases zoom factor using next greater factor in supported factors array.

Decrease zoom factor / Zoom Out

if( UIScale.zoomOut() )
    FlatLaf.updateUI();

This decreases zoom factor using next smaller factor in supported factors array.

Reset Zoom

if( UIScale.zoomReset() )
    FlatLaf.updateUI();

Resets zoom factor to 1.

Define supported zoom factors for zoom in/out

UIScale.setSupportedZoomFactors( new float[] { 1f, 1.1f, 1.25f, 1.5f, 1.75f, 2f } );

Sets the supported zoom factors used for zoomIn() and zoomOut().
Default is [ 1f, 1.1f, 1.25f, 1.5f, 1.75f, 2f ].