Package com.formdev.flatlaf.util

Class UIScale

  • public class UIScale
extends java.lang.Object
    This class handles scaling in Swing UIs. It computes user scaling factor based on font size and provides methods to scale integer, float, Dimension and Insets. This class is look and feel independent.

    Two scaling modes are supported by FlatLaf for HiDPI displays:

    1) system scaling mode

    This mode is supported since Java 9 on all platforms and in some Java 8 VMs (e.g. Apple and JetBrains). The JRE determines the scale factor per-display and adds a scaling transformation to the graphics object. E.g. invokes java.awt.Graphics2D.scale( 1.5, 1.5 ) for 150%. So the JRE does the scaling itself. E.g. when you draw a 10px line, a 15px line is drawn on screen. The scale factor may be different for each connected display. The scale factor may change for a window when moving the window from one display to another one.

    2) user scaling mode

    This mode is mainly for Java 8 compatibility, but is also used on Linux or if the default font is changed. The user scale factor is computed based on the used font. The JRE does not scale anything. So we have to invoke scale(float) where necessary. There is only one user scale factor for all displays. The user scale factor may change if the active LaF, "defaultFont" or "Label.font" has changed. If system scaling mode is available the user scale factor is usually 1, but may be larger on Linux or if the default font is changed.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static java.beans.PropertyChangeSupport changeSupport  
      private static boolean DEBUG  
      private static boolean initialized  
      private static java.lang.Boolean jreHiDPI  
      private static float scaleFactor  

    • Constructor Summary

      Constructors 
      Constructor Description
      UIScale()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void addPropertyChangeListener​(java.beans.PropertyChangeListener listener)  
      static javax.swing.plaf.FontUIResource applyCustomScaleFactor​(javax.swing.plaf.FontUIResource font)
      Applies a custom scale factor given in system property "flatlaf.uiScale" to the given font.
      static float computeFontScaleFactor​(java.awt.Font font)
      For internal use only.
      private static float computeScaleFactor​(java.awt.Font font)  
      private static float getCustomScaleFactor()
      Get custom scale factor specified in system property "flatlaf.uiScale".
      static double getSystemScaleFactor​(java.awt.Graphics2D g)
      Returns the system scale factor for the given graphics context.
      static double getSystemScaleFactor​(java.awt.GraphicsConfiguration gc)
      Returns the system scale factor for the given graphics configuration.
      static float getUserScaleFactor()
      Returns the user scale factor.
      private static void initialize()  
      static boolean isSystemScalingEnabled()
      Returns whether system scaling is enabled.
      private static boolean isUserScalingEnabled()  
      private static float parseScaleFactor​(java.lang.String s)
      Similar to sun.java2d.SunGraphicsEnvironment.getScaleFactor(String)
      static void removePropertyChangeListener​(java.beans.PropertyChangeListener listener)  
      static float scale​(float value)
      Multiplies the given value by the user scale factor.
      static int scale​(int value)
      Multiplies the given value by the user scale factor and rounds the result.
      static java.awt.Dimension scale​(java.awt.Dimension dimension)
      Scales the given dimension with the user scale factor.
      static java.awt.Insets scale​(java.awt.Insets insets)
      Scales the given insets with the user scale factor.
      static int scale2​(int value)
      Similar as scale(int) but always "rounds down".
      static void scaleGraphics​(java.awt.Graphics2D g)
      If user scale factor is not 1, scale the given graphics context by invoking Graphics2D.scale(double, double) with user scale factor.
      private static void setUserScaleFactor​(float scaleFactor, boolean normalize)
      Sets the user scale factor.
      static float unscale​(float value)
      Divides the given value by the user scale factor.
      static int unscale​(int value)
      Divides the given value by the user scale factor and rounds the result.
      private static void updateScaleFactor()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • changeSupport

        private static java.beans.PropertyChangeSupport changeSupport

      • jreHiDPI

        private static java.lang.Boolean jreHiDPI

      • scaleFactor

        private static float scaleFactor

      • initialized

        private static boolean initialized

    • Constructor Detail

      • UIScale

        public UIScale()

    • Method Detail

      • addPropertyChangeListener

        public static void addPropertyChangeListener​(java.beans.PropertyChangeListener listener)

      • removePropertyChangeListener

        public static void removePropertyChangeListener​(java.beans.PropertyChangeListener listener)

      • isSystemScalingEnabled

        public static boolean isSystemScalingEnabled()
        Returns whether system scaling is enabled.

      • getSystemScaleFactor

        public static double getSystemScaleFactor​(java.awt.Graphics2D g)
        Returns the system scale factor for the given graphics context.

      • getSystemScaleFactor

        public static double getSystemScaleFactor​(java.awt.GraphicsConfiguration gc)
        Returns the system scale factor for the given graphics configuration.

      • initialize

        private static void initialize()

      • updateScaleFactor

        private static void updateScaleFactor()

      • computeFontScaleFactor

        public static float computeFontScaleFactor​(java.awt.Font font)
        For internal use only.
        Since:
        2

      • computeScaleFactor

        private static float computeScaleFactor​(java.awt.Font font)

      • isUserScalingEnabled

        private static boolean isUserScalingEnabled()

      • applyCustomScaleFactor

        public static javax.swing.plaf.FontUIResource applyCustomScaleFactor​(javax.swing.plaf.FontUIResource font)
        Applies a custom scale factor given in system property "flatlaf.uiScale" to the given font.

      • getCustomScaleFactor

        private static float getCustomScaleFactor()
        Get custom scale factor specified in system property "flatlaf.uiScale".

      • parseScaleFactor

        private static float parseScaleFactor​(java.lang.String s)
        Similar to sun.java2d.SunGraphicsEnvironment.getScaleFactor(String)

      • getUserScaleFactor

        public static float getUserScaleFactor()
        Returns the user scale factor.

      • setUserScaleFactor

        private static void setUserScaleFactor​(float scaleFactor,
                                       boolean normalize)
        Sets the user scale factor.

      • scale

        public static float scale​(float value)
        Multiplies the given value by the user scale factor.

      • scale

        public static int scale​(int value)
        Multiplies the given value by the user scale factor and rounds the result.

      • scale2

        public static int scale2​(int value)
        Similar as scale(int) but always "rounds down".

        For use in special cases. scale(int) is the preferred method.

      • unscale

        public static float unscale​(float value)
        Divides the given value by the user scale factor.

      • unscale

        public static int unscale​(int value)
        Divides the given value by the user scale factor and rounds the result.

      • scaleGraphics

        public static void scaleGraphics​(java.awt.Graphics2D g)
        If user scale factor is not 1, scale the given graphics context by invoking Graphics2D.scale(double, double) with user scale factor.

      • scale

        public static java.awt.Dimension scale​(java.awt.Dimension dimension)
        Scales the given dimension with the user scale factor.

        If user scale factor is 1, then the given dimension is simply returned. Otherwise, a new instance of Dimension or DimensionUIResource is returned, depending on whether the passed dimension implements UIResource.

      • scale

        public static java.awt.Insets scale​(java.awt.Insets insets)
        Scales the given insets with the user scale factor.

        If user scale factor is 1, then the given insets is simply returned. Otherwise, a new instance of Insets or InsetsUIResource is returned, depending on whether the passed dimension implements UIResource.