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With JDK 9 my swing app works well on Windows with 4k highdpi and normal 1080p normal dpi. Labels, Comboboxes etc. all look nice and are scaled up on the 4k screen. But so is my JPanel where i draw custom images. Can i disable the scaling for this one JPanel to handle drawing myself? I am using apache-commons bicubic interpolation to draw more details on the higher unscaled resolution, but as it is scaled out of the box, i just have the "normal" dimensions to draw.
Kind regards
200
(EDIT: Pasted new version from my library in the form that resulted after about 2 years of use. Comments may not be up to date, but is more production-code worthy now.)
The scaling in Java 9 seems to work like this: Your paint(Component)() methods receive a Graphics2D object which is already scaled. Additionally, the component sizes (e.g. myJFrame.setSize(), myJPanel.getWidth()) are scaled invisibly to the program, meaning that when you say setSize(800,600) on a 200% desktop, the component will be 1600x1200 but getWidth/getHeight will return 800/600.
Can i disable the scaling for this one JPanel to handle drawing myself?
To "reset" your Graphics object to scaling 1, do this:
final Graphics2D g = (Graphics2D) graphics;
final AffineTransform t = g.getTransform();
final double scaling = t.getScaleX(); // Assuming square pixels :P
t.setToScale(1, 1);
g.setTransform(t);
To get the correct dimensions, e.g. for filling the whole background with blackness before drawing:
final int w = (int) Math.round(getWidth() * scaling);
If you do it like this, you should get the desired result on Java 9 and Java 8.
I just created a class for Java devs who strive for a more custom Component design and/or raw drawing, where the system's display scaling should be known and manual scaling is often necessary. It should solve all scaling problems on Java 8 and Java 9. Here it is:
import javax.swing.*;
import java.awt.*;
import java.awt.geom.AffineTransform;
// Please note: This class emerged over time. It gets the job done, but it's horrible. Even the commenting is horrible.
/**
* TL;DR:
* <p>
* Call GUIScaling.initialize() at application start on the Swing thread.
* <p>
* If you set your own Component font sizes or border sizes or window sizes, multiply them by GUIScaling.GUISCALINGFACTOR_COMPONENTSANDFONTS and/or use the
* helper methods newDimension() and scaleForComponent(). Works on Java 8 and 9.
* <p>
* If you do your own custom graphics and want to have control down to the actual pixel, create an instance of GUIScalingCustomGraphics to obtain your
* Graphics2D at scaling 1 and your component's true physical width and height (Which Java 9 reports differently!), and scale all your graphics using
* GUIScaling.GUISCALINGFACTOR_CUSTOMGRAPHICS and/or use the helper method scaleForCustom(). The helper method scaleForRealComponentSize() can transform your
* mouse coordinates to the real physical coordinate, which Java 9 reports differently!
* <p>
* <p>
* <p>
* <p>
* <p>
* <p>
* <p>
* <p>
* <p>
* <p>
* GUIScaling class v[4, 2022-01-15 07!00 UTC] by dreamspace-president.com
* <p>
* This Swing class detects the system's display scaling setting, which is important to make your GUI and custom graphics scale properly like the user wants it.
* On a 4K display, for example, you'd probably set 200% in your system.
* <p>
* Not tested with Java less than 8!
* <p>
* On Java 8 (and with most but not all (e.g. no the default) LooksAndFeels), component sizes (e.g. JButton) and their font sizes will scale automatically, but
* if you have a certain border width in mind, or decided for a certain min and default window size or a certain font size, you have to upscale those on a
* non-100%-system. With this class, just multiply the values with GUISCALINGFACTOR_COMPONENTSANDFONTS. Done. newDimension() and scaleForComponent() help with
* that.
* <p>
* On Java 9, component sizes and their font sizes DO NOT SCALE from the perspective of the application, but in reality they are scaled: A window set to 800x600
* size will really be 1600x1200, but it will still report half this size when asked. A border of 50 pixels will really be 100 pixels. A Graphics2D object
* (paint method etc.) will have a scaling of 2! (Not if you just create a BufferedImage object and do createGraphics(), the scale here will be 1.) So, you
* don't have to bother with GUI scaling here at all. YOU CAN STILL USE GUISCALINGFACTOR_COMPONENTSANDFONTS, because this class will set it to 1 on Java 9. This
* is detected by indeed checking the scaling of a Graphics2D object. So, your Java 8 and 9 component/font code will be exactly the same in regards to scaling.
* <p>
* CUSTOM GRAPHICS: If you do your own painting and want to insist on true physical pixels (in which case obviously you'd have to scale your fonts with
* GUISCALINGFACTOR_CUSTOMGRAPHICS instead of GUISCALINGFACTOR_COMPONENTSANDFONTS), on Java 9 you have to reset the scaling of the Graphics2D object the
* paint(Component)() method gives you from 2 to 1, and (also Java 9) you have to adjust the width/height reported by your component. Both is done by making an
* instance of GUIScalingCustomGraphics. You can do this blindly on Java 8 and 9, your code will stay the same. And then, apply this class'
* GUISCALINGFACTOR_CUSTOMGRAPHICS to scale everything according to system settings. Or, instead of insisting on true physical pixels, you could trust Java 9
* and not mess with the initial scaling - but then you'd have to distinguish whether you're dealing with Java 8 or 9, because on 8, you'd still have to scale
* your custom graphics. In case you decide for this, use GUISCALINGFACTOR_COMPONENTSANDFONTS for your custom graphics instead of
* GUISCALINGFACTOR_CUSTOMGRAPHICS because the former will be ***1*** on Java 9 but will be proper (e.g. 2.0 for a 200% system) on Java 8.
* <p>
* A weird problem that comes with Java 9: If you use the mouse coordinates as reported by the system (instead of, say, quasi-fix the physical mouse pointer
* invisibly at the screen center and make your own pointer based on coordinate differences), you will have HALF THE USUAL RESOLUTION. On Java 8, a 3840x2160
* screen will give you according mouse coordinates, but on Java 9, you get half these coordinates (if the system is set to scaling 200%). While
* scaleForRealComponentSize() helps correct this, a custom drawn mouse pointer will now step in 2 pixel distances, it can not reach every individual pixel any
* longer. I wish they had updated the MouseEvent class accordingly with additional float methods.
*/
final public class GUIScaling { // INITIAL TOUCHING of this class MUST be on Swing thread!
/**
* Call this at the start of your application ON THE SWING THREAD. This initializes the class and hence its values.
*/
public static void initialize() {
System.err.print("");
}
public static void setLookAndFeelDefault() {
// The last three (Nimbus etc.) DO NOT automatically scale their font sizes with the system's GUI scaling,
// so using the font size in those cases to derive the scaling WILL FAIL.
// Btw., the JButton font size at 100% Windows 10 system scaling is 11.0 in all cases but the last three.
GUIScaling.setLookAndFeel("Windows",
UIManager.getSystemLookAndFeelClassName(),
UIManager.getCrossPlatformLookAndFeelClassName(),
"Windows Classic",
"Nimbus",
"Metal",
"CDE/Motif");
}
/**
* By calling this, you ALSO initialize the class, so you don't HAVE TO use initialize() in that case (but it really doesn't matter). And you can indeed set
* a LookAndFeel of your choice, even though initialization of this class also sets AND TEMPORARILY USES a LookAndFeel.
*
* @param intendedLAFIs ANYTHING, but ideally a LookAndFeel name or several. The first value that equalsIgnoreCase an installed LookAndFeelInfo.getName()
* will be used.
*/
public static void setLookAndFeel(final String... intendedLAFIs) {
if (intendedLAFIs != null && intendedLAFIs.length > 0) {
final UIManager.LookAndFeelInfo[] installedLAFIs = UIManager.getInstalledLookAndFeels();
LAFILOOP:
for (String intendedLAFI : intendedLAFIs) {
for (final UIManager.LookAndFeelInfo lafi : UIManager.getInstalledLookAndFeels()) {
if (lafi.getName().equalsIgnoreCase(intendedLAFI)) {
try {
UIManager.setLookAndFeel(lafi.getClassName());
break LAFILOOP;
} catch (Exception e) {
continue LAFILOOP;
}
}
}
}
} else {
throw new IllegalArgumentException("intendedLAFIs is null or empty.");
}
}
/**
* Convenience method, compatible with Java 8 and 9.
*/
public static Dimension newDimension(final int w,
final int h) {
return new Dimension(scaleForComponent(w), scaleForComponent(h));
}
/**
* @param v E.g. the width of a component, or the size of a border.
* @return v scaled by the necessary display scaling factor for components and fonts, compatible with Java 8 and 9.
*/
public static int scaleForComponent(final double v) {
return (int) Math.round(v * GUISCALINGFACTOR_COMPONENTSANDFONTS);
}
/**
* @param v E.g. the width of a rectangle being drawn in a paint() or paintComponent() override.
* @return v scaled by the necessary display scaling factor for custom graphics, compatible with Java 8 and 9.
*/
public static int scaleForCustom(final double v) {
return (int) Math.round(v * GUISCALINGFACTOR_CUSTOMGRAPHICS);
}
/**
* E.g. when the GraphicsContext tells you the screen bounds. Which in Java 8 on 2x 4K desktop will be the full 4K numbers. But, same conditions except Java
* 9, will be half that. Even though you still need the full size.
* <p>
* But this is just an example case. The method was originally made for different cases.
*
* @param v E.g. the width as reported by a component. (Java 9 on 200% desktop reports e.g. 200, but the physical size is actually 400. This method returns
* 400 then.)
* @return v scaled so that it represents real physical pixels, compatible with Java 8 and 9.
*/
public static int scaleForRealComponentSize(final double v) {
return (int) Math.round(v * GUISCALINGFACTOR_REALCOMPONENTSIZE);
}
/**
* E.g. when you scaled the mouse location with the partner method, and now you want to use the mouse action result to scale/locate a window - then you need
* to UNDO the damage.
*/
public static int scaleForRealComponentSizeInverted(final double v) {
return (int) Math.round(v / GUISCALINGFACTOR_REALCOMPONENTSIZE);
}
public static Point scaleMouseEventCoordinatesForCustomGraphics(final Point mouseEventPoint) {
return new Point(scaleForRealComponentSize(mouseEventPoint.x),
scaleForRealComponentSize(mouseEventPoint.y));
}
/**
* @param font A font instance (Or null. Returns null.) whose size has been derived kinda like this: "new JLabel().getFont().getSize()" So it will look
* correct when used in components, no matter the current Java version. ......... WAIT WTF why does that look correct on Java 8
* ?!??!?!?!?!?!?!?! Anyway ... when you want to use THAT font in custom drawing, you'll have a bad time once you get on Java 9. Because
* components will have SMALLER font sizes than on Java 8 on a 200% desktop because their Graphics objects are scaled. But if you use custom
* drawing, you'll use the class GUIScalingCustomGraphics below, which reset the scaling to 1. But then the font is too small. THIS METHOD
* RETURNS THE SCALED FONT independent of the Java version.
* @return
*/
public static Font scaleFontForCustom(final Font font) {
if (font != null) {
return font.deriveFont(font.getSize2D() * (float) GUISCALINGFACTOR_REALCOMPONENTSIZE);
}
return null;
}
/**
* @param font A font instance (Or null. Returns null.) whose size is just a constant number in your source code, and which you want to use in an already
* normalized custom graphics context (meaning you used GUIScaling.GUIScalingCustomGraphics on it.) This font has to be scaled simply by the
* derived System scaling factor to look correct. This method does that.
* @return
*/
public static Font scaleMagicConstantFontForCustom(final Font font) {
if (font != null) {
return font.deriveFont(font.getSize2D() * (float) GUISCALINGFACTOR_SYSTEM);
}
return null;
}
/**
* For Java 9, but can blindly be used in Java 8, too. Ensures that the scaling of a paint(Component)()'s Graphics2D object is 1. Conveniently does the
* usual casting, too.
* <p>
* Also calculates the physical pixel width/height of the component, which is reported differently on Java 9 if the display scaling is not 100%.
*/
final public static class GUIScalingCustomGraphics {
final public double guiScalingFactor_manualDrawing = GUISCALINGFACTOR_CUSTOMGRAPHICS;
final public double guiScalingFactor_fontsThatLookCorrectInComponents = GUISCALINGFACTOR_FONTINCUSTOMGRAPHICSCONTEXT;
final public Component component; // Just for convenience. You can hand the whole instance down your paint call hierarchy.
final public int w; // The physical pixel width of the component.
final public int h; // dto. height
final public Graphics2D g; // Scale will be 1, even on Java 9 with a non-100% display scaling.
/**
* @param component NOT NULL. The component (e.g. JPanel or JFrame) whose paint() method you're overriding.
* @param graphics NOT NULL. The Graphics argument given to your paint() method.
*/
public GUIScalingCustomGraphics(final Component component,
final Graphics graphics) {
this.component = component;
w = scaleForRealComponentSize(component.getWidth());
h = scaleForRealComponentSize(component.getHeight());
g = (Graphics2D) graphics;
final AffineTransform t = g.getTransform();
final double xTrans = t.getTranslateX();
final double yTrans = t.getTranslateY();
t.setToScale(1, 1);
t.translate(xTrans, yTrans);
g.setTransform(t);
}
/**
* @param graphics NOT NULL. The Graphics argument given to your paint() method.
*/
public GUIScalingCustomGraphics(final Graphics graphics) {
component = null;
w = 0;
h = 0;
g = (Graphics2D) graphics;
final AffineTransform t = g.getTransform();
t.setToScale(1, 1);
g.setTransform(t);
}
/**
* @param x E.g. the width of a rectangle to be drawn.
* @return x scaled so that it represents real physical pixels, compatible with Java 8 and 9.
*/
public int scale(final double x) {
return (int) Math.round(x * guiScalingFactor_manualDrawing);
}
/**
* Scales the font and then sets it. Assumption: The given font looked correct in components. In Java 9, it would be TOO SMALL in custom graphics via
* this class. This method fixes that.
*
* @param font NULL = null will be returned and G's font will not change.
* @return returns the set font for convenience. NULL if your argument was null.
*/
public Font setFont(final Font font) {
final Font ret = font == null ? null : font.deriveFont(font.getSize2D() * (float) guiScalingFactor_fontsThatLookCorrectInComponents);
g.setFont(ret);
return ret;
}
@Override
public String toString() {
return "[GUIScalingCustomGraphics" +
" guiScalingFactor_manualDrawing=" + guiScalingFactor_manualDrawing +
" w=" + w +
" h=" + h +
" component=" + component +
" g=" + g +
']';
}
/**
* Convenience method that saves you unnecessary calls and code clutter. In your live painting method, you'll probably check first if your component has
* any pixels, aka if with AND height are at least 1. If they're not, you return before doing anything.
* <p>
* This method is a shortcut. Call this right at the beginning. If it returns true, you abort.
*/
public boolean isSizeZero() {
return w < 1 || h < 1;
}
}
/**
* A tiny rectangle will be filled with the current color and width/height of HAIRLINETHICKNESS.
*/
public static void drawPixel(final Graphics2D g,
final int x,
final int y) {
g.fillRect(x - GUIScaling.HAIRLINETHICKNESS_HALF,
y - GUIScaling.HAIRLINETHICKNESS_HALF,
GUIScaling.HAIRLINETHICKNESS,
GUIScaling.HAIRLINETHICKNESS);
}
final public static double JBUTTONFONTSIZE_ON_100PERCENTSCALE_JAVA8_W10_WITH_LOOKANDFEEL_WINDOWSORSYSTEMORXPLATFORMORWINCLASSIC = 11.0;
final public static float JBUTTONFONTSIZE_ON_UNKNOWNSCALE_UNKNOWNJAVA_UNKNOWNOS_WITH_LOOKANDFEEL_WINDOWSORSYSTEMORXPLATFORMORWINCLASSIC;
final public static double GUISCALINGFACTOR_SYSTEM; // The scaling set in the system.
final public static double GUISCALINGFACTOR_COMPONENTSANDFONTS; // The scaling necessary if you set component/font sizes yourself.
final public static double GUISCALINGFACTOR_CUSTOMGRAPHICS; // The scaling necessary if you want your custom graphics, too, to be scaled according to System settings.
final public static double GUISCALINGFACTOR_REALCOMPONENTSIZE; // The factor by which getWidth() and such return values have to be multiplied, because Java 9 reports them differently.
final public static double GUISCALINGFACTOR_FONTINCUSTOMGRAPHICSCONTEXT; // (This is exactly the custom graphics scaling probed by this class.) The factor by which a proper looking font would have to be scaled when used in custom graphics whose scale is 1. (Java 9 pre-scales it to e.g. 2 if Desktop is at 200%, then you reset that with the class above. Then the fonts that look right in the components will be TOO SMALL in the custom graphics. Use this factor / the method above to fix that.)
final public static int HAIRLINETHICKNESS; // A "hairline" would be a line with pixel thickness 1. However, if the GUI is scaled up, that should be a little thicker. This value will have a value of AT LEAST 1. If the GUI scaling of the system is 200%, the value will be 2. If it's 175%, the value will ALSO be 2 due to rounding.
final public static int HAIRLINETHICKNESS_HALF;
final public static double HAIRLINETHICKNESS_HALF_DOUBLE;
static {
if (!SwingUtilities.isEventDispatchThread()) { // This also makes sure an obfuscator doesn't remove this method and its calls.
throw new IllegalStateException("Must be initialized on Swing thread!");
}
System.err.println("Initializing GUI scaling ...");
GUIScaling.setLookAndFeelDefault();
JBUTTONFONTSIZE_ON_UNKNOWNSCALE_UNKNOWNJAVA_UNKNOWNOS_WITH_LOOKANDFEEL_WINDOWSORSYSTEMORXPLATFORMORWINCLASSIC =
new JButton().getFont().getSize2D(); // 21.0 on 200% desktop on Java 8 // 11.0 on 100% desktop on Java 8
final Integer[] paintScalingInPercent = new Integer[1];
final JDialog bruteForceJava9ScalingCheck = new JDialog((Frame) null, "", true) {
{
// setLocation(-1000, -1000); // Outamysight!
setLocation(100,
100); // else you might have compatibility problems (see stackoverflow where I posted this class)
final Runnable fallbackInCaseOlderJavaVersionDoesNotEndUpClosingThisWindow = () -> {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
SwingUtilities.invokeLater(() -> {
paintScalingInPercent[0] = 100;
dispose();
});
};
final Thread t = new Thread(fallbackInCaseOlderJavaVersionDoesNotEndUpClosingThisWindow);
t.setDaemon(true);
t.setName("GUI scaling detector fallback thread");
t.start();
}
@Override
public void paint(final Graphics graphics) {
final Graphics2D g = (Graphics2D) graphics;
final AffineTransform originalTransform = g.getTransform();
paintScalingInPercent[0] = (int) Math.round(originalTransform.getScaleX() * 100);
dispose();
}
};
bruteForceJava9ScalingCheck.setVisible(true); // This call blocks until dispose() is reached.
if (paintScalingInPercent[0] == null) {
throw new Error("Unexpected behavior: Modal dialog did not block!");
} else if (paintScalingInPercent[0] != 100) {
// Must be Java 9 (or newer?).
GUISCALINGFACTOR_SYSTEM = paintScalingInPercent[0] * 0.01;
GUISCALINGFACTOR_COMPONENTSANDFONTS = 1; // Java 9 does everything. The developer's considerations are made unnecessary/harmless by this "1".
GUISCALINGFACTOR_CUSTOMGRAPHICS = GUISCALINGFACTOR_SYSTEM;
GUISCALINGFACTOR_FONTINCUSTOMGRAPHICSCONTEXT = GUISCALINGFACTOR_SYSTEM;
} else {
// Either Java 8 (or older?) or scaling IS just at the normal 1 (100).
final double factorPreliminary = JBUTTONFONTSIZE_ON_UNKNOWNSCALE_UNKNOWNJAVA_UNKNOWNOS_WITH_LOOKANDFEEL_WINDOWSORSYSTEMORXPLATFORMORWINCLASSIC / JBUTTONFONTSIZE_ON_100PERCENTSCALE_JAVA8_W10_WITH_LOOKANDFEEL_WINDOWSORSYSTEMORXPLATFORMORWINCLASSIC;
// System.err.println("FIX MEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!");
// final double factorPreliminary = 1;
// If we just divide the two, we get 1.454545... on a 150% desktop, because the font sizes
// chosen by Java are integer values, so we experience a rounding error.
// The crappy but probably in most cases nicely working solution is: We round the result to .25 steps!
GUISCALINGFACTOR_SYSTEM = Math.round(factorPreliminary * 4) / 4d;
GUISCALINGFACTOR_COMPONENTSANDFONTS = GUISCALINGFACTOR_SYSTEM;
GUISCALINGFACTOR_CUSTOMGRAPHICS = GUISCALINGFACTOR_SYSTEM;
GUISCALINGFACTOR_FONTINCUSTOMGRAPHICSCONTEXT = 1; // No font scaling, the fonts used will look correct in custom scaling without extra treatment.
}
GUISCALINGFACTOR_REALCOMPONENTSIZE = GUISCALINGFACTOR_CUSTOMGRAPHICS / GUISCALINGFACTOR_COMPONENTSANDFONTS;
HAIRLINETHICKNESS = (int) Math.max(1, Math.round(GUISCALINGFACTOR_CUSTOMGRAPHICS));
HAIRLINETHICKNESS_HALF_DOUBLE = HAIRLINETHICKNESS * 0.5;
HAIRLINETHICKNESS_HALF = (int) Math.round(HAIRLINETHICKNESS_HALF_DOUBLE);
// System.err.println("GUISCALINGFACTOR_SYSTEM = " + GUISCALINGFACTOR_SYSTEM);
// System.err.println("GUISCALINGFACTOR_COMPONENTSANDFONTS = " + GUISCALINGFACTOR_COMPONENTSANDFONTS);
// System.err.println("GUISCALINGFACTOR_CUSTOMGRAPHICS = " + GUISCALINGFACTOR_CUSTOMGRAPHICS);
// System.err.println("GUISCALINGFACTOR_REALCOMPONENTSIZE = " + GUISCALINGFACTOR_REALCOMPONENTSIZE);
System.err.println("... done.");
}
}
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