Fixed wrongly printing a warning.

Adjusted demos for new theme system.

core/src/main/java/com/github/weisj/darklaf/theme/PropertyFontMapper.java

@@ -46,7 +46,7 @@ public class PropertyFontMapper implements FontMapper {
         adjustment = getSize(defaults);
         // No need to create a new font.
         if (adjustment == 0) return font;
-        if (adjustment < font.getSize2D()) {
+        if (adjustment + font.getSize2D() <= 0) {
             if (adjustment != Integer.MIN_VALUE) {
                 LOGGER.warning("Font " + font + " would be invisible after applying "
                                + "an adjustment of " + adjustment + ". Aborting!");

core/src/test/java/ui/ComponentDemo.java

@@ -33,7 +33,9 @@ import java.awt.event.ActionEvent;
 public interface ComponentDemo {
 
     static Theme getTheme() {
-        return new IntelliJTheme();
+        return LafManager.themeForPreferredStyle(new PreferredThemeStyle(ContrastRule.STANDARD,
+                                                                         StyleRule.LIGHT,
+                                                                         FontSizeRule.DEFAULT));
     }
 
     JComponent createComponent();

core/src/test/java/ui/tabFrame/TabFrameDemo.java

@@ -48,7 +48,7 @@ public class TabFrameDemo implements ComponentDemo {
     private static Component createTextArea() {
         NumberedTextComponent numberPane = new NumberedTextComponent(new NonWrappingTextPane() {{
             setText(StringUtil.repeat(DemoResources.LOREM_IPSUM, 10));
-            setFont(new Font(Font.MONOSPACED, Font.PLAIN, 14));
+            setFont(new Font(Font.MONOSPACED, Font.PLAIN, getFont().getSize()));
         }});
         NumberingPane numbering = numberPane.getNumberingPane();
         Icon icon = IconLoader.get().getIcon("navigation/arrowRight.svg");