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Java/JavaScript browser detection

Bugs and disappointing features in runtime environments

Java:

• Java Plugin
  • getPrintJob() does not work properly in Java 1.3 and 1.4.0
• AWT bugs
  • Menu items do not work in PopupMenu in Sun Java 1.3-1.3.1
  • State change not detected for CheckboxMenuItem of a PopupMenu in MSIE 5.0
    
  • Menu labels cannot be changed in MSIE 4.01
    
  • Polygon.inside(x,y) may fail due to bug in updateBounds in JDK 1.0-1.1.6, Netscape 2.0-4.7, MSIE 3.0-?
  • GridBagLayout can not deal with more than 128 rows. in JDK 1.0x, Netscape 2.0-4.05, MS Explorer 3.0-?
  • The maximum value of Scrollbar is the rightmost position of the left instead of the right side of the slider.
    MS Explorer 3.0-5.0 (java.version <= 1.1), Netscape 2.0-4.05 (java.version<=1.1.2)
• Microsoft Windows, any browser
  • A component is in front of other windows if and only if it has the keyboard focus.
    W: always requestFocus after show but never on mouseEnter.
    Drawback: a button under the mouse cannot receive keyboard events.
  • Mouse MOVE and DRAG events follow every DOWN and UP without reason.
    
    • DOWN->DRAG, UP->MOVE in Netscape 2 and MSIE 3
    • UP->MOVE in Netscape 4 and MSIE 4
• MS Explorer only
  • Scrolling the page may mix up applets in MSIE 4.0x
    Especially frustrating for large applets.
  • Arrays are not instanceof Object sometimes in MSIE 3.0x
    W: do not use arrays as objects.
• Netscape/Mozilla only
  • Cannot use consecutive space characters in applet parameters in Mozilla 0.9.7-1.0
  • Applet methods containing I/O operations may throw AccessControlException in Netscape 6 when called from JavaScript
  • Applet freezes in Linux Netscape 6 if a method called from JavaScript tries to download a class file from the web server.
  • Thread constructor throws AccessControlException in Netscape 6/MSWindows
  • Netscape 4.0-4.7 may crash when the user closes a window containing frames, tables and applets
  • The browser freezes when the user closes a window containing an applet in Netscape 4.51-4.7/MSWindows98
    
  • JIT DAG failure for codes like a=b*(c=d?e:f) or method(c=d?e:f) in Netscape 4.0 for MSWindows/Symantec JIT
    W: c=d?e:f; a=b*c;
  • getApplet(String) does not work in Netscape 3.0 for MSWindows
    W: use getApplets() instead.
  • Extremely slow Font constructor in Netscape 4.06-4.61 (java.version=1.1.5)
  • drawImage extremely slow for partly transparent images (pixels with alpha=0) in Netscape 4.06-4.61 (java.version=1.1.5)
    This feature may cause animation to slow down noticably in Netscape 4.06 compared to 4.05 or any other previous version.
    
• X window
  • Fonts are ugly, their actual size is not an always increasing function of the logical size in points. Netscape 4.06-4.6 for Linux

Java to JavaScript communication:

• Netscape 4.6-4.7
  • Security exception for getApplets and MAYSCRIPT
• Netscape 4.6
  • Security exception for eval

JavaScript to Java communication:

• Netscape 6
  • Deadconnect: Netscape 6.0 may die if a script in a frame tries to call a Java method.
• Netscape 4.0-4.7
  • Applet method call at onLoad may result in "document.X has no properties"

Obfuscation-related:

• Verifier error in Netscape 2.x for method and variable names not matching the pattern "[a-zA-Z][a-zA-Z0-9]*".
  W: be careful with the obfuscator.