JDK-5086593 : Java AWT panel cannot display more than 1820 canvas objects
  • Type: Bug
  • Component: client-libs
  • Sub-Component: java.awt
  • Affected Version: 5.0
  • Priority: P4
  • Status: Closed
  • Resolution: Won't Fix
  • OS: windows_xp
  • CPU: x86
  • Submitted: 2004-08-13
  • Updated: 2005-12-28
  • Resolved: 2005-12-28
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Description
Name: dk106046			Date: 08/12/2004

SYNOPSIS: 
Java AWT panel cannot display more than 1820 canvas objects.

OPERATING SYSTEM(S):
Win32 - Microsoft Windows XP Professional, Version 2002, Service Pack 1.

FULL JDK VERSION(S): Sun jdks 1.4.2_05, 5.0 Beta2


A task item consists of taskName, taskDescription, runningState, taskIndex and superTaskID. Each task item is created by a canvas object and added to a vector. The vector is then added to a panel which is then added to a scrollpane. If 1900 task items are added to the panel, it displays only 1820 task items. When we scroll past task 1820, there is only blank space at the end of the scrollpane. 

Exact steps to reproduce:
1. Compile the java files: javac *.java.
2. Create a folder by name rsCopyServices and copy the generated .class files inside this  folder.
3. Run the test by running the appletviewer or by loading the testTaskPanel.html file in a browser that supports the Java Runtime Environment (JRE)

Minimal source code that demonstrates the problem
We are providing the entire testcase which demonstrates the problem. The testcase is attached herewith.

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Comments
WORK AROUND 1) display components page by page 2) use tabs
12-07-2006
EVALUATION As this happens due to a system specifics I'm closing it out as will not fix.
28-12-2005
EVALUATION Happens probably due to the limitation of ScrollPane. Usually, the size of heavyweight component on Windows is limited to 15 bit. However, we could expect WinXP to not have such limitation. Should verify that we don't do anything to cause this limitation. ###@###.### 2004-08-13 Testcase uploaded ###@###.### 2004-08-16 Similar problem is seen on Solaris where 1856 (1861 with XToolkit) items shown. Further down scrolling cause hiding of all the items in applet window. The same on RHAS2.1 ###@###.### 2004-08-25 Name: ad153231 Date: 08/26/2004 Will check if a native applications behaves similarly. Seems that this problem occur because of platform limitations. ====================================================================== Name: ad153231 Date: 08/26/2004 AWT do not make anything causing this bug. This is a system limitation result. One of the possible solution is to avoid using HW Container which lies under the ScrollPane. Workaround: using Swing instead AWT could help to show all the items in ScrollPane. ======================================================================
27-08-2004
WORK AROUND Name: dk106046 Date: 08/12/2004 None known ======================================================================
27-08-2004