Bug 188081

Summary:

ScrollBar rendered incorrectly when the range model contains large numbers

Product:

[Tools] GEF

Reporter:

fictivy

Component:

GEF-Legacy Draw2d

Assignee:

gef-inbox <gef-inbox>

Status:

NEW ---

QA Contact:

Severity:

normal

Priority:

CC:

nyssen

Version:

unspecified

Target Milestone:

---

Hardware:

OS:

Windows 2000

Whiteboard:

Attachments:

Description	Flags
code example	none
Patch to increase range of scrollbar values	none

Description fictivy

2007-05-21 08:40:30 EDT

Build ID: 3.2.2

Create a scrollbar with e.g. 
minimum:  -50000000
maximum:   50000000
value: 0
The thumb will not be drawn in the middle but over the up arrow button. It cannot be dragged to the middle either.

Comment 1 fictivy

2007-05-21 08:41:50 EDT

Created attachment 67973 [details]
code example

Comment 2 Randy Hudson

2007-05-21 09:32:30 EDT

Would you care to provide a patch to this problem? 50 million is a very large number and well beyond what most GEF clients are trying to display, so this would receive low priority from the GEF team.

Comment 3 Matt Scarpino

2007-08-14 11:44:17 EDT

Created attachment 76053 [details]
Patch to increase range of scrollbar values

The location of the scrollbar thumb is currently calculated using integer math. When the integers become too large, overflow causes unpredictable results. This patch increases the range of possible values by replacing the integer math with floating-point calculations and rounding.

These floating-point calculations increase the range of possible scrollbar values, but it's questionable whether the increased range is worth the additional processing time.