[NETBEANS-4166] Review likely inaccurate int-based character width calculations in editor UI

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 11.3
• Component/s: editor - Painting & Printing
• Labels: HiDPI

Environment

Windows and MacOS with HiDPI/retina displays, Java 9 and above

• Assignee: Unassigned
• Reporter: Eirik Bakke
• Created: 13/Apr/20 21:29
• Updated: 13/Apr/20 21:31

Description

While fixing NETBEANS-346, I discovered several other editor painting coordinate calculations which are likely inaccurate due to rounding errors. Fixing these will be a bit of work, though, and it may be preferable to wait until specific bugs are identified before doing so, so that the changes can be verified to have had the desired effect.

The following members should likely be changed from an int to a float, and initialized from font metrics to full precision:

• org.netbeans.editor.EditorUI.defaultSpaceWidth
• org.netbeans.modules.editor.lib.drawing.DrawEngine.spaceWidth, defaultSpaceWidth, and possibly fragmentWidth
• org.netbeans.modules.editor.lib.drawing.DrawGraphics.defaultSpaceWidth

Changing these from int to float will require various other methods and members to be updated as well.

Issue Links

• relates to: NETBEANS-346 Tabs, characters, and the right Margin don't line up