Ticket #72 (closed Defect: fixed)
Canvas Oddities
| Reported by: | jri | Owned by: | jri |
|---|---|---|---|
| Priority: | Major | Milestone: | Release 4.1 |
| Component: | DeepaMehta Standard Distribution | Version: | 4.0.2 |
| Keywords: | Cc: | JuergeN, dgf, irau, Malte | |
| Complexity: | 3 | Area: | GUI |
| Module: | deepamehta-webclient |
Description
The canvas shows several drawing and event handling problems:
- A topic can't be moved if it is "in the range" of anothers topic label. In this case text selection is initiated by accident.
- A topic's context menu doesn't appear if the topic is "in the range" of anothers topic label. In this case the browser's generic context menu appears.
- Right-clicking a topic label triggers the browser's generic context menu by accident.
- While a topic is dragged others topic labels are selected by accident (at least in Safari 5.1 on Mac OS X).
- Double clicking the canvas selects it by accident (at least in Safari 5.1 on Mac OS X).
- If a topic with a long label (more than 2 lines) is placed at the canvas bottom browser window scrollbars might appear by accident (at least in Safari 5.1 on Mac OS X).
Possibly most of the problems disappear when replacing the topic label DOM elements by native canvas text rendering. At the time DM4 development has started (2009) the browsers support for canvas text rendering was weak. Possibly this has improved meanwhile.
Change History
comment:2 Changed 13 years ago by Jörg Richter
Webclient: fix some of the canvas oddities (#72).
The topic label DOM elements are now replaced by native canvas text rendering.
Most of the described problems are gone now.
... at the cost of one slight disadvantage: in contrast to DOM element rendering the text rendering quality (anti-aliasing) is now slightly diminished (at least for Safari and Firefox on Mac OS X).
One topic label related feature needs to be completed: line breaking of long labels (as it was before).
=> Please test with different browsers!
See ticket 72.
