MantisBT - NetSurf
View Issue Details
IDProjectCategoryView StatusDate SubmittedLast Update
0002121NetSurfLayoutpublic2014-05-11 15:452014-07-19 10:34
ReporterChris Young 
Assigned ToMichael Drake 
PrioritynormalSeverityminorReproducibilityalways
StatusconfirmedResolutionopen 
PlatformAmigaOSAmigaOSOS Version4.1
Product Version3.2 
Target VersionFixed in Version 
Fixed in CI build #
Reported in CI build #1862
URL of problem pagehttp://www.eurovision.tv/page/results?event=1893&voter=UA
Summary0002121: CSS alpha support
DescriptionThe lack of CSS (plotter?) alpha channel support is causing some pages to be unreadable without highlighting text.
Steps To ReproduceThe Eurovision results pages (eg. http://www.eurovision.tv/page/results?event=1893&voter=UA) have all the information in boxes above a background image. On other web browsers these boxes are largely transparent, however on NetSurf they are opaque. Without the alpha channel they consist of black or white boxes with white text on top of them.
Additional InformationI believe it is things like this in the CSS causing the problem:
background:rgba(0,0,0,0.6)

The two screenshots show the Amiga and GTK frontends display the page the same way.
TagsNo tags attached.
Relationships
Attached Filespng css_alpha.png (99,969) 2014-05-11 15:45
https://bugs.netsurf-browser.org/mantis/file_download.php?file_id=138&type=bug
png

png eu.png (97,228) 2014-05-11 15:51
https://bugs.netsurf-browser.org/mantis/file_download.php?file_id=139&type=bug
png

Notes
(0000416)
Michael Drake   
2014-07-19 10:34   
The plotter interface could be extended to support rgba() backgrounds and colours. It would be a backwards incompatible change that would need all core and frontend code's handling of NS_TRANSPARENT changed. I may look at doing this.

If the issue comes from the use of the CSS opacity property we can't do anything about it with the current layout engine. CSS opacity affects the descendants of a box as well as the box itself, so there would need to be some compositing of the rendering in a memory buffer, before plotting the result with opacity applied.

Issue History
Date ModifiedUsernameFieldChange
2014-05-11 15:45Chris YoungNew Issue
2014-05-11 15:45Chris YoungFile Added: css_alpha.png
2014-05-11 15:51Chris YoungFile Added: eu.png
2014-05-11 15:52Chris YoungAdditional Information Updatedbug_revision_view_page.php?rev_id=1207#r1207
2014-05-11 16:30Vincent SandersAssigned To => Michael Drake
2014-05-11 16:30Vincent SandersStatusnew => confirmed
2014-05-11 16:30Vincent SandersDescription Updatedbug_revision_view_page.php?rev_id=1209#r1209
2014-05-11 16:30Vincent SandersSteps to Reproduce Updatedbug_revision_view_page.php?rev_id=1211#r1211
2014-05-11 16:30Vincent SandersAdditional Information Updatedbug_revision_view_page.php?rev_id=1212#r1212
2014-07-19 10:34Michael DrakeNote Added: 0000416