MantisBT - NetSurf
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0002688NetSurfLayoutpublic2019-08-02 15:032019-11-30 11:08
ReporterHarriet Bazley 
Assigned ToMichael Drake 
PlatformIyonixOSRISC OSOS Version5.22
Product Version 
Target VersionFixed in Version 
Fixed in CI build #
Reported in CI build #4760
URL of problem page
Summary0002688: No images visible
DescriptionNetsurf does not display any of the images on the page

The slow speed of redraw would suggest that it has loaded and is trying to render them, but all I see is blank boxes.
Steps To ReproduceVisit URL.
Additional InformationThe <IMG> tags look fairly straightforward, and if I save the raw HTML and strip out all the stylesheet links the images appear (albeit at a much larger size than evidently intended), so it is presumably a CSS issue. I was unable to test by tweaking the stylesheets directly, owing to bug 0002687 crashing Netsurf.

Netsurf v4712 simply rendered the blank boxes on the page without the textual overlay.
TagsNo tags attached.
Attached Filesjpg screen.jpg (55,451) 2019-08-02 15:09

jpg C1698-018.jpg (285,173) 2019-08-09 17:00

Dave Higton   
2019-08-09 15:14   
I just saved one of the JPEGs from the problem URL, and found that SwiftJPEG cannot render it, but PrivateEye can. So it seems there is some compatibility issue with the particular JPEG format used.
Harriet Bazley   
2019-08-09 17:00   
I used Object=>Save over one of the blank boxes and dragged the resulting file back into Netsurf, which seems to render the JPEG OK without any problems (although not at a scale which would fit in the box provided)
Michael Drake   
2019-11-30 11:08   
The JPEGs are fine, and render correctly in NetSurf.

The problem is that over all the images, the web site places a white rectangle. On browsers that support the CSS opacity property, this is rendered as transparent. When you hover over it it becomes opaque. If we implemented the opacity property it would fix this. The page also specifies the white box as rbga(255, 255, 255, 0.6), so when you over and it becomes opaque, it remains partially transparent anyway.

The alpha channel on the colour specifier is reasonably easy to implement; we just need to pass the value through to the potters, and have the front ends implement it.

However, the opacity property is more work. Its value applies to the element as a whole, including the children. So to implement it properly we would need to do compositing.

Issue History
2019-08-02 15:03Harriet BazleyNew Issue
2019-08-02 15:09Harriet BazleyFile Added: screen.jpg
2019-08-09 15:14Dave HigtonNote Added: 0002070
2019-08-09 17:00Harriet BazleyFile Added: C1698-018.jpg
2019-08-09 17:00Harriet BazleyNote Added: 0002071
2019-10-21 16:42Vincent SandersStatusnew => confirmed
2019-10-21 16:42Vincent SandersDescription Updatedbug_revision_view_page.php?rev_id=2146#r2146
2019-10-21 16:42Vincent SandersAdditional Information Updatedbug_revision_view_page.php?rev_id=2148#r2148
2019-11-29 20:32Daniel SilverstoneAssigned To => Michael Drake
2019-11-29 20:32Daniel SilverstoneStatusconfirmed => assigned
2019-11-30 11:08Michael DrakeNote Added: 0002141