Thumbnail Cache for HtmlDialog with many images?



I’m playing with an HtmlDialog content browser in SketchUp which extracts the thumbnail images from .skm and .style files using RubyZip, then adds them to the dialog to allow users to select them.

What’s the best way to handle the images? Should I try to cache the thumbnails on disk so as not to have to extract them every time the user browses the materials? Or maybe base64 encode the image directly from the UnzipStream and add the encoded string to a data URI in an img tag? Something else?

How can I manipulate textures and materials with HtmlDialog?

On Windows, they should already be (after display) in the “Temporary Internet Files” folder if you’ve loaded them into a webpage.

But on Windows I am seeing SKM thumbnails generated by “thumbsup.dll”.

I thought that Windows usually stores the file thumbnails in hidden zip database files, so it doesn’t have to regenerate them ?

I’d say you could do similar beneath your extension folder.
Either zipped folders or not, your choice.

FYI, This works in MSIE WebDialog.

dlg = UI::WebDialog::new("Test")

dlg.set_url('file://C:\Program Files\SketchUp\SketchUp 2016\Materials\Brick, Cladding and Siding')

Then, right click and choose View > Large Icons

Does it in Chromium ?

Hmmm, I guess not, no simplified view of thumbnails on context menu, and no built-in rendering of sortable & filterable columns in details mode. (Maybe a Chrome extension ?)


I extract the images in one of my mac plugin using the builtin unzip as it’s faster…

but I also found the ‘thumbnails’ for textures poor so I dig deeper and save them in my own folders…

@files.each do |file|
                path = File.join( @color, File.basename(file, '.skm'))
                path = File.join( @texture, File.basename(file, '.skm')) if is_texture(file)
                  %x( unzip "#{file}" -d "#{path}")
                  tex = %x(find "#{path}"/ref/*.*[gf]).chomp!
                  img = File.join(path,'doc_thumbnail.png')
                  if  tex == nil
                    img_batch(file, img)
                    tex = tex.split("\n")[0] if tex.include?("\n")
                    img_batch(file, tex)
              end # if is_texture(file)

for the SU ones I process once and keep the files, but I re-scan the ‘User’ folders looking for updated content only…

seem fast enough in a WebDialog…

with the HtmlDialog being written to a tmp file by SU, I’m not sure Session Storage will help as they seem to be cleared…



Thanks to both of you for the feedback.

I was able to test directly encoding the thumbnail to base64 from the Zip InputStream, and it works sufficiently fast enough that performance is not a concern. I load an initial 20 items immediately, then “timer-in” the rest at a rate which keeps the dialog responsive. It works nicely.

Not caching the thumbnails on disk will work out better because otherwise I may have needed to write a cache manager to keep the thumbnails updated and synchronized.