Use QuickLook API to generate thumbnails and previews.
to dump "c" symbols from qlmanage
nm -g /usr/bin/qlmanage
to dump "obj-c" symbols from qlmanage
otool -ov /usr/bin/qlmanage
or use class-dump
previous version was using a hidden function QLPreviewCopyData to generate preview.
this API has been removed on Catalina and Big Sur.
current version is using - synchronousGetData of the hidden QLPreview class.
thumbnail:=QL Create thumbnail (path;options)
| Parameter | Type | Description |
|---|---|---|
| path | Text | |
| thumbnail | Picture |
preview:=QL Create preview (path;options)
| Parameter | Type | Description |
|---|---|---|
| path | Text | |
| options | Object | |
| preview | BLOB |
Possible properties of options on output:
Height
PDFStyle (0=standard, 3=right, 4=left)
BaseBundlePath (converted to HFS)
TextEncoding
PageElementXPath
MimeType
Width
AllowJavascript
Attachments[]
Attachments[].cid
Attachments[].data
For documents with multiple pages, an HTML preview is generally returned.
If the preview document is a single page, the data is returned in preview. You can use MimeType to find out its internal format. The generator decides what kind of preview to draw. For example, Microsoft Office generators tend to create JPG. Apple iWorks tend to create PDF.
If the preview document has several pages, a container HTML is returned in preview. The cid and data (raw picture) of each page is returned in options.Attachments[].
Note that QuickLook is actually a collection of generators and viewers. A "preview" is not limited to image, it can be audio, video, etc. Likewise, the viewer could be a web browser engine, PDF or text viewer, even a media player or stream player (BaseBundlePath indicates the type of viewer).