PdfDocument has a property password and also passwordRequired signal. However, these are only used for that PdfDocument instance.
In Qt Quick API (Pdf*PageView), PDF pages are actually rendered through Image component with imageformats plugin provided by the module. That plugin has its own instance of QPdfDocument internally and there is no way to pass the password from QML to the plugin so opening the file fails and no image is rendered.
|For Gerrit Dashboard: QTBUG-96574|
|287726,8||WIP allow loading images from arbitrary QFile subclasses||dev||qt/qtdeclarative||Status: NEW||-2||0|
|297308,3||WIP add QQuickPdfPageImage||5.15||qt/qtwebengine||Status: NEW||-2||0|