[SOLVED] VS Code Extension: open PDF side-by-side

VS Code Extension: open PDF side-by-side

Problem

I am writing a VS Code extension for VS Code 1.94.2 which shall open a PDF file side-by-side and I got this far using vscode.openWith:

vscode.commands.executeCommand(
    'vscode.openWith',
    uri_pointing_to_my_pdf_file,
    'default',
    vscode.ViewColumn.Beside
)

This opens an editor just as expected but the editor says:

The file is not displayed in the text editor because it is either binary or uses an unsupported text encoding.

If I click the Open Anyway button, I am offered the two options:

Text Editor - Active (Built-In)
Pdf Preview - Default (vscode-pdf)

Choosing vscode-pdf then lets the side-by-side editor show the PDF. However, I have to manually choose that every time.

Question

How can I change my code so that the editor will show the PDF without the user choosing the vscode-pdf editor manually every time?

Unsuccessful Attempts

change `viewId`

Changing the viewId from 'default' to 'vscode-pdf' had no effect. Documentation says:

viewId - Custom editor view id or 'default' to use VS Code's default editor

`'vscode.open'` command

Using the 'vscode.open' command will open an editor which shows the PDF properly. But the editor opens in a new tab and not side-by-side.

Solution

I actually found the answer myself by looking at the source of the vscode-pdf extension: Their implementation of the vscode.CustomReadonlyEditorProvider interface defines viewType = 'pdf.preview' in this source file.

I changed my code to:

vscode.commands.executeCommand(
    'vscode.openWith',
    uri_pointing_to_my_pdf_file,
    'pdf.preview', // use correct editor provider name here: "pdf.preview"
    vscode.ViewColumn.Beside
)

This appears to be the correct way to use the 'vscode.openWith' command when opening a PDF.