vscode: support keepScrollPosition for QuickPick

[vince-fugnitto]

What it does

The pull-request adds support for keepScrollPosition when creating a QuickPick. The option is used to enforce that the menu does not scroll back to the top of the list when there is an update to the items in the list.

The updates should also help with our VS Code compatibility report.

Extension Videos

master:

master-quick-pick.mov

pull-request:

pr-quick-pick.mov

How to test

The following extension (vscode-keep-scroll-position-0.0.1.vsix.zip) can be used to test the option when creating a quick-pick, the extension creates a quick-pick with keepScrollPosition set to true, and after some time it will update the list.

On master this would cause the list to jump to the top after the update.

Extension Code

let disposable = vscode.commands.registerCommand('vscode-keep-scroll-position.show', async () => {

    // Create the quick pick.
    const pick = vscode.window.createQuickPick();

    // Set options for the quick pick.
    const initialItems = [...Array(50).keys()].map(i => <vscode.QuickPickItem>{ label: `Initial Item ${i.toFixed()}` });
    pick.items = initialItems;
    pick.keepScrollPosition = true;

    // Display the quick pick.
    pick.show();

    // Wait some time.
    await new Promise(resolve => setTimeout(resolve, 5000));

    // Update the items to test the update.
    const updatedItems = [...Array(20).keys()].map(i => <vscode.QuickPickItem>{ label: `Updated Item: ${i.toFixed()}` });
    pick.items = [...initialItems, ...updatedItems];
});

1. include vscode-keep-scroll-position-0.0.1.vsix.zip
2. start the application
3. trigger the command Quick Pick: Show
4. scroll the quick pick menu to the end
5. confirm that after a few seconds the position is kept
6. scroll to the bottom - confirm the updated items exist

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

Signed-off-by: vince-fugnitto [email protected]

[msujew]

Looks good. I can confirm that the quick input dropdown moves to the start on master and keeps the current position with the changes 👍