Fire onDidChangeVisibleTextEditors on editors change

[mmorhun]

Signed-off-by: Mykola Morhun mmorhun@redhat.com

Before we fired onDidChangeVisibleTextEditors on documents change what is wrong. This PR fixes that problem and reacts on editors change now.

Resolves: #4221

[benoitf]

hello, how were you able to test ?

[akosyakov]

@mmorhun the same as @benoitf, could you clarify how one can check (with which VS Code extension) that issue is gone, #4221 is not informative

[mmorhun]

@benoitf @akosyakov I've tested it with simple plug-in, which just logs data from each onDidChangeVisibleTextEditors event.

[akosyakov]

@mmorhun Do you still have it?

[mmorhun]

@akosyakov just generated frontend plug-in with the following code:

import * as theia from '@theia/plugin';

export function start(context: theia.PluginContext) {
    theia.window.onDidChangeVisibleTextEditors((editors: theia.TextEditor[]) => {
        let list: string = '';
        for (let editor of editors) {
            list += editor.document.uri.toString() + ', ';
        }
        console.log(list);
    });
}

export function stop() { }

[vitaliy-guliy]

@mmorhun Thanks for the fix!!