Disable outline button when unavailable

[saebekassebil]

This is a little accessibility that bugs me, the outline button is clickable although there's no outline available. This PR disables the button (but still creates the DocumentOutlineView).

Thoughts on this? If you like this, maybe I should just prevent the creation of a DocumentOutlineView in cases where there's no outline?

[Snuffleupagus]

A shorter solution for this would be: document.getElementById('viewOutline').disabled = !outline;

[saebekassebil]

Quite right.

[Snuffleupagus]

Personally I like this idea!
If this is a change that the developers agree should be done, I would suggest adding disabled to the HTML tag: https://github.com/mozilla/pdf.js/blob/master/web/viewer.html#L85. This would prevent the the button from appearing click-able before the outline has been loaded.

[waddlesplash]

/botio-linux preview

[pdfjsbot]

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[pdfjsbot]

From: Bot.io (Linux)

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Full output at http://107.21.233.14:8877/55620789660af52/output.txt

Total script time: 0.16 mins

Published

• Viewer: http://107.21.233.14:8877/55620789660af52/web/viewer.html
• Extension: http://107.21.233.14:8877/55620789660af52/extensions/firefox/pdf.js.xpi
• Extension (AMO): http://107.21.233.14:8877/55620789660af52/extensions/firefox/pdf.js.amo.xpi

[waddlesplash]

Very nice!
You can also remove the "No outline available" from all L10N files as it won't be needed anymore, and the text span and CSS rules for it.

[saebekassebil]

@waddlesplash I've removed the no_outline locale property, per 6fbc8bc, .noOutline per 51abfe6 and finally assured that the outline view in the sidebar, cannot be visible when no outline is available per afb039a

[waddlesplash]

/botio-linux preview

[pdfjsbot]

From: Bot.io (Linux)

---

Received

Command cmd_preview from @waddlesplash received. Current queue size: 1

Live output at: http://107.21.233.14:8877/50f761e11ae9955/output.txt

[pdfjsbot]

From: Bot.io (Linux)

---

Success

Full output at http://107.21.233.14:8877/50f761e11ae9955/output.txt

Total script time: 0.18 mins

Published

• Viewer: http://107.21.233.14:8877/50f761e11ae9955/web/viewer.html
• Extension: http://107.21.233.14:8877/50f761e11ae9955/extensions/firefox/pdf.js.xpi
• Extension (AMO): http://107.21.233.14:8877/50f761e11ae9955/extensions/firefox/pdf.js.amo.xpi

[brendandahl]

Squash then good to go.

[xixixao]

The button is still sort-of clickable, at least that's the graphics for it. Actually, even the active button is clickable and that leads me to think that it has some action (like closing the sidebar), when in fact it doesn't.

What about removing both buttons altogether when only one options is available? Imo would provide better experience.