support initial on fullscreen

[pinghe]

emit inFullscreen when change state of fullscreen

Signed-off-by: pinghe mzhx.meng@gmail.com

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
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Does this PR introduce a breaking change? (check one)

• Yes
• No

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• It's submitted to the dev branch and not the master branch
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix: #xxx[,#xxx], where "xxx" is the issue number)
• It's been tested with all Quasar themes
• It's been tested on a Cordova (iOS, Android) app
• It's been tested on a Electron app
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Other information:

[pinghe]

support initial on fullscreen
emit inFullscreen when change state of fullscreen

[rstoenescu]

Hi, thanks for taking time for a PR! Have a few comments on this one though:

• Following line cannot work because it will say "initfullscreen" is not defined: https://github.com/quasarframework/quasar/pull/549/files#diff-6b23faecf76ef12cb91496acfa206b7fL71
• Same effect can be achieved if on the component using QSlider (probably a page, anyway doesn't matter) you put a mounted() { this.$refs.[refToSlider].toggleFullscreen() }. Since QSlider fullscreen tampers with window history (so it can be closed with back button) it's generally a bad idea to set fullscreen before mount point of QSlider as it can mess with page navigation in certain circumstances.

I'd be ok for adding a @fullscreen(bool) event though. Can you please reopen (or create new PR) with just the event addition?

Thanks!