Adding support for selecting language dynamically

[ldebello]

Motivation

Following the idea of supporting i18n I think it would be good to select the language from the UI directly.

Note: This is work in progress and I am sending the PR to check if this is something you want to support and if you agree on the approach if you confirm this I can continue working in the final solution and make the remaining components bound to the resource factory

Solution based on https://stackoverflow.com/questions/32464974/javafx-change-application-language-on-the-run

Proposal

Adding a combobox with the available language and instead of setting text directly into components make they bound to a resource factory so a change in the resource factory will make them to update.

Initial UI

After changing language

Only "Start" translate to "Empezar" because that is the only translation available.

Changes

• Add label for language combobox
• Add combobox
• Comment out setText update because this will not work with bound properties

[chriswhocodes]

Hi @ldebello this looks like a nice clean way to switch languages. Do you think it will work (binding) for all components that can contain translated text (e.g. buttons, labels, perhaps table column headers) ?

I'm happy for you to continue on this path and I will wait until there is a working prototype before I make any more i18n changes so that we don't conflict.

Thank you and to all the translators for your help! I will add your names to the POM as contributors.

[ldebello]

Hi @ldebello this looks like a nice clean way to switch languages. Do you think it will work (binding) for all components that can contain translated text (e.g. buttons, labels, perhaps table column headers) ?

I'm happy for you to continue on this path and I will wait until there is a working prototype before I make any more i18n changes so that we don't conflict.

Thank you and to all the translators for your help! I will add your names to the POM as contributors.

Hi, it should work for all the components I will continue working on this and let you know when it is ready for your review.

[ldebello]

Hi @chriswhocodes the PR is ready for review.

Changes

• Support for dynamic changing text and tooltip in textbox and checkbox
• Support for dynamic changes in table column
• Support for parameters in i18n messages each position is defined as $(index) and the UI code shares the N bindings to check (so a change in any binding recompute the text)
• Changing ch file to zh which seems is support by intellij and lang zh is simplified chinese

[chriswhocodes]

Awesome work @ldebello ! I've merged your patch and will start to replace some more of the UI string literals with properties in the lang.properties file :)