fix(android): semantic colors with alpha value

[drauggres]

JIRA: https://jira.appcelerator.org/browse/TIMOB-27519

Test case:

Resources/app.js

const image = 'https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/64_365_Color_Macro_%285498808099%29.jpg/1280px-64_365_Color_Macro_%285498808099%29.jpg';
const CFG = {
    color: {}
};
const fileName = 'semantic.colors.json';
const colorsetFile = Ti.Filesystem.getFile(Ti.Filesystem.resourcesDirectory, fileName);
if (colorsetFile.exists()) {
    const colorset = JSON.parse(colorsetFile.read().text);
    Object.keys(colorset).forEach(name => {
        CFG.color[name] = Ti.UI.fetchSemanticColor(name);
    });
}

const win = Ti.UI.createWindow({
    backgroundImage: image
});

const container = Ti.UI.createView({
    width: Ti.UI.FILL,
    height: Ti.UI.SIZE,
    backgroundColor: 'transparent',
    layout: 'vertical',
    center: {
        y: '50%'
    }
});

Object.keys(CFG.color).forEach(name => {
    appendView(name, CFG.color[name])
});

appendView('Not semantic', 'gray');
appendView('Not semantic', 'rgba(255, 0, 255, 0.33)');

function appendView(name, colorValue) {
    const view = Ti.UI.createView({
        backgroundColor: colorValue,
        width: Ti.UI.FILL,
        height: 30
    });
    const label = Ti.UI.createLabel({
        color: 'black',
        text: `${name}: ${colorValue}`,
        center: {x: '50%'}
    });
    view.add(label);
    container.add(view);
}

win.add(container);

win.open();

Resources/semantic.colors.json

```javascript { "green_100.0": { "light": { "color": "#00ff00", "alpha": "100.0" }, "dark": { "color": "#8000", "alpha": "100.0" } }, "blue_75.0": { "light": { "color": "#0000ff", "alpha": "75.0" }, "dark": { "color": "#80", "alpha": "75.0" } }, "cyan_50.0": { "light": { "color": "#00ffff", "alpha": "50.0" }, "dark": { "color": "#8080", "alpha": "50.0" } }, "red_25.0": { "light": { "color": "#ff0000", "alpha": "25.0" }, "dark": { "color": "#800000", "alpha": "25.0" } }, "magenta_0": { "light": { "color": "#ff00ff", "alpha": "0" }, "dark": { "color": "#800080", "alpha": "0.0" } }, "yellow_noalpha": { "light": "#ffff00", "dark": "#808000" } }

</details>

[build]

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	🎉 Another contribution from our awesome community member, drauggres! Thanks again for helping us make Titanium SDK better. 👍
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.
📖	✅ All tests are passing Nice one! All 6642 tests are passing. (There are 703 skipped tests not included in that total)

Generated by 🚫 dangerJS against c2d88b0

[sgtcoolguy]

So I was a bit confused about this one, but there's a few points to mention:

• There's already roughly equivalent code in the _build.js scripts for iOS/android
• This PR deals with iOS < 13 and android at runtime fetching colors
• You could actually hack this in using a hex with the alpha value (i.e '#00FF0080') - but I don't think the _build.js logic would handle that correctly

I've fixed the merge conflicts and unified the code used both at runtime and during the app build. A semantic.colors.json file can have a hex string value, or an object with a separate hex/alpha properties with string values. You can use an RRGGBBAA format hex string (used by iOS and CSS - but NOTE that typically Android natively uses AARRGGBB). If you use a hex string and a separate alpha, we throw an Error (which to choose?!).

When we return a value from Ti.UI.fetchSemanticColor on Android/older iOS - we return a rgba() expression - because of the aforementioned platform parity issue of iOS/Android differing in whether they expect the alpha to be first or last in 8-character hex strings. Both platforms should correctly handle rgba().