Fading ActionBar in Titanium

README.md

Fading Actionbar

This is a quick example of how to create a fading actionbar effect like this in Appcelerator Titanium

How this works

This is actually very simple. The trick is putting the Actionbar in overlay mode by configuring the theme with windowActionBarOverlay:true. Then all you need to do is updating the color of the Actionbar, in this case by scrolling a ScrollView.

License

The MIT License (MIT)

Copyright (c) 2015 Manuel Lehner

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

index.js

var abx = require('com.alcoapps.actionbarextras');

function onOpen(e) {
    // initial state: full transparency
    abx.setBackgroundColor('#00009688');
}

function onScroll(e){
	
	// Okay, let me explain what's going on here:
	var alpha = "";
	
	// I want to apply the fading effect to the first 500 pixels of scrolling
	// So, I'm only setting the alpha channel for 0 <= y < 500
	if (e.y < 500 && e.y >= 0){
		
		//calculate the opacity factor and convert it to hexadecimal
		alpha = (Math.round(e.y / 500 * 255).toString(16));
		
		// add leading zero if needed
		(alpha.length === 1) && (alpha = '0' + alpha);
	}
	
	// update actionbar color
	abx.setBackgroundColor('#'+ alpha +'009688');
	
}

$.index.open();

index.tss

".container": {
	title: "Fading Actionbar",
	theme: 'Theme.OverlayActionbar',
	backgroundColor:"white"
},
".verticalScroll":{
	scrollType: 'vertical',
	layout: 'vertical',
	top: 0,
	width: Ti.UI.FILL,
	height: Ti.UI.SIZE
},
".header":{
	width: Titanium.UI.FILL,
	height: 300,
	backgroundImage: '/images/night-clouds.jpg'
},
".title":{
	color: '#000',
	width: Titanium.UI.FILL,
	height: Titanium.UI.SIZE,
	top: 12,
	left: 8,
	font: {
		fontSize: '20dp',
		fontFamily: 'Roboto',
		fontWeight: 'bold'
	}
},
".text":{
	color: '#000',
	width: Titanium.UI.FILL,
	height: Titanium.UI.SIZE,
	top: 8,
	left: 8,
	right: 8,
	font: {
		fontSize: '16dp',
		fontFamily: 'Roboto'
	}
}

index.xml

<Alloy>
	<Window class="container" onOpen="onOpen">
		<ScrollView class="verticalScroll" onScroll="onScroll">
			<View class="header" />
			<Label class="title" text="Lorem Ipsum" />
			<Label class="text">
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				Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi.   
	
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				At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, At accusam aliquyam diam diam dolore dolores duo eirmod eos erat, et nonumy sed tempor et et invidunt justo labore Stet clita ea et gubergren, kasd magna no rebum. sanctus sea sed takimata ut vero voluptua. est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur
			</Label>
		</ScrollView>
	</Window>
</Alloy>

theme.xml

<?xml version="1.0" encoding="utf-8"?>

<resources xmlns:android="http://schemas.android.com/apk/res/android">
	
	<style name="Theme.OverlayActionbar" parent="@style/Theme.AppCompat.Light.DarkActionBar">
		<item name="android:windowActionBarOverlay">true</item>
	     <!-- Support library compatibility -->
	    <item name="windowActionBarOverlay">true</item>
		<item name="colorPrimary">@color/primary</item>
		<item name="colorPrimaryDark">@color/primaryDark</item>
	
	</style>
	
	<color name="primary">#009688</color>
	<color name="primaryDark">#00796B</color>

</resources>