path: root/README.md

# KAU

Kotlin Android Utils

This library contains small helper functions used throughout almost all of my other projects. The goal is to make common interactions executable in a single line.

[Changelog](https://github.com/AllanWang/KAU/tree/master/docs/Changelog.md)

------------

KAU is available on JitPack

[![](https://jitpack.io/v/ca.allanwang/kau.svg)](https://jitpack.io/#ca.allanwang/kau) 
[![Build Status](https://travis-ci.org/AllanWang/KAU.svg?branch=master)](https://travis-ci.org/AllanWang/KAU)
[![GitHub license](https://img.shields.io/badge/license-Apache%202-blue.svg)](https://raw.githubusercontent.com/AllanWang/KAU/master/LICENSE)

To apply, add the following to your root build.gradle:

```gradle
allprojects {
    repositories {
        ...
        maven { url "https://jitpack.io" }
    }
}
```

And add the following dependencies (You can use a specific version, commit, or -SNAPSHOT):

```gradle
dependencies {
    compile "ca.allanwang:kau:$KAU"
}

```

-----------

# Features
* [KPrefs](#kprefs)
* [KPref Items](#kpref-items)
* [Changelog XML](#changelog)
* [Search View](#search-view)
* [Ripple Canvas](#ripple-canvas)
* [Timber Logger](#timber-logger)
* [Extensions](#extensions)
* [Email Builder](#email-builder)

<a name="kprefs"></a>
## KPrefs

A typical SharedPreference contains items that look like so:

```Java
class MyPrefs {
    public static final String TEXT_COLOR = "TEXT_COLOR";

    private static SharedPreference prefs = ...

    public static void setTextColor(int color) {
        prefs.edit().putInt(TEXT_COLOR, color).apply();
    }

    public static int getTextColor() {
        prefs.getInt(TEXT_COLOR, Color.WHITE);
    }
}
```
  
KPrefs greatly simplifies it by using Kotlin's object pattern and delegates to achieve the following:

```Kotlin
object MyPrefs : KPref() {
    var textColor: Int by kpref("TEXT_COLOR", Color.WHITE)
    var bgColor: Int by kpref("BG_COLOR", Color.BLACK)
    var isFirstLaunch: Boolean by kpref("IS_FIRST_LAUNCH", true)
    ...
}
```

By using `KPrefSample.textColor = Color.RED` or `textView.setTextColor(KPrefSample.textColor)` we can effectively set and save the value.

The values are retrieved lazily and are only done so once; future retrievals will be done with a local value, and updating a preference will both save it in the SharedPreference and update it locally.

The object inherits the initializer method `fun initialize(c: Context, preferenceName: String)`, which must be invoked (preferably in the Application class) before using a preference.

There is also a `reset()` method to clear the local values and have them retrieve from the SharedPreference again

<a name="kpref-items"></a>
## KPref Items

KAU supports Preferences that are created without xmls and through AppCompat. 
The items are backed by a [FastAdapter](https://github.com/mikepenz/FastAdapter) and support [iicons](https://github.com/mikepenz/Android-Iconics)

<img src="https://github.com/AllanWang/Storage-Hub/blob/master/kau/kau_kpref_items.gif">

The easiest way to create the settings is to extend `KPrefActivity`.

We will then override `onCreateKPrefs` to generate our adapter builder.

The adapter builder can easily add items using defined functions. 
Each item added extends one or more contracts to configure it.

The contracts are as follows:

Contract | Mandatory | Optional | Description
:--- | :--- | :--- | :---
`CoreAttributeContract` | `NA` | `textColor` `accentColor` | Defines stylings that are added in every item
`CoreContract` | `titleRes` | `descRes` `iicon` | Implemented by every item
`BaseContract` | `getter` `setter` | `enabler` `onClick` `onDisabledClick` | Implemented by every preference item
`KPrefColorContract` | `NA` | `showPreview` | Additional configurations for the color picker
`KPrefTextContract` | `NA` | `textGetter` | Additional configurations for the text item
`KPrefSubItemsContract` | `itemBuilder` | `NA` | Contains a new list for the adapter to load when clicked

The kpref items are as followed:

Item | Implements | Description
:--- | :--- | :---
`checkbox` | `CoreContract` `BaseContract` | Checkbox item; by default, clicking it will toggle the checkbox and the kpref
`colorPicker` | `CoreContract` `BaseContract` `KPrefColorContract` | Color picker item; by default, clicking it will open a dialog which will change the color (int)
`header` | `CoreContract` | Header; just a title that isn't clickable
`text` | `CoreContract` `BaseContract` `KPrefTextContract` | Text item; displays the kpref as a String on the right; does not have click implementation by default
`plainText` | `BaseContract` | Plain text item; like `text` but does not deal with any preferences directly, so it doesn't need a getter or setter
This can be used to display text or deal with preference that are completely handed within the click event (eg a dialog).
`subItems` | `CoreContract` `KPrefSubItemsContract` | Sub items; contains a new page for the activity to load when clicked
 
An example of the adapter builder:
 
```kotlin
override fun onCreateKPrefs(savedInstanceState: android.os.Bundle?): KPrefAdapterBuilder.() -> Unit = {
	
	textColor = { KPrefSample.textColor } // getter function so the new text color will be retrieved for every reload
	accentColor = { KPrefSample.accentColor }

	header(R.string.header)

	/**
	 * This is how the setup looks like with all the proper tags
	 */
	checkbox(title = R.string.checkbox_1, getter = { KPrefSample.check1 }, setter = { KPrefSample.check1 = it },
			builder = {
				descRes = R.string.desc
			})
			
	/**
	 * This is how it looks like without the tags
	 */
	checkbox(R.string.checkbox_3, { KPrefSample.check3 }, { KPrefSample.check3 = it }) {
		descRes = R.string.desc_dependent
		enabler = { KPrefSample.check2 }
		onDisabledClick = {
			itemView, _, _ ->
			itemView.context.toast("I am still disabled")
			true
		}
	}
}
```

<a name="changelog"></a>
## Changelog XML

Create an xml resource with the following structure:

```xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <version title="v0.1" />
    <item text="Initial Changelog" />
    <item text="Bullet point here" />
    <item text="More points" />
    <item text="" /> <!-- this one is empty and therefore ignored -->
</resources>
```

And show it with `context.showChangelog(@XmlRes xmlRes: Int)`
There is an optional `customize` argument to modify the builder before showing the changelog.

As mentioned, blank items will be ignored, so feel free to create a bunch of empty lines to facilitate updating the items in the future.

<a name="search-view"></a>
## Search View

Kau contains a fully functional SearchView that can be added programmatically with one line. 
It contains a `bindSearchView` extension functions for both activities and viewgroups.

<img src="https://github.com/AllanWang/Storage-Hub/blob/master/kau/kau_search_view.gif">

The search view is:
* Fully themable - set the foreground or background color to style every portion, from text colors to backgrounds to ripples
* Complete - binding the search view to a menu id will set the menu icon (if not previously set) and attach all the necessary listeners
* Configurable - modify any portion of the inner Config class when binding the search view
* Thread friendly - the search view is built with observables and emits values in a separate thread, 
which means that you don't have to worry about long processes in the text watcher. Likewise, all adapter changes are automatically done on the ui thread.

<a name="ripple-canvas"></a>
## Ripple Canvas

Ripple canvas provides a way to create simultaneous ripples against a background color. 
They can be used as transitions, or as a toolbar background to replicate the look for [Google Calendar](https://stackoverflow.com/questions/27872324/how-can-i-animate-the-color-change-of-the-statusbar-and-toolbar-like-the-new-ca)

<img src="https://github.com/AllanWang/Storage-Hub/blob/master/kau/kau_kpref_accent.gif">

Many ripples can be stacked on top of each other to run at the same time from different locations.
The canvas also supports color fading and direct color setting so it can effectively replace any background.

<a name="timber-logger"></a>
## Timber Logger

[Timber](https://github.com/JakeWharton/timber)'s DebugTree uses the tag to specify the current class that is being logged. To add the tag directly in the message, create an object that extends the TimberLogger class with the tag name as the argument.

<a name="extensions"></a>
## Extension Functions

> "[Extensions](https://kotlinlang.org/docs/reference/extensions.html) provide the ability to extend a class with new functionality without having to inherit from the class"

### AnimUtils
> Extends View
* Fade In/Fade Out/Circle Reveal with callbacks
* Switch texts in a TextView with a fade transition

### ColorUtils
> Extends Int
* Check if color is dark or light
* Check if color is visible against another color
* Convert color to HSV (float[]) or hex (String)
* Get the disabled color of a theme
* Adjust alpha
> Extends String
* Parses color; adds onto the original parser by supporting #AAA values
> Extends View
* Various tinting for different views; taken from [MDTintHelper](https://github.com/afollestad/material-dialogs/blob/master/core/src/main/java/com/afollestad/materialdialogs/internal/MDTintHelper.java)

### ContextUtils
> Extends Activity
* Restart an activity
> Extends Context
* Start Activity using the class, with optional intents and stack clearing
* Create a toast directly
* Get resource values through `.color(id)`, `.dimen(id)`, `.drawable(id)`, `.integer(id)`, `.string(id)`
* Get attribute values through resolve methods
* Show a Changelog by parsing an xml resource
* Check if network is available

### FragmentUtils
> Extends Fragment
* `withBundle` Directly put extras into a fragment; if a bundle does not exist, it will be created

### IIconUtils
> Extends [IIcon](https://github.com/mikepenz/Android-Iconics)
* `toDrawable` method that only requires a context; defaults to a white icon of size 24dp and uses a ColorStateList to allow for dimming

### Utils [Misc]
> Extends Int
* dpToPx & pxToDp conversions
* Check sdk version
* Check if app is installed

### ViewUtils
> Extends View
* `visible()`, `invisible()`, `gone()`, `isVisible()`, `isInvisible()`, `isGone()` methods
* matchParent method to set the layout params to match_parent
* Create snackbar directly
* Set IIcon into ImageView directly

<a name="email-builder"></a>
## Email Builder

Easily send an email through `Context.sendEmail`. 
Include your email and subject, along with other optional configurations such as retrieving device info.