# KAU :core
> The framework of everything
## Contents
* [KPrefs](#kprefs)
* [Changelog XML](#changelog-xml)
* [FAQ XML](#faq-xml)
* [Kotterknife](#kotterknife)
* [Ripple Canvas](#ripple-canvas)
* [MeasureSpecDelegate](#measure-spec-delegate)
* [CollapsibleViewDelegate](#collapsible-view-delegate)
* [Swipe](#swipe)
* [Debounce](#debounce)
* [KAU Logger](#kau-logger)
* [Email Builder](#email-builder)
* [Extension Functions](#extension-functions)
* [Lazy Resettable](#lazy-resettable)
## 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.
In shared preferences, we often require a boolean that returns true once, so we can use it to showcase views or display prompts on the first load.
KPref supports special preferences like these through the `KPrefSingleDelgate`
It can be used in a KPref like so:
```Kotlin
object MyPrefs : KPref() {
val displayHelper: Boolean by kprefSingle("KEY_HERE")
...
}
```
Notice that it is a `val` and takes no default. It will return true the first time and false for all subsequent calls.
### KPref Testing
If your android components can be tested without an emulator, you can also modify KPref to operate without shared preferences.
To do so, call `KPref(KPrefBuilderInMemory)` when creating your preferences.
This variant does not pass updates to the shared preferences.
To set the builder, you may wish to use dependency injection or service locators to supply the builder and the KPref.
In that case, your preferences would be a class instead of an object.
## Changelog XML
Create an xml resource with the following structure:
```xml