DobDroidMiscUtils

A small and useful set of Android utility classes written in kotlin to reduce boilerplate

Import

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.andob:DobDroidMiscUtils:v1.0.3'
}

ToolbarX
BottomNavigationViewX
ViewPagerX
EditTextX
ScreenSize
PermissionsHandler
Keyboard
FileManager
RetrofitX
CacheDelegate
Async

ToolbarX

Toolbar eXtension methods. To setup a toolbar with back button:

toolbar.setupBackIcon()

Toolbar with menu on the right:

toolbar.setMenu(R.menu.menu_main)
toolbar[R.id.add] = {
    Log.e("a", "add logic")
}

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      tools:context=".MainActivity">
    <item
        android:id="@+id/add"
        android:title="Add"
        app:showAsAction="always" />
</menu>

If you are using menu or back button, override:

override fun onCreateOptionsMenu(menu: Menu?): Boolean
{
    toolbar.onCreateOptionsMenu(menuInflater, menu)
    return super.onCreateOptionsMenu(menu)
}

If you are using menu, override:

override fun onOptionsItemSelected(item: MenuItem?) : Boolean
{
    toolbar.onOptionsItemSelected(item)
    return super.onOptionsItemSelected(item)
}

Toolbar with hamburger menu icon: Please import this library.

implementation 'com.balysv.materialmenu:material-menu:2.0.0'

toolbar.setupHamburgerMenu()
toolbar.setOnHamburgerMenuClickedListener {
    Log.e("a", "toggle drawer")
}

BottomNavigationViewX

BottomNavigationView eXtension method

bottomNavigationView.setupWithViewPager(viewPager)

bottomNavigationView.setupWithViewPager(viewPager, initialTab = 0)

ViewPagerX

ViewPager eXtension method

viewPager.setOnPageChangedListener { page ->
    Log.e("a", "You're on page $page")
}

EditTextX

EditText eXtension methods

editText.setOnTextChangedListener { newText ->
    Log.e("a", newText)
}

editText.setOnEditorActionListener { actionId ->
    if (actionId==EditorInfo.IME_ACTION_DONE)
        Log.e("a", "enter pressed")
}

ScreenSize

Used to get the width, height and density of the screen. In Application Class onCreate method:

ScreenSize.init(withContext = this)

Then, you can simply use the properties from ScreenSize:

if (ScreenSize.width<ScreenSize.height)
    if (ScreenSize.density>=2.0) {...code...}

PermissionsHandler

Used to ask for dangerous permisssions. In the Activity class:

class MainActivity : AppCompatActivity()
{
    val permissionsHandler = PermissionsHandler()
    
    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray)
    {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        permissionsHandler.onRequestPermissionsResult(requestCode, permissions, grantResults)
    }
}

To ask for permissions, simply use:

permissionsHandler.askFor(arrayOf(Manifest.permission.CAMERA))
    .onGranted { Log.e("a", "YAY") }
    .onDenied { Log.e("a", "NAY") }
    .withContext(context = this)

Keyboard

Used to open or close the keyboard

Keyboard.open(on = context)

Keyboard.close(on = context)

FileManager

Extend FileManager class to create classes that manages app file's paths. For instance, getSampleFilePath will return /storage/emulated/0/Dob/sample.pdf

object AppFileManager : FileManager()
{
    override fun folderBasePath() : String = Environment.getExternalStorageDirectory().absolutePath
    override fun folderName() : String = "Dob"

    fun getSampleFilePath() : String = getFilePath("sample.pdf")
}

Retrofit extensions

Download and upload files:

interface IApiClient
{
    @Streaming
    @GET("/samples/pdf.pdf")
    fun downloadPdf() : Call<ResponseBody>

    @Multipart
    @POST("/samples/pdf.pdf")
    fun uploadPdf(@Part file : MultipartBody.Part) : Call<Unit?>
}

To download a file:

ApiClient.Instance.downloadPdf().enqueue(object : Callback<ResponseBody>
{
    override fun onFailure(call: Call<ResponseBody>, t: Throwable)
    {
        Log.e("a", "fail")
    }

    override fun onResponse(call: Call<ResponseBody>, response: Response<ResponseBody>)
    {
        Thread {
            try
            {
                downloadFile(response.body()!!, outputPath = AppFileManager.getSampleFilePath())
                Log.e("a", "success")
            }
            catch (ex : Exception)
            {
                Log.e("a", "fail")
            }
        }.start()
    }
})

To upload a file:

ApiClient.Instance.uploadPdf(fileUpload(context = this, path = AppFileManager.getSampleFilePath()))
    .enqueue(object : Callback<Unit?>
    {
        override fun onFailure(call: Call<Unit?>, t: Throwable)
        {
            Log.e("a", "fail")
        }

        override fun onResponse(call: Call<Unit?>, response: Response<Unit?>)
        {
            Log.e("a", "success")
        }
    })

Cache delegate

Use by cache() delegate to cache in memory values returned by other delegates. For instance, with kotpref library:

object Preferences : KotprefModel()
{
    var username by cached(stringPref())
    var level by cached(intPref())
    var firstRun by booleanPref(default = true)
}

Username will be returned from memory cache. If not found in cache, it will be fetched by stringPref delegate, from SharedPreferences.

Async

In Application onCreate,

Run.handler=Handler(mainLooper)

To run on UI thread:

Run.onUIThread {
    println("on ui thread")
}

To run delayed on UI thread:

Run.delayed(1000) {
    println("delayed")
}

To run async on a new thread:

Run.async {
    println("on new thread")
}

To run async and return a result, handling success and error cases (promises style). onAny will alwats be called before onSuccess or onError. Callback methods are run on UI thread

Run.async(task = {
    println("on new thread with result")
    Thread.sleep(1000)
    return@async 1
},
onAny = { println("hide loading dialog") },
onError = { it.printStackTrace() },
onSuccess = { println("result: $it") })

To run async without a result, handing success:

Run.async(task = {
    println("on new thread without result")
    Thread.sleep(1000)
},
onSuccess = { println("done!") })

To run a lambda only once:

val dispatcher=DispatchOnce { println("yes") }
dispatcher.invoke() //prints yes
dispatcher.invoke() //doesn't do anything

To run lambdas in paralel. onDone is called after all tasks are done. onError is called after a task throws exception. If a task has an error, remaining tasks will not be executed anymore. Specify maximumNumberOfThreads = value argument to set the maximum amount of paralel running threads at a given time. Default value is 8

Run.paralel(tasks = mutableListOf(
{
    println("task 1")
},
{
    println("task 2")
},
{
    println("task 3")
}), onDone = DispatchOnce {
    println("Done!")
}, onError = {
    println("Exception: $it")
})

License

Copyright 2019 Andrei Dobrescu

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.`

DobDroidMiscUtils

General

Additional

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DobDroidMiscUtils

A small and useful set of Android utility classes written in kotlin to reduce boilerplate

Import

Table of Contents

ToolbarX

BottomNavigationViewX

ViewPagerX

EditTextX

ScreenSize

PermissionsHandler

Keyboard

FileManager

Retrofit extensions

Cache delegate

Async

License