suclike

Things I believe

This is a collection of the things I believe about software development. I have worked for years building backend and data processing systems, so read the below within that context.

Agree? Disagree? Feel free to let me know at @JanStette. See also my blog at www.janvsmachine.net.

Fundamentals

Keep it simple, stupid. You ain't gonna need it.

suclike

        public static float convertPixelsToDp(float px){
	    DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
	    float dp = px / (metrics.densityDpi / 160f);
	    return Math.round(dp);
	}
	
       public static float convertDpToPixel(float dp){
	    DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
	    float px = dp * (metrics.densityDpi / 160f);
	    return Math.round(px);

suclike

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

suclike

[alias]
  #current branch
	me = !git rev-parse --abbrev-ref HEAD
  
	st = status
	sta = !git status && git add . --all && git status && echo 'Staged all changes, if any.'
	unsta = !git status && git reset HEAD && git status && echo 'Unstaged all changes, if any.'
  
	stachbst = !git status && git add . --all && echo 'Staged all changes, if any.' && git checkout -b $branchname && git status

suclike

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.0"

    defaultConfig {
        applicationId "com.abc.example"
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"

suclike

Centralize the support libraries dependencies in gradle

Working with multi-modules project, it is very useful to centralize the dependencies, especially the support libraries.

A very good way is to separate gradle build files, defining something like:

root
  --gradleScript
 ----dependencies.gradle

suclike

Symbols Naming

! - Exclamation point
@ - "At" sign
# - Number sign or Pound sign, depending upon context
& - Technically called "ampersand," most folks refer to it as "the 'and' sign"
() - Parentheses
[] - Brackets
{} - Braces

suclike

# delete local tag '12345'
git tag -d 12345
# delete remote tag '12345' (eg, GitHub version too)
git push origin :refs/tags/12345
# alternative approach
git push --delete origin tagName
git tag -d tagName

suclike

import android.arch.lifecycle.GenericLifecycleObserver
import android.arch.lifecycle.Lifecycle
import android.arch.lifecycle.Lifecycle.Event.ON_DESTROY
import android.arch.lifecycle.LifecycleOwner
import kotlinx.coroutines.experimental.Job

fun Lifecycle.createJob(cancelEvent: Lifecycle.Event = ON_DESTROY): Job = Job().also { job ->
    addObserver(object : GenericLifecycleObserver {
        override fun onStateChanged(source: LifecycleOwner?, event: Lifecycle.Event) {
            if (event == cancelEvent) {

suclike

Basic HTTP

The Client Server Model

The core working of the internet is based on the idea of client / server communication. The client is anything close to the user (a web browser, an app, a terminal with ssh) and a server that can respond to client queries.

Clients can talk to servers via a variety of protocols. The protocols are just a way for the client and server to agree on how to send data back and forth. Its like you and I talking. We can agree that we use English and with a friend of mine I can use Hindi.

Different Client / Server protocols include:

• HTTP