vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

klein-artur

// get a complementary color to this color:
func getComplementaryForColor(color: UIColor) -> UIColor {
    
    let ciColor = CIColor(color: color)
    
    // get the current values and make the difference from white:
    let compRed: CGFloat = 1.0 - ciColor.red
    let compGreen: CGFloat = 1.0 - ciColor.green
    let compBlue: CGFloat = 1.0 - ciColor.blue
    

VegaFromLyra

using System;

// Determine whether a circular array of relative indices is composed 
// of a single complete cycle
// ToDO - Do it O(1) space

namespace SingleCompleteCycle
{
    public class Program
    {

dannguyen

Use wget to mirror a single page and its visible dependencies (images, styles)

Graphic via State of Florida CFO Vendor Payment Search (flair.myfloridacfo.com)

This is a quick command I use to snapshot webpages that have a fun image I want to keep for my own collection of WTFViz. Why not just right-click and save the image? Oftentimes, the webpage in which the image is embedded contains necessary context, such as captions and links to important documentation just incase you forget what exactly that fun graphic was trying to explain.

whistler

from csv import DictWriter
from glob import glob
from ofxparse import OfxParser

DATE_FORMAT = "%m/%d/%Y"

def write_csv(statement, out_file):
    print "Writing: " + out_file
    fields = ['date', 'payee', 'debit', 'credit', 'balance']
    with open(out_file, 'w') as f:

kaushikgopal

Bitmap batmapBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.batman);
RoundedBitmapDrawable circularBitmapDrawable = RoundedBitmapDrawableFactory.create(getResources(), batmapBitmap);

// option 1 h/t [Chris Banes](https://chris.banes.me/) 
circularBitmapDrawable.setCornerRadius(batmapBitmap.getWidth());

// option 2 h/t @csorgod in the comments
circularBitmapDrawable.setCircular(true);

gabrielemariotti

You can use this class to realize a simple sectioned RecyclerView.Adapter without changing your code.

The RecyclerView should use a LinearLayoutManager. You can use this code also with the TwoWayView with the ListLayoutManager (https://github.com/lucasr/twoway-view)

This is a porting of the class SimpleSectionedListAdapter provided by Google

Example:

jonathanyee

#!/bin/bash

# This is a wrapper for adb.  If there are multiple devices / emulators, this script will prompt for which device to use
# Then it'll pass whatever commands to that specific device or emulator.

# Run adb devices once, in event adb hasn't been started yet
BLAH=$(adb devices)

# Grab the IDs of all the connected devices / emulators
IDS=($(adb devices | sed '1,1d' | sed '$d' | cut -f 1 | sort))

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

elsnosrap

#!/bin/bash

# This is a wrapper for adb.  If there are multiple devices / emulators, this script will prompt for which device to use
# Then it'll pass whatever commands to that specific device or emulator.

# Run adb devices once, in event adb hasn't been started yet
BLAH=$(adb devices)

# Grab the IDs of all the connected devices / emulators
IDS=($(adb devices | sed '1,1d' | sed '$d' | cut -f 1 | sort))