staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

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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.

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andymatuschak

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

lawloretienne

Table Of Contents

• Data Structures
  • Linked Lists
  • Trees
    • Binary Trees
    • Binary Search Tree
    • Red-Black Tree
    • AVL Tree
• Tries

Pkmmte

package com.pkmmte.widget;

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.view.WindowInsets;
import android.widget.FrameLayout;

/**

iago-suarez

Setting Up OpenCL for OpenCV on Android, the full story

The tutorial Use OpenCL in Android camera preview based CV application show us how we can use the Transparent API to dramatically increase the performance of some expensive operations.

The first step in order to be able to execute the tutorial example is to re-compile opencv with the correct flags:

# Export your NDK, it will be looked for OpenCV to compile your project. In my case
export ANDROID_NDK=~/graffter/libs/android-ndk-r10d/

# Download the necessary code

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:

anorth

package au.id.alexn;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.FrameLayout;

Mariovc

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.media.ExifInterface;

Sloy

import android.os.Parcel;
import java.util.ArrayList;
import java.util.List;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyLong;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.doAnswer;

iiredalert

<?xml version="1.0" encoding="utf-8"?>
<resources>

<!-- google's material design colours from 
http://www.google.com/design/spec/style/color.html#color-ui-color-palette -->

    <!--reds-->
    <color name="md_red_50">#FFEBEE</color>
    <color name="md_red_100">#FFCDD2</color>
    <color name="md_red_200">#EF9A9A</color>