Slide 1
Slide 1 text
Optimizing Your Apps
For Emerging Markets
#DroidconMtl
Slide 2
Slide 2 text
No content
Slide 3
Slide 3 text
Emerging Markets
Drive Growth
Slide 4
Slide 4 text
Source: Mediacells via The Guardian
Slide 5
Slide 5 text
Source: Mediacells via The Guardian
Slide 6
Slide 6 text
44
36
21
51
37
11
80
10
9
25
66
9
Smartphone Feature phone Multimedia phone
Brazil Russia
India China
Slide 7
Slide 7 text
1. Optimizing App Size
Slide 8
Slide 8 text
The smaller, the better
Slide 9
Slide 9 text
Color Filters
Slide 10
Slide 10 text
Use Color Filter
• Faster way to experiment with color schemes.
• Reduce the number of assets, which in turn reduc
the apk size.
• Less memory used as the number of assets are
reduced.
Slide 11
Slide 11 text
Code
ImageView redCircle = (ImageView) findV
iewById(R.id.circle_red_imageview);
ImageView greenCircle = (ImageView) findV
iewById(R.id.circle_green_imageview);
ImageView blueCircle = (ImageView) findV
iewById(R.id.circle_blue_imageview);
// we can create the color values in different ways:
redCircle.getDrawable().setColorFilter(C
olor.RED, PorterDuff.M
ode.M
U
LTIPLY );
greenCircle.getDrawable().setColorFilter(0xff00ff00, PorterDuff.M
ode.M
U
LTIPLY );
blueCircle.getDrawable().setColorFilter(getResources().getColor(R.color.blue),PorterDuff.M
ode.
M
U
LTIPLY );
Slide 12
Slide 12 text
Image
Optimizations
Color Filters
Slide 13
Slide 13 text
JPEG WEBP PNG GIF
Lossy
Lossless
Transparenc
y
Animation
WebP
Slide 14
Slide 14 text
No Noticeable Change
PNG
24 kb
WebP
10 kb
Slide 15
Slide 15 text
Compatibility
• You can use the native WebP decoder on 4.2 and
later.
• For lower versions, use libpng to convert to PNG
format and then use it in the app.
Slide 16
Slide 16 text
Other Libraries
• Use programs like OptiPNG, TruePNG and PNGC
to significantly reduce the size of PNG images.
• Use mozjpeg for jpeg images.
• 5-10% size reduction
• Won’t cause any visible changes to the images.
Slide 17
Slide 17 text
Remove
Unused
Content
Image
Optimizations
Color Filters
Slide 18
Slide 18 text
Remove Unused Content
• Use Resource Shrinking.
Slide 19
Slide 19 text
Code
android {
...
buildTypes {
release {
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
Slide 20
Slide 20 text
Remove Unused Content
• Use Resource Shrinking.
• Use tools like Lint and ProGuard.
• Use Android-Unused-Resources jar file if you are
still using Eclipse.
https://code.google.com/p/android-unused-resources/
Slide 21
Slide 21 text
2. Optimizing Network
Calls
Slide 22
Slide 22 text
Expensive
Data
Flaky
Networks
Challenges
Slide 23
Slide 23 text
Build for Failure
Slide 24
Slide 24 text
Most efficient way to
transfer is to not transfer
Slide 25
Slide 25 text
Image Scaling
Slide 26
Slide 26 text
Appropriate Image Size
• Store multiple image sizes on the server
• Low-res devices might never need a full resolutio
image
• Most times the smallest image size is sufficient.
Slide 27
Slide 27 text
No content
Slide 28
Slide 28 text
Checksum
Image Scaling
Slide 29
Slide 29 text
Client A Client B
Server
Checksum
ID
Send File ID
Transfer File
CS ID
Slide 30
Slide 30 text
Code
public static String getM
D5EncryptedString(String encTarget){
M
essageDigest mdEnc = null;
mdEnc = M
essageDigest.getInstance("M
D5");
// Encryption algorithm
mdEnc.update(encTarget.getBytes(), 0, encTarget.length());
String md5 = new BigInteger(1, mdEnc.digest()).toString(16);
while ( md5.length() < 32 ) {
md5 = "0"+md5;
}
return md5;
}
Slide 31
Slide 31 text
Checksum
• Avoid transfers as much as possible.
• For file transfers, first compute the md5 checksum
and send it to the server to check if it already exis
on the server.
• The cost to upload the entire file again can be
avoided.
Slide 32
Slide 32 text
Image Scaling Checksum
Transfer in
Blocks
Slide 33
Slide 33 text
Transfer in blocks
• Do data transfers in blocks.
• Keep track of the blocks that have been transferre
and yet to be transferred.
• The block size can vary based on the type of
connection.
Slide 34
Slide 34 text
Testing for different
networks is a pain
Slide 35
Slide 35 text
Testing for different networks
• Facebook recently open-sourced Augmented Traf
Control (ATC).
• It is a tool to simulate network conditions.
• It can simulate 2G, Edge, 3G, and LTE networks.
• Has multiple profiles for a lot of different countri
http://facebook.github.io/augmented-traffic-control/
Slide 36
Slide 36 text
3. Optimizing for Differen
Phones
Slide 37
Slide 37 text
Small Screens
Slow
Processing
Challenges
Slide 38
Slide 38 text
Developing for flagship
devices is easy
Slide 39
Slide 39 text
Year Class
Slide 40
Slide 40 text
No content
Slide 41
Slide 41 text
Code
int year = Y
earC
lass.get(getA
pplicationContext());
if (year >= 2013) {
// Do advanced animation
} else if (year > 2010) {
// Do simple animation
} else {
// Phone too slow, don't do any animations
}
https://github.com/facebook/device-year-class
Slide 42
Slide 42 text
Redesign
Year Class
Slide 43
Slide 43 text
Redesign
• Remove features from low-end devices if they wo
have the best user experience.
• This could be animations, videos or even
functionalities.
• No feature >>> Bad feature
Slide 44
Slide 44 text
@vinaygaba
Questions?