Optimize for Android (Go version): Classes from Google apps – Half 1

Method

• At all times add framework/library updates after analyzing the adjustments and verifying its influence early on.
• Be sure to launch reminiscence earlier than assigning new worth to a pointer pointing to different object allocation in heap in Java. (native backend java objects) 

ClassA obj = new ClassA(“x”); // … one thing obj = new ClassB(“y”);

GC ought to clear this up ultimately.

if ClassA allocates native assets beneath and does not cleanup robotically on finalize(..) and requires caller to name some launch(..)  technique, it must be like this 

ClassA obj = new ClassA(“x”); // … one thing // Specific cleanup. obj.launch(); obj = new ClassB(“y”);

else it’s going to leak native heap reminiscence. 

• Optimize your bitmaps: Massive photographs/drawables often eat extra reminiscence within the app. Google apps recognized and optimized giant bitmaps which might be used of their apps. 

• Desire Lazy/on-demand initializations of huge drawables.
• Launch view when crucial.
• Keep away from utilizing full coloured bitmaps when attainable. 

// Creating the bitmap for trails. trailBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ALPHA_8); … // Setup paint for trails. trailPaint.setColorFilter(new ColorMatrixColorFilter(new ColorMatrix(new float[] {   0, 0, 0, 0, (colour >> 16) & 0xFF,   0, 0, 0, 0, (colour >> 8) & 0xFF,   0, 0, 0, 0, colour & 0xFF,   0, 0, 0, 1, 0 }))); … // onDraw @Override protected void onDraw(Canvas canvas) {   tremendous.onDraw(canvas);   if (trailBitmap != null) {     canvas.drawBitmap(trailBitmap, 0, 0, trailPaint);   } }

A screenshot of glide typing on Gboard

• Verify and solely set the alpha channel for the bitmap for complicated customized views used within the app. This saved them a few MBs (per display screen measurement/density).
• Whereas utilizing Glide, 
• The ARGB_8888 format has 4 bytes/pixel consumption whereas RGB_565 has 2 bytes/pixel. Reminiscence footprint will get decreased to half when RGB_565 format is used however utilizing decrease bitmap high quality comes with a value too. Whether or not you want alpha values or not, attempt to suit your case accordingly.
• Configure and use cache correctly when utilizing a 3P lib like Glide for picture rendering.

• Attempt to decide on different choices for GIFs in your app when constructing for Android (Go version) as GIFs take a variety of reminiscence.
• The aapt device can optimize the picture assets positioned in res/drawable/ with lossless compression through the construct course of. For instance, the aapt device can convert a true-color PNG that doesn’t require greater than 256 colours to an 8-bit PNG with a colour palette. Doing so ends in a picture of equal high quality however a smaller reminiscence footprint. Learn extra right here.
• You’ll be able to scale back PNG file sizes with out shedding picture high quality utilizing instruments like pngcrush, pngquant, or zopflipng. All of those instruments can scale back PNG file measurement whereas preserving the perceptive picture high quality.
• You could possibly use resizable bitmaps. The Draw 9-patch device is a WYSIWYG editor included in Android Studio that means that you can create bitmap photographs that robotically resize to accommodate the contents of the view and the dimensions of the display screen. Study extra in regards to the device right here. 

Recap

This a part of the weblog outlines why builders ought to take into account constructing for Android (Go version), an ordinary method to comply with whereas optimizing their apps and a few suggestions & learnings from Google apps to enhance their app reminiscence and appropriately allocate assets.

Within the subsequent a part of this weblog, we are going to discuss the perfect practices on Startup latency, app measurement and the instruments utilized by Google apps to determine and repair efficiency points.