Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
unraveling custom drawing
Search
Matheus Cassiano Candido
August 07, 2018
Programming
0
84
unraveling custom drawing
Matheus Cassiano Candido
August 07, 2018
Tweet
Share
More Decks by Matheus Cassiano Candido
See All by Matheus Cassiano Candido
Kotlin Static Analysis - Kotlin Everywhere 2019
mcassiano
0
110
JUnit rules and test parameterization
mcassiano
0
120
The Basis of Android Threading: Loopers and Handlers
mcassiano
1
130
Hackeando sua próxima entrevista: dicas para conseguir seu próximo estágio ou emprego
mcassiano
1
93
text spans: what, why and how?
mcassiano
0
640
Navigation patterns on Android and something new
mcassiano
3
390
Como conseguir o estágio (ou emprego) dos sonhos
mcassiano
0
45
Databinding e padrão MVVM
mcassiano
1
25
Desenvolvimento móvel: práticas de sucesso
mcassiano
0
28
Other Decks in Programming
See All in Programming
WebViewの現在地 - SwiftUI時代のWebKit - / The Current State Of WebView
marcy731
0
100
生成AIコーディングとの向き合い方、AIと共創するという考え方 / How to deal with generative AI coding and the concept of co-creating with AI
seike460
PRO
1
340
PHP 8.4の新機能「プロパティフック」から学ぶオブジェクト指向設計とリスコフの置換原則
kentaroutakeda
2
680
Java on Azure で LangGraph!
kohei3110
0
170
Railsアプリケーションと パフォーマンスチューニング ー 秒間5万リクエストの モバイルオーダーシステムを支える事例 ー Rubyセミナー 大阪
falcon8823
4
1k
第9回 情シス転職ミートアップ 株式会社IVRy(アイブリー)の紹介
ivry_presentationmaterials
1
250
Google Agent Development Kit でLINE Botを作ってみた
ymd65536
2
210
WindowInsetsだってテストしたい
ryunen344
1
200
ruby.wasmで多人数リアルタイム通信ゲームを作ろう
lnit
2
320
Create a website using Spatial Web
akkeylab
0
310
ReadMoreTextView
fornewid
1
490
deno-redisの紹介とJSRパッケージの運用について (toranoana.deno #21)
uki00a
0
160
Featured
See All Featured
Build The Right Thing And Hit Your Dates
maggiecrowley
36
2.8k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
233
17k
How to Think Like a Performance Engineer
csswizardry
24
1.7k
Easily Structure & Communicate Ideas using Wireframe
afnizarnur
194
16k
The Pragmatic Product Professional
lauravandoore
35
6.7k
Stop Working from a Prison Cell
hatefulcrawdad
270
20k
Learning to Love Humans: Emotional Interface Design
aarron
273
40k
Fantastic passwords and where to find them - at NoRuKo
philnash
51
3.3k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
30
2.1k
The Illustrated Children's Guide to Kubernetes
chrisshort
48
50k
Building Better People: How to give real-time feedback that sticks.
wjessup
367
19k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
5
230
Transcript
Desvendando Custom Drawing Matheus C. Candido Android @ Concrete speakerdeck.com/mcassiano
pixabay/somraya
val default = Paint() val smoother = Paint(FLAG_ANTI_ALIAS) val copy
= Paint(smoother)
FLAG_ANTI_ALIAS
stroke width paint.strokeWidth = 4f paint.strokeWidth = 6f paint.strokeWidth =
8f todos os valores são em pixels!
style Paint.Style.STROKE Paint.Style.FILL_AND_STROKE Paint.Style.FILL
join (ligações) Paint.Join.MITER Paint.Join.ROUND Paint.Join.BEVEL
cap (pontas) Source: Microsoft Xamarin Docs
pixabay/coyot
formas
formas canvas.drawRect( rectBounds, paint )
rectBounds???
formas canvas.drawRoundRect( rectFBounds, radiusX, radiusY, paint )
formas canvas.drawArc( rectFBounds, startAngle, sweepAngle, useCenter, paint )
formas canvas.drawCircle( centerX, centerY, radius, paint )
paths
transformações canvas.save() // faça alguma transformação canvas.restore()
transformações val count = canvas.save() // faça alguma transformação canvas.restoreToCount(count)
translate canvas.translate(deltaX, deltaY)
rotate canvas.rotate(degrees) canvas.rotate(degrees, pivotX, pivotY)
scale canvas.scale(scaleX, scaleY) canvas.scale(scaleX, scaleY, pivotX, pivotY)
skew canvas.skew(skewX, skewY)
clipping (recortes)
clipping (recortes) clipOutPath clipOutRect
clipping (recortes) clipRect clipPath
bitmaps
bitmaps drawables
bitmaps drawables Levels example: https://ryanharter.com/blog/2015/04/03/custom-drawables/
bitmaps drawables custom views
bitmaps drawables custom views item decorators
performance • evite alocações no onDraw • faça clip nas
regiões que não for desenhar • use as ferramentas de profiling para verificar overdraw e debugar quebra de frames
acessibilidade AccessibilityNodeProvider ExploreByTouchHelper
acessibilidade getVirtualViewAt(x: Float, y: Float) getVisibleVirtualViews(virtualViewIds: MutableList<Int>) onPerformActionForVirtualView( virtualViewId: Int,
action: Int, arguments: Bundle? ) onPopulateNodeForVirtualView( virtualViewId: Int, node: AccessibilityNodeInfoCompat )
acessibilidade ????
virtual view data class VirtualView( var id: Int = View.NO_ID,
var contentDescription: CharSequence, val rect: Rect = Rect() )
node provider override fun getVirtualViewAt( x: Float, y: Float ):
Int { val view = virtualViews.find{ it.rect.contains(x, y) } return view?.id ?: HOST_ID }
node provider override fun onPopulateNodeForVirtualView( virtualViewId: Int, node: AccessibilityNodeInfoCompat )
{ val view = virtualViews.find { it.id == virtualViewId } view?.let { node.setBoundsInParent(it.rect) node.contentDescription = it.contentDescription } }
exemplos
backgrounds (itemdecoration) Exemplo: https://github.com/ajarl/item-decoration-sample/blob/master/ app/src/main/java/com/example/itemdecorationsample/ItemDecoration.kt
backgrounds (itemdecoration) Exemplo: https://github.com/ajarl/item-decoration-sample/blob/master/ app/src/main/java/com/example/itemdecorationsample/ItemDecoration.kt
backgrounds (itemdecoration) Exemplo: https://github.com/ajarl/item-decoration-sample/blob/master/ app/src/main/java/com/example/itemdecorationsample/ItemDecoration.kt
histograma Exemplo: https://github.com/mcassiano/custom-drawing
mcassiano
None