Øredev 2017: Cool ConstraintLayout

Huyen's presentation at Øredev 2017 on cool things about and cool things to do with ConstraintLayout on Android.

1. HUYEN TUE DAO @QUEENCODEMONKEY COOL CONSTRAINT LAYOUT
2. COOL THINGS ABOUT CONSTRAINT LAYOUT COOL THINGS TO DO WITH CONSTRAINT LAYOUT
3. WHAT IS THE CONSTRAINT LAYOUT?
4. RELATIONSHIPS BETWEEN VIEWS RELATIVE LAYOUT++ + (≈LINEARLAYOUT) EXPRESSIVE PERFORMANT
5. UNBUNDLED SUPPORTS API 9+ UI BUILDER USABLE WITH XML ONLY 1.1.0 BETA 3 → 2017.10.12
6. HOW DOES IT WORK?
7. CONSTRAINTS EQUATIONS SOLVER 7 HOW DOES IT WORK?
8. HOW DOES IT WORK? CONSTRAINTS EQUATIONS SOLVER POSITION FIXED WRAP CONTENT MATCH CONSTRAINT RATIO PERCENT EDGE CENTER BASELINE CIRCULAR (1.1) DIMENSION OTHER 8 CHAINS CONSTRAINT SET PLACEHOLDERS GUIDELINES GROUPS BARRIERS
9. CONSTRAINTS EQUATIONS SOLVER LINEAR SYSTEM OF EQUATIONS/INEQUALITIES 9 HOW DOES IT WORK? 11 + … + 1n = 11 + … + 1n ≤ 11 + … + 1n ≥
10. CONSTRAINTS EQUATIONS SOLVER CASSOWARY LINEAR ARITHMETIC CONSTRAINT SOLVING ALGORITHM VIEW BOUNDS 10 HOW DOES IT WORK?
11. CONSTRAINTLAYOUT, INSIDE AND OUT: PART 2 DAVE SMITH
12. LET’S TAKE A QUICK TOUR
14. CONSTRAINT LAYOUT CHEAT SHEET
15. SOURCE TARGET EDGE CONSTRAINT 
 app:layout_constraintLeft_toLeftOf="parent" 
 app:layout_constraint<source>_to<target>Of=“a_view"
16. CENTER CONSTRAINT 
 app:layout_constraintHorizontal_bias="0.75"
17. BASELINE CONSTRAINT app:layout_constraintBaseline_toBaselineOf="@+id/view"
18. CIRCULAR CONSTRAINT app:layout_constraintCircle="@id/centerTextView" app:layout_constraintCircleAngle="90" app:layout_constraintCircleRadius="@dimen/circular_radius"
19. SIZE CONSTRAINTS
20. !!!<!-- Match Constraint Modifiers —> !!!<!-- Min/Max —> app:layout_constraintWidth_max="200dp" app:layout_constraintHeight_min="wrap" !!!<!-- Percent !!--> app:layout_constraintWidth_percent=".75" app:layout_constraintHeight_percent=".5" !!!<!-- Ratio !!--> app:layout_constraintDimensionRatio="1:1"
21. GUIDELINES
22. <android.support.constraint.Guideline
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/guideline_start"
 android:orientation="vertical"
 app:layout_constraintGuide_begin="16dp" />
 
 
 <android.support.constraint.Guideline
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/horizontal"
 android:orientation="horizontal"
 app:layout_constraintGuide_percent="0.37" />
23. BARRIERS
24. <android.support.constraint.Barrier android:id="@+id/barrier" android:layout_width="wrap_content" android:layout_height="wrap_content" app:barrierDirection="end" app:constraint_referenced_ids="title,artist" !/>
25. GROUPS
26. SO WHAT CAN WE DO WITH CONSTRAINT LAYOUT?
27. public class SquareImageView extends ImageView { @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 
 final int size = Math.min(getMeasuredWidth(), getMeasuredHeight());
 setMeasuredDimension(size, size);
 }
28. <ImageView
 android:id=“@+id/square_image”
 android:layout_width="0dp"
 android:layout_height="0dp"
 app:layout_constraintDimensionRatio=“W,1:1"
30. <!-- Dimension ratios -->
 <string name="dimension_ratio_home_hero">H,16:10</string> <!-- In action in XML --> app:layout_constraintDimensionRatio=“@string/hero_ratio"
31. IS IT REALLY BETTER THAN RELATIVE LAYOUT?
32. STYLING ANDROID CONSTRAINTLAYOUT PART 6
34. private fun updateManualAnchors() {
 val size = anchorMinSize + seekBar.progress
 val halfSize = Math.round(size * 0.5f)
 val horizontalMargin = resources.getDimensionPixelSize(R.dimen.content_margin_horizontal) - halfSize
 val verticalMargin = resources.getDimensionPixelSize(R.dimen.alignment_rectangle_margin_vertical) - halfSize
 updateManualAnchor(frameAnchorTop, size, verticalMargin, 0, 0, 0)
 updateManualAnchor(frameAnchorStart, size, 0, horizontalMargin, 0, 0)
 updateManualAnchor(frameAnchorBottom, size, 0, 0, verticalMargin, 0)
 updateManualAnchor(frameAnchorEnd, size, 0, 0, 0, horizontalMargin)
 }
 
 private fun updateManualAnchor(anchor: View, size: Int,
 marginTop: Int, marginStart: Int,
 marginBottom: Int, marginEnd: Int) {
 val layoutParams = anchor.layoutParams as FrameLayout.LayoutParams layoutParams.width = size
 layoutParams.height = size
 layoutParams.topMargin = marginTop
 layoutParams.bottomMargin = marginBottom
 layoutParams.marginStart = marginStart
 layoutParams.marginEnd = marginEnd anchor.layoutParams = layoutParams
 } WITH CONSTRAINTLAYOUT JUST CHANGE THE SIZE…
35. WHAT WAS THAT ABOUT LINEAR LAYOUT?
36. CHAINS. CHAINS. CHAINS. FROM CONSTRAINTLAYOUT DOCUMENTATION
37. SPREAD INSIDE CHAIN <TextView
 android:id=“@+id/spread_inside_head”
 app:layout_constraintHorizontal_chainStyle="spread_inside"
 … />
38. <TextView
 android:id=“@+id/weighted_chain_head
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 app:layout_constraintHorizontal_chainStyle="spread"
 app:layout_constraintHorizontal_weight=“1" /> <TextView
 android:id=“@+id/next android:layout_width="0dp"
 android:layout_height="wrap_content"
 app:layout_constraintHorizontal_weight="2" /> <TextView
 android:id=“@+id/last
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 app:layout_constraintHorizontal_weight="1" /> 38 WEIGHTED CHAIN
39. <TextView
 android:id=“@+id/packed_chain_head”
 app:layout_constraintHorizontal_chainStyle="packed"
 app:layout_constraintHorizontal_bias="0.12" /> 39 PACKED CHAIN
42. A CONSTRAINT LAYOUT SPECIAL CONSTRAINT SET
43. CONSTRAINT SET CREATE/SAVE/APPLY CREATE MANUALLY CLONE A LAYOUT FILE CLONE A CONSTRAINT LAYOUT AWESOME WITH TRANSITIONS DEFINE SET OF CONSTRAINTS PROGRAMMATICALLY
46. // Inflate initial layout as usual. setContentView(R.layout.activity_constraintset_01) // Get references to controls
 constraintLayout = findViewById(R.id.constraint_layout) as ConstraintLayout
 
 // Load ConstraintSets.
 constraintSet01.clone(constraintLayout)
 constraintSet02.clone(this, R.layout.activity_constraintset_02) …some time later… // Toggle ConstraintSets. TransitionManager.beginDelayedTransition(constraintLayout)
 if (original) constraintSet02.applyTo(constraintLayout)
 else constraintSet01.applyTo(constraintLayout)
 original = !original 44
47. YES, LIST ITEMS CAN BE CONSTRAINT LAYOUTS
48. CONSTRAINT SET IN LIEU OF CUSTOM VIEWGROUP
49. CUSTOM VIEW GROUPS GENERALIZED, REUSABLE LAYOUTS PERFORMANT COMPOSITE LAYOUTS LAYOUT IS LOW-LEVEL (X, Y) EVEN SIMPLE ONES = MUCH CODE ADVANCED LAYOUTS… WOAH
50. @Override
 protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
 MarginLayoutParams layoutParams = (MarginLayoutParams) icon.getLayoutParams();
 
 // Figure out the x-coordinate and y-coordinate of the icon.
 int x = getPaddingLeft() + layoutParams.leftMargin;
 int y = getPaddingTop() + layoutParams.topMargin;
 
 // Layout the icon.
 icon.layout(x, y, x + icon.getMeasuredWidth(), y + icon.getMeasuredHeight());
 
 // Calculate the x-coordinate of the title: icon's right coordinate +
 // the icon's right margin.
 x += icon.getMeasuredWidth() + layoutParams.rightMargin;
 
 // Add in the title's left margin.
 layoutParams = (MarginLayoutParams) titleView.getLayoutParams();
 x += layoutParams.leftMargin;
 
 // Calculate the y-coordinate of the title: this ViewGroup's top padding +
 // the title's top margin
 y = getPaddingTop() + layoutParams.topMargin;
 
 // Layout the title.
 titleView.layout(x, y, x + titleView.getMeasuredWidth(), y + titleView.getMeasuredHeight());
 
 // The subtitle has the same x-coordinate as the title. So no more calculating there.
 
 // Calculate the y-coordinate of the subtitle: the title's bottom coordinate +
 // the title's bottom margin.
 y += titleView.getMeasuredHeight() + layoutParams.bottomMargin;
 layoutParams = (MarginLayoutParams) subtitleView.getLayoutParams();
 
 // Add in the subtitle's top margin.
 y += layoutParams.topMargin;
 
 // Layout the subtitle.
 subtitleView.layout(x, y,
 x + subtitleView.getMeasuredWidth(), y + subtitleView.getMeasuredHeight());
 } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // Measure icon. measureChildWithMargins(icon, widthMeasureSpec, 0, heightMeasureSpec, 0); // Figure out how much width the icon used. MarginLayoutParams lp = (MarginLayoutParams) icon.getLayoutParams(); int widthUsed = icon.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; int heightUsed = 0; // Measure title measureChildWithMargins( titleView, // Pass width constraints and width already used. widthMeasureSpec, widthUsed, // Pass height constraints and height already used. heightMeasureSpec, heightUsed ); // Measure the Subtitle. measureChildWithMargins( subtitleView, // Pass width constraints and width already used. widthMeasureSpec, widthUsed, // Pass height constraints and height already used. heightMeasureSpec, titleView.getMeasuredHeight()); // Calculate this view's measured width and height. // Figure out how much total space the icon used. int iconWidth = icon.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; int iconHeight = icon.getMeasuredHeight() + lp.topMargin + lp.bottomMargin; lp = (MarginLayoutParams) titleView.getLayoutParams(); // Figure out how much total space the title used. int titleWidth = titleView.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; int titleHeight = titleView.getMeasuredHeight() + lp.topMargin + lp.bottomMargin; lp = (MarginLayoutParams) subtitleView.getLayoutParams(); // Figure out how much total space the subtitle used. int subtitleWidth = subtitleView.getMeasuredWidth() + lp.leftMargin + lp.rightMargin; int subtitleHeight = subtitleView.getMeasuredHeight() + lp.topMargin + lp.bottomMargin; // The width taken by the children + padding. int width = getPaddingTop() + getPaddingBottom() + iconWidth + Math.max(titleWidth, subtitleWidth); // The height taken by the children + padding. int height = getPaddingTop() + getPaddingBottom() + Math.max(iconHeight, titleHeight + subtitleHeight); // Reconcile the measured dimensions with the this view's constraints and // set the final measured width and height. setMeasuredDimension( resolveSize(width, widthMeasureSpec), resolveSize(height, heightMeasureSpec) ); }
51. CONSTRAINT SET IN LIEU OF CUSTOM VIEWGROUP
52. private fun addRow(view: View) {
 constraintLayout.addView(view)
 
 val id = view.id
 constraintSet.constrainWidth(id, MATCH_CONSTRAINT)
 constraintSet.constrainHeight(id, rowHeight)
 
 // Constrain new view vertically.
 val target = if (lastRowId  PARENT_ID) TOP else BOTTOM
 constraintSet.connect(id, TOP, lastRowId, target) // Constrain new view horizontally.
 constraintSet.connect(id, START, PARENT_ID, START)
 constraintSet.connect(id, END, PARENT_ID, END)
 
 // Toggle elevation to elevate last added view.
 constraintSet.setElevation(id, resources.getDimension(R.dimen.elevation))
 constraintSet.setElevation(lastViewId, 0f)
 
 // Apply constraints.
 constraintSet.applyTo(constraintLayout) 50
53. private fun addRowItem(view: View) {
 …
 constraintLayout.addView(view)
 
 val id = view.id
 
 // Initialize width and height of new view.
 constraintSet.constrainWidth(id, MATCH_CONSTRAINT)
 constraintSet.constrainHeight(id, rowHeight)
 
 // Constrain new view vertically.
 val target = if (lastRowId  PARENT_ID) TOP else BOTTOM
 constraintSet.connect(id, TOP, lastRowId, target) 51
54. // Update current row.
 currentRowIds.add(id)
 // Re-create horizontal chain with other row items.
 constraintSet.createHorizontalChainRtl(
 PARENT_ID, START,
 PARENT_ID, END,
 currentRowIds.toIntArray(), FloatArray(currentRow.size, { 1f }),
 CHAIN_SPREAD_INSIDE)
 
 // Toggle elevation to elevate last added view.
 constraintSet.setElevation(id, resources.getDimension(R.dimen.elevation))
 constraintSet.setElevation(lastViewId, 0f)
 
 // Apply constraints.
 constraintSet.applyTo(constraintLayout) 52
55. SERIOUSLY COOL THINGS IN CONSTRAINT LAYOUT
56. constraintLayout.update { guideline(R.id.content_start, VERTICAL_GUIDELINE, LEFT, getDimenSize(R.dimen.keyline_start)) guideline(R.id.content_top, HORIZONTAL_GUIDELINE, TOP, getDimenSize(R.dimen.content_padding_top)) constrain(R.id.image) { width = MATCH_CONSTRAINT_SPREAD height = MATCH_CONSTRAINT_SPREAD start = START of PARENT_ID top = TOP of PARENT_ID end = END of PARENT_ID bottom = BOTTOM of PARENT_ID } constrain(R.id.title) { width = WRAP_CONTENT height = WRAP_CONTENT end = END of R.id.content_start top = TOP of R.id.content_top } constrain(R.id.artist) { width = WRAP_CONTENT height = WRAP_CONTENT start = END of R.id.title top = BOTTOM of R.id.title } } 54 CONSTRAINT SET DSL github.com/queencodemonkey/the-road-to-kotlintown-ii
57. ANDROID DEVELOPERS BACKSTAGE EPISODE 50: CONSTRAINT LAYOUT
58. CONSTRAINTLAYOUT CREW JOHN HOFORD @JOHNHOFORD NICOLAS ROARD @CAMAELON ADVANCED ANIMATIONS & CONSTRAINTLAYOUT DROIDCON SAN FRANCISCO 2017
60. THANK YOU! SPEAKERDECK.COM/QUEENCODEMONKEY YOUTUBE.COM/ANDROIDDIALOGS RANDOMLYTYPING.COM HUYEN TUE DAO @QUEENCODEMONKEY QUEENCODEMONKEY/PRESENTATION-COOL-CONSTRAINTLAYOUT
61. REFERENCES 59 CONSTRAINT LAYOUT APIS DOCUMENTATION https://developer.android.com/reference/android/support/constraint/package-summary.html BUILD A RESPONSIVE UI WITH CONSTRAINTLAYOUT developer.android.com/training/constraint-layout/index.html ANDROID DEVELOPERS BACKSTAGE: EPISODE 50: CONSTRAINT LAYOUT androidbackstage.blogspot.com/2016/06/episode-50-constraint-layout.html USING CONSTRAINTLAYOUT TO DESIGN YOUR VIEWS | CODE LABS codelabs.developers.google.com/codelabs/constraint-layout/index.html ANDROID LAYOUTS: A NEW WORLD | GOOGLE I/O 2016 https://youtu.be/sO9aX87hq9c ADVANCED ANIMATIONS & CONSTRAINTLAYOUT https://speakerdeck.com/camaelon/advanced-animations-and-constraintlayout ADVANCED CONSTRAINTLAYOUT http://cfp.devoxx.us/2017/talk/XOD-8930/Advanced_ConstraintLayout
62. REFERENCES 60 CONSTRAINTLAYOUT https://speakerdeck.com/writtmeyer/constraintlayout-1 CONSTRAINTLAYOUT – PART 1 blog.stylingandroid.com/constraintlayout-part-1/ CONSTRAINTLAYOUT, INSIDE AND OUT: PART 1 http://wiresareobsolete.com/2016/07/constraintlayout-part-1/ SOME THOUGHTS ON ANDROID’S NEW CONSTRAINTLAYOUT AND ANDROID STUDIO’S NEW DESIGN EDITOR http://www.grokkingandroid.com/thoughts-on-constraintlayout-and-design-editor/ BUILD A UI WITH LAYOUT EDITOR developer.android.com/studio/write/layout-editor.html WHAT'S NEW IN ANDROID DEVELOPMENT TOOLS | GOOGLE I/O 2016 https://youtu.be/csaXml4xtN8 THE EXPERTS' GUIDE TO ANDROID DEVELOPMENT TOOLS | GOOGLE I/O 2016 https://youtu.be/hHnTIMjd1Y8 JOHN HOFORD & NICOLAS ROARD : CONSTRAINTLAYOUT | ANDROID DIALOGS https://youtu.be/hHnTIMjd1Y8