Transcript
https://goo.gl/T7CFJ5
Before we begin
LayoutsViews ,Layouts ,Tools and everything in between
View
● Knows it dimensions● Able to draw itself● Handles input from the user
What are its responsibilities?
Let’s look at some examples
ImageView
Hello World!
TextView Button
Also known as widgets
Hello!● textSize● textColor● Ellipsize● Style (bold, italid)● Change font in code*
scaleType: CENTER, CENTER_CROP, CENTER_INSIDE, FIT_CENTERFIT_XY
Click meDont use onClick=”method”
ViewGroup?
A view that hold onto other views
View extends ViewGroup
LinearLayout
RelativeLayout
Hello World!FrameLayout
RecyclerView
● TableLayout● ScrollView● ViewPager● GridLayout
SetupCreate the project
Our Layout goes here
wrap_content
BALL_RED.PNG
match_parent
absoluteDP
Dimensions in android
● PX - pixels● DP - density independent pixel● SP - scale independent pixels
LinearLayoutThe one you will use the most
LinearLayout - basic example
LinearLayout orientation
LinearLayout - gravity
LinearLayout - layout_gravity
LinearLayout - weight
Margin
Padding
Padding + Margin
LinearLayout - match reset trick
LinearLayout - common mistake #1
?
Linear Layout - common mistake #2
Use TableLayout - not nested weight GridLayout
TextView and ImageView
TOOLS<>
Debugging a Layout
Purple = margin
NO COLOR = PADDING
LinearLayout
1 2 3
LinearLayout
123
Debugging a Layout
Padding of the parent
Margin of the child
Debugging a Layout ...
Debugging a Layout
Hierarchy Viewer
● Works on emulator out of the box● Android Device Monitor
Measure Layout Draw
FrameLayoutOverlapping views
FrameLayout
FrameLayout - Drawing order
1
2
3OPPOSITE
RelativeLayout
● Hard to understand● Cyclic dependency● Unexpected results*● Inefficient*
ReusingAvoid code duplication
<include>
What is wrong?
<merge>
Custom Viewcreate our own component
*
*
Much more sophisticated logic goes here
<Merge>
What is wrong?
NOTES
Questions
https://goo.gl/T7CFJ5
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