Add comments to kt files

zzzzVv · Aug 28, 2020 · 5ceffa2 · 5ceffa2
1 parent a7bf147
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diff --git a/...ons/src/main/java/com/example/androidstudio/motionlayoutintegrations/CollapsingToolbar.kt b/...ons/src/main/java/com/example/androidstudio/motionlayoutintegrations/CollapsingToolbar.kt
@@ -34,6 +34,9 @@ import androidx.core.view.WindowInsetsCompat
 import com.example.androidstudio.motionlayoutintegrations.databinding.ActivityCollapsingToolbarBinding
 import com.google.android.material.appbar.AppBarLayout
 
+/**
+ * Display a collapsing toolbar built using MotionLayout that handles insets and uses a custom view
+ */
 class CollapsingToolbar : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -79,14 +82,15 @@ class CollapsingToolbar : AppCompatActivity() {
         }
     }
 
+    /**
+     * Set various flags to go edge to edge
+     */
     private fun Window.goEdgeToEdge() {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
-            clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS)
-        }
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS)
             statusBarColor = Color.TRANSPARENT
         }
+        // TODO: replace this with non-deprecated edge to edge option
         decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
     }
 }
@@ -97,7 +101,9 @@ class CollapsingToolbar : AppCompatActivity() {
  * Animation of this view is driven by motionLayout controlling [bottomCutSize] and [endCutSize]
  * and [translationProgress].
  *
- * This View will overwrite scaleType from XML to be matrix to allow custom translation.
+ * This View will overwrite scaleType from XML to be matrix to allow custom translation. This is
+ * a slightly more efficient way to translate a background than oversizing the view and changing
+ * constraints as is done in [Entrance].
  */
 class CutoutImage @JvmOverloads constructor(
     context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0

diff --git a/...integrations/src/main/java/com/example/androidstudio/motionlayoutintegrations/Entrance.kt b/...integrations/src/main/java/com/example/androidstudio/motionlayoutintegrations/Entrance.kt
@@ -20,6 +20,9 @@ import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.example.androidstudio.motionlayoutintegrations.databinding.ActivityEntranceBinding
 
+/**
+ * Show an entrance animation built using MotionLayout
+ */
 class Entrance : AppCompatActivity() {
 
     private lateinit var binding: ActivityEntranceBinding

diff --git a/...grations/src/main/java/com/example/androidstudio/motionlayoutintegrations/MainActivity.kt b/...grations/src/main/java/com/example/androidstudio/motionlayoutintegrations/MainActivity.kt
@@ -21,6 +21,9 @@ import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.example.androidstudio.motionlayoutintegrations.databinding.ActivityMainBinding
 
+/**
+ * Launcher activity for navigating the sample.
+ */
 class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {

diff --git a/.../src/main/java/com/example/androidstudio/motionlayoutintegrations/ViewPagerIntegration.kt b/.../src/main/java/com/example/androidstudio/motionlayoutintegrations/ViewPagerIntegration.kt
@@ -27,13 +27,18 @@ import androidx.fragment.app.FragmentPagerAdapter
 import androidx.viewpager.widget.ViewPager
 import com.example.androidstudio.motionlayoutintegrations.databinding.ActivityViewPagerIntegrationBinding
 
+/**
+ * Demonstrate driving an animated header built using MotionLayout from a user swiping in a
+ * ViewPager
+ */
 class ViewPagerIntegration : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         val binding = ActivityViewPagerIntegrationBinding.inflate(layoutInflater)
         setContentView(binding.root)
 
+        // set up view pager to have three tabs
         val adapter = ViewPagerAdapter(supportFragmentManager)
 
         adapter.addPageFragment(Page1(), "List")
@@ -43,9 +48,13 @@ class ViewPagerIntegration : AppCompatActivity() {
         binding.pager.adapter = adapter
         binding.tabs.setupWithViewPager(binding.pager)
 
+        // use a page change listener to transfer swipe progress to MotionLayout
         binding.pager.addOnPageChangeListener(object : ViewPager.OnPageChangeListener {
             override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {
+                // calculate the swipe progress to a percent between 0f and 1f, where 0f is the
+                // first tab and 1f is the last tab
                 val progress = (position + positionOffset) / (adapter.count - 1)
+                // ask MotionLayout to snap to the current progress
                 binding.motionLayout.progress = progress
             }
 
@@ -61,7 +70,9 @@ class ViewPagerIntegration : AppCompatActivity() {
     }
 }
 
-
+/**
+ * Adapter needed for ViewPager
+ */
 class ViewPagerAdapter(fragmentManager: FragmentManager) : FragmentPagerAdapter(
     fragmentManager,
     BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT
@@ -88,18 +99,27 @@ class ViewPagerAdapter(fragmentManager: FragmentManager) : FragmentPagerAdapter(
     }
 }
 
+/**
+ * Fragments for ViewPager
+ */
 class Page1 : Fragment() {
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.page_1, container, false)
     }
 }
 
+/**
+ * Fragments for ViewPager
+ */
 class Page2 : Fragment() {
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.page_2, container, false)
     }
 }
 
+/**
+ * Fragments for ViewPager
+ */
 class Page3 : Fragment() {
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.page_3, container, false)