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Add comments to XML files
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‎ConstraintLayoutExamples/motionlayoutintegrations/src/main/java/com/example/androidstudio/motionlayoutintegrations/CollapsingToolbar.kt‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,6 @@ import androidx.core.view.ViewCompat
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import androidx.core.view.WindowInsetsCompat
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import com.example.androidstudio.motionlayoutintegrations.databinding.ActivityCollapsingToolbarBinding
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import com.google.android.material.appbar.AppBarLayout
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import kotlinx.android.synthetic.main.activity_entrance.*
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class CollapsingToolbar : AppCompatActivity() {
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@@ -50,7 +49,7 @@ class CollapsingToolbar : AppCompatActivity() {
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binding.motionLayout.minimumHeight = desiredToolbarHeight + insetTopHeight
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// modify the end ConstraintSet to set a guideline at the top and bottom of inset
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val endConstraintSet = binding.motionLayout.getConstraintSet(R.id.end)
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val endConstraintSet = binding.motionLayout.getConstraintSet(R.id.collapsed)
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// this guideline is the bottom of the inset area
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endConstraintSet.setGuidelineEnd(R.id.inset, desiredToolbarHeight)
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// this guideline is the top of the inset area (top of screen)

‎ConstraintLayoutExamples/motionlayoutintegrations/src/main/res/layout/activity_entrance.xml‎

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Original file line numberDiff line numberDiff line change
@@ -14,13 +14,13 @@
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<ImageView
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android:id="@+id/scrolling_background"
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android:layout_width="0dp"
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android:layout_height="4478px"
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android:layout_height="wrap_content"
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android:scaleType="centerCrop"
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android:src="@drawable/star_paralax"
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app:layout_constraintBottom_toBottomOf="parent"
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app:layout_constraintEnd_toEndOf="parent"
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app:layout_constraintStart_toStartOf="parent"
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tools:ignore="PxUsage" />
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/>
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<TextView

‎ConstraintLayoutExamples/motionlayoutintegrations/src/main/res/xml/activity_entrance_scene.xml‎

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Original file line numberDiff line numberDiff line change
@@ -3,14 +3,22 @@
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xmlns:android="http://schemas.android.com/apk/res/android"
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xmlns:motion="http://schemas.android.com/apk/res-auto">
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<ConstraintSet android:id="@+id/Welcome" >
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<!-- This animation uses a series of autoprogress between different ConstraintSet to build
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keyframes of the animation.
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As the animation plays, MotionLayout will display each ConstraintSet in turn.
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Each ConstraintSet uses deriveConstraintsFrom the previous constraint set to only specify the
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changes needed for the next KeyFrame.
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-->
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<ConstraintSet android:id="@+id/initial" >
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<Constraint
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android:id="@+id/scrolling_background"
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motion:layout_constraintBottom_toBottomOf="parent"
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motion:layout_constraintStart_toStartOf="parent"
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motion:layout_constraintEnd_toEndOf="parent"
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android:layout_width="0dp"
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android:layout_height="4478px"
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android:layout_height="wrap_content"
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android:alpha="0"
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/>
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</ConstraintSet>
@@ -172,8 +180,10 @@
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android:layout_marginEnd="16dp"
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/>
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</ConstraintSet>
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<!-- Each transition uses animateToEnd to combine a sequence of smaller animations into one
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big entrance animation. -->
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<Transition
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motion:constraintSetStart="@+id/Welcome"
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motion:constraintSetStart="@+id/initial"
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motion:constraintSetEnd="@+id/empty"
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motion:motionInterpolator="linear"
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motion:autoTransition="animateToEnd"

‎ConstraintLayoutExamples/motionlayoutintegrations/src/main/res/xml/collapsing_toolbar.xml‎

Lines changed: 20 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -3,35 +3,42 @@
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xmlns:android="http://schemas.android.com/apk/res/android">
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<Transition
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app:constraintSetEnd="@+id/end"
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app:constraintSetStart="@id/start"
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app:constraintSetEnd="@+id/collapsed"
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app:constraintSetStart="@id/expanded"
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>
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<KeyFrameSet >
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<!-- Hold title in place -->
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<KeyPosition
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app:motionTarget="@+id/title"
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app:framePosition="25"
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app:percentX="0.0"
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app:percentY=".2" />
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<!-- At 55, title should still be in place -->
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<KeyPosition
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app:motionTarget="@+id/title"
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app:framePosition="55"
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app:percentX="0" />
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<!-- at 75, title is 50% to destination -->
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<KeyPosition
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app:motionTarget="@+id/title"
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app:framePosition="75"
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app:percentX=".5" />
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<!-- Hide subtitle until 55 -->
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<KeyAttribute
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app:motionTarget="@+id/subtitle"
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app:framePosition="55"
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android:alpha="0" />
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<!-- Hold subtitle in place until 55 -->
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<KeyPosition
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app:motionTarget="@+id/subtitle"
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app:framePosition="55"
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app:percentX="0" />
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<!-- at 55, subtitle is 50% to destination -->
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<KeyPosition
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app:motionTarget="@+id/subtitle"
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app:framePosition="75"
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app:percentX=".5" />
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<!-- "pop" icon out at 35, with some translation to make it visually stay in place -->
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<KeyAttribute
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app:motionTarget="@+id/icon"
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app:framePosition="35"
@@ -40,34 +47,40 @@
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android:translationY="30dp"
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android:translationX="0dp"
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app:curveFit="linear" />
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<!-- Don't move icon along curve until 35 -->
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<KeyPosition
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app:motionTarget="@+id/icon"
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app:framePosition="35"
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app:percentX="0"
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app:percentY="0"
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app:curveFit="linear" />
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<!-- Between 35 and 36 while icon is not visible, jump icon to it's final location -->
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<KeyPosition
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app:motionTarget="@+id/icon"
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app:framePosition="36"
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app:percentX="1"
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app:percentY="1"
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app:curveFit="linear" />
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<!-- Translate icon a bit to make it "fill in" after jump -->
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<KeyAttribute
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app:motionTarget="@+id/icon"
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app:framePosition="36"
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android:translationY="-30dp"
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android:translationX="20dp"
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app:curveFit="linear" />
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<!-- Animate the bottomCutSize to 0 -->
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<KeyAttribute
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app:motionTarget="@id/background"
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app:framePosition="60">
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<CustomAttribute app:attributeName="bottomCutSize" app:customDimension="0dp" />
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</KeyAttribute>
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<!-- animate the endCutSize to 200, a little before the end of animation -->
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<KeyAttribute
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app:motionTarget="@id/background"
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app:framePosition="80">
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<CustomAttribute app:attributeName="endCutSize" app:customDimension="200dp" />
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</KeyAttribute>
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<!-- bring the system bar overlay in slightly early (numbers decided visually) -->
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<KeyPosition
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app:motionTarget="@+id/systembar_overlay"
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app:framePosition="45"
@@ -76,7 +89,8 @@
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</KeyFrameSet>
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</Transition>
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<ConstraintSet android:id="@+id/start">
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<!-- Start constraint set uses expanded_bottom and parent as bottom and top bounds -->
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<ConstraintSet android:id="@+id/expanded">
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<Constraint
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android:id="@+id/title"
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android:layout_width="wrap_content"
@@ -128,7 +142,9 @@
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app:layout_constraintEnd_toEndOf="parent" />
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</ConstraintSet>
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<ConstraintSet android:id="@+id/end" >
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<!-- end constraint set uses collapsed_top and parent as top and bottom, with inset as
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guideline -->
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<ConstraintSet android:id="@+id/collapsed" >
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<Constraint
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android:id="@+id/title"
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android:layout_height="wrap_content"

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