├── MaterialButtonBehavior.java
├── README.md
└── preview.gif


/MaterialButtonBehavior.java:
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 1 | package <your package>;
 2 | 
 3 | import android.animation.ValueAnimator;
 4 | import android.content.Context;
 5 | import android.support.annotation.NonNull;
 6 | import android.support.design.button.MaterialButton;
 7 | import android.support.design.widget.CoordinatorLayout;
 8 | import android.support.v7.widget.RecyclerView;
 9 | import android.util.AttributeSet;
10 | import android.view.View;
11 | import android.view.animation.DecelerateInterpolator;
12 | 
13 | /**
14 |  * Created by ImanX.
15 |  */
16 | public class MaterialButtonBehavior extends CoordinatorLayout.Behavior<MaterialButton> {
17 |     private ValueAnimator valueAnimator = new ValueAnimator();
18 |     private int           expandWidth;
19 |     private int           collapseWidth;
20 | 
21 |     public MaterialButtonBehavior() {
22 |     }
23 | 
24 |     public MaterialButtonBehavior(Context context, AttributeSet attrs) {
25 |         super(context, attrs);
26 |     }
27 | 
28 |     @Override
29 |     public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull MaterialButton child, @NonNull View directTargetChild, @NonNull View target, int axes, int type) {
30 |         return true;
31 |     }
32 | 
33 |     @Override
34 |     public boolean layoutDependsOn(CoordinatorLayout parent, MaterialButton child, View dependency) {
35 | 
36 |         if (expandWidth == 0 && child.getMeasuredWidth() != 0) {
37 |             expandWidth = child.getMeasuredWidth();
38 |         }
39 | 
40 |         if (collapseWidth == 0 && child.getMinWidth() != 0) {
41 |             collapseWidth = child.getMinWidth();
42 |         }
43 | 
44 |         return dependency instanceof RecyclerView;
45 | 
46 |     }
47 | 
48 | 
49 |     @Override
50 |     public void onNestedScroll(CoordinatorLayout coordinatorLayout,
51 |                                MaterialButton child, View target, int dxConsumed,
52 |                                int dyConsumed, int dxUnconsumed, int dy) {
53 |         if (dyConsumed < 0) {
54 |             //Scrolling down
55 |             measure(child, 170, expandWidth);
56 | 
57 |         } else if (dyConsumed > 0) {
58 |             // Scrolling up
59 |             measure(child, 170, collapseWidth);
60 | 
61 | 
62 |         }
63 |     }
64 | 
65 |     private void measure(final View v, int duration, int width) {
66 | 
67 |         if (valueAnimator.isRunning()) {
68 |             return;
69 |         }
70 | 
71 | 
72 |         int preWidth = v.getMeasuredWidth();
73 |         valueAnimator.setIntValues(preWidth, width);
74 |         valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
75 |             @Override
76 |             public void onAnimationUpdate(ValueAnimator animation) {
77 |                 v.getLayoutParams().width = (int) animation.getAnimatedValue();
78 |                 v.requestLayout();
79 |             }
80 |         });
81 |         valueAnimator.setInterpolator(new DecelerateInterpolator());
82 |         valueAnimator.setDuration(duration);
83 |         valueAnimator.start();
84 |     }
85 | 
86 | }
87 | 


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/README.md:
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 1 | # Android Material Button Behavior on RecyclerView
 2 | 
 3 | ### Preview
 4 | <img src="https://raw.githubusercontent.com/ImanX/android-materialButton-behavior/master/preview.gif" alt="sample"/>
 5 | 
 6 | ### Getting Started
 7 | Download `MaterialButtonBehavior` and copy or put your project.
 8 | add `MaterialButton` component in your `xml` layout that parent it should be `CoordinatorLayout`
 9 | 
10 | `android:layout_width` size of expande
11 | 
12 | `android:minWidth` size of collapse
13 | 
14 | `app:layout_behavior` for set `MaterialButtonBehavior` 
15 | 
16 | ### Example
17 | ```xml
18 |   <android.support.design.widget.CoordinatorLayout
19 |         android:layout_width="match_parent"
20 |         android:layout_height="match_parent">
21 |         .
22 |         .
23 |         .
24 |         
25 |            <android.support.design.button.MaterialButton
26 |             android:id="@+id/btn_add"
27 |             android:layout_width="160dp"
28 |             android:layout_height="65dp"
29 |             android:elevation="3dp"
30 |             android:gravity="center"
31 |             android:maxLines="1"
32 |             android:text="@string/new_ticket"
33 |             android:textColor="@android:color/white"
34 |             android:textSize="16sp"
35 |             android:minWidth="55dp"
36 |             app:backgroundTint="@color/colorAccent"
37 |             app:cornerRadius="28dp"
38 |             app:icon="@drawable/ic_add"
39 |             app:layout_anchor="@id/recycler"
40 |             app:layout_anchorGravity="bottom|left|end"
41 |             app:layout_behavior="<Your Package>.MaterialButtonBehavior"
42 |             />
43 | ```
44 | 


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/preview.gif:
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https://raw.githubusercontent.com/ImanX/android-materialButton-behavior/cf344198f1f95bec940e9178dc59d49366c15f3b/preview.gif


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