Android碎纸机效果

1.总体思想

活用padding和margin

2.实现过程

 public class PopupShredderView extends FrameLayout{
     public PopupShredderView(Context context, AttributeSet attrs, int defStyle) {

         super(context, attrs, defStyle);
         init();
     }

     public PopupShredderView(Context context, AttributeSet attrs) {

         super(context, attrs);
     init() ;
     }

     public PopupShredderView(Context context) {

         super(context);
     init();
     }

     private void init(){
       final LayoutInflater layoutInflater = LayoutInflater.from(context);
       mView = layoutInflater.inflate(R.layout.popup_shredder_clean, this, false);

       mCleanText1.setImageDrawable(themeManager.getDrawable(R.drawable.exit_clean_date));
       mCleanText2.setBackgroundDrawable(themeManager.getDrawable(R.drawable.exit_clean_result));
       mCleanText2.setVisibility(View.INVISIBLE);
     }

     public void update(int step, int offset){
             if (step == STEP_END) {
                    return;
                }
         int clean1Offset = mCleanText1.getMeasuredHeight() * step / STEP_END;
         int maxClean1Offset=mCleanText1.getMeasuredHeight();
         if (offset + clean1Offset < maxClean1Offset) {
             clean1Offset = clean1Offset + offset;
         } else {
             clean1Offset = maxClean1Offset;
         }
         mCleanText1.setPadding(0, clean1Offset, 0, 0);
         mCleanText2.setVisibility(View.VISIBLE);
         int clean2Offset = ((View) mCleanText2.getParent()).getMeasuredHeight() * (STEP_END - step)
                 / STEP_END;
         int maxClean2Offset= 0;
         if (clean2Offset - offset > maxClean2Offset) {
             clean2Offset = clean2Offset - offset;
         } else {
             clean2Offset = maxClean2Offset;
         }
         LinearLayout.LayoutParams layoutParams = (android.widget.LinearLayout.LayoutParams) mCleanText2
                 .getLayoutParams();
         layoutParams.bottomMargin = clean2Offset;
         mCleanText2.setLayoutParams(layoutParams);
         invalidate();
     }

 }

3.布局文件

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/menubar"
     android:layout_width="192dp"
     android:layout_height="wrap_content"
     android:layout_gravity="center"
     android:orientation="vertical" >

     <ImageView
         android:id="@+id/exit_clean1"
         android:layout_width="wrap_content"
         android:layout_height="@dimen/popup_shredder_top_heigh"
         android:layout_gravity="center_horizontal"
         android:layout_marginLeft="21dp"
         android:contentDescription="@string/app_name"
         android:scaleType="matrix" />

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="@dimen/popup_shredder_top_heigh"
         android:layout_marginLeft="28dp"
         android:layout_marginTop="@dimen/popup_shredder_bottom_top_margin"
         android:orientation="vertical" >

         <ImageView
             android:id="@+id/exit_clean2"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_gravity="center_horizontal"
             android:contentDescription="@string/app_name" />
     </LinearLayout>

     <ImageView
         android:id="@+id/exit_clean3"
         android:layout_width="wrap_content"
         android:layout_height="@dimen/popup_shredder_delete_heigh"
         android:layout_gravity="center_horizontal"
         android:layout_marginTop="@dimen/popup_shredder_delete_top_margin"
         android:contentDescription="@string/app_name" />

 </RelativeLayout>