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>