?// 在up事件中调用了该方法，目的是检查是否把浮层拖出了屏幕
?protected void checkBounds() {
? int newLeft = mDrawableFloat.left;
? int newTop = mDrawableFloat.top;

? boolean isChange = false;
? if (mDrawableFloat.left < getLeft()) {
? ?newLeft = getLeft();
? ?isChange = true;
? }

? if (mDrawableFloat.top < getTop()) {
? ?newTop = getTop();
? ?isChange = true;
? }

? if (mDrawableFloat.right > getRight()) {
? ?newLeft = getRight() - mDrawableFloat.width();
? ?isChange = true;
? }

? if (mDrawableFloat.bottom > getBottom()) {
? ?newTop = getBottom() - mDrawableFloat.height();
? ?isChange = true;
? }

? mDrawableFloat.offsetTo(newLeft, newTop);
? if (isChange) {
? ?invalidate();
? }
?}

?// 进行图片的裁剪，所谓的裁剪就是根据Drawable的新的坐标在画布上创建一张新的图片
?public Bitmap getCropImage() {
? Bitmap tmpBitmap = Bitmap.createBitmap(getWidth(), getHeight(),
? ? Config.RGB_565);
? Canvas canvas = new Canvas(tmpBitmap);
? mDrawable.draw(canvas);

? Matrix matrix = new Matrix();
? float scale = (float) (mDrawableSrc.width())
? ? / (float) (mDrawableDst.width());
? matrix.postScale(scale, scale);

? Bitmap ret = Bitmap.createBitmap(tmpBitmap, mDrawableFloat.left,
? ? mDrawableFloat.top, mDrawableFloat.width(),
? ? mDrawableFloat.height(), matrix, true);
? tmpBitmap.recycle();
? tmpBitmap = null;

? return ret;
?}

?public int dipTopx(Context context, float dpValue) {
? final float scale = context.getResources().getDisplayMetrics().density;
? return (int) (dpValue * scale + 0.5f);
?}
}

FloatDrawable.java

继承自Drawable

功能：图片上面的浮动框，通过拖动确定位置

public class FloatDrawable extends Drawable {

?private Context mContext;
?private int offset = 50;
?private Paint mLinePaint = new Paint();
?private Paint mLinePaint2 = new Paint();
?{
? mLinePaint.setARGB(200, 50, 50, 50);
? mLinePaint.setStrokeWidth(1F);
? mLinePaint.setStyle(Paint.Style.STROKE);
? mLinePaint.setAntiAlias(true);
? mLinePaint.setColor(Color.WHITE);
? //
? mLinePaint2.setARGB(200, 50, 50, 50);
? mLinePaint2.setStrokeWidth(7F);
? mLinePaint2.setStyle(Paint.Style.STROKE);
? mLinePaint2.setAntiAlias(true);
? mLinePaint2.setColor(Color.WHITE);
?}

?public FloatDrawable(Context context) {
? super();
? this.mContext = context;

?}

?public int getBorderWidth() {
? return dipTopx(mContext, offset);//根据dip计算的像素值，做适配用的
?}

?public int getBorderHeight() {
? return dipTopx(mContext, offset);
?}

?@Override
?public void draw(Canvas canvas) {

? int left = getBounds().left;
? int top = getBounds().top;
? int right = getBounds().right;
? int bottom = getBounds().bottom;