使用 SwipeFlingAdapterView 库的 Android 刷卡缩放 ImageView

Question

我正在使用 this 实现 刷卡 和 捏缩放 功能库，当我只使用 image view 时，它工作正常意味着滑动工作正常，但我想要像库一样的滑动功能以及 pinch to zoom 所以我添加了 TouchImageView 类，其中只有 pinch to zoom 起作用，但滑动功能不起作用。那么，您能否帮我解决这个问题，或者向我推荐任何可以使用 swipe card 和 pinch to zoom 的替代库。以下是我的 Activity

    public class MainActivity extends AppCompatActivity{

    private SwipeFlingAdapterView flingContainer;
    public static ArrayList<SwipModel> al;
    public SwipViewAdapter swipViewAdapter;
    private SwipModel swipModel;
    private Uri uri;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        getId();
        setSwipeCard();

    }

    private void getId() {
        flingContainer = (SwipeFlingAdapterView) findViewById(R.id.frame);
    }

    private void setSwipeCard() {

        uri = Uri.parse("android.resource://" + getApplicationContext().getPackageName() + "/drawable/picture1");

        swipModel = new SwipModel();

        al = new ArrayList<>();
        swipModel.setCardImageDrawable(uri);
        al.add(swipModel);


        swipViewAdapter = new SwipViewAdapter(getApplicationContext(), al);

        flingContainer.setAdapter(swipViewAdapter);
        flingContainer.setFlingListener(new SwipeFlingAdapterView.onFlingListener() {
            @Override
            public void removeFirstObjectInAdapter() {
                // this is the simplest way to delete an object from the Adapter (/AdapterView)
                Log.d("LIST", "removed object!");
//                al.remove(0);
//                swipViewAdapter.notifyDataSetChanged();
            }

            @Override
            public void onLeftCardExit(Object dataObject) {
                //Do something on the left!
                //You also have access to the original object.
                //If you want to use it just cast it (String) dataObject
//                makeToast(MainActivity.this, "Left!");
            }

            @Override
            public void onRightCardExit(Object dataObject) {
//                makeToast(MainActivity.this, "Right!");
            }

            @Override
            public void onAdapterAboutToEmpty(int itemsInAdapter) {
                // Ask for more data here
//                al = new ArrayList<>();
//                swipModel.setCardImageDrawable(uri);
//                al.add(swipModel);
            }

            @Override
            public void onScroll(float scrollProgressPercent) {
                View view = flingContainer.getSelectedView();
            }
        });


        // Optionally add an OnItemClickListener.
        flingContainer.setOnItemClickListener(new SwipeFlingAdapterView.OnItemClickListener() {
            @Override
            public void onItemClicked(int itemPosition, Object dataObject) {

            }
        });
    }    
}

这里是activity_main.xml

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.example.android.swipecardtesting.MainActivity">

    <com.lorentzos.flingswipe.SwipeFlingAdapterView
        android:id="@+id/frame"
        android:background="#ffeee9e2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:rotation_degrees="15.5"
        tools:context=".MyActivity"
        android:layout_centerInParent="true"
        />

</RelativeLayout>

这是我的适配器

    public class SwipViewAdapter extends BaseAdapter {

    public static ArrayList<SwipModel> list;
    Context context;
    private LayoutInflater l_Inflater;
    public static ViewHolder holder;

    public SwipViewAdapter(Context mContext, ArrayList<SwipModel> al) {
        this.context = mContext;
        list = al;
        l_Inflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int i) {
        return i;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        if (view == null) {
            holder = new ViewHolder();

            l_Inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = l_Inflater.inflate(R.layout.swip_item, viewGroup, false);


            holder.ivZoomable = (TouchImageView) view.findViewById(R.id.ivZoomable);

            view.setTag(holder);
        }



        holder.ivZoomable.setImageURI(list.get(i).getCardImageDrawable());


        return view;
    }

    public static class ViewHolder {
        public static TouchImageView ivZoomable;
    }
}

和我的TouchImageView 类

public class TouchImageView extends ImageView {

    Matrix matrix;

    // We can be in one of these 3 states
    static final int NONE = 0;
    static final int DRAG = 1;
    static final int ZOOM = 2;
    int mode = NONE;

    // Remember some things for zooming
    PointF last = new PointF();
    PointF start = new PointF();
    float minScale = 1f;
    float maxScale = 3f;
    float[] m;

    int viewWidth, viewHeight;
    static final int CLICK = 3;
    public static float saveScale = 1f;
    protected float origWidth, origHeight;
    int oldMeasuredWidth, oldMeasuredHeight;

    ScaleGestureDetector mScaleDetector;

    Context context;

    public TouchImageView(Context context) {
        super(context);
        sharedConstructing(context);
    }

    public TouchImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        sharedConstructing(context);
    }

    private void sharedConstructing(Context context) {
        super.setClickable(true);
        this.context = context;
        mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
        matrix = new Matrix();
        m = new float[9];
        setImageMatrix(matrix);
        setScaleType(ScaleType.MATRIX);

        setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                mScaleDetector.onTouchEvent(event);
                PointF curr = new PointF(event.getX(), event.getY());

                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        last.set(curr);
                        start.set(last);
                        mode = DRAG;
                        break;

                    case MotionEvent.ACTION_MOVE:
                        if (mode == DRAG) {
                            float deltaX = curr.x - last.x;
                            float deltaY = curr.y - last.y;
                            float fixTransX = getFixDragTrans(deltaX, viewWidth,
                                    origWidth * saveScale);
                            float fixTransY = getFixDragTrans(deltaY, viewHeight,
                                    origHeight * saveScale);
                            matrix.postTranslate(fixTransX, fixTransY);
                            fixTrans();
                            last.set(curr.x, curr.y);
                        }
                        break;

                    case MotionEvent.ACTION_UP:
                        mode = NONE;
                        int xDiff = (int) Math.abs(curr.x - start.x);
                        int yDiff = (int) Math.abs(curr.y - start.y);
                        if (xDiff < CLICK && yDiff < CLICK)
                            performClick();
                        break;

                    case MotionEvent.ACTION_POINTER_UP:
                        mode = NONE;
                        break;
                }

                setImageMatrix(matrix);
                invalidate();
                return true; // indicate event was handled
            }

        });
    }

    public void setMaxZoom(float x) {
        maxScale = x;
    }


    private class ScaleListener extends
            ScaleGestureDetector.SimpleOnScaleGestureListener {
        @Override
        public boolean onScaleBegin(ScaleGestureDetector detector) {
            mode = ZOOM;
            return true;
        }

        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float mScaleFactor = detector.getScaleFactor();
            float origScale = saveScale;
            saveScale *= mScaleFactor;

            if(saveScale<1)
            {
                Log.e("saveScale is ","executing =====> "+saveScale);
                SwipViewAdapter.ViewHolder.imageView.setVisibility(VISIBLE);
                SwipViewAdapter.ViewHolder.ivZoomable.setVisibility(GONE);
            }
            else
            {
                Log.e("saveScale is ","executing =====> "+saveScale);
                SwipViewAdapter.ViewHolder.imageView.setVisibility(GONE);
                SwipViewAdapter.ViewHolder.ivZoomable.setVisibility(VISIBLE);
            }



            if (saveScale > maxScale) {
                saveScale = maxScale;
                mScaleFactor = maxScale / origScale;
            }
            else if (saveScale < minScale) {
                saveScale = minScale;
                mScaleFactor = minScale / origScale;
            }

            if (origWidth * saveScale <= viewWidth
                    || origHeight * saveScale <= viewHeight)
                matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
                        viewHeight / 2);
            else
                matrix.postScale(mScaleFactor, mScaleFactor,
                        detector.getFocusX(), detector.getFocusY());

            fixTrans();
            return true;
        }
    }

    void fixTrans() {
        matrix.getValues(m);
        float transX = m[Matrix.MTRANS_X];
        float transY = m[Matrix.MTRANS_Y];

        float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
        float fixTransY = getFixTrans(transY, viewHeight, origHeight
                * saveScale);

        if (fixTransX != 0 || fixTransY != 0)
            matrix.postTranslate(fixTransX, fixTransY);
    }

    float getFixTrans(float trans, float viewSize, float contentSize) {
        float minTrans, maxTrans;

        if (contentSize <= viewSize) {
            minTrans = 0;
            maxTrans = viewSize - contentSize;
        } else {
            minTrans = viewSize - contentSize;
            maxTrans = 0;
        }

        if (trans < minTrans)
            return -trans + minTrans;
        if (trans > maxTrans)
            return -trans + maxTrans;
        return 0;
    }

    float getFixDragTrans(float delta, float viewSize, float contentSize) {
        if (contentSize <= viewSize) {
            return 0;
        }
        return delta;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        viewWidth = MeasureSpec.getSize(widthMeasureSpec);
        viewHeight = MeasureSpec.getSize(heightMeasureSpec);

        //
        // Rescales image on rotation
        //
        if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
                || viewWidth == 0 || viewHeight == 0)
            return;
        oldMeasuredHeight = viewHeight;
        oldMeasuredWidth = viewWidth;

        if (saveScale == 1) {
            // Fit to screen.
            float scale;

            Drawable drawable = getDrawable();
            if (drawable == null || drawable.getIntrinsicWidth() == 0
                    || drawable.getIntrinsicHeight() == 0)
                return;
            int bmWidth = drawable.getIntrinsicWidth();
            int bmHeight = drawable.getIntrinsicHeight();

            Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);

            float scaleX = (float) viewWidth / (float) bmWidth;
            float scaleY = (float) viewHeight / (float) bmHeight;
            scale = Math.min(scaleX, scaleY);
            matrix.setScale(scale, scale);

            // Center the image
            float redundantYSpace = (float) viewHeight
                    - (scale * (float) bmHeight);
            float redundantXSpace = (float) viewWidth
                    - (scale * (float) bmWidth);
            redundantYSpace /= (float) 2;
            redundantXSpace /= (float) 2;

            matrix.postTranslate(redundantXSpace, redundantYSpace);

            origWidth = viewWidth - 2 * redundantXSpace;
            origHeight = viewHeight - 2 * redundantYSpace;
            setImageMatrix(matrix);
        }
        fixTrans();
    }

}

Answer 1

当只有一个指针按下时，TouchImageView 类中的OnTouchListener.onTouch() 返回false，如下所示:

@Override
public boolean onTouch(View v, MotionEvent event) {

    // Touch logic here

    return event.getPointerCount() > 1;
}

通过这种方式，双指缩放只会在存在两个指针时消耗触摸事件(执行双指缩放所必需的)。

更新:

扩展 SwipeFlingAdapterView 类并重写 onInterceptTouchEvent() 方法，就像这里所做的那样:Using onInterceptTouchEvent

然后你可以像这样拦截指向 ImageView 的触摸事件:

public void onInterceptTouchEvent(MotionEvent event) {
    if(event.getPointerCount() == 1) {
        onTouchEvent(event);
    }
    return false;
}

更多关于触摸拦截的文档在这里:https://developer.android.com/training/gestures/viewgroup.html

希望对您有所帮助!