Android-使用展开/捏放大/缩小RelativeLayout

Question

我有一个包含RelativeLayout和的私有类的活动，该活动扩展了SimpleOnScaleGestureListener。在onScale听众的方法中，我想通过用户展开/捏手指来放大/缩小整个布局（用户看到的一切）。我想改变的布局不被永久的，即当病毒/捏合手势是在我想的布局回去这是什么在首位（任何复位可能在做onScaleEnd的方法SimpleOnScaleGestureListener例如）。我试图通过调用setScaleX和setScaleY在上RelativeLayout以及还使用来实现它ScaleAnimation。两者均不会导致平滑缩放（或任何可能被称为缩放的东西）。甚至可以放大/缩小RelativeLayout？我剩下的唯一想法是从缓存中读取屏幕截图，并将其作为ImageView整个布局的顶部，并通过放大/缩小此图像setImageMatrix。但是，我不知道如何实现这一点。May布局还包含一个片段的容器，在应该进行缩放时该片段为空。通过该onScaleEnd手势，将片段放入其容器中（已经实现并且可以正常工作）。这是我的布局：<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/layout_pinch"android:layout_width="match_parent"android:layout_height="match_parent"android:background="#ffffff" >   <!-- Layout containing the thumbnail ImageViews --><LinearLayout    android:id="@+id/thumbnail_group_pui"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_centerVertical="true"    android:orientation="horizontal" >    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c1"/>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c2"/>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c3"/>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c4"/>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c5"/>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/tn_c6"/></LinearLayout>我没有实。我必须在扩展类中包括哪些其他方法来实际缩放布局或重置布局？

Answer 1

因此，我创建了RelativeLayout上述主题中所述的的子类。看起来像这样：

public class ZoomableRelativeLayout extends RelativeLayout {

float mScaleFactor = 1;

float mPivotX;

float mPivotY;

public ZoomableRelativeLayout(Context context) {

    super(context);

    // TODO Auto-generated constructor stub

}

public ZoomableRelativeLayout(Context context, AttributeSet attrs) {

    super(context, attrs);

    // TODO Auto-generated constructor stub

}

public ZoomableRelativeLayout(Context context, AttributeSet attrs,

        int defStyle) {

    super(context, attrs, defStyle);

    // TODO Auto-generated constructor stub

}

protected void dispatchDraw(Canvas canvas) {

    canvas.save(Canvas.MATRIX_SAVE_FLAG);

    canvas.scale(mScaleFactor, mScaleFactor, mPivotX, mPivotY);

    super.dispatchDraw(canvas);

    canvas.restore();

}

public void scale(float scaleFactor, float pivotX, float pivotY) {

    mScaleFactor = scaleFactor;

    mPivotX = pivotX;

    mPivotY = pivotY;

    this.invalidate();

}

public void restore() {

    mScaleFactor = 1;

    this.invalidate();

}

}

我对SimpleOnScaleGestureListener外观的实现如下所示：

private class OnPinchListener extends SimpleOnScaleGestureListener {

    float startingSpan; 

    float endSpan;

    float startFocusX;

    float startFocusY;

    public boolean onScaleBegin(ScaleGestureDetector detector) {

        startingSpan = detector.getCurrentSpan();

        startFocusX = detector.getFocusX();

        startFocusY = detector.getFocusY();

        return true;

    }

    public boolean onScale(ScaleGestureDetector detector) {

        mZoomableRelativeLayout.scale(detector.getCurrentSpan()/startingSpan, startFocusX, startFocusY);

        return true;

    }

    public void onScaleEnd(ScaleGestureDetector detector) {

        mZoomableRelativeLayout.restore();

    }

}

希望这可以帮助！

更新：

您可以整合OnPinchListener你的ZoomableRelativelayout使用ScaleGestureDetector：

ScaleGestureDetector scaleGestureDetector = new ScaleGestureDetector(this, new OnPinchListener());

并且您需要将Zoomable布局的触摸侦听器与ScaleGestureDetector的触摸侦听器绑定：

mZoomableLayout.setOnTouchListener(new OnTouchListener() {

                @Override

                public boolean onTouch(View v, MotionEvent event) {

                    // TODO Auto-generated method stub

                    scaleGestureDetector.onTouchEvent(event);

                    return true;

                }

            });

Answer 2

我认为我设法提高了Schnodahipfe的答案。我向ZoomableRelativeLayout类添加了两个方法。

public void relativeScale(float scaleFactor, float pivotX, float pivotY)

{

    mScaleFactor *= scaleFactor;

    if(scaleFactor >= 1)

    {

        mPivotX = mPivotX + (pivotX - mPivotX) * (1 - 1 / scaleFactor);

        mPivotY = mPivotY + (pivotY - mPivotY) * (1 - 1 / scaleFactor);

    }

    else

    {

        pivotX = getWidth()/2;

        pivotY = getHeight()/2;

        mPivotX = mPivotX + (pivotX - mPivotX) * (1 - scaleFactor);

        mPivotY = mPivotY + (pivotY - mPivotY) * (1 - scaleFactor);

    }

    this.invalidate();

}

public void release()

{

    if(mScaleFactor < MIN_SCALE)

    {

        final float startScaleFactor = mScaleFactor;

        Animation a = new Animation()

        {

            @Override

            protected void applyTransformation(float interpolatedTime, Transformation t)

            {

                scale(startScaleFactor + (MIN_SCALE - startScaleFactor)*interpolatedTime,mPivotX,mPivotY);

            }

        };

        a.setDuration(300);

        startAnimation(a);

    }

    else if(mScaleFactor > MAX_SCALE)

    {

        final float startScaleFactor = mScaleFactor;

        Animation a = new Animation()

        {

            @Override

            protected void applyTransformation(float interpolatedTime, Transformation t)

            {

                scale(startScaleFactor + (MAX_SCALE - startScaleFactor)*interpolatedTime,mPivotX,mPivotY);

            }

        };

        a.setDuration(300);

        startAnimation(a);

    }

}

并像这样重写OnPinchListener类

private class OnPinchListener extends ScaleGestureDetector.SimpleOnScaleGestureListener

{

    float currentSpan;

    float startFocusX;

    float startFocusY;

    public boolean onScaleBegin(ScaleGestureDetector detector)

    {

        currentSpan = detector.getCurrentSpan();

        startFocusX = detector.getFocusX();

        startFocusY = detector.getFocusY();

        return true;

    }

    public boolean onScale(ScaleGestureDetector detector)

    {

        ZoomableRelativeLayout zoomableRelativeLayout= (ZoomableRelativeLayout) ImageFullScreenActivity.this.findViewById(R.id.imageWrapper);

        zoomableRelativeLayout.relativeScale(detector.getCurrentSpan() / currentSpan, startFocusX, startFocusY);

        currentSpan = detector.getCurrentSpan();

        return true;

    }

    public void onScaleEnd(ScaleGestureDetector detector)

    {

        ZoomableRelativeLayout zoomableRelativeLayout= (ZoomableRelativeLayout) ImageFullScreenActivity.this.findViewById(R.id.imageWrapper);

        zoomableRelativeLayout.release();

    }

}

每次触摸事件结束时，原始答案都会重置比例，但是像这样，您可以放大和缩小多次。