使用MotionEvent.ACTION_MOVE创建类似主屏幕的ViewFlipper

Question

好的,我有ViewFlipper三个LinearLayouts嵌套在里面.它默认显示第一个.这段代码:

// Assumptions in my Activity class:
// oldTouchValue is a float
// vf is my view flipper
@Override
public boolean onTouchEvent(MotionEvent touchEvent) {
  switch (touchEvent.getAction()) {
    case MotionEvent.ACTION_DOWN: {
      oldTouchValue = touchEvent.getX();
      break;
    }
    case MotionEvent.ACTION_UP: {
      float currentX = touchEvent.getX();
      if (oldTouchValue < currentX) {
        vf.setInAnimation(AnimationHelper.inFromLeftAnimation());
        vf.setOutAnimation(AnimationHelper.outToRightAnimation());
        vf.showNext();
      }
      if (oldTouchValue > currentX) {
        vf.setInAnimation(AnimationHelper.inFromRightAnimation());
        vf.setOutAnimation(AnimationHelper.outToLeftAnimation());
        vf.showPrevious();
      }
      break;
    }
    case MotionEvent.ACTION_MOVE: {
      // TODO: Some code to make the ViewFlipper
      // act like the home screen.
      break;
    }
  }
  return false;
}

public static class AnimationHelper {
  public static Animation inFromRightAnimation() {
    Animation inFromRight = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, +1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    inFromRight.setDuration(350);
    inFromRight.setInterpolator(new AccelerateInterpolator());
    return inFromRight;
  }

  public static Animation outToLeftAnimation() {
    Animation outtoLeft = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, -1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    outtoLeft.setDuration(350);
    outtoLeft.setInterpolator(new AccelerateInterpolator());
    return outtoLeft;
  }

  // for the next movement
  public static Animation inFromLeftAnimation() {
    Animation inFromLeft = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, -1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    inFromLeft.setDuration(350);
    inFromLeft.setInterpolator(new AccelerateInterpolator());
    return inFromLeft;
  }

  public static Animation outToRightAnimation() {
    Animation outtoRight = new TranslateAnimation(
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, +1.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f,
    Animation.RELATIVE_TO_PARENT, 0.0f);
    outtoRight.setDuration(350);
    outtoRight.setInterpolator(new AccelerateInterpolator());
    return outtoRight;
  }
}

...处理视图翻转,但动画非常"开/关".我想知道是否有人可以帮我解决最后一部分问题.假设我可以访问LinearLayouts,有没有办法可以根据deltaX和deltaY设置布局的位置？

有人给了我这个链接,并说我应该参考applyTransformation方法提示如何做到这一点,但我不知道如何重复这种相同的行为.

Answer 1

在移动手指的同时移动视图很容易:

case MotionEvent.ACTION_MOVE:
    final View currentView = vf.getCurrentView();
    currentView.layout((int)(touchEvent.getX() - oldTouchValue), 
            currentView.getTop(), currentView.getRight(), 
            currentView.getBottom());
break;

现在这只会移动当前视图,而不是邻居.我还没有测试过,但那些可能是由getChildAt获得的:

vf.getChildAt(vf.getDisplayedChild() - 1); // previous
vf.getChildAt(vf.getDisplayedChild() + 1); // next

希望有所帮助.