将视图层次结构旋转 90 度 [英] Rotate View Hierarchy 90 degrees

问题描述

我正在研究 FrameLayout 的一个子类，它应该将其所有子类旋转 90 度.我这样做是为了克服 android 2.1 及更低版本中存在的仅限横向的相机限制，方法是让活动处于横向状态，但将我的相机叠加层放入此框架布局叠加层中，使其看起来好像是纵向的(Layar 就是这样做的) 为了实现这一点，我正在调整 Jeff Sharkey 的代码来旋转视图.我的问题是我可以旋转 Framelayout，但我无法调整它的大小以匹配新尺寸.因此，在我的 g1 上，不是在 480x320 相机视图上的横向 320x480 纵向视图，我在中间得到一个 320x320 框，显示我的纵向视图，侧面被切掉.

I am working on a subclass of FrameLayout that is supposed to rotate all of its children by 90 degrees. I am doing this to overcome the landscape-only camera limitation present in android 2.1 and below, by having the activity be in landscape, but placing my camera overlay into this framelayout overlay to cause it to appear as if it was portrait (this is how Layar does it) To accomplish this, I'm adapting Jeff Sharkey's code to rotate views. My problem is that I can rotate the Framelayout, but I cannot resize it to match the new dimensions. So on my g1, instead of a 320x480 portrait view over a 480x320 camera view in landscape, I get a 320x320 box in the middle showing my portrait view with the sides chopped off.

这是我目前的代码:

public class RotateLayout extends FrameLayout {
    private Matrix mForward = new Matrix();
    private Matrix mReverse = new Matrix();
    private float[] mTemp = new float[2];

    public RotateLayout(Context context) {
        super(context);
    }

    public RotateLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

    }


    /* (non-Javadoc)
     * @see android.widget.FrameLayout#onMeasure(int, int)
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //This didn't work:
        //super.onMeasure(heightMeasureSpec, widthMeasureSpec);
    }

    /* (non-Javadoc)
     * @see android.widget.FrameLayout#onSizeChanged(int, int, int, int)
     */
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        canvas.rotate(270, getWidth()/2, getHeight()/2);
        //This code will stretch the canvas to accommodate the new screen size. This is not what I want.
        //float scaleX=(float)getHeight()/getWidth();
        //float scaleY=(float)getWidth()/getHeight();
        //canvas.scale(scaleX, scaleY,  getWidth()/2, getHeight()/2);
        mForward = canvas.getMatrix();
        mForward.invert(mReverse);
        canvas.save();
        canvas.setMatrix(mForward); //This is the matrix we need to use for proper positioning of touch events
        super.dispatchDraw(canvas);
        canvas.restore();
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        final float[] temp = mTemp;
        temp[0] = event.getX();
        temp[1] = event.getY();

        mReverse.mapPoints(temp);

        event.setLocation(temp[0], temp[1]);
        return super.dispatchTouchEvent(event);
    }
}

我已尝试覆盖 OnMeasure 来切换视图的 X 和 Y 维度，但无法使其正常工作.非常感谢您能提供的任何帮助.

I have tried overriding OnMeasure to switch the X and Y dimensions of the View, but have not been able to get that to work. Any help you can provide is greatly appreciated.

推荐答案

我遇到了同样的问题并设法解决了它.我没有手动旋转每个视图或布局，而是使用了 LayoutAnimationController.

I had the same problem and managed to solve it. Instead of rotating each view or the layout by hand, I used a LayoutAnimationController.

首先，在/res/anim/中放置一个名为 rotation.xml 的文件

First, place a file in /res/anim/ called rotation.xml

<?xml version="1.0" encoding="utf-8"?>
<rotate
 xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="-90"
    android:pivotX="50%"
    android:pivotY="50%"
    android:duration="0" android:fillAfter="true">
</rotate>

然后，在您的 Activity 的 onCreate 中，执行

Then, in your Activity's onCreate, do

  @Override
  public void onCreate(Bundle icicle) {
  super.onCreate(icicle);

     setContentView(R.layout.myscreen);

     Animation rotateAnim = AnimationUtils.loadAnimation(this, R.anim.rotation);
     LayoutAnimationController animController = new LayoutAnimationController(rotateAnim, 0);
     FrameLayout layout = (FrameLayout)findViewById(R.id.MyScreen_ContentLayout);
     layout.setLayoutAnimation(animController);
 }

如果您想旋转位于相机预览视图 (SurfaceHolder) 上方的元素，只需将 FrameLayout 放置在 SurfaceHolder 上方，将所有元素放置在该 FrameLayout 中，然后将布局命名为MyScreen_ContentLayout".完成.

If you want to rotate elements that lie above your camera preview view (SurfaceHolder), simply place a FrameLayout above the SurfaceHolder, place all your elements in that FrameLayout and call the Layout "MyScreen_ContentLayout". Done.

希望对某人有所帮助，我花了很长时间才把所有东西放在一起.

Hope that helped someone out, took me quite a while to get everything together.

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