缩放系列（三）：一个可以手势缩放、拖拽、旋转的layout
弄了一个下午，终于搞出来了，PowerfulLayout
下面是一个功能强大的改造的例子：
可以实现以下需求：
1.两个手指进行缩放布局
2.所有子控件也随着缩放，
3.子控件该有的功能不能丢失（像button有可被点击的功能，缩放后不能丢失该功能）
相对上个例子，多了一个功能---
4.拖拽（平移）layout
运行效果图：http://pan.baidu.com/s/1geIoG8r
图片太大就不贴出来了。
布局文件test.xml、超级简单的
<?xml version="1.0" encoding="utf-8"?> <com.example.testbitmapscale.PowerfulLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <FrameLayout android:background="@drawable/home_tools" android:layout_width="match_parent" android:layout_height="match_parent" > <ImageButton android:id="@+id/imageButton2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/selector_button1" /> </FrameLayout> </com.example.testbitmapscale.PowerfulLayout>
java代码：
MainActivity也是超级简单
public class MainActivity extends ActionBarActivity { private View view; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // setContentView(R.layout.test); view = View.inflate(this, R.layout.test, null); setContentView(view); } // @Override // public boolean onTouchEvent(MotionEvent event) { // if (event.getPointerCount() > 1) { // // 多点触控 // // 返回给ScaleGestureDetector来处理 // return mScaleGestureDetector.onTouchEvent(event); // } else { // // 单点触控 // switch (event.getAction()) { // case MotionEvent.ACTION_DOWN: // downX = (int) event.getX(); // downY = (int) event.getY(); // newHeight = view.getLayoutParams().height; // newWidth = view.getLayoutParams().width; //// int widthMeasureSpec = //// View.MeasureSpec.makeMeasureSpec(2000,View.MeasureSpec.AT_MOST); //// //// int heightMeasureSpec //// =View.MeasureSpec.makeMeasureSpec(2000,View.MeasureSpec.AT_MOST); //// //// view.measure(widthMeasureSpec,heightMeasureSpec); //// //// newHeight = view.getMeasuredHeight(); //// //// newWidth = view.getMeasuredWidth(); // break; // case MotionEvent.ACTION_MOVE: // long currentTimeMillis = System.currentTimeMillis(); // if (currentTimeMillis - lastMultiTouchTime > 200) { // // 双指触控后要等待200毫秒才能执行单指触控的操作，避免双指触控后出现颤抖的情况 // int moveX = (int) event.getX();// 移动手指的时候手指的x // int moveY = (int) event.getY();// 移动手指的时候手指的y // int deltaX = (int) (moveX - downX); // int deltaY = (int) (moveY - downY); // int newLeft = left + deltaX;// view的新left // int newTop = top + deltaY;// view的新top // int newRight = right + deltaX;// view的新right // int newBottom = bottom + deltaY;// view的新bottom //// int newWidth = (int) (preScale * originalWidth); //// int newHeight = (int) (preScale * originalHeight); //// if (deltaX>(newWidth-originalHeight)/2||deltaY>(newHeight-originalHeight)/2) { //// return false; //// } // // int newWidth = view.getWidth(); // // int newHeight = view.getHeight(); // System.out.println("newWidth:" + newWidth + "newHeight:" // + newHeight); //// System.out.println(preScale); // if (newLeft < originalWidth - newWidth) { // newLeft = originalWidth - newWidth; // newRight = newLeft + newWidth; // } // // if (newTop < originalHeight - newHeight){ // // newTop = originalHeight - newHeight; // // newBottom= newTop+newHeight; // // } // // if(newRight>originalWidth){ // // newRight=originalWidth; // // newLeft=newRight-newWidth; // // } // // if(newBottom>originalHeight){ // // newBottom=originalHeight; // // newTop=newBottom-newHeight; // // } // view.layout(newLeft, newTop, newRight, newBottom);// 重新摆放view的位置 // } else { // return false; // } // // break; // case MotionEvent.ACTION_UP: // // 更新位置信息 // left = view.getLeft(); // top = view.getTop(); // right = view.getRight(); // bottom = view.getBottom(); // break; // // default: // break; // } // return true;// 代表消费了事件 // } // } }
PowerfulLayout.java:
package com.example.testbitmapscale; import android.content.Context; import android.support.v4.widget.ViewDragHelper; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; import android.widget.FrameLayout; import com.nineoldandroids.view.ViewHelper; public class PowerfulLayout extends FrameLayout { // 屏幕宽高 private int screenHeight; private int screenWidth; private ViewDragHelper mDragHelper; private long lastMultiTouchTime;// 记录多点触控缩放后的时间 private int originalWidth;// view宽度 private int originalHeight;// view高度 private ScaleGestureDetector mScaleGestureDetector = null; // private View view; private int downX;// 手指按下的x坐标值 private int downY;// 手指按下的y坐标值 private int left;// view的左坐标值 private int top;// view的上坐标值 private int right;// view的右坐标值 private int bottom;// view的下坐标值 private int newHeight; private int newWidth; private float scale; private float preScale = 1;// 默认前一次缩放比例为1 public PowerfulLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(context); } public PowerfulLayout(Context context, AttributeSet attrs) { super(context, attrs); init(context); } public PowerfulLayout(Context context) { super(context); init(context); } private void init(Context context) { mDragHelper = ViewDragHelper.create(this, callback); mScaleGestureDetector = new ScaleGestureDetector(context, new ScaleGestureListener()); // view.post(new Runnable() { // // @Override // public void run() { // left = view.getLeft(); // top = view.getTop(); // right = view.getRight(); // bottom = view.getBottom(); // originalWidth = view.getWidth(); // originalHeight = view.getHeight(); // } // }); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); screenWidth = getMeasuredWidth(); screenHeight = getMeasuredHeight(); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { super.onInterceptTouchEvent(ev); boolean b = mDragHelper.shouldInterceptTouchEvent(ev);// 由mDragHelper决定是否拦截事件，并传递给onTouchEvent return b; } private boolean needToHandle=true; @Override public boolean onTouchEvent(MotionEvent event) { int pointerCount = event.getPointerCount(); // 获得多少点 if (pointerCount > 1) {// 多点触控， switch (event.getAction()) { case MotionEvent.ACTION_DOWN: needToHandle=false; break; case MotionEvent.ACTION_MOVE: break; case MotionEvent.ACTION_POINTER_2_UP://第二个手指抬起的时候 needToHandle=true; break; default: break; } return mScaleGestureDetector.onTouchEvent(event);//让mScaleGestureDetector处理触摸事件 } else { long currentTimeMillis = System.currentTimeMillis(); if (currentTimeMillis - lastMultiTouchTime > 200&&needToHandle) { // 多点触控全部手指抬起后要等待200毫秒才能执行单指触控的操作，避免多点触控后出现颤抖的情况 try { mDragHelper.processTouchEvent(event); } catch (Exception e) { e.printStackTrace(); } return true; } // } } return false; } private ViewDragHelper.Callback callback = new ViewDragHelper.Callback() { /** * 用于判断是否捕获当前child的触摸事件 * * @param child * 当前触摸的子view * @param pointerId * @return true就捕获并解析；false不捕获 */ @Override public boolean tryCaptureView(View child, int pointerId) { if (preScale > 1) return true; return false; } /** * 控制水平方向上的位置 */ @Override public int clampViewPositionHorizontal(View child, int left, int dx) { if (left < (screenWidth - screenWidth * preScale) / 2) left = (int) (screenWidth - screenWidth * preScale) / 2;// 限制mainView可向左移动到的位置 if (left > (screenWidth * preScale - screenWidth) / 2) left = (int) (screenWidth * preScale - screenWidth) / 2;// 限制mainView可向右移动到的位置 return left; } public int clampViewPositionVertical(View child, int top, int dy) { if (top < (screenHeight - screenHeight * preScale) / 2) { top = (int) (screenHeight - screenHeight * preScale) / 2;// 限制mainView可向上移动到的位置 } if (top > (screenHeight * preScale - screenHeight) / 2) { top = (int) (screenHeight * preScale - screenHeight) / 2;// 限制mainView可向上移动到的位置 } return top; } }; public class ScaleGestureListener implements ScaleGestureDetector.OnScaleGestureListener { @Override public boolean onScale(ScaleGestureDetector detector) { float previousSpan = detector.getPreviousSpan();// 前一次双指间距 float currentSpan = detector.getCurrentSpan();// 本次双指间距 if (currentSpan < previousSpan) { // 缩小 // scale = preScale-detector.getScaleFactor()/3; scale = preScale - (previousSpan - currentSpan) / 1000; } else { // 放大 // scale = preScale+detector.getScaleFactor()/3; scale = preScale + (currentSpan - previousSpan) / 1000; } // 缩放view if (scale > 0.5) { ViewHelper.setScaleX(PowerfulLayout.this, scale);// x方向上缩放 ViewHelper.setScaleY(PowerfulLayout.this, scale);// y方向上缩放 } return false; } @Override public boolean onScaleBegin(ScaleGestureDetector detector) { // 一定要返回true才会进入onScale()这个函数 return true; } @Override public void onScaleEnd(ScaleGestureDetector detector) { preScale = scale;// 记录本次缩放比例 lastMultiTouchTime = System.currentTimeMillis();// 记录双指缩放后的时间 } } }
可以手势缩放、拖拽、旋转的layout应用场景，例子：qq侧滑菜单。侧滑的时候菜单中所有子控件跟随父控件从小变大，不过它不支持双指缩放，只是单指操作。链接：http://blog.csdn.net/qq_30948129/article/details/52282451
