自己写的手势缩放 字体大小 控件

这是抄的某位大神代码后自己改的 可惜忘记了原帖地址。。。。先贴下代码以备忘记

使用这个textview 控件就可以 手势缩放字体大小 不过好像在有scrollbar 的情况下 效果不是很好。。

package com.joosee.app.ui;import android.content.Context;import android.graphics.Matrix;import android.graphics.PointF;import android.util.AttributeSet;import android.util.FloatMath;import android.util.Log;import android.view.MotionEvent;import android.widget.TextView;public class JooseeContentTextView extends TextView {Matrix matrix = new Matrix();Matrix savedMatrix = new Matrix();// We can be in one of these 3 statesstatic final int NONE = 0;static final int DRAG = 1;static final int ZOOM = 2;static final float zoomSpeed = 1.5f;private static int minSize = 8;private static int maxSize = 30;int mode = NONE;private int nowSize = 12;// Remember some things for zoomingPointF start = new PointF();PointF mid = new PointF();float oldDist = 1f;public JooseeContentTextView(Context context, AttributeSet attrs) {super(context, attrs);}@Overridepublic boolean onTouchEvent(MotionEvent event) {// TODO Auto-generated method stubswitch (event.getAction() & MotionEvent.ACTION_MASK) {case MotionEvent.ACTION_DOWN:savedMatrix.set(matrix);start.set(event.getX(), event.getY());// Log.d(TAG, "mode=DRAG");mode = DRAG;// Log.d(TAG, "mode=NONE");break;case MotionEvent.ACTION_POINTER_DOWN:oldDist = spacing(event);// Log.d(TAG, "oldDist=" + oldDist);if (oldDist > 10f) {savedMatrix.set(matrix);midPoint(mid, event);mode = ZOOM;Log.d("textview", "mode=ZOOM");}break;case MotionEvent.ACTION_UP:case MotionEvent.ACTION_POINTER_UP:mode = NONE;// Log.e("view.getWidth", view.getWidth() + "");// Log.e("view.getHeight", view.getHeight() + "");break;case MotionEvent.ACTION_MOVE:if (mode == DRAG) {// ...matrix.set(savedMatrix);matrix.postTranslate(event.getX() - start.x, event.getY()- start.y);} else if (mode == ZOOM) {float newDist = spacing(event);// Log.d(TAG, "newDist=" + newDist);Log.d("textview", "old=" + oldDist + "new" + newDist);//if (newDist > 10f) {//matrix.set(savedMatrix);//float scale = newDist / oldDist;//matrix.postScale(scale, scale, mid.x, mid.y);//}zoom(newDist, oldDist);}break;}return true; // indicate event was handled}private float spacing(MotionEvent event) {float x = event.getX(0) - event.getX(1);float y = event.getY(0) - event.getY(1);return FloatMath.sqrt(x * x + y * y);}private void midPoint(PointF point, MotionEvent event) {float x = event.getX(0) + event.getX(1);float y = event.getY(0) + event.getY(1);point.set(x / 2, y / 2);}private void zoom(Float newDist, Float oldDist) {if (newDist > 10f) {if (oldDist > newDist) {nowSize = (int) (nowSize - zoomSpeed);if (nowSize > minSize) {this.setTextSize(nowSize);} else {nowSize = minSize;this.setTextSize(minSize);}Log.d("textview", "small " + nowSize + "");} else {nowSize = (int) (nowSize + zoomSpeed);if (nowSize < maxSize) {this.setTextSize(nowSize);} else {nowSize = maxSize;this.setTextSize(nowSize);}Log.d("textview", "large " + nowSize + "");}}}}