編輯:關於Android編程
終極版
package com.zhy.view; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Matrix; import android.graphics.RectF; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.ScaleGestureDetector.OnScaleGestureListener; import android.view.View; import android.view.View.OnTouchListener; import android.view.ViewTreeObserver; import android.widget.ImageView; /** * * @author zhy * 博客地址:http://blog.csdn.net/lmj623565791 */ public class ZoomImageView extends ImageView implements OnScaleGestureListener, OnTouchListener, ViewTreeObserver.OnGlobalLayoutListener { private static final String TAG = ZoomImageView.class.getSimpleName(); public static final float SCALE_MAX = 4.0f; private static final float SCALE_MID = 2.0f; /** * 初始化時的縮放比例,如果圖片寬或高大於屏幕,此值將小於0 */ private float initScale = 1.0f; private boolean once = true; /** * 用於存放矩陣的9個值 */ private final float[] matrixValues = new float[9]; /** * 縮放的手勢檢測 */ private ScaleGestureDetector mScaleGestureDetector = null; private final Matrix mScaleMatrix = new Matrix(); /** * 用於雙擊檢測 */ private GestureDetector mGestureDetector; private boolean isAutoScale; private int mTouchSlop; private float mLastX; private float mLastY; private boolean isCanDrag; private int lastPointerCount; private boolean isCheckTopAndBottom = true; private boolean isCheckLeftAndRight = true; public ZoomImageView(Context context) { this(context, null); } public ZoomImageView(Context context, AttributeSet attrs) { super(context, attrs); super.setScaleType(ScaleType.MATRIX); mGestureDetector = new GestureDetector(context, new SimpleOnGestureListener() { @Override public boolean onDoubleTap(MotionEvent e) { if (isAutoScale == true) return true; float x = e.getX(); float y = e.getY(); Log.e("DoubleTap", getScale() + " , " + initScale); if (getScale() < SCALE_MID) { ZoomImageView.this.postDelayed( new AutoScaleRunnable(SCALE_MID, x, y), 16); isAutoScale = true; } else if (getScale() >= SCALE_MID && getScale() < SCALE_MAX) { ZoomImageView.this.postDelayed( new AutoScaleRunnable(SCALE_MAX, x, y), 16); isAutoScale = true; } else { ZoomImageView.this.postDelayed( new AutoScaleRunnable(initScale, x, y), 16); isAutoScale = true; } return true; } }); mScaleGestureDetector = new ScaleGestureDetector(context, this); this.setOnTouchListener(this); } /** * 自動縮放的任務 * * @author zhy * */ private class AutoScaleRunnable implements Runnable { static final float BIGGER = 1.07f; static final float SMALLER = 0.93f; private float mTargetScale; private float tmpScale; /** * 縮放的中心 */ private float x; private float y; /** * 傳入目標縮放值,根據目標值與當前值,判斷應該放大還是縮小 * * @param targetScale */ public AutoScaleRunnable(float targetScale, float x, float y) { this.mTargetScale = targetScale; this.x = x; this.y = y; if (getScale() < mTargetScale) { tmpScale = BIGGER; } else { tmpScale = SMALLER; } } @Override public void run() { // 進行縮放 mScaleMatrix.postScale(tmpScale, tmpScale, x, y); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); final float currentScale = getScale(); // 如果值在合法范圍內,繼續縮放 if (((tmpScale > 1f) && (currentScale < mTargetScale)) || ((tmpScale < 1f) && (mTargetScale < currentScale))) { ZoomImageView.this.postDelayed(this, 16); } else // 設置為目標的縮放比例 { final float deltaScale = mTargetScale / currentScale; mScaleMatrix.postScale(deltaScale, deltaScale, x, y); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); isAutoScale = false; } } } @SuppressLint("NewApi") @Override public boolean onScale(ScaleGestureDetector detector) { float scale = getScale(); float scaleFactor = detector.getScaleFactor(); if (getDrawable() == null) return true; /** * 縮放的范圍控制 */ if ((scale < SCALE_MAX && scaleFactor > 1.0f) || (scale > initScale && scaleFactor < 1.0f)) { /** * 最大值最小值判斷 */ if (scaleFactor * scale < initScale) { scaleFactor = initScale / scale; } if (scaleFactor * scale > SCALE_MAX) { scaleFactor = SCALE_MAX / scale; } /** * 設置縮放比例 */ mScaleMatrix.postScale(scaleFactor, scaleFactor, detector.getFocusX(), detector.getFocusY()); checkBorderAndCenterWhenScale(); setImageMatrix(mScaleMatrix); } return true; } /** * 在縮放時,進行圖片顯示范圍的控制 */ private void checkBorderAndCenterWhenScale() { RectF rect = getMatrixRectF(); float deltaX = 0; float deltaY = 0; int width = getWidth(); int height = getHeight(); // 如果寬或高大於屏幕,則控制范圍 if (rect.width() >= width) { if (rect.left > 0) { deltaX = -rect.left; } if (rect.right < width) { deltaX = width - rect.right; } } if (rect.height() >= height) { if (rect.top > 0) { deltaY = -rect.top; } if (rect.bottom < height) { deltaY = height - rect.bottom; } } // 如果寬或高小於屏幕,則讓其居中 if (rect.width() < width) { deltaX = width * 0.5f - rect.right + 0.5f * rect.width(); } if (rect.height() < height) { deltaY = height * 0.5f - rect.bottom + 0.5f * rect.height(); } Log.e(TAG, "deltaX = " + deltaX + " , deltaY = " + deltaY); mScaleMatrix.postTranslate(deltaX, deltaY); } /** * 根據當前圖片的Matrix獲得圖片的范圍 * * @return */ private RectF getMatrixRectF() { Matrix matrix = mScaleMatrix; RectF rect = new RectF(); Drawable d = getDrawable(); if (null != d) { rect.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); matrix.mapRect(rect); } return rect; } @Override public boolean onScaleBegin(ScaleGestureDetector detector) { return true; } @Override public void onScaleEnd(ScaleGestureDetector detector) { } @Override public boolean onTouch(View v, MotionEvent event) { if (mGestureDetector.onTouchEvent(event)) return true; mScaleGestureDetector.onTouchEvent(event); float x = 0, y = 0; // 拿到觸摸點的個數 final int pointerCount = event.getPointerCount(); // 得到多個觸摸點的x與y均值 for (int i = 0; i < pointerCount; i++) { x += event.getX(i); y += event.getY(i); } x = x / pointerCount; y = y / pointerCount; /** * 每當觸摸點發生變化時,重置mLasX , mLastY */ if (pointerCount != lastPointerCount) { isCanDrag = false; mLastX = x; mLastY = y; } lastPointerCount = pointerCount; RectF rectF = getMatrixRectF(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (rectF.width() > getWidth() || rectF.height() > getHeight()) { getParent().requestDisallowInterceptTouchEvent(true); } break; case MotionEvent.ACTION_MOVE: if (rectF.width() > getWidth() || rectF.height() > getHeight()) { getParent().requestDisallowInterceptTouchEvent(true); } Log.e(TAG, "ACTION_MOVE"); float dx = x - mLastX; float dy = y - mLastY; if (!isCanDrag) { isCanDrag = isCanDrag(dx, dy); } if (isCanDrag) { if (getDrawable() != null) { // if (getMatrixRectF().left == 0 && dx > 0) // { // getParent().requestDisallowInterceptTouchEvent(false); // } // // if (getMatrixRectF().right == getWidth() && dx < 0) // { // getParent().requestDisallowInterceptTouchEvent(false); // } isCheckLeftAndRight = isCheckTopAndBottom = true; // 如果寬度小於屏幕寬度,則禁止左右移動 if (rectF.width() < getWidth()) { dx = 0; isCheckLeftAndRight = false; } // 如果高度小雨屏幕高度,則禁止上下移動 if (rectF.height() < getHeight()) { dy = 0; isCheckTopAndBottom = false; } mScaleMatrix.postTranslate(dx, dy); checkMatrixBounds(); setImageMatrix(mScaleMatrix); } } mLastX = x; mLastY = y; break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: Log.e(TAG, "ACTION_UP"); lastPointerCount = 0; break; } return true; } /** * 獲得當前的縮放比例 * * @return */ public final float getScale() { mScaleMatrix.getValues(matrixValues); return matrixValues[Matrix.MSCALE_X]; } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); getViewTreeObserver().addOnGlobalLayoutListener(this); } @SuppressWarnings("deprecation") @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); getViewTreeObserver().removeGlobalOnLayoutListener(this); } @Override public void onGlobalLayout() { if (once) { Drawable d = getDrawable(); if (d == null) return; Log.e(TAG, d.getIntrinsicWidth() + " , " + d.getIntrinsicHeight()); int width = getWidth(); int height = getHeight(); // 拿到圖片的寬和高 int dw = d.getIntrinsicWidth(); int dh = d.getIntrinsicHeight(); float scale = 1.0f; // 如果圖片的寬或者高大於屏幕,則縮放至屏幕的寬或者高 if (dw > width && dh <= height) { scale = width * 1.0f / dw; } if (dh > height && dw <= width) { scale = height * 1.0f / dh; } // 如果寬和高都大於屏幕,則讓其按按比例適應屏幕大小 if (dw > width && dh > height) { scale = Math.min(width * 1.0f / dw, height * 1.0f / dh); } initScale = scale; Log.e(TAG, "initScale = " + initScale); mScaleMatrix.postTranslate((width - dw) / 2, (height - dh) / 2); mScaleMatrix.postScale(scale, scale, getWidth() / 2, getHeight() / 2); // 圖片移動至屏幕中心 setImageMatrix(mScaleMatrix); once = false; } } /** * 移動時,進行邊界判斷,主要判斷寬或高大於屏幕的 */ private void checkMatrixBounds() { RectF rect = getMatrixRectF(); float deltaX = 0, deltaY = 0; final float viewWidth = getWidth(); final float viewHeight = getHeight(); // 判斷移動或縮放後,圖片顯示是否超出屏幕邊界 if (rect.top > 0 && isCheckTopAndBottom) { deltaY = -rect.top; } if (rect.bottom < viewHeight && isCheckTopAndBottom) { deltaY = viewHeight - rect.bottom; } if (rect.left > 0 && isCheckLeftAndRight) { deltaX = -rect.left; } if (rect.right < viewWidth && isCheckLeftAndRight) { deltaX = viewWidth - rect.right; } mScaleMatrix.postTranslate(deltaX, deltaY); } /** * 是否是推動行為 * * @param dx * @param dy * @return */ private boolean isCanDrag(float dx, float dy) { return Math.sqrt((dx * dx) + (dy * dy)) >= mTouchSlop; } }
布局文件:activity_main.xml
在activity中使用:
package com.zhy.zhy_scalegesturedetector02; import android.app.Activity; import android.os.Bundle; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import com.zhy.view.ZoomImageView; public class MainActivity extends Activity { private ViewPager mViewPager; private int[] mImgs = new int[] { R.drawable.tbug, R.drawable.a, R.drawable.xx }; private ImageView[] mImageViews = new ImageView[mImgs.length]; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.vp); mViewPager = (ViewPager) findViewById(R.id.id_viewpager); mViewPager.setAdapter(new PagerAdapter() { @Override public Object instantiateItem(ViewGroup container, int position) { ZoomImageView imageView = new ZoomImageView( getApplicationContext()); imageView.setImageResource(mImgs[position]); container.addView(imageView); mImageViews[position] = imageView; return imageView; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView(mImageViews[position]); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public int getCount() { return mImgs.length; } }); } }
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