Maz*_*har 8 android zoom pinch imageview
我正在寻找iphone,如使用Android ImageView轻拍和捏缩放. Mike Ortiz在TouchImageView上做了一些非常出色的工作来检测边界.他的代码可以在这里找到.
此代码只缺少一件事,即双击缩放.任何人都可以帮助将此功能添加到Mike Ortiz代码中吗?
Pinch放大Android中的ImageView并使用方向处理
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PointF;
import android.os.Handler;
import android.util.AttributeSet;
import android.util.FloatMath;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.GestureDetector.SimpleOnGestureListener;
public class ZoomableImageView extends View {
private static final String TAG = "ZoomableImageView";
private Bitmap imgBitmap = null;
private int containerWidth;
private int containerHeight;
Paint background;
//Matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
PointF start = new PointF();
float currentScale;
float curX;
float curY;
//We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
//For animating stuff
float targetX;
float targetY;
float targetScale;
float targetScaleX;
float targetScaleY;
float scaleChange;
float targetRatio;
float transitionalRatio;
float easing = 0.2f;
boolean isAnimating = false;
float scaleDampingFactor = 0.5f;
//For pinch and zoom
float oldDist = 1f;
PointF mid = new PointF();
private Handler mHandler = new Handler();
float minScale;
float maxScale = 8.0f;
float wpRadius = 25.0f;
float wpInnerRadius = 20.0f;
float screenDensity;
private GestureDetector gestureDetector;
public static final int DEFAULT_SCALE_FIT_INSIDE = 0;
public static final int DEFAULT_SCALE_ORIGINAL = 1;
private int defaultScale;
public int getDefaultScale() {
return defaultScale;
}
public void setDefaultScale(int defaultScale) {
this.defaultScale = defaultScale;
}
public ZoomableImageView(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
screenDensity = context.getResources().getDisplayMetrics().density;
initPaints();
gestureDetector = new GestureDetector(new MyGestureDetector());
}
public ZoomableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
screenDensity = context.getResources().getDisplayMetrics().density;
initPaints();
gestureDetector = new GestureDetector(new MyGestureDetector());
defaultScale = ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE;
}
private void initPaints() {
background = new Paint();
}
@Override
protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
super.onSizeChanged(width, height, oldWidth, oldHeight);
//Reset the width and height. Will draw bitmap and change
containerWidth = width;
containerHeight = height;
if(imgBitmap != null) {
int imgHeight = imgBitmap.getHeight();
int imgWidth = imgBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
if(defaultScale == ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initY = (containerHeight - (int)imgHeight)/2;
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}
}
@Override
protected void onDraw(Canvas canvas) {
if(imgBitmap != null && canvas != null)
{
canvas.drawBitmap(imgBitmap, matrix, background);
}
}
//Checks and sets the target image x and y co-ordinates if out of bounds
private void checkImageConstraints() {
if(imgBitmap == null) {
return;
}
float[] mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
if(currentScale < minScale) {
float deltaScale = minScale / currentScale;
float px = containerWidth/2;
float py = containerHeight/2;
matrix.postScale(deltaScale, deltaScale, px, py);
invalidate();
}
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
int rangeLimitX = containerWidth - (int)(imgBitmap.getWidth() * currentScale);
int rangeLimitY = containerHeight - (int)(imgBitmap.getHeight() * currentScale);
boolean toMoveX = false;
boolean toMoveY = false;
if(rangeLimitX < 0) {
if(curX > 0) {
targetX = 0;
toMoveX = true;
}
else if(curX < rangeLimitX) {
targetX = rangeLimitX;
toMoveX = true;
}
}
else {
targetX = rangeLimitX / 2;
toMoveX = true;
}
if(rangeLimitY < 0) {
if(curY > 0) {
targetY = 0;
toMoveY = true;
}
else if(curY < rangeLimitY) {
targetY = rangeLimitY;
toMoveY = true;
}
}
else {
targetY = rangeLimitY / 2;
toMoveY = true;
}
if(toMoveX == true || toMoveY == true) {
if(toMoveY == false) {
targetY = curY;
}
if(toMoveX == false) {
targetX = curX;
}
//Disable touch event actions
isAnimating = true;
//Initialize timer
mHandler.removeCallbacks(mUpdateImagePositionTask);
mHandler.postDelayed(mUpdateImagePositionTask, 100);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if(gestureDetector.onTouchEvent(event)) {
return true;
}
if(isAnimating == true) {
return true;
}
//Handle touch events here
float[] mvals = new float[9];
switch(event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
if(isAnimating == false) {
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if(oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
if(isAnimating == false) {
checkImageConstraints();
}
break;
case MotionEvent.ACTION_MOVE:
if(mode == DRAG && isAnimating == false) {
matrix.set(savedMatrix);
float diffX = event.getX() - start.x;
float diffY = event.getY() - start.y;
matrix.postTranslate(diffX, diffY);
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
}
else if(mode == ZOOM && isAnimating == false) {
float newDist = spacing(event);
if(newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.getValues(mvals);
currentScale = mvals[0];
if(currentScale * scale <= minScale) {
matrix.postScale(minScale/currentScale, minScale/currentScale, mid.x, mid.y);
}
else if(currentScale * scale >= maxScale) {
matrix.postScale(maxScale/currentScale, maxScale/currentScale, mid.x, mid.y);
}
else {
matrix.postScale(scale, scale, mid.x, mid.y);
}
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
}
}
break;
}
//Calculate the transformations and then invalidate
invalidate();
return true;
}
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);
}
public void setImageBitmap(Bitmap b) {
if(b != null) {
imgBitmap = b;
containerWidth = getWidth();
containerHeight = getHeight();
int imgHeight = imgBitmap.getHeight();
int imgWidth = imgBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
matrix.reset();
if(defaultScale == ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initX = 0;
if(imgHeight > containerHeight) {
initY = 0;
}
else {
initY = (containerHeight - (int)imgHeight)/2;
}
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
if(imgHeight > containerHeight) {
initY = 0;
}
else {
initY = (containerHeight - (int)imgHeight)/2;
}
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}
else {
Log.d(TAG, "bitmap is null");
}
}
public Bitmap getPhotoBitmap() {
return imgBitmap;
}
private Runnable mUpdateImagePositionTask = new Runnable() {
public void run() {
float[] mvals;
if(Math.abs(targetX - curX) < 5 && Math.abs(targetY - curY) < 5) {
isAnimating = false;
mHandler.removeCallbacks(mUpdateImagePositionTask);
mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
//Set the image parameters and invalidate display
float diffX = (targetX - curX);
float diffY = (targetY - curY);
matrix.postTranslate(diffX, diffY);
}
else {
isAnimating = true;
mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
//Set the image parameters and invalidate display
float diffX = (targetX - curX) * 0.3f;
float diffY = (targetY - curY) * 0.3f;
matrix.postTranslate(diffX, diffY);
mHandler.postDelayed(this, 25);
}
invalidate();
}
};
private Runnable mUpdateImageScale = new Runnable() {
public void run() {
float transitionalRatio = targetScale / currentScale;
float dx;
if(Math.abs(transitionalRatio - 1) > 0.05) {
isAnimating = true;
if(targetScale > currentScale) {
dx = transitionalRatio - 1;
scaleChange = 1 + dx * 0.2f;
currentScale *= scaleChange;
if(currentScale > targetScale) {
currentScale = currentScale / scaleChange;
scaleChange = 1;
}
}
else {
dx = 1 - transitionalRatio;
scaleChange = 1 - dx * 0.5f;
currentScale *= scaleChange;
if(currentScale < targetScale) {
currentScale = currentScale / scaleChange;
scaleChange = 1;
}
}
if(scaleChange != 1) {
matrix.postScale(scaleChange, scaleChange, targetScaleX, targetScaleY);
mHandler.postDelayed(mUpdateImageScale, 15);
invalidate();
}
else {
isAnimating = false;
scaleChange = 1;
matrix.postScale(targetScale/currentScale, targetScale/currentScale, targetScaleX, targetScaleY);
currentScale = targetScale;
mHandler.removeCallbacks(mUpdateImageScale);
invalidate();
checkImageConstraints();
}
}
else {
isAnimating = false;
scaleChange = 1;
matrix.postScale(targetScale/currentScale, targetScale/currentScale, targetScaleX, targetScaleY);
currentScale = targetScale;
mHandler.removeCallbacks(mUpdateImageScale);
invalidate();
checkImageConstraints();
}
}
};
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE", "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN || actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
}
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onDoubleTap(MotionEvent event) {
if(isAnimating == true) {
return true;
}
scaleChange = 1;
isAnimating = true;
targetScaleX = event.getX();
targetScaleY = event.getY();
if(Math.abs(currentScale - maxScale) > 0.1) {
targetScale = maxScale;
}
else {
targetScale = minScale;
}
targetRatio = targetScale / currentScale;
mHandler.removeCallbacks(mUpdateImageScale);
mHandler.post(mUpdateImageScale);
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
return super.onFling(e1, e2, velocityX, velocityY);
}
@Override
public boolean onDown(MotionEvent e) {
return false;
}
}
}
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它很旧,但是由于没有答案是正确的,因此我想分享一下。
我在此答案中调整了TouchImageView类,以通过实现GestureDetector.OnGestureListener,GestureDetector.OnDoubleTapListener接口支持双击以放大/缩小
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
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.View;
import android.widget.ImageView;
public class TouchImageView extends ImageView implements GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
Matrix matrix;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;
int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
GestureDetector mGestureDetector;
private void sharedConstructing(Context context) {
super.setClickable(true);
this.context = context;
mGestureDetector = new GestureDetector(context, this);
mGestureDetector.setOnDoubleTapListener(this);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
matrix = new Matrix();
m = new float[9];
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
mGestureDetector.onTouchEvent(event);
PointF curr = new PointF(event.getX(), event.getY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
last.set(curr);
start.set(last);
mode = DRAG;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
float deltaX = curr.x - last.x;
float deltaY = curr.y - last.y;
float fixTransX = getFixDragTrans(deltaX, viewWidth,
origWidth * saveScale);
float fixTransY = getFixDragTrans(deltaY, viewHeight,
origHeight * saveScale);
matrix.postTranslate(fixTransX, fixTransY);
fixTrans();
last.set(curr.x, curr.y);
}
break;
case MotionEvent.ACTION_UP:
mode = NONE;
int xDiff = (int) Math.abs(curr.x - start.x);
int yDiff = (int) Math.abs(curr.y - start.y);
if (xDiff < CLICK && yDiff < CLICK)
performClick();
break;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
}
setImageMatrix(matrix);
invalidate();
return true; // indicate event was handled
}
});
}
public void setMaxZoom(float x) {
maxScale = x;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
return false;
}
@Override
public boolean onDoubleTap(MotionEvent e) {
// Double tap is detected
Log.i("MAIN_TAG", "Double tap detected");
float origScale = saveScale;
float mScaleFactor;
if (saveScale == maxScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
} else {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
}
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
fixTrans();
return false;
}
@Override
public boolean onDoubleTapEvent(MotionEvent e) {
return false;
}
@Override
public boolean onDown(MotionEvent e) {
return false;
}
@Override
public void onShowPress(MotionEvent e) {
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
return false;
}
@Override
public void onLongPress(MotionEvent e) {
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
return false;
}
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
mode = ZOOM;
return true;
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
float mScaleFactor = detector.getScaleFactor();
float origScale = saveScale;
saveScale *= mScaleFactor;
if (saveScale > maxScale) {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
} else if (saveScale < minScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
}
if (origWidth * saveScale <= viewWidth
|| origHeight * saveScale <= viewHeight)
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
else
matrix.postScale(mScaleFactor, mScaleFactor,
detector.getFocusX(), detector.getFocusY());
fixTrans();
return true;
}
}
void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
float fixTransY = getFixTrans(transY, viewHeight, origHeight
* saveScale);
if (fixTransX != 0 || fixTransY != 0)
matrix.postTranslate(fixTransX, fixTransY);
}
float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
viewWidth = MeasureSpec.getSize(widthMeasureSpec);
viewHeight = MeasureSpec.getSize(heightMeasureSpec);
//
// Rescales image on rotation
//
if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
|| viewWidth == 0 || viewHeight == 0)
return;
oldMeasuredHeight = viewHeight;
oldMeasuredWidth = viewWidth;
if (saveScale == 1) {
// Fit to screen.
float scale;
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0
|| drawable.getIntrinsicHeight() == 0)
return;
int bmWidth = drawable.getIntrinsicWidth();
int bmHeight = drawable.getIntrinsicHeight();
Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);
float scaleX = (float) viewWidth / (float) bmWidth;
float scaleY = (float) viewHeight / (float) bmHeight;
scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
// Center the image
float redundantYSpace = (float) viewHeight
- (scale * (float) bmHeight);
float redundantXSpace = (float) viewWidth
- (scale * (float) bmWidth);
redundantYSpace /= (float) 2;
redundantXSpace /= (float) 2;
matrix.postTranslate(redundantXSpace, redundantYSpace);
origWidth = viewWidth - 2 * redundantXSpace;
origHeight = viewHeight - 2 * redundantYSpace;
setImageMatrix(matrix);
}
fixTrans();
}
}
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用法:
您可以ImageView在XML和Java中将TouchImageView 替换为
1.对于XML
<?xml version="1.0" encoding="utf-8"?>
<com.example.android.myapp.TouchImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/imViewedImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
android:focusable="true" />
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2.对于Java
TouchImageView imViewedImage = findViewById(R.id.imViewedImage);
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