如何解决如何使用 MotionEvent.MOVE
我有可以放大和缩小的自定义图像视图。但我在 onDraw 方法中有“canvas.drawBitmap”:
@Override
protected void onDraw(Canvas canvas) {
// Todo Auto-generated method stub
super.onDraw(canvas);
if (isPinShouldbedrawn) {
Bitmap marker = BitmapFactory.decodeResource(getResources(),R.drawable.ic_pin_raster_64);
canvas.drawBitmap(marker,lastTouchX,lastTouchY,null);
}
isPinShouldbedrawn = false;
}
在“onTouchEvent”方法中,我可以移动图像:
@SuppressWarnings("deprecation")
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mDetector.onTouchEvent(event)) {
return true;
}
int touchCount = event.getPointerCount();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_1_DOWN:
case MotionEvent.ACTION_POINTER_2_DOWN:
if (touchCount >= 2) {
float distance = distance(event.getX(0),event.getX(1),event.getY(0),event.getY(1));
mPrevdistance = distance;
isScaling = true;
} else {
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
}
case MotionEvent.ACTION_MOVE:
if (touchCount >= 2 && isScaling) {
float dist = distance(event.getX(0),event.getY(1));
float scale = (dist - mPrevdistance) / dispdistance();
mPrevdistance = dist;
scale += 1;
scale = scale * scale;
zoomTo(scale,mWidth / 2,mHeight / 2);
cutting();
} else if (!isScaling) {
int distanceX = mPrevMoveX - (int) event.getX();
int distanceY = mPrevMoveY - (int) event.getY();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
mMatrix.postTranslate(-distanceX,-distanceY);
cutting();
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_POINTER_2_UP:
if (event.getPointerCount() <= 1) {
isScaling = false;
}
break;
}
return true;
}
但是来自 onDraw 的位图不动。如果我试图保存新的位图,它只保存可见区域,之后我根本无法缩放或移动它;保存方法:
public void save() {
Bitmap returnedBitmap = Bitmap.createBitmap(
getWidth(),getHeight(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
draw(canvas);
setimageBitmap(returnedBitmap);
}
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import androidx.appcompat.widget.AppCompatimageView;
import com.signalsense.signalsenseapp.R;
public class ScaleImageView extends AppCompatimageView implements OnTouchListener {
static final float stroke_WIDTH = 10f;
static final float HALF_stroke_WIDTH = stroke_WIDTH / 2;
public static Path path = new Path();
public static int imageheight,imagewidth;
private static Matrix mMatrix;
final RectF dirtyRect = new RectF();
private final Context mContext;
private final float MAX_SCALE = 2f;
private final float[] mMatrixValues = new float[9];
float lastTouchX;
float lastTouchY;
Paint paint = new Paint();
String TAG = "ScaleImageView";
private boolean isPinShouldbedrawn = false;
// display width height.
private int mWidth;
private int mHeight;
private int mIntrinsicWidth;
private int mIntrinsicHeight;
private float mScale;
private float mMinScale;
private float mPrevdistance;
private boolean isScaling;
private int mPrevMoveX;
private int mPrevMoveY;
private GestureDetector mDetector;
public ScaleImageView(Context context,AttributeSet attr) {
super(context,attr);
this.mContext = context;
initialize();
}
public ScaleImageView(Context context) {
super(context);
this.mContext = context;
initialize();
}
private void resetDirtyRect(float eventX,float eventY) {
dirtyRect.left = Math.min(lastTouchX,eventX);
dirtyRect.right = Math.max(lastTouchX,eventX);
dirtyRect.top = Math.min(lastTouchY,eventY);
dirtyRect.bottom = Math.max(lastTouchY,eventY);
}
@Override
public void setimageBitmap(Bitmap bm) {
super.setimageBitmap(bm);
this.initialize();
}
@Override
public void setimageResource(int resId) {
super.setimageResource(resId);
this.initialize();
}
private void initialize() {
this.setScaleType(ScaleType.MATRIX);
mMatrix = new Matrix();
Drawable d = getDrawable();
paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.stroke);
paint.setstrokeJoin(Paint.Join.ROUND);
paint.setstrokeWidth(stroke_WIDTH);
if (d != null) {
mIntrinsicWidth = d.getIntrinsicWidth();
mIntrinsicHeight = d.getIntrinsicHeight();
setonTouchListener(this);
}
mDetector = new GestureDetector(mContext,new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDoubleTap(MotionEvent e) {
maxZoomTo((int) e.getX(),(int) e.getY());
cutting();
return super.onDoubleTap(e);
}
@Override
public void onLongPress(MotionEvent e) {
super.onLongPress(e);
lastTouchX = e.getX();
lastTouchY = e.getY();
isPinShouldbedrawn = true;
invalidate();
save();
}
});
}
@Override
protected boolean setFrame(int l,int t,int r,int b) {
mWidth = r - l;
mHeight = b - t;
mMatrix.reset();
int r_norm = r - l;
mScale = (float) r_norm / (float) mIntrinsicWidth;
int paddingHeight = 0;
int paddingWidth = 0;
// scaling vertical
if (mScale * mIntrinsicHeight > mHeight) {
mScale = (float) mHeight / (float) mIntrinsicHeight;
mMatrix.postScale(mScale,mScale);
paddingWidth = (r - mWidth) / 2;
paddingHeight = 0;
// scaling horizontal
} else {
mMatrix.postScale(mScale,mScale);
paddingHeight = (b - mHeight) / 2;
paddingWidth = 0;
}
mMatrix.postTranslate(paddingWidth,paddingHeight);
setimageMatrix(mMatrix);
mMinScale = mScale;
zoomTo(mScale,mHeight / 2);
cutting();
return super.setFrame(l,t,r,b);
}
protected float getValue(Matrix matrix,int whichValue) {
matrix.getValues(mMatrixValues);
return mMatrixValues[whichValue];
}
protected float getScale() {
return getValue(mMatrix,Matrix.MSCALE_X);
}
public float getTranslateX() {
return getValue(mMatrix,Matrix.MTRANS_X);
}
protected float getTranslateY() {
return getValue(mMatrix,Matrix.MTRANS_Y);
}
protected void maxZoomTo(int x,int y) {
if (mMinScale != getScale() && (getScale() - mMinScale) > 0.1f) {
// threshold 0.1f
float scale = mMinScale / getScale();
zoomTo(scale,x,y);
} else {
float scale = MAX_SCALE / getScale();
zoomTo(scale,y);
}
}
public void zoomTo(float scale,int x,int y) {
if (getScale() * scale < mMinScale) {
return;
}
if (scale >= 1 && getScale() * scale > MAX_SCALE) {
return;
}
mMatrix.postScale(scale,scale);
// move to center
mMatrix.postTranslate(-(mWidth * scale - mWidth) / 2,-(mHeight * scale - mHeight) / 2);
// move x and y distance
mMatrix.postTranslate(-(x - (mWidth / 2)) * scale,0);
mMatrix.postTranslate(0,-(y - (mHeight / 2)) * scale);
setimageMatrix(mMatrix);
}
public void cutting() {
int width = (int) (mIntrinsicWidth * getScale());
int height = (int) (mIntrinsicHeight * getScale());
imagewidth = width;
imageheight = height;
if (getTranslateX() < -(width - mWidth)) {
mMatrix.postTranslate(-(getTranslateX() + width - mWidth),0);
}
if (getTranslateX() > 0) {
mMatrix.postTranslate(-getTranslateX(),0);
}
if (getTranslateY() < -(height - mHeight)) {
mMatrix.postTranslate(0,-(getTranslateY() + height - mHeight));
}
if (getTranslateY() > 0) {
mMatrix.postTranslate(0,-getTranslateY());
}
if (width < mWidth) {
mMatrix.postTranslate((mWidth - width) / 2,0);
}
if (height < mHeight) {
mMatrix.postTranslate(0,(mHeight - height) / 2);
}
setimageMatrix(mMatrix);
}
private float distance(float x0,float x1,float y0,float y1) {
float x = x0 - x1;
float y = y0 - y1;
return (float) Math.sqrt(x * x + y * y);
}
private float dispdistance() {
return (float) Math.sqrt(mWidth * mWidth + mHeight * mHeight);
}
public void clear() {
path.reset();
invalidate();
}
public void save() {
Bitmap returnedBitmap = Bitmap.createBitmap(
getWidth(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
draw(canvas);
setimageBitmap(returnedBitmap);
}
@SuppressWarnings("deprecation")
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mDetector.onTouchEvent(event)) {
return true;
}
int touchCount = event.getPointerCount();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_1_DOWN:
case MotionEvent.ACTION_POINTER_2_DOWN:
if (touchCount >= 2) {
float distance = distance(event.getX(0),-distanceY);
cutting();
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_POINTER_2_UP:
if (event.getPointerCount() <= 1) {
isScaling = false;
}
break;
}
return true;
}
@Override
protected void onDraw(Canvas canvas) {
// Todo Auto-generated method stub
super.onDraw(canvas);
if (isPinShouldbedrawn) {
Bitmap marker = BitmapFactory.decodeResource(getResources(),null);
}
isPinShouldbedrawn = false;
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouch(View v,MotionEvent event) {
return super.onTouchEvent(event);
}
}
对不起,英语不是我的母语:)
解决方法
记录触摸事件的标准化坐标,
public void onLongPress(MotionEvent e) {
super.onLongPress(e);
//lastTouchX = e.getX();
//lastTouchY = e.getY();
float[] touchCoords = new float[]{ e.getX(),e.getY()}; // Touch point in screen-X,Y coords.
Matrix matrix_inverse = new Matrix();
mMatrix.invert(matrix_inverse); // XY to UV mapping matrix.
matrix_inverse.mapPoints(touchCoords); // Touch point in bitmap-U,V coords.
lastTouchX = touchCoords[0];
lastTouchY = touchCoords[1];
isPinShouldBeDrawn = true;
invalidate();
save();
}
然后,通过应用变换绘制叠加位图。
protected void onDraw(Canvas canvas)
{
// TODO Auto-generated method stub
super.onDraw(canvas);
if (isPinShouldBeDrawn)
{
Bitmap marker = BitmapFactory.decodeResource(getResources(),R.drawable.ic_pin_raster_64);
//canvas.drawBitmap(marker,lastTouchX,lastTouchY,null);
Matrix matrix_marker = new Matrix();
matrix_marker.setTranslate(lastTouchX,lastTouchY);
matrix_marker.postConcat(mMatrix);
canvas.drawBitmap(marker,matrix_marker,null);
}
isPinShouldBeDrawn = false;
}
如果您想将叠加层烘焙到位图上,请将反转矩阵设置为画布并调用 draw()。
public void save()
{
Bitmap returnedBitmap = Bitmap.createBitmap(
mIntrinsicWidth,mIntrinsicHeight,Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
Matrix matrix_inverse = new Matrix();
mMatrix.invert(matrix_inverse);
canvas.setMatrix(matrix_inverse);
draw(canvas);
setImageBitmap(returnedBitmap);
}
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。