Мне нужно было что-то похожее, но мне нужна была возможность легко получать размеры, а также перетаскивать. Я основал это на ответе, который дал @ Николас Тайлер, и изменил его оттуда.
Возможности увеличения / уменьшения, длительное нажатие на вибрацию / выделенное перетаскивание.
Чтобы использовать его, добавьте этот класс CustomZoomView в ваш проект.
public class CustomZoomView extends View implements View.OnTouchListener, View.OnLongClickListener{
private Paint mPaint;
Vibrator v;
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
static final int MOVE = 3;
private int mode = NONE;
Rect src;
Rect mTempDst = new Rect();
Rect dst = new Rect();
Bitmap mBitmap;
private int mBitmapWidth = -1;
private int mBitmapHeight = -1;
private PointF mStartPoint = new PointF();
private PointF mMiddlePoint = new PointF();
private PointF mStartDragPoint = new PointF();
private PointF mMovePoint = new PointF();
private float oldDist = 1f;
private float scale;
private float oldEventX = 0;
private float oldEventY = 0;
private float oldStartPointX = 0;
private float oldStartPointY = 0;
private int mViewWidth = -1;
private int mViewHeight = -1;
private boolean mDraggable = false;
public CustomZoomView(Context context) {
this(context, null, 0);
}
public CustomZoomView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CustomZoomView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.setOnTouchListener(this);
this.setOnLongClickListener(this);
v = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
mPaint = new Paint();
mPaint.setColorFilter(new PorterDuffColorFilter(Color.argb(100,255,255,255), PorterDuff.Mode.SRC_IN));
}
@Override
public void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mViewWidth = w;
mViewHeight = h;
}
public void setBitmap(Bitmap bitmap) {
if (bitmap != null) {
src = new Rect();
src.left = 0;
src.top = 0;
src.right = bitmap.getWidth();
src.bottom = bitmap.getHeight();
mBitmap = bitmap;
mBitmapWidth = bitmap.getWidth() * 1;
mBitmapHeight = bitmap.getHeight() * 1;
dst = new Rect();
dst.left = (mViewWidth / 2) - (mBitmapWidth / 2);
dst.top = (mViewHeight / 2) - (mBitmapHeight / 2);
dst.right = (mViewWidth / 2) + (mBitmapWidth / 2);
dst.bottom = (mViewHeight / 2) + (mBitmapHeight / 2);
}
}
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
mStartPoint.set(event.getX(), event.getY());
mStartDragPoint.set(event.getX(), event.getY());
mTempDst.set(dst.left, dst.top, dst.right, dst.bottom);
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
midPoint(mMiddlePoint, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
if (mode == ZOOM) {
mBitmapWidth = dst.right - dst.left;
mBitmapHeight = dst.bottom - dst.top;
}
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
mMovePoint.x = event.getX();
mMovePoint.y = event.getY();
drag(event);
} else if (mode == ZOOM) {
zoom(event);
} else if (mode == MOVE) {
move(event);
}
break;
}
return false;
}
public void move(MotionEvent event) {
int xChange = (int) (event.getX() - mStartPoint.x);
int yChange = (int) (event.getY() - mStartPoint.y);
dst.left = mTempDst.left + (xChange);
dst.top = mTempDst.top + (yChange);
dst.right = mTempDst.right + (xChange);
dst.bottom = mTempDst.bottom + (yChange);
invalidate();
}
public void drag(MotionEvent event) {
float eventX = event.getX();
float eventY = event.getY();
float spacingX = eventX - mStartDragPoint.x;
float spacingY = eventY - mStartDragPoint.y;
float newPositionLeft = (dst.left < 0 ? spacingX : spacingX * -1) + dst.left;
float newPositionRight = (spacingX) + dst.right;
float newPositionTop = (dst.top < 0 ? spacingY : spacingY * -1) + dst.top;
float newPositionBottom = (spacingY) + dst.bottom;
boolean x = true;
boolean y = true;
if (newPositionRight < 0.0f || newPositionLeft > 0.0f) {
if (newPositionRight < 0.0f && newPositionLeft > 0.0f) {
x = false;
} else {
eventX = oldEventX;
mStartDragPoint.x = oldStartPointX;
}
}
if (newPositionBottom < 0.0f || newPositionTop > 0.0f) {
if (newPositionBottom < 0.0f && newPositionTop > 0.0f) {
y = false;
} else {
eventY = oldEventY;
mStartDragPoint.y = oldStartPointY;
}
}
if (mDraggable) {
if (x) oldEventX = eventX;
if (y) oldEventY = eventY;
if (x) oldStartPointX = mStartDragPoint.x;
if (y) oldStartPointY = mStartDragPoint.y;
}
}
public void zoom(MotionEvent event) {
float newDist = spacing(event);
boolean in = newDist > oldDist;
if (!in && scale < .01f) {
return;
}
scale = newDist / oldDist;
int xChange = (int) ((mBitmapWidth * scale) / 2);
int yChange = (int) ((mBitmapHeight * scale) / 2);
if (xChange > 10 && yChange > 10) { //ADDED THIS TO KEEP IT FROM GOING INVERSE
int xMidPoint = ((dst.right - dst.left) / 2) + dst.left;
int yMidPoint = ((dst.bottom - dst.top) / 2) + dst.top;
dst.left = (int) (float) (xMidPoint - xChange);
dst.top = (int) (float) (yMidPoint - yChange);
dst.right = (int) (float) (xMidPoint + xChange);
dst.bottom = (int) (float) (yMidPoint + yChange);
}
invalidate();
}
/**
* Determine the space between the first two fingers
*/
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
/**
* Calculate the mid point of the first two fingers
*/
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);
}
@Override
public boolean onLongClick(View view) {
if (mode == DRAG) {
if ((mStartPoint.x > dst.left && mStartPoint.x < dst.right) && (mStartPoint.y < dst.bottom && mStartPoint.y > dst.top)
&& (mMovePoint.x > dst.left && mMovePoint.x < dst.right) && (mMovePoint.y < dst.bottom && mMovePoint.y > dst.top)) {
mode = MOVE;
v.vibrate(500);
}
}
return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mode == MOVE) {
canvas.drawBitmap(mBitmap, src, dst, null);
canvas.drawBitmap(mBitmap, src, dst, mPaint);
} else {
canvas.drawBitmap(mBitmap, src, dst, null);
}
}
}
... затем добавьте это к своей деятельности
CustomZoomView customImageView = (CustomZoomView) findViewById(R.id.customZoomView);
customImageView.setBitmap(yourBitmap);
... и это по вашему мнению в xml.
<your.package.name.CustomZoomView
android:id="@+id/customZoomView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:longClickable="true"/>
... и добавьте это в свой манифест
<uses-permission android:name="android.permission.VIBRATE"/>