줌인되는 커스텀 리스트 뷰 소스

출처 : https://raw.githubusercontent.com/Polidea/android-zoom-view/master/src/pl/polidea/view/ZoomView.java public class ZoomListView extends ListView { private static final int INVALID_POINTER_ID = -1; private int mActivePointerId = INVALID_POINTER_ID; private ScaleGestureDetector mScaleDetector; private float mScaleFactor = 1.f; private float maxWidth = 0.0f; private float maxHeight = 0.0f; private float mLastTouchX; private float mLastTouchY; private float mPosX; private float mPosY; private float width; private float height; public ZoomListView(Context context) { super(context); mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener()); } public ZoomListView(Context context, AttributeSet attrs) { super(context, attrs); mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener()); } public ZoomListView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener()); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { width = MeasureSpec.getSize(widthMeasureSpec); height = MeasureSpec.getSize(heightMeasureSpec); super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override public boolean onTouchEvent(@NonNull MotionEvent ev) { super.onTouchEvent(ev); final int action = ev.getAction(); mScaleDetector.onTouchEvent(ev); switch (action & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: { final float x = ev.getX(); final float y = ev.getY(); mLastTouchX = x; mLastTouchY = y; mActivePointerId = ev.getPointerId(0); break; } case MotionEvent.ACTION_MOVE: { final int pointerIndex = ev.findPointerIndex(mActivePointerId); final float x = ev.getX(pointerIndex); final float y = ev.getY(pointerIndex); final float dx = x - mLastTouchX; final float dy = y - mLastTouchY; mPosX += dx; mPosY += dy; if (mPosX > 0.0f) mPosX = 0.0f; else if (mPosX < maxWidth) mPosX = maxWidth; if (mPosY > 0.0f) mPosY = 0.0f; else if (mPosY < maxHeight) mPosY = maxHeight; mLastTouchX = x; mLastTouchY = y; invalidate(); break; } case MotionEvent.ACTION_UP: { mActivePointerId = INVALID_POINTER_ID; break; } case MotionEvent.ACTION_CANCEL: { mActivePointerId = INVALID_POINTER_ID; break; } case MotionEvent.ACTION_POINTER_UP: { final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT; final int pointerId = ev.getPointerId(pointerIndex); if (pointerId == mActivePointerId) { final int newPointerIndex = pointerIndex == 0 ? 1 : 0; mLastTouchX = ev.getX(newPointerIndex); mLastTouchY = ev.getY(newPointerIndex); mActivePointerId = ev.getPointerId(newPointerIndex); } break; } } return true; } @Override public void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.save(Canvas.MATRIX_SAVE_FLAG); canvas.translate(mPosX, mPosY); canvas.scale(mScaleFactor, mScaleFactor); canvas.restore(); } @Override protected void dispatchDraw(@NonNull Canvas canvas) { canvas.save(Canvas.MATRIX_SAVE_FLAG); if (mScaleFactor == 1.0f) { mPosX = 0.0f; mPosY = 0.0f; } canvas.translate(mPosX, mPosY); canvas.scale(mScaleFactor, mScaleFactor); super.dispatchDraw(canvas); canvas.restore(); invalidate(); } private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { @Override public boolean onScale(ScaleGestureDetector detector) { mScaleFactor *= detector.getScaleFactor(); mScaleFactor = Math.max(1.0f, Math.min(mScaleFactor, 3.0f)); maxWidth = width - (width * mScaleFactor); maxHeight = height - (height * mScaleFactor); invalidate(); return true; } } }

}