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[android]代码库

public boolean onTouchEvent(MotionEvent event) {
                switch (event.getAction() & MotionEvent.ACTION_MASK) {
                case MotionEvent.ACTION_DOWN:
                        mode = DRAG;
                        x_down = event.getX();
                        y_down = event.getY();
                        savedMatrix.set(matrix);
                        break;
                case MotionEvent.ACTION_POINTER_DOWN:
                        mode = ZOOM;
                        oldDist = spacing(event);
                        oldRotation = rotation(event);
                        savedMatrix.set(matrix);
                        midPoint(mid, event);
                        break;
                case MotionEvent.ACTION_MOVE:
                        if (mode == ZOOM) {
                                matrix1.set(savedMatrix);
                                float rotation = rotation(event) - oldRotation;
                                float newDist = spacing(event);
                                float scale = newDist / oldDist;
                                matrix1.postScale(scale, scale, mid.x, mid.y);// 縮放
                                matrix1.postRotate(rotation, mid.x, mid.y);// 旋轉
                                matrixCheck = matrixCheck();
                                if (matrixCheck == false) {
                                        matrix.set(matrix1);
                                        invalidate();
                                }
                        } else if (mode == DRAG) {
                                matrix1.set(savedMatrix);
                                matrix1.postTranslate(event.getX() - x_down, event.getY()
                                                - y_down);// 平移
                                matrixCheck = matrixCheck();
                                matrixCheck = matrixCheck();
                                if (matrixCheck == false) {
                                        matrix.set(matrix1);
                                        invalidate();
                                }
                        }
                        break;
                case MotionEvent.ACTION_UP:
                case MotionEvent.ACTION_POINTER_UP:
                        mode = NONE;
                        break;
                }
                return true;
}